linux/drivers/gpio/gpiolib.c
Lars-Peter Clausen 953b956a2e gpio: GPIO_GET_LINE{HANDLE,EVENT}_IOCTL: Fix file descriptor leak
When allocating a new line handle or event a file is allocated that it is
associated to. The file is attached to a file descriptor of the current
process and the file descriptor is returned to userspace using
copy_to_user(). If this copy operation fails the line handle or event
allocation is aborted, all acquired resources are freed and an error is
returned.

But the file struct is not freed and left attached to the userspace
application and even though the file descriptor number was not copied it is
trivial to guess. If a userspace application performs a IOCTL on such a
left over file descriptor it will trigger a use-after-free and if the file
descriptor is closed (latest when the application exits) a double-free is
triggered.

anon_inode_getfd() performs 3 tasks, allocate a file struct, allocate a
file descriptor for the current process and install the file struct in the
file descriptor. As soon as the file struct is installed in the file
descriptor it is accessible by userspace (even if the IOCTL itself hasn't
completed yet), this means uninstalling the fd on the error path is not an
option, since userspace might already got a reference to the file.

Instead anon_inode_getfd() needs to be broken into its individual steps.
The allocation of the file struct and file descriptor is done first, then
the copy_to_user() is executed and only if it succeeds the file is
installed.

Since the file struct is reference counted it can not be just freed, but
its reference needs to be dropped, which will also call the release()
callback, which will free the state attached to the file. So in this case
the normal error cleanup path should not be taken.

Cc: stable@vger.kernel.org
Fixes: d932cd4918 ("gpio: free handles in fringe cases")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-31 21:23:44 +01:00

3653 lines
96 KiB
C

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/pinctrl/consumer.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/compat.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/kfifo.h>
#include <linux/poll.h>
#include <linux/timekeeping.h>
#include <uapi/linux/gpio.h>
#include "gpiolib.h"
#define CREATE_TRACE_POINTS
#include <trace/events/gpio.h>
/* Implementation infrastructure for GPIO interfaces.
*
* The GPIO programming interface allows for inlining speed-critical
* get/set operations for common cases, so that access to SOC-integrated
* GPIOs can sometimes cost only an instruction or two per bit.
*/
/* When debugging, extend minimal trust to callers and platform code.
* Also emit diagnostic messages that may help initial bringup, when
* board setup or driver bugs are most common.
*
* Otherwise, minimize overhead in what may be bitbanging codepaths.
*/
#ifdef DEBUG
#define extra_checks 1
#else
#define extra_checks 0
#endif
/* Device and char device-related information */
static DEFINE_IDA(gpio_ida);
static dev_t gpio_devt;
#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
static struct bus_type gpio_bus_type = {
.name = "gpio",
};
/* gpio_lock prevents conflicts during gpio_desc[] table updates.
* While any GPIO is requested, its gpio_chip is not removable;
* each GPIO's "requested" flag serves as a lock and refcount.
*/
DEFINE_SPINLOCK(gpio_lock);
static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
LIST_HEAD(gpio_devices);
static void gpiochip_free_hogs(struct gpio_chip *chip);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
static bool gpiolib_initialized;
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
d->label = label;
}
/**
* Convert a GPIO number to its descriptor
*/
struct gpio_desc *gpio_to_desc(unsigned gpio)
{
struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
if (gdev->base <= gpio &&
gdev->base + gdev->ngpio > gpio) {
spin_unlock_irqrestore(&gpio_lock, flags);
return &gdev->descs[gpio - gdev->base];
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (!gpio_is_valid(gpio))
WARN(1, "invalid GPIO %d\n", gpio);
return NULL;
}
EXPORT_SYMBOL_GPL(gpio_to_desc);
/**
* Get the GPIO descriptor corresponding to the given hw number for this chip.
*/
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
u16 hwnum)
{
struct gpio_device *gdev = chip->gpiodev;
if (hwnum >= gdev->ngpio)
return ERR_PTR(-EINVAL);
return &gdev->descs[hwnum];
}
/**
* Convert a GPIO descriptor to the integer namespace.
* This should disappear in the future but is needed since we still
* use GPIO numbers for error messages and sysfs nodes
*/
int desc_to_gpio(const struct gpio_desc *desc)
{
return desc->gdev->base + (desc - &desc->gdev->descs[0]);
}
EXPORT_SYMBOL_GPL(desc_to_gpio);
/**
* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
* @desc: descriptor to return the chip of
*/
struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
if (!desc || !desc->gdev || !desc->gdev->chip)
return NULL;
return desc->gdev->chip;
}
EXPORT_SYMBOL_GPL(gpiod_to_chip);
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base(int ngpio)
{
struct gpio_device *gdev;
int base = ARCH_NR_GPIOS - ngpio;
list_for_each_entry_reverse(gdev, &gpio_devices, list) {
/* found a free space? */
if (gdev->base + gdev->ngpio <= base)
break;
else
/* nope, check the space right before the chip */
base = gdev->base - ngpio;
}
if (gpio_is_valid(base)) {
pr_debug("%s: found new base at %d\n", __func__, base);
return base;
} else {
pr_err("%s: cannot find free range\n", __func__);
return -ENOSPC;
}
}
/**
* gpiod_get_direction - return the current direction of a GPIO
* @desc: GPIO to get the direction of
*
* Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
*
* This function may sleep if gpiod_cansleep() is true.
*/
int gpiod_get_direction(struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
int status = -EINVAL;
chip = gpiod_to_chip(desc);
offset = gpio_chip_hwgpio(desc);
if (!chip->get_direction)
return status;
status = chip->get_direction(chip, offset);
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
clear_bit(FLAG_IS_OUT, &desc->flags);
}
if (status == 0) {
/* GPIOF_DIR_OUT */
set_bit(FLAG_IS_OUT, &desc->flags);
}
return status;
}
EXPORT_SYMBOL_GPL(gpiod_get_direction);
/*
* Add a new chip to the global chips list, keeping the list of chips sorted
* by range(means [base, base + ngpio - 1]) order.
*
* Return -EBUSY if the new chip overlaps with some other chip's integer
* space.
*/
static int gpiodev_add_to_list(struct gpio_device *gdev)
{
struct gpio_device *prev, *next;
if (list_empty(&gpio_devices)) {
/* initial entry in list */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
next = list_entry(gpio_devices.next, struct gpio_device, list);
if (gdev->base + gdev->ngpio <= next->base) {
/* add before first entry */
list_add(&gdev->list, &gpio_devices);
return 0;
}
prev = list_entry(gpio_devices.prev, struct gpio_device, list);
if (prev->base + prev->ngpio <= gdev->base) {
/* add behind last entry */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
list_for_each_entry_safe(prev, next, &gpio_devices, list) {
/* at the end of the list */
if (&next->list == &gpio_devices)
break;
/* add between prev and next */
if (prev->base + prev->ngpio <= gdev->base
&& gdev->base + gdev->ngpio <= next->base) {
list_add(&gdev->list, &prev->list);
return 0;
}
}
dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
return -EBUSY;
}
/**
* Convert a GPIO name to its descriptor
*/
static struct gpio_desc *gpio_name_to_desc(const char * const name)
{
struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
int i;
for (i = 0; i != gdev->ngpio; ++i) {
struct gpio_desc *desc = &gdev->descs[i];
if (!desc->name || !name)
continue;
if (!strcmp(desc->name, name)) {
spin_unlock_irqrestore(&gpio_lock, flags);
return desc;
}
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
return NULL;
}
/*
* Takes the names from gc->names and checks if they are all unique. If they
* are, they are assigned to their gpio descriptors.
*
* Warning if one of the names is already used for a different GPIO.
