linux/drivers/gpio/gpiolib.c
Linus Torvalds 1eccc6e152 This is the bulk of GPIO changes for kernel cycle v4.7:
Core infrastructural changes:
 
 - Support for natively single-ended GPIO driver stages. This
   means that if the hardware has registers to configure open
   drain or open source configuration, we use that rather than
   (as we did before) try to emulate it by switching the line
   to an input to get high impedance. This is also documented
   throughly in Documentation/gpio/driver.txt for those of you
   who did not understand one word of what I just wrote.
 
 - Start to do away with the unnecessarily complex and
   unitelligible ARCH_REQUIRE_GPIOLIB and
   ARCH_WANT_OPTIONAL_GPIOLIB, another evolutional artifact from
   the time when the GPIO subsystem was unmaintained. Archs can
   now just select GPIOLIB and be done with it, cleanups to
   arches will trickle in for the next kernel. Some minor archs
   ACKed the changes immediately so these are included in this
   pull request.
 
 - Advancing the use of the data pointer inside the GPIO device
   for storing driver data by switching the PowerPC, Super-H
   Unicore and a few other subarches or subsystem drivers in
   ALSA SoC, Input, serial, SSB, staging etc to use it.
 
 - The initialization now reads the input/output state of the
   GPIO lines, so that each GPIO descriptor knows - if this
   callback is implemented - whether the line is input or
   output. This also reflects nicely in userspace "lsgpio".
 
 - It is now possible to name GPIO producer names, line names,
   from the device tree. (Platform data has been supported for
   a while.) I bet we will get a similar mechanism for ACPI
   one of those days. This makes is possible to get sensible
   producer names for e.g. GPIO rails in "lsgpio" in userspace.
 
 New drivers:
 
 - New driver for the Loongson1.
 
 - The XLP driver now supports Broadcom Vulcan ARM64.
 
 - The IT87 driver now supports IT8620 and IT8628.
 
 - The PCA953X driver now supports Galileo Gen2.
 
 Driver improvements:
 
 - MCP23S08 was switched to use the gpiolib irqchip helpers and
   now also suppors level-triggered interrupts.
 
 - 74x164 and RCAR now supports the .set_multiple() callback
 
 - AMDPT was converted to use generic GPIO.
 
 - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
   support the new single ended callback for open drain
   and in some cases open source.
 
 - Implement the .get_direction() callback for a few more drivers
   like PL061, Xgene.
 
 Cleanups:
 
 - Paul Gortmaker combed through the drivers and de-modularized
   those who are not really modules.
 
 - Move the GPIO poweroff DT bindings to the power subdir where
   they belong.
 
 - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
   point. That's what it is handling, nothing more, nothing less.
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Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...
2016-05-17 17:39:42 -07:00

3075 lines
82 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/idr.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/uaccess.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 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_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;
int __user *ip = (int __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;
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;
}
return -EINVAL;
}
/**
* 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,
.compat_ioctl = gpio_ioctl,
};
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = dev_get_drvdata(dev);
cdev_del(&gdev->chrdev);
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;
get_device(&gdev->dev);
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;
} else {
#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;
}
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);
}
}
spin_unlock_irqrestore(&gpio_lock, 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 = 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);
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.
*/
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;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (match(gdev->chip, data))
break;
/* No match? */
if (&gdev->list == &gpio_devices)
chip = NULL;
else
chip = gdev->chip;
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.
*/
/**
* 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++)
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++)
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_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;
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
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++) {
irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
if (offset == 0)
/*
* Store the base into the gpiochip to be used when
* unmapping the irqs.
*/
gpiochip->irq_base = irq_base;
}
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) {}
#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:
if (status < 0) {
/* Clear flags that might have been set by the caller before
* requesting the GPIO.
*/
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
}
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.
*/
#define VALIDATE_DESC(desc) do { \
if (!desc || !desc->gdev) { \
pr_warn("%s: invalid GPIO\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 || !desc->gdev) { \
pr_warn("%s: invalid GPIO\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;
VALIDATE_DESC(desc);
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)
{
if (offset >= chip->ngpio)
return -EINVAL;
if (test_bit(FLAG_IS_OUT, &chip->gpiodev->descs[offset].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, &chip->gpiodev->descs[offset].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 gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
unsigned int idx,
enum gpio_lookup_flags *flags)
{
char prop_name[32]; /* 32 is max size of property name */
enum of_gpio_flags of_flags;
struct gpio_desc *desc;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id)
snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
gpio_suffixes[i]);
else
snprintf(prop_name, sizeof(prop_name), "%s",
gpio_suffixes[i]);
desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
&of_flags);
if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
break;
}
if (IS_ERR(desc))
return desc;
if (of_flags & OF_GPIO_ACTIVE_LOW)
*flags |= GPIO_ACTIVE_LOW;
if (of_flags & OF_GPIO_SINGLE_ENDED) {
if (of_flags & OF_GPIO_ACTIVE_LOW)
*flags |= GPIO_OPEN_DRAIN;
else
*flags |= GPIO_OPEN_SOURCE;
}
return desc;
}
static struct gpio_desc *acpi_find_gpio(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags,
enum gpio_lookup_flags *lookupflags)
{
struct acpi_device *adev = ACPI_COMPANION(dev);
struct acpi_gpio_info info;
struct gpio_desc *desc;
char propname[32];
int i;
/* Try first from _DSD */
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id && strcmp(con_id, "gpios")) {
snprintf(propname, sizeof(propname), "%s-%s",
con_id, gpio_suffixes[i]);
} else {
snprintf(propname, sizeof(propname), "%s",
gpio_suffixes[i]);
}
desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
break;
}
/* Then from plain _CRS GPIOs */
if (IS_ERR(desc)) {
if (!acpi_can_fallback_to_crs(adev, con_id))
return ERR_PTR(-ENOENT);
desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
if (IS_ERR(desc))
return desc;
if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
info.gpioint) {
dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
return ERR_PTR(-ENOENT);
}
}
if (info.polarity == GPIO_ACTIVE_LOW)
*lookupflags |= GPIO_ACTIVE_LOW;
return desc;
}
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_parse_flags - helper function to parse GPIO lookup flags
* @desc: gpio to be setup
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
* of_get_gpio_hog()
*
* Set the GPIO descriptor flags based on the given GPIO lookup flags.
*/
static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags)
{
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);
}
/**
* gpiod_configure_flags - helper function to configure a given GPIO
* @desc: gpio whose value will be assigned
* @con_id: function within the GPIO consumer
* @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,
enum gpiod_flags dflags)
{
int status;
/* 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;
}
gpiod_parse_flags(desc, lookupflags);
status = gpiod_request(desc, con_id);
if (status < 0)
return ERR_PTR(status);
status = gpiod_configure_flags(desc, con_id, 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;
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);
}
ret = gpiod_request(desc, NULL);
if (ret)
return ERR_PTR(ret);
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);
gpiod_parse_flags(desc, lflags);
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, 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 */