*/
static int gpiochip_set_desc_names(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
int i;
if (!gc->names)
return 0;
/* First check all names if they are unique */
for (i = 0; i != gc->ngpio; ++i) {
struct gpio_desc *gpio;
gpio = gpio_name_to_desc(gc->names[i]);
if (gpio)
dev_warn(&gdev->dev,
"Detected name collision for GPIO name '%s'\n",
gc->names[i]);
}
/* Then add all names to the GPIO descriptors */
for (i = 0; i != gc->ngpio; ++i)
gdev->descs[i].name = gc->names[i];
return 0;
}
/*
* GPIO line handle management
*/
/**
* struct linehandle_state - contains the state of a userspace handle
* @gdev: the GPIO device the handle pertains to
* @label: consumer label used to tag descriptors
* @descs: the GPIO descriptors held by this handle
* @numdescs: the number of descriptors held in the descs array
*/
struct linehandle_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *descs[GPIOHANDLES_MAX];
u32 numdescs;
};
#define GPIOHANDLE_REQUEST_VALID_FLAGS \
(GPIOHANDLE_REQUEST_INPUT | \
GPIOHANDLE_REQUEST_OUTPUT | \
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
static long linehandle_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct linehandle_state *lh = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
int i;
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
int val;
memset(&ghd, 0, sizeof(ghd));
/* TODO: check if descriptors are really input */
for (i = 0; i < lh->numdescs; i++) {
val = gpiod_get_value_cansleep(lh->descs[i]);
if (val < 0)
return val;
ghd.values[i] = val;
}
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
int vals[GPIOHANDLES_MAX];
/* TODO: check if descriptors are really output */
if (copy_from_user(&ghd, ip, sizeof(ghd)))
return -EFAULT;
/* Clamp all values to [0,1] */
for (i = 0; i < lh->numdescs; i++)
vals[i] = !!ghd.values[i];
/* Reuse the array setting function */
gpiod_set_array_value_complex(false,
true,
lh->numdescs,
lh->descs,
vals);
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static int linehandle_release(struct inode *inode, struct file *filep)
{
struct linehandle_state *lh = filep->private_data;
struct gpio_device *gdev = lh->gdev;
int i;
for (i = 0; i < lh->numdescs; i++)
gpiod_free(lh->descs[i]);
kfree(lh->label);
kfree(lh);
put_device(&gdev->dev);
return 0;
}
static const struct file_operations linehandle_fileops = {
.release = linehandle_release,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = linehandle_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = linehandle_ioctl_compat,
#endif
};
static int linehandle_create(struct gpio_device *gdev, void __user *ip)
{
struct gpiohandle_request handlereq;
struct linehandle_state *lh;
struct file *file;
int fd, i, ret;
if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
return -EFAULT;
if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
return -EINVAL;
lh = kzalloc(sizeof(*lh), GFP_KERNEL);
if (!lh)
return -ENOMEM;
lh->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
if (strlen(handlereq.consumer_label)) {
lh->label = kstrdup(handlereq.consumer_label,
GFP_KERNEL);
if (!lh->label) {
ret = -ENOMEM;
goto out_free_lh;
}
}
/* Request each GPIO */
for (i = 0; i < handlereq.lines; i++) {
u32 offset = handlereq.lineoffsets[i];
u32 lflags = handlereq.flags;
struct gpio_desc *desc;
if (offset >= gdev->ngpio) {
ret = -EINVAL;
goto out_free_descs;
}
/* Return an error if a unknown flag is set */
if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
ret = -EINVAL;
goto out_free_descs;
}
desc = &gdev->descs[offset];
ret = gpiod_request(desc, lh->label);
if (ret)
goto out_free_descs;
lh->descs[i] = desc;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
/*
* Lines have to be requested explicitly for input
* or output, else the line will be treated "as is".
*/
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
int val = !!handlereq.default_values[i];
ret = gpiod_direction_output(desc, val);
if (ret)
goto out_free_descs;
} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_descs;
}
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
offset);
}
/* Let i point at the last handle */
i--;
lh->numdescs = handlereq.lines;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_descs;
}
file = anon_inode_getfile("gpio-linehandle",
&linehandle_fileops,
lh,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
handlereq.fd = fd;
if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
lh->numdescs);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_descs:
for (; i >= 0; i--)
gpiod_free(lh->descs[i]);
kfree(lh->label);
out_free_lh:
kfree(lh);
put_device(&gdev->dev);
return ret;
}
/*
* GPIO line event management
*/
/**
* struct lineevent_state - contains the state of a userspace event
* @gdev: the GPIO device the event pertains to
* @label: consumer label used to tag descriptors
* @desc: the GPIO descriptor held by this event
* @eflags: the event flags this line was requested with
* @irq: the interrupt that trigger in response to events on this GPIO
* @wait: wait queue that handles blocking reads of events
* @events: KFIFO for the GPIO events
* @read_lock: mutex lock to protect reads from colliding with adding
* new events to the FIFO
*/
struct lineevent_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *desc;
u32 eflags;
int irq;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioevent_data, 16);
struct mutex read_lock;
};
#define GPIOEVENT_REQUEST_VALID_FLAGS \
(GPIOEVENT_REQUEST_RISING_EDGE | \
GPIOEVENT_REQUEST_FALLING_EDGE)
static unsigned int lineevent_poll(struct file *filep,
struct poll_table_struct *wait)
{
struct lineevent_state *le = filep->private_data;
unsigned int events = 0;
poll_wait(filep, &le->wait, wait);
if (!kfifo_is_empty(&le->events))
events = POLLIN | POLLRDNORM;
return events;
}
static ssize_t lineevent_read(struct file *filep,
char __user *buf,
size_t count,
loff_t *f_ps)
{
struct lineevent_state *le = filep->private_data;
unsigned int copied;
int ret;
if (count < sizeof(struct gpioevent_data))
return -EINVAL;
do {
if (kfifo_is_empty(&le->events)) {
if (filep->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(le->wait,
!kfifo_is_empty(&le->events));
if (ret)
return ret;
}
if (mutex_lock_interruptible(&le->read_lock))
return -ERESTARTSYS;
ret = kfifo_to_user(&le->events, buf, count, &copied);
mutex_unlock(&le->read_lock);
if (ret)
return ret;
/*
* If we couldn't read anything from the fifo (a different
* thread might have been faster) we either return -EAGAIN if
* the file descriptor is non-blocking, otherwise we go back to
* sleep and wait for more data to arrive.
*/
if (copied == 0 && (filep->f_flags & O_NONBLOCK))
return -EAGAIN;
} while (copied == 0);
return copied;
}
static int lineevent_release(struct inode *inode, struct file *filep)
{
struct lineevent_state *le = filep->private_data;
struct gpio_device *gdev = le->gdev;
free_irq(le->irq, le);
gpiod_free(le->desc);
kfree(le->label);
kfree(le);
put_device(&gdev->dev);
return 0;
}
static long lineevent_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct lineevent_state *le = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
/*
* We can get the value for an event line but not set it,
* because it is input by definition.
*/
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
int val;
memset(&ghd, 0, sizeof(ghd));
val = gpiod_get_value_cansleep(le->desc);
if (val < 0)
return val;
ghd.values[0] = val;
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static const struct file_operations lineevent_fileops = {
.release = lineevent_release,
.read = lineevent_read,
.poll = lineevent_poll,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = lineevent_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = lineevent_ioctl_compat,
#endif
};
static irqreturn_t lineevent_irq_thread(int irq, void *p)
{
struct lineevent_state *le = p;
struct gpioevent_data ge;
int ret;
ge.timestamp = ktime_get_real_ns();
if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
int level = gpiod_get_value_cansleep(le->desc);
if (level)
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
else
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else {
return IRQ_NONE;
}
ret = kfifo_put(&le->events, ge);
if (ret != 0)
wake_up_poll(&le->wait, POLLIN);
return IRQ_HANDLED;
}
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
{
struct gpioevent_request eventreq;
struct lineevent_state *le;
struct gpio_desc *desc;
struct file *file;
u32 offset;
u32 lflags;
u32 eflags;
int fd;
int ret;
int irqflags = 0;
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
return -EFAULT;
le = kzalloc(sizeof(*le), GFP_KERNEL);
if (!le)
return -ENOMEM;
le->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
if (strlen(eventreq.consumer_label)) {
le->label = kstrdup(eventreq.consumer_label,
GFP_KERNEL);
if (!le->label) {
ret = -ENOMEM;
goto out_free_le;
}
}
offset = eventreq.lineoffset;
lflags = eventreq.handleflags;
eflags = eventreq.eventflags;
if (offset >= gdev->ngpio) {
ret = -EINVAL;
goto out_free_label;
}
/* Return an error if a unknown flag is set */
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
ret = -EINVAL;
goto out_free_label;
}
/* This is just wrong: we don't look for events on output lines */
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
ret = -EINVAL;
goto out_free_label;
}
desc = &gdev->descs[offset];
ret = gpiod_request(desc, le->label);
if (ret)
goto out_free_desc;
le->desc = desc;
le->eflags = eflags;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_desc;
le->irq = gpiod_to_irq(desc);
if (le->irq <= 0) {
ret = -ENODEV;
goto out_free_desc;
}
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
irqflags |= IRQF_TRIGGER_RISING;
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
irqflags |= IRQF_TRIGGER_FALLING;
irqflags |= IRQF_ONESHOT;
irqflags |= IRQF_SHARED;
INIT_KFIFO(le->events);
init_waitqueue_head(&le->wait);
mutex_init(&le->read_lock);
/* Request a thread to read the events */
ret = request_threaded_irq(le->irq,
NULL,
lineevent_irq_thread,
irqflags,
le->label,
le);
if (ret)
goto out_free_desc;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_irq;
}
file = anon_inode_getfile("gpio-event",
&lineevent_fileops,
le,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
eventreq.fd = fd;
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_irq:
free_irq(le->irq, le);
out_free_desc:
gpiod_free(le->desc);
out_free_label:
kfree(le->label);
out_free_le:
kfree(le);
put_device(&gdev->dev);
return ret;
}
/**
* gpio_ioctl() - ioctl handler for the GPIO chardev
*/
static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gpio_device *gdev = filp->private_data;
struct gpio_chip *chip = gdev->chip;
void __user *ip = (void __user *)arg;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!chip)
return -ENODEV;
/* Fill in the struct and pass to userspace */
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
struct gpiochip_info chipinfo;
memset(&chipinfo, 0, sizeof(chipinfo));
strncpy(chipinfo.name, dev_name(&gdev->dev),
sizeof(chipinfo.name));
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
strncpy(chipinfo.label, gdev->label,
sizeof(chipinfo.label));
chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
chipinfo.lines = gdev->ngpio;
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
struct gpioline_info lineinfo;
struct gpio_desc *desc;
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
return -EFAULT;
if (lineinfo.line_offset >= gdev->ngpio)
return -EINVAL;
desc = &gdev->descs[lineinfo.line_offset];
if (desc->name) {
strncpy(lineinfo.name, desc->name,
sizeof(lineinfo.name));
lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
} else {
lineinfo.name[0] = '\0';
}
if (desc->label) {
strncpy(lineinfo.consumer, desc->label,
sizeof(lineinfo.consumer));
lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
} else {
lineinfo.consumer[0] = '\0';
}
/*
* Userspace only need to know that the kernel is using
* this GPIO so it can't use it.
*/
lineinfo.flags = 0;
if (test_bit(FLAG_REQUESTED, &desc->flags) ||
test_bit(FLAG_IS_HOGGED, &desc->flags) ||
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
test_bit(FLAG_EXPORT, &desc->flags) ||
test_bit(FLAG_SYSFS, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
if (test_bit(FLAG_IS_OUT, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
return linehandle_create(gdev, ip);
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
return lineevent_create(gdev, ip);
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
unsigned long arg)
{
return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#endif
/**
* gpio_chrdev_open() - open the chardev for ioctl operations
* @inode: inode for this chardev
* @filp: file struct for storing private data
* Returns 0 on success
*/
static int gpio_chrdev_open(struct inode *inode, struct file *filp)
{
struct gpio_device *gdev = container_of(inode->i_cdev,
struct gpio_device, chrdev);
/* Fail on open if the backing gpiochip is gone */
if (!gdev || !gdev->chip)
return -ENODEV;
get_device(&gdev->dev);
filp->private_data = gdev;
return 0;
}
/**
* gpio_chrdev_release() - close chardev after ioctl operations
* @inode: inode for this chardev
* @filp: file struct for storing private data
* Returns 0 on success
*/
static int gpio_chrdev_release(struct inode *inode, struct file *filp)
{
struct gpio_device *gdev = container_of(inode->i_cdev,
struct gpio_device, chrdev);
if (!gdev)
return -ENODEV;
put_device(&gdev->dev);
return 0;
}
static const struct file_operations gpio_fileops = {
.release = gpio_chrdev_release,
.open = gpio_chrdev_open,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = gpio_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = gpio_ioctl_compat,
#endif
};
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = dev_get_drvdata(dev);
list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
kfree(gdev->label);
kfree(gdev->descs);
kfree(gdev);
}
static int gpiochip_setup_dev(struct gpio_device *gdev)
{
int status;
cdev_init(&gdev->chrdev, &gpio_fileops);
gdev->chrdev.owner = THIS_MODULE;
gdev->chrdev.kobj.parent = &gdev->dev.kobj;
gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
if (status < 0)
chip_warn(gdev->chip, "failed to add char device %d:%d\n",
MAJOR(gpio_devt), gdev->id);
else
chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
MAJOR(gpio_devt), gdev->id);
status = device_add(&gdev->dev);
if (status)
goto err_remove_chardev;
status = gpiochip_sysfs_register(gdev);
if (status)
goto err_remove_device;
/* From this point, the .release() function cleans up gpio_device */
gdev->dev.release = gpiodevice_release;
pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
__func__, gdev->base, gdev->base + gdev->ngpio - 1,
dev_name(&gdev->dev), gdev->chip->label ? : "generic");
return 0;
err_remove_device:
device_del(&gdev->dev);
err_remove_chardev:
cdev_del(&gdev->chrdev);
return status;
}
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
int err;
list_for_each_entry(gdev, &gpio_devices, list) {
err = gpiochip_setup_dev(gdev);
if (err)
pr_err("%s: Failed to initialize gpio device (%d)\n",
dev_name(&gdev->dev), err);
}
}
/**
* gpiochip_add_data() - register a gpio_chip
* @chip: the chip to register, with chip->base initialized
* Context: potentially before irqs will work
*
* Returns a negative errno if the chip can't be registered, such as
* because the chip->base is invalid or already associated with a
* different chip. Otherwise it returns zero as a success code.
*
* When gpiochip_add_data() is called very early during boot, so that GPIOs
* can be freely used, the chip->parent device must be registered before
* the gpio framework's arch_initcall(). Otherwise sysfs initialization
* for GPIOs will fail rudely.
*
* gpiochip_add_data() must only be called after gpiolib initialization,
* ie after core_initcall().
*
* If chip->base is negative, this requests dynamic assignment of
* a range of valid GPIOs.
*/
int gpiochip_add_data(struct gpio_chip *chip, void *data)
{
unsigned long flags;
int status = 0;
unsigned i;
int base = chip->base;
struct gpio_device *gdev;
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
*/
gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
if (!gdev)
return -ENOMEM;
gdev->dev.bus = &gpio_bus_type;
gdev->chip = chip;
chip->gpiodev = gdev;
if (chip->parent) {
gdev->dev.parent = chip->parent;
gdev->dev.of_node = chip->parent->of_node;
}
#ifdef CONFIG_OF_GPIO
/* If the gpiochip has an assigned OF node this takes precedence */
if (chip->of_node)
gdev->dev.of_node = chip->of_node;
#endif
gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
if (gdev->id < 0) {
status = gdev->id;
goto err_free_gdev;
}
dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
device_initialize(&gdev->dev);
dev_set_drvdata(&gdev->dev, gdev);
if (chip->parent && chip->parent->driver)
gdev->owner = chip->parent->driver->owner;
else if (chip->owner)
/* TODO: remove chip->owner */
gdev->owner = chip->owner;
else
gdev->owner = THIS_MODULE;
gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
if (!gdev->descs) {
status = -ENOMEM;
goto err_free_gdev;
}
if (chip->ngpio == 0) {
chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
status = -EINVAL;
goto err_free_descs;
}
if (chip->label)
gdev->label = kstrdup(chip->label, GFP_KERNEL);
else
gdev->label = kstrdup("unknown", GFP_KERNEL);
if (!gdev->label) {
status = -ENOMEM;
goto err_free_descs;
}
gdev->ngpio = chip->ngpio;
gdev->data = data;
spin_lock_irqsave(&gpio_lock, flags);
/*
* TODO: this allocates a Linux GPIO number base in the global
* GPIO numberspace for this chip. In the long run we want to
* get *rid* of this numberspace and use only descriptors, but
* it may be a pipe dream. It will not happen before we get rid
* of the sysfs interface anyways.
*/
if (base < 0) {
base = gpiochip_find_base(chip->ngpio);
if (base < 0) {
status = base;
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
/*
* TODO: it should not be necessary to reflect the assigned
* base outside of the GPIO subsystem. Go over drivers and
* see if anyone makes use of this, else drop this and assign
* a poison instead.
*/
chip->base = base;
}
gdev->base = base;
status = gpiodev_add_to_list(gdev);
if (status) {
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
spin_unlock_irqrestore(&gpio_lock, flags);
for (i = 0; i < chip->ngpio; i++) {
struct gpio_desc *desc = &gdev->descs[i];
desc->gdev = gdev;
/*
* REVISIT: most hardware initializes GPIOs as inputs
* (often with pullups enabled) so power usage is
* minimized. Linux code should set the gpio direction
* first thing; but until it does, and in case
* chip->get_direction is not set, we may expose the
* wrong direction in sysfs.
*/
if (chip->get_direction) {
/*
* If we have .get_direction, set up the initial
* direction flag from the hardware.
*/
int dir = chip->get_direction(chip, i);
if (!dir)
set_bit(FLAG_IS_OUT, &desc->flags);
} else if (!chip->direction_input) {
/*
* If the chip lacks the .direction_input callback
* we logically assume all lines are outputs.
*/
set_bit(FLAG_IS_OUT, &desc->flags);
}
}
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif
status = gpiochip_set_desc_names(chip);
if (status)
goto err_remove_from_list;
status = gpiochip_irqchip_init_valid_mask(chip);
if (status)
goto err_remove_from_list;
status = of_gpiochip_add(chip);
if (status)
goto err_remove_chip;
acpi_gpiochip_add(chip);
/*
* By first adding the chardev, and then adding the device,
* we get a device node entry in sysfs under
* /sys/bus/gpio/devices/gpiochipN/dev that can be used for
* coldplug of device nodes and other udev business.
* We can do this only if gpiolib has been initialized.
* Otherwise, defer until later.
*/
if (gpiolib_initialized) {
status = gpiochip_setup_dev(gdev);
if (status)
goto err_remove_chip;
}
return 0;
err_remove_chip:
acpi_gpiochip_remove(chip);
gpiochip_free_hogs(chip);
of_gpiochip_remove(chip);
gpiochip_irqchip_free_valid_mask(chip);
err_remove_from_list:
spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
err_free_label:
kfree(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_gdev:
ida_simple_remove(&gpio_ida, gdev->id);
/* failures here can mean systems won't boot... */
pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
gdev->base, gdev->base + gdev->ngpio - 1,
chip->label ? : "generic");
kfree(gdev);
return status;
}
EXPORT_SYMBOL_GPL(gpiochip_add_data);
/**
* gpiochip_get_data() - get per-subdriver data for the chip
*/
void *gpiochip_get_data(struct gpio_chip *chip)
{
return chip->gpiodev->data;
}
EXPORT_SYMBOL_GPL(gpiochip_get_data);
/**
* gpiochip_remove() - unregister a gpio_chip
* @chip: the chip to unregister
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void gpiochip_remove(struct gpio_chip *chip)
{
struct gpio_device *gdev = chip->gpiodev;
struct gpio_desc *desc;
unsigned long flags;
unsigned i;
bool requested = false;
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
/* Numb the device, cancelling all outstanding operations */
gdev->chip = NULL;
gpiochip_irqchip_remove(chip);
acpi_gpiochip_remove(chip);
gpiochip_remove_pin_ranges(chip);
gpiochip_free_hogs(chip);
of_gpiochip_remove(chip);
/*
* We accept no more calls into the driver from this point, so
* NULL the driver data pointer
*/
gdev->data = NULL;
spin_lock_irqsave(&gpio_lock, flags);
for (i = 0; i < gdev->ngpio; i++) {
desc = &gdev->descs[i];
if (test_bit(FLAG_REQUESTED, &desc->flags))
requested = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (requested)
dev_crit(&gdev->dev,
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
/*
* The gpiochip side puts its use of the device to rest here:
* if there are no userspace clients, the chardev and device will
* be removed, else it will be dangling until the last user is
* gone.
*/
cdev_del(&gdev->chrdev);
device_del(&gdev->dev);
put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
static void devm_gpio_chip_release(struct device *dev, void *res)
{
struct gpio_chip *chip = *(struct gpio_chip **)res;
gpiochip_remove(chip);
}
static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
{
struct gpio_chip **r = res;
if (!r || !*r) {
WARN_ON(!r || !*r);
return 0;
}
return *r == data;
}
/**
* devm_gpiochip_add_data() - Resource manager piochip_add_data()
* @dev: the device pointer on which irq_chip belongs to.
* @chip: the chip to register, with chip->base initialized
* Context: potentially before irqs will work
*
* Returns a negative errno if the chip can't be registered, such as
* because the chip->base is invalid or already associated with a
* different chip. Otherwise it returns zero as a success code.
*
* The gpio chip automatically be released when the device is unbound.
*/
int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
void *data)
{
struct gpio_chip **ptr;
int ret;
ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = gpiochip_add_data(chip, data);
if (ret < 0) {
devres_free(ptr);
return ret;
}
*ptr = chip;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
/**
* devm_gpiochip_remove() - Resource manager of gpiochip_remove()
* @dev: device for which which resource was allocated
* @chip: the chip to remove
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
{
int ret;
ret = devres_release(dev, devm_gpio_chip_release,
devm_gpio_chip_match, chip);
if (!ret)
WARN_ON(ret);
}
EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
/**
* gpiochip_find() - iterator for locating a specific gpio_chip
* @data: data to pass to match function
* @callback: Callback function to check gpio_chip
*
* Similar to bus_find_device. It returns a reference to a gpio_chip as
* determined by a user supplied @match callback. The callback should return
* 0 if the device doesn't match and non-zero if it does. If the callback is
* non-zero, this function will return to the caller and not iterate over any
* more gpio_chips.
*/
struct gpio_chip *gpiochip_find(void *data,
int (*match)(struct gpio_chip *chip,
void *data))
{
struct gpio_device *gdev;
struct gpio_chip *chip = NULL;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (gdev->chip && match(gdev->chip, data)) {
chip = gdev->chip;
break;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return chip;
}
EXPORT_SYMBOL_GPL(gpiochip_find);
static int gpiochip_match_name(struct gpio_chip *chip, void *data)
{
const char *name = data;
return !strcmp(chip->label, name);
}
static struct gpio_chip *find_chip_by_name(const char *name)
{
return gpiochip_find((void *)name, gpiochip_match_name);
}
#ifdef CONFIG_GPIOLIB_IRQCHIP
/*
* The following is irqchip helper code for gpiochips.
*/
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
int i;
if (!gpiochip->irq_need_valid_mask)
return 0;
gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
sizeof(long), GFP_KERNEL);
if (!gpiochip->irq_valid_mask)
return -ENOMEM;
/* Assume by default all GPIOs are valid */
for (i = 0; i < gpiochip->ngpio; i++)
set_bit(i, gpiochip->irq_valid_mask);
return 0;
}
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
{
kfree(gpiochip->irq_valid_mask);
gpiochip->irq_valid_mask = NULL;
}
static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
unsigned int offset)
{
/* No mask means all valid */
if (likely(!gpiochip->irq_valid_mask))
return true;
return test_bit(offset, gpiochip->irq_valid_mask);
}
/**
* gpiochip_set_chained_irqchip() - sets a chained irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip chain to
* @irqchip: the irqchip to chain to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* chained irqchip
* @parent_handler: the parent interrupt handler for the accumulated IRQ
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
int parent_irq,
irq_flow_handler_t parent_handler)
{
unsigned int offset;
if (!gpiochip->irqdomain) {
chip_err(gpiochip, "called %s before setting up irqchip\n",
__func__);
return;
}
if (parent_handler) {
if (gpiochip->can_sleep) {
chip_err(gpiochip,
"you cannot have chained interrupts on a "
"chip that may sleep\n");
return;
}
/*
* The parent irqchip is already using the chip_data for this
* irqchip, so our callbacks simply use the handler_data.
*/
irq_set_chained_handler_and_data(parent_irq, parent_handler,
gpiochip);
gpiochip->irq_parent = parent_irq;
}
/* Set the parent IRQ for all affected IRQs */
for (offset = 0; offset < gpiochip->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
continue;
irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
parent_irq);
}
}
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
* @irq: the global irq number used by this GPIO irqchip irq
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
*
* This function will set up the mapping for a certain IRQ line on a
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
* stored inside the gpiochip.
*/
static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *chip = d->host_data;
irq_set_chip_data(irq, chip);
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
irq_set_lockdep_class(irq, chip->lock_key);
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
/* Chips that can sleep need nested thread handlers */
if (chip->can_sleep && !chip->irq_not_threaded)
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
*/
if (chip->irq_default_type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, chip->irq_default_type);
return 0;
}
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *chip = d->host_data;
if (chip->can_sleep)
irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
static const struct irq_domain_ops gpiochip_domain_ops = {
.map = gpiochip_irq_map,
.unmap = gpiochip_irq_unmap,
/* Virtually all GPIO irqchips are twocell:ed */
.xlate = irq_domain_xlate_twocell,
};
static int gpiochip_irq_reqres(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
if (!try_module_get(chip->gpiodev->owner))
return -ENODEV;
if (gpiochip_lock_as_irq(chip, d->hwirq)) {
chip_err(chip,
"unable to lock HW IRQ %lu for IRQ\n",
d->hwirq);
module_put(chip->gpiodev->owner);
return -EINVAL;
}
return 0;
}
static void gpiochip_irq_relres(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
gpiochip_unlock_as_irq(chip, d->hwirq);
module_put(chip->gpiodev->owner);
}
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
{
return irq_find_mapping(chip->irqdomain, offset);
}
/**
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
* @gpiochip: the gpiochip to remove the irqchip from
*
* This is called only from gpiochip_remove()
*/
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
{
unsigned int offset;
acpi_gpiochip_free_interrupts(gpiochip);
if (gpiochip->irq_parent) {
irq_set_chained_handler(gpiochip->irq_parent, NULL);
irq_set_handler_data(gpiochip->irq_parent, NULL);
}
/* Remove all IRQ mappings and delete the domain */
if (gpiochip->irqdomain) {
for (offset = 0; offset < gpiochip->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
continue;
irq_dispose_mapping(
irq_find_mapping(gpiochip->irqdomain, offset));
}
irq_domain_remove(gpiochip->irqdomain);
}
if (gpiochip->irqchip) {
gpiochip->irqchip->irq_request_resources = NULL;
gpiochip->irqchip->irq_release_resources = NULL;
gpiochip->irqchip = NULL;
}
gpiochip_irqchip_free_valid_mask(gpiochip);
}
/**
* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
* @gpiochip: the gpiochip to add the irqchip to
* @irqchip: the irqchip to add to the gpiochip
* @first_irq: if not dynamically assigned, the base (first) IRQ to
* allocate gpiochip irqs from
* @handler: the irq handler to use (often a predefined irq core function)
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
* to have the core avoid setting up any default type in the hardware.
* @lock_key: lockdep class
*
* This function closely associates a certain irqchip with a certain
* gpiochip, providing an irq domain to translate the local IRQs to
* global irqs in the gpiolib core, and making sure that the gpiochip
* is passed as chip data to all related functions. Driver callbacks
* need to use gpiochip_get_data() to get their local state containers back
* from the gpiochip passed as chip data. An irqdomain will be stored
* in the gpiochip that shall be used by the driver to handle IRQ number
* translation. The gpiochip will need to be initialized and registered
* before calling this function.
*
* This function will handle two cell:ed simple IRQs and assumes all
* the pins on the gpiochip can generate a unique IRQ. Everything else
* need to be open coded.
*/
int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type,
struct lock_class_key *lock_key)
{
struct device_node *of_node;
bool irq_base_set = false;
unsigned int offset;
unsigned irq_base = 0;
if (!gpiochip || !irqchip)
return -EINVAL;
if (!gpiochip->parent) {
pr_err("missing gpiochip .dev parent pointer\n");
return -EINVAL;
}
of_node = gpiochip->parent->of_node;
#ifdef CONFIG_OF_GPIO
/*
* If the gpiochip has an assigned OF node this takes precedence
* FIXME: get rid of this and use gpiochip->parent->of_node
* everywhere
*/
if (gpiochip->of_node)
of_node = gpiochip->of_node;
#endif
/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
* used to configure the interrupts, as you may end-up with
* conflicting triggers. Tell the user, and reset to NONE.
*/
if (WARN(of_node && type != IRQ_TYPE_NONE,
"%s: Ignoring %d default trigger\n", of_node->full_name, type))
type = IRQ_TYPE_NONE;
if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
"Ignoring %d default trigger\n", type);
type = IRQ_TYPE_NONE;
}
gpiochip->irqchip = irqchip;
gpiochip->irq_handler = handler;
gpiochip->irq_default_type = type;
gpiochip->to_irq = gpiochip_to_irq;
gpiochip->lock_key = lock_key;
gpiochip->irqdomain = irq_domain_add_simple(of_node,
gpiochip->ngpio, first_irq,
&gpiochip_domain_ops, gpiochip);
if (!gpiochip->irqdomain) {
gpiochip->irqchip = NULL;
return -EINVAL;
}
/*
* It is possible for a driver to override this, but only if the
* alternative functions are both implemented.
*/
if (!irqchip->irq_request_resources &&
!irqchip->irq_release_resources) {
irqchip->irq_request_resources = gpiochip_irq_reqres;
irqchip->irq_release_resources = gpiochip_irq_relres;
}
/*
* Prepare the mapping since the irqchip shall be orthogonal to
* any gpiochip calls. If the first_irq was zero, this is
* necessary to allocate descriptors for all IRQs.
*/
for (offset = 0; offset < gpiochip->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
continue;
irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
if (!irq_base_set) {
/*
* Store the base into the gpiochip to be used when
* unmapping the irqs.
*/
gpiochip->irq_base = irq_base;
irq_base_set = true;
}
}
acpi_gpiochip_request_interrupts(gpiochip);
return 0;
}
EXPORT_SYMBOL_GPL(_gpiochip_irqchip_add);
#else /* CONFIG_GPIOLIB_IRQCHIP */
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
return 0;
}
static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
{ }
#endif /* CONFIG_GPIOLIB_IRQCHIP */
/**
* gpiochip_generic_request() - request the gpio function for a pin
* @chip: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to request for GPIO function
*/
int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_request_gpio(chip->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
/**
* gpiochip_generic_free() - free the gpio function from a pin
* @chip: the gpiochip to request the gpio function for
* @offset: the offset of the GPIO to free from GPIO function
*/
void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_free_gpio(chip->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_free);
#ifdef CONFIG_PINCTRL
/**
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
* @chip: the gpiochip to add the range for
* @pctldev: the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_group: name of the pin group inside the pin controller
*/
int gpiochip_add_pingroup_range(struct gpio_chip *chip,
struct pinctrl_dev *pctldev,
unsigned int gpio_offset, const char *pin_group)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = chip->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(chip, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = chip;
pin_range->range.name = chip->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->pctldev = pctldev;
ret = pinctrl_get_group_pins(pctldev, pin_group,
&pin_range->range.pins,
&pin_range->range.npins);
if (ret < 0) {
kfree(pin_range);
return ret;
}
pinctrl_add_gpio_range(pctldev, &pin_range->range);
chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
gpio_offset, gpio_offset + pin_range->range.npins - 1,
pinctrl_dev_get_devname(pctldev), pin_group);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
/**
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
* @chip: the gpiochip to add the range for
* @pinctrl_name: the dev_name() of the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_offset: the start offset in the pin controller number space
* @npins: the number of pins from the offset of each pin space (GPIO and
* pin controller) to accumulate in this range
*/
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = chip->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(chip, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = chip;
pin_range->range.name = chip->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->range.pin_base = pin_offset;
pin_range->range.npins = npins;
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
&pin_range->range);
if (IS_ERR(pin_range->pctldev)) {
ret = PTR_ERR(pin_range->pctldev);
chip_err(chip, "could not create pin range\n");
kfree(pin_range);
return ret;
}
chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
gpio_offset, gpio_offset + npins - 1,
pinctl_name,
pin_offset, pin_offset + npins - 1);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
/**
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
* @chip: the chip to remove all the mappings for
*/
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
struct gpio_pin_range *pin_range, *tmp;
struct gpio_device *gdev = chip->gpiodev;
list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
#endif /* CONFIG_PINCTRL */
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
*/
static int __gpiod_request(struct gpio_desc *desc, const char *label)
{
struct gpio_chip *chip = desc->gdev->chip;
int status;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
desc_set_label(desc, label ? : "?");
status = 0;
} else {
status = -EBUSY;
goto done;
}
if (chip->request) {
/* chip->request may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
status = chip->request(chip, gpio_chip_hwgpio(desc));
spin_lock_irqsave(&gpio_lock, flags);
if (status < 0) {
desc_set_label(desc, NULL);
clear_bit(FLAG_REQUESTED, &desc->flags);
goto done;
}
}
if (chip->get_direction) {
/* chip->get_direction may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
gpiod_get_direction(desc);
spin_lock_irqsave(&gpio_lock, flags);
}
done:
spin_unlock_irqrestore(&gpio_lock, flags);
return status;
}
/*
* This descriptor validation needs to be inserted verbatim into each
* function taking a descriptor, so we need to use a preprocessor
* macro to avoid endless duplication. If the desc is NULL it is an
* optional GPIO and calls should just bail out.
*/
#define VALIDATE_DESC(desc) do { \
if (!desc) \
return 0; \
if (IS_ERR(desc)) { \
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
return PTR_ERR(desc); \
} \
if (!desc->gdev) { \
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return -EINVAL; \
} \
if ( !desc->gdev->chip ) { \
dev_warn(&desc->gdev->dev, \
"%s: backing chip is gone\n", __func__); \
return 0; \
} } while (0)
#define VALIDATE_DESC_VOID(desc) do { \
if (!desc) \
return; \
if (IS_ERR(desc)) { \
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
return; \
} \
if (!desc->gdev) { \
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return; \
} \
if (!desc->gdev->chip) { \
dev_warn(&desc->gdev->dev, \
"%s: backing chip is gone\n", __func__); \
return; \
} } while (0)
int gpiod_request(struct gpio_desc *desc, const char *label)
{
int status = -EPROBE_DEFER;
struct gpio_device *gdev;
VALIDATE_DESC(desc);
gdev = desc->gdev;
if (try_module_get(gdev->owner)) {
status = __gpiod_request(desc, label);
if (status < 0)
module_put(gdev->owner);
else
get_device(&gdev->dev);
}
if (status)
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
return status;
}
static bool __gpiod_free(struct gpio_desc *desc)
{
bool ret = false;
unsigned long flags;
struct gpio_chip *chip;
might_sleep();
gpiod_unexport(desc);
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->gdev->chip;
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
if (chip->free) {
spin_unlock_irqrestore(&gpio_lock, flags);
might_sleep_if(chip->can_sleep);
chip->free(chip, gpio_chip_hwgpio(desc));
spin_lock_irqsave(&gpio_lock, flags);
}
desc_set_label(desc, NULL);
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_REQUESTED, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
ret = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
}
void gpiod_free(struct gpio_desc *desc)
{
if (desc && desc->gdev && __gpiod_free(desc)) {
module_put(desc->gdev->owner);
put_device(&desc->gdev->dev);
} else {
WARN_ON(extra_checks);
}
}
/**
* gpiochip_is_requested - return string iff signal was requested
* @chip: controller managing the signal
* @offset: of signal within controller's 0..(ngpio - 1) range
*
* Returns NULL if the GPIO is not currently requested, else a string.
* The string returned is the label passed to gpio_request(); if none has been
* passed it is a meaningless, non-NULL constant.
*
* This function is for use by GPIO controller drivers. The label can
* help with diagnostics, and knowing that the signal is used as a GPIO
* can help avoid accidentally multiplexing it to another controller.
*/
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
{
struct gpio_desc *desc;
if (offset >= chip->ngpio)
return NULL;
desc = &chip->gpiodev->descs[offset];
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
return NULL;
return desc->label;
}
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
/**
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
* @desc: GPIO descriptor to request
* @label: label for the GPIO
*
* Function allows GPIO chip drivers to request and use their own GPIO
* descriptors via gpiolib API. Difference to gpiod_request() is that this
* function will not increase reference count of the GPIO chip module. This
* allows the GPIO chip module to be unloaded as needed (we assume that the
* GPIO chip driver handles freeing the GPIOs it has requested).
*/
struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
const char *label)
{
struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
int err;
if (IS_ERR(desc)) {
chip_err(chip, "failed to get GPIO descriptor\n");
return desc;
}
err = __gpiod_request(desc, label);
if (err < 0)
return ERR_PTR(err);
return desc;
}
EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
/**
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
* @desc: GPIO descriptor to free
*
* Function frees the given GPIO requested previously with
* gpiochip_request_own_desc().
*/
void gpiochip_free_own_desc(struct gpio_desc *desc)
{
if (desc)
__gpiod_free(desc);
}
EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
/*
* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
*
* As a rule these aren't called more than once (except for drivers
* using the open-drain emulation idiom) so these are natural places
* to accumulate extra debugging checks. Note that we can't (yet)
* rely on gpio_request() having been called beforehand.
*/
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
*
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
* be called safely on it.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_input(struct gpio_desc *desc)
{
struct gpio_chip *chip;
int status = -EINVAL;
VALIDATE_DESC(desc);
chip = desc->gdev->chip;
if (!chip->get || !chip->direction_input) {
gpiod_warn(desc,
"%s: missing get() or direction_input() operations\n",
__func__);
return -EIO;
}
status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
if (status == 0)
clear_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_direction(desc_to_gpio(desc), 1, status);
return status;
}
EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
struct gpio_chip *gc = desc->gdev->chip;
int ret;
/* GPIOs used for IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
gpiod_err(desc,
"%s: tried to set a GPIO tied to an IRQ as output\n",
__func__);
return -EIO;
}
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
/* First see if we can enable open drain in hardware */
if (gc->set_single_ended) {
ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
LINE_MODE_OPEN_DRAIN);
if (!ret)
goto set_output_value;
}
/* Emulate open drain by not actively driving the line high */
if (value)
return gpiod_direction_input(desc);
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
if (gc->set_single_ended) {
ret = gc->set_single_ended(gc, gpio_chip_hwgpio(desc),
LINE_MODE_OPEN_SOURCE);
if (!ret)
goto set_output_value;
}
/* Emulate open source by not actively driving the line low */
if (!value)
return gpiod_direction_input(desc);
} else {
/* Make sure to disable open drain/source hardware, if any */
if (gc->set_single_ended)
gc->set_single_ended(gc,
gpio_chip_hwgpio(desc),
LINE_MODE_PUSH_PULL);
}
set_output_value:
if (!gc->set || !gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() or direction_output() operations\n",
__func__);
return -EIO;
}
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), value);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, value);
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
return ret;
}
/**
* gpiod_direction_output_raw - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as raw value on the physical line without regard for the ACTIVE_LOW status.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
return _gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
/**
* gpiod_direction_output - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return _gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
* gpiod_set_debounce - sets @debounce time for a @gpio
* @gpio: the gpio to set debounce time
* @debounce: debounce time is microseconds
*
* returns -ENOTSUPP if the controller does not support setting
* debounce.
*/
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
struct gpio_chip *chip;
VALIDATE_DESC(desc);
chip = desc->gdev->chip;
if (!chip->set || !chip->set_debounce) {
gpiod_dbg(desc,
"%s: missing set() or set_debounce() operations\n",
__func__);
return -ENOTSUPP;
}
return chip->set_debounce(chip, gpio_chip_hwgpio(desc), debounce);
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
/**
* gpiod_is_active_low - test whether a GPIO is active-low or not
* @desc: the gpio descriptor to test
*
* Returns 1 if the GPIO is active-low, 0 otherwise.
*/
int gpiod_is_active_low(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
*
* "Get" operations are often inlinable as reading a pin value register,
* and masking the relevant bit in that register.
*
* When "set" operations are inlinable, they involve writing that mask to
* one register to set a low value, or a different register to set it high.
* Otherwise locking is needed, so there may be little value to inlining.
*
*------------------------------------------------------------------------
*
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
* have requested the GPIO. That can include implicit requesting by
* a direction setting call. Marking a gpio as requested locks its chip
* in memory, guaranteeing that these table lookups need no more locking
* and that gpiochip_remove() will fail.
*
* REVISIT when debugging, consider adding some instrumentation to ensure
* that the GPIO was actually requested.
*/
static int _gpiod_get_raw_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
int value;
chip = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
value = chip->get ? chip->get(chip, offset) : -EIO;
value = value < 0 ? value : !!value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}
/**
* gpiod_get_raw_value() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_raw_value(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
return _gpiod_get_raw_value(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
/**
* gpiod_get_value() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_value(const struct gpio_desc *desc)
{
int value;
VALIDATE_DESC(desc);
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
value = _gpiod_get_raw_value(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value);
/*
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
{
int err = 0;
struct gpio_chip *chip = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
err = chip->direction_input(chip, offset);
if (!err)
clear_bit(FLAG_IS_OUT, &desc->flags);
} else {
err = chip->direction_output(chip, offset, 0);
if (!err)
set_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), value, err);
if (err < 0)
gpiod_err(desc,
"%s: Error in set_value for open drain err %d\n",
__func__, err);
}
/*
* _gpio_set_open_source_value() - Set the open source gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
{
int err = 0;
struct gpio_chip *chip = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
err = chip->direction_output(chip, offset, 1);
if (!err)
set_bit(FLAG_IS_OUT, &desc->flags);
} else {
err = chip->direction_input(chip, offset);
if (!err)
clear_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), !value, err);
if (err < 0)
gpiod_err(desc,
"%s: Error in set_value for open source err %d\n",
__func__, err);
}
static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
{
struct gpio_chip *chip;
chip = desc->gdev->chip;
trace_gpio_value(desc_to_gpio(desc), 0, value);
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
_gpio_set_open_drain_value(desc, value);
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
_gpio_set_open_source_value(desc, value);
else
chip->set(chip, gpio_chip_hwgpio(desc), value);
}
/*
* set multiple outputs on the same chip;
* use the chip's set_multiple function if available;
* otherwise set the outputs sequentially;
* @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
* defines which outputs are to be changed
* @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
* defines the values the outputs specified by mask are to be set to
*/
static void gpio_chip_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
if (chip->set_multiple) {
chip->set_multiple(chip, mask, bits);
} else {
int i;
for (i = 0; i < chip->ngpio; i++) {
if (mask[BIT_WORD(i)] == 0) {
/* no more set bits in this mask word;
* skip ahead to the next word */
i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1;
continue;
}
/* set outputs if the corresponding mask bit is set */
if (__test_and_clear_bit(i, mask))
chip->set(chip, i, test_bit(i, bits));
}
}
}
void gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
int i = 0;
while (i < array_size) {
struct gpio_chip *chip = desc_array[i]->gdev->chip;
unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
int count = 0;
if (!can_sleep)
WARN_ON(chip->can_sleep);
memset(mask, 0, sizeof(mask));
do {
struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
int value = value_array[i];
if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
trace_gpio_value(desc_to_gpio(desc), 0, value);
/*
* collect all normal outputs belonging to the same chip
* open drain and open source outputs are set individually
*/
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
_gpio_set_open_drain_value(desc, value);
} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
_gpio_set_open_source_value(desc, value);
} else {
__set_bit(hwgpio, mask);
if (value)
__set_bit(hwgpio, bits);
else
__clear_bit(hwgpio, bits);
count++;
}
i++;
} while ((i < array_size) &&
(desc_array[i]->gdev->chip == chip));
/* push collected bits to outputs */
if (count != 0)
gpio_chip_set_multiple(chip, mask, bits);
}
}
/**
* gpiod_set_raw_value() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
* gpiod_set_value() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value);
/**
* gpiod_set_raw_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array)
{
if (!desc_array)
return;
gpiod_set_array_value_complex(true, false, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
/**
* gpiod_set_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array)
{
if (!desc_array)
return;
gpiod_set_array_value_complex(false, false, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
/**
* gpiod_cansleep() - report whether gpio value access may sleep
* @desc: gpio to check
*
*/
int gpiod_cansleep(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return desc->gdev->chip->can_sleep;
}
EXPORT_SYMBOL_GPL(gpiod_cansleep);
/**
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
* @desc: gpio whose IRQ will be returned (already requested)
*
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
* error.
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
/*
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
* requires this function to not return zero on an invalid descriptor
* but rather a negative error number.
*/
if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
return -EINVAL;
chip = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
if (chip->to_irq) {
int retirq = chip->to_irq(chip, offset);
/* Zero means NO_IRQ */
if (!retirq)
return -ENXIO;
return retirq;
}
return -ENXIO;
}
EXPORT_SYMBOL_GPL(gpiod_to_irq);
/**
* gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
* @chip: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to lock down
* a certain GPIO line to be used for IRQs.
*/
int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(chip, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
/* Flush direction if something changed behind our back */
if (chip->get_direction) {
int dir = chip->get_direction(chip, offset);
if (dir)
clear_bit(FLAG_IS_OUT, &desc->flags);
else
set_bit(FLAG_IS_OUT, &desc->flags);
}
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
chip_err(chip,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
/**
* gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
* @chip: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to indicate
* that a certain GPIO is no longer used exclusively for IRQ.
*/
void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return;
clear_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return false;
return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return false;
return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return false;
return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
/**
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
might_sleep_if(extra_checks);
VALIDATE_DESC(desc);
return _gpiod_get_raw_value(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
/**
* gpiod_get_value_cansleep() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
int value;
might_sleep_if(extra_checks);
VALIDATE_DESC(desc);
value = _gpiod_get_raw_value(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
/**
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
VALIDATE_DESC_VOID(desc);
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
/**
* gpiod_set_value_cansleep() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep_if(extra_checks);
VALIDATE_DESC_VOID(desc);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
/**
* gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
might_sleep_if(extra_checks);
if (!desc_array)
return;
gpiod_set_array_value_complex(true, true, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
/**
* gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
might_sleep_if(extra_checks);
if (!desc_array)
return;
gpiod_set_array_value_complex(false, true, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
/**
* gpiod_add_lookup_table() - register GPIO device consumers
* @table: table of consumers to register
*/
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
{
mutex_lock(&gpio_lookup_lock);
list_add_tail(&table->list, &gpio_lookup_list);
mutex_unlock(&gpio_lookup_lock);
}
/**
* gpiod_remove_lookup_table() - unregister GPIO device consumers
* @table: table of consumers to unregister
*/
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
{
mutex_lock(&gpio_lookup_lock);
list_del(&table->list);
mutex_unlock(&gpio_lookup_lock);
}
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
struct gpiod_lookup_table *table;
mutex_lock(&gpio_lookup_lock);
list_for_each_entry(table, &gpio_lookup_list, list) {
if (table->dev_id && dev_id) {
/*
* Valid strings on both ends, must be identical to have
* a match
*/
if (!strcmp(table->dev_id, dev_id))
goto found;
} else {
/*
* One of the pointers is NULL, so both must be to have
* a match
*/
if (dev_id == table->dev_id)
goto found;
}
}
table = NULL;
found:
mutex_unlock(&gpio_lookup_lock);
return table;
}
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
struct gpio_desc *desc = ERR_PTR(-ENOENT);
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
table = gpiod_find_lookup_table(dev);
if (!table)
return desc;
for (p = &table->table[0]; p->chip_label; p++) {
struct gpio_chip *chip;
/* idx must always match exactly */
if (p->idx != idx)
continue;
/* If the lookup entry has a con_id, require exact match */
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
continue;
chip = find_chip_by_name(p->chip_label);
if (!chip) {
dev_err(dev, "cannot find GPIO chip %s\n",
p->chip_label);
return ERR_PTR(-ENODEV);
}
if (chip->ngpio <= p->chip_hwnum) {
dev_err(dev,
"requested GPIO %d is out of range [0..%d] for chip %s\n",
idx, chip->ngpio, chip->label);
return ERR_PTR(-EINVAL);
}
desc = gpiochip_get_desc(chip, p->chip_hwnum);
*flags = p->flags;
return desc;
}
return desc;
}
static int dt_gpio_count(struct device *dev, const char *con_id)
{
int ret;
char propname[32];
unsigned int i;
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id)
snprintf(propname, sizeof(propname), "%s-%s",
con_id, gpio_suffixes[i]);
else
snprintf(propname, sizeof(propname), "%s",
gpio_suffixes[i]);
ret = of_gpio_named_count(dev->of_node, propname);
if (ret >= 0)
break;
}
return ret;
}
static int platform_gpio_count(struct device *dev, const char *con_id)
{
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
unsigned int count = 0;
table = gpiod_find_lookup_table(dev);
if (!table)
return -ENOENT;
for (p = &table->table[0]; p->chip_label; p++) {
if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
(!con_id && !p->con_id))
count++;
}
if (!count)
return -ENOENT;
return count;
}
/**
* gpiod_count - return the number of GPIOs associated with a device / function
* or -ENOENT if no GPIO has been assigned to the requested function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
*/
int gpiod_count(struct device *dev, const char *con_id)
{
int count = -ENOENT;
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
count = dt_gpio_count(dev, con_id);
else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
count = acpi_gpio_count(dev, con_id);
if (count < 0)
count = platform_gpio_count(dev, con_id);
return count;
}
EXPORT_SYMBOL_GPL(gpiod_count);
/**
* gpiod_get - obtain a GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* Return the GPIO descriptor corresponding to the function con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get);
/**
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
* the requested function it will return NULL. This is convenient for drivers
* that need to handle optional GPIOs.
*/
struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index_optional(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get_optional);
/**
* gpiod_configure_flags - helper function to configure a given GPIO
* @desc: gpio whose value will be assigned
* @con_id: function within the GPIO consumer
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
* of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*
* Return 0 on success, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
unsigned long lflags, enum gpiod_flags dflags)
{
int status;
if (lflags & GPIO_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIO_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
/* No particular flag request, return here... */
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
pr_debug("no flags found for %s\n", con_id);
return 0;
}
/* Process flags */
if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
status = gpiod_direction_output(desc,
dflags & GPIOD_FLAGS_BIT_DIR_VAL);
else
status = gpiod_direction_input(desc);
return status;
}
/**
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This variant of gpiod_get() allows to access GPIOs other than the first
* defined one for functions that define several GPIOs.
*
* Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags)
{
struct gpio_desc *desc = NULL;
int status;
enum gpio_lookup_flags lookupflags = 0;
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
if (dev) {
/* Using device tree? */
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
dev_dbg(dev, "using device tree for GPIO lookup\n");
desc = of_find_gpio(dev, con_id, idx, &lookupflags);
} else if (ACPI_COMPANION(dev)) {
dev_dbg(dev, "using ACPI for GPIO lookup\n");
desc = acpi_find_gpio(dev, con_id, idx, flags, &lookupflags);
}
}
/*
* Either we are not using DT or ACPI, or their lookup did not return
* a result. In that case, use platform lookup as a fallback.
*/
if (!desc || desc == ERR_PTR(-ENOENT)) {
dev_dbg(dev, "using lookup tables for GPIO lookup\n");
desc = gpiod_find(dev, con_id, idx, &lookupflags);
}
if (IS_ERR(desc)) {
dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
return desc;
}
status = gpiod_request(desc, con_id);
if (status < 0)
return ERR_PTR(status);
status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
if (status < 0) {
dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
gpiod_put(desc);
return ERR_PTR(status);
}
return desc;
}
EXPORT_SYMBOL_GPL(gpiod_get_index);
/**
* fwnode_get_named_gpiod - obtain a GPIO from firmware node
* @fwnode: handle of the firmware node
* @propname: name of the firmware property representing the GPIO
*
* This function can be used for drivers that get their configuration
* from firmware.
*
* Function properly finds the corresponding GPIO using whatever is the
* underlying firmware interface and then makes sure that the GPIO
* descriptor is requested before it is returned to the caller.
*
* In case of error an ERR_PTR() is returned.
*/
struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
const char *propname)
{
struct gpio_desc *desc = ERR_PTR(-ENODEV);
bool active_low = false;
bool single_ended = false;
int ret;
if (!fwnode)
return ERR_PTR(-EINVAL);
if (is_of_node(fwnode)) {
enum of_gpio_flags flags;
desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0,
&flags);
if (!IS_ERR(desc)) {
active_low = flags & OF_GPIO_ACTIVE_LOW;
single_ended = flags & OF_GPIO_SINGLE_ENDED;
}
} else if (is_acpi_node(fwnode)) {
struct acpi_gpio_info info;
desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
if (!IS_ERR(desc))
active_low = info.polarity == GPIO_ACTIVE_LOW;
}
if (IS_ERR(desc))
return desc;
ret = gpiod_request(desc, NULL);
if (ret)
return ERR_PTR(ret);
if (active_low)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (single_ended) {
if (active_low)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
else
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
}
return desc;
}
EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
/**
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
* specified index was assigned to the requested function it will return NULL.
* This is convenient for drivers that need to handle optional GPIOs.
*/
struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
desc = gpiod_get_index(dev, con_id, index, flags);
if (IS_ERR(desc)) {
if (PTR_ERR(desc) == -ENOENT)
return NULL;
}
return desc;
}
EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
/**
* gpiod_hog - Hog the specified GPIO desc given the provided flags
* @desc: gpio whose value will be assigned
* @name: gpio line name
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
* of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*/
int gpiod_hog(struct gpio_desc *desc, const char *name,
unsigned long lflags, enum gpiod_flags dflags)
{
struct gpio_chip *chip;
struct gpio_desc *local_desc;
int hwnum;
int status;
chip = gpiod_to_chip(desc);
hwnum = gpio_chip_hwgpio(desc);
local_desc = gpiochip_request_own_desc(chip, hwnum, name);
if (IS_ERR(local_desc)) {
status = PTR_ERR(local_desc);
pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
name, chip->label, hwnum, status);
return status;
}
status = gpiod_configure_flags(desc, name, lflags, dflags);
if (status < 0) {
pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n",
name, chip->label, hwnum, status);
gpiochip_free_own_desc(desc);
return status;
}
/* Mark GPIO as hogged so it can be identified and removed later */
set_bit(FLAG_IS_HOGGED, &desc->flags);
pr_info("GPIO line %d (%s) hogged as %s%s\n",
desc_to_gpio(desc), name,
(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
(dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
(dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
return 0;
}
/**
* gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
* @chip: gpio chip to act on
*
* This is only used by of_gpiochip_remove to free hogged gpios
*/
static void gpiochip_free_hogs(struct gpio_chip *chip)
{
int id;
for (id = 0; id < chip->ngpio; id++) {
if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
}
}
/**
* gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This function acquires all the GPIOs defined under a given function.
*
* Return a struct gpio_descs containing an array of descriptors, -ENOENT if
* no GPIO has been assigned to the requested function, or another IS_ERR()
* code if an error occurred while trying to acquire the GPIOs.
*/
struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
struct gpio_descs *descs;
int count;
count = gpiod_count(dev, con_id);
if (count < 0)
return ERR_PTR(count);
descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count,
GFP_KERNEL);
if (!descs)
return ERR_PTR(-ENOMEM);
for (descs->ndescs = 0; descs->ndescs < count; ) {
desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
if (IS_ERR(desc)) {
gpiod_put_array(descs);
return ERR_CAST(desc);
}
descs->desc[descs->ndescs] = desc;
descs->ndescs++;
}
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array);
/**
* gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_array(), except that when no GPIO was
* assigned to the requested function it will return NULL.
*/
struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_descs *descs;
descs = gpiod_get_array(dev, con_id, flags);
if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
return NULL;
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
/**
* gpiod_put - dispose of a GPIO descriptor
* @desc: GPIO descriptor to dispose of
*
* No descriptor can be used after gpiod_put() has been called on it.
*/
void gpiod_put(struct gpio_desc *desc)
{
gpiod_free(desc);
}
EXPORT_SYMBOL_GPL(gpiod_put);
/**
* gpiod_put_array - dispose of multiple GPIO descriptors
* @descs: struct gpio_descs containing an array of descriptors
*/
void gpiod_put_array(struct gpio_descs *descs)
{
unsigned int i;
for (i = 0; i < descs->ndescs; i++)
gpiod_put(descs->desc[i]);
kfree(descs);
}
EXPORT_SYMBOL_GPL(gpiod_put_array);
static int __init gpiolib_dev_init(void)
{
int ret;
/* Register GPIO sysfs bus */
ret = bus_register(&gpio_bus_type);
if (ret < 0) {
pr_err("gpiolib: could not register GPIO bus type\n");
return ret;
}
ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
bus_unregister(&gpio_bus_type);
} else {
gpiolib_initialized = true;
gpiochip_setup_devs();
}
return ret;
}
core_initcall(gpiolib_dev_init);
#ifdef CONFIG_DEBUG_FS
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
{
unsigned i;
struct gpio_chip *chip = gdev->chip;
unsigned gpio = gdev->base;
struct gpio_desc *gdesc = &gdev->descs[0];
int is_out;
int is_irq;
for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
if (gdesc->name) {
seq_printf(s, " gpio-%-3d (%-20.20s)\n",
gpio, gdesc->name);
}
continue;
}
gpiod_get_direction(gdesc);
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s",
gpio, gdesc->name ? gdesc->name : "", gdesc->label,
is_out ? "out" : "in ",
chip->get
? (chip->get(chip, i) ? "hi" : "lo")
: "? ",
is_irq ? "IRQ" : " ");
seq_printf(s, "\n");
}
}
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
{
unsigned long flags;
struct gpio_device *gdev = NULL;
loff_t index = *pos;
s->private = "";
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (index-- == 0) {
spin_unlock_irqrestore(&gpio_lock, flags);
return gdev;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return NULL;
}
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
unsigned long flags;
struct gpio_device *gdev = v;
void *ret = NULL;
spin_lock_irqsave(&gpio_lock, flags);
if (list_is_last(&gdev->list, &gpio_devices))
ret = NULL;
else
ret = list_entry(gdev->list.next, struct gpio_device, list);
spin_unlock_irqrestore(&gpio_lock, flags);
s->private = "\n";
++*pos;
return ret;
}
static void gpiolib_seq_stop(struct seq_file *s, void *v)
{
}
static int gpiolib_seq_show(struct seq_file *s, void *v)
{
struct gpio_device *gdev = v;
struct gpio_chip *chip = gdev->chip;
struct device *parent;
if (!chip) {
seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
dev_name(&gdev->dev));
return 0;
}
seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
dev_name(&gdev->dev),
gdev->base, gdev->base + gdev->ngpio - 1);
parent = chip->parent;
if (parent)
seq_printf(s, ", parent: %s/%s",
parent->bus ? parent->bus->name : "no-bus",
dev_name(parent));
if (chip->label)
seq_printf(s, ", %s", chip->label);
if (chip->can_sleep)
seq_printf(s, ", can sleep");
seq_printf(s, ":\n");
if (chip->dbg_show)
chip->dbg_show(s, chip);
else
gpiolib_dbg_show(s, gdev);
return 0;
}
static const struct seq_operations gpiolib_seq_ops = {
.start = gpiolib_seq_start,
.next = gpiolib_seq_next,
.stop = gpiolib_seq_stop,
.show = gpiolib_seq_show,
};
static int gpiolib_open(struct inode *inode, struct file *file)
{
return seq_open(file, &gpiolib_seq_ops);
}
static const struct file_operations gpiolib_operations = {
.owner = THIS_MODULE,
.open = gpiolib_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init gpiolib_debugfs_init(void)
{
/* /sys/kernel/debug/gpio */
(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
NULL, NULL, &gpiolib_operations);
return 0;
}
subsys_initcall(gpiolib_debugfs_init);
#endif /* DEBUG_FS */