linux/drivers/pinctrl/core.c
Stephen Rothwell a5a697cdef pinctrl: EXPORT_SYMBOL needs export.h
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:21 -04:00

600 lines
15 KiB
C

/*
* Core driver for the pin control subsystem
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
* Based on bits of regulator core, gpio core and clk core
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) "pinctrl core: " fmt
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/sysfs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/machine.h>
#include "core.h"
#include "pinmux.h"
/* Global list of pin control devices */
static DEFINE_MUTEX(pinctrldev_list_mutex);
static LIST_HEAD(pinctrldev_list);
static void pinctrl_dev_release(struct device *dev)
{
struct pinctrl_dev *pctldev = dev_get_drvdata(dev);
kfree(pctldev);
}
const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev)
{
/* We're not allowed to register devices without name */
return pctldev->desc->name;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_name);
void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev)
{
return pctldev->driver_data;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_drvdata);
/**
* get_pinctrl_dev_from_dev() - look up pin controller device
* @dev: a device pointer, this may be NULL but then devname needs to be
* defined instead
* @devname: the name of a device instance, as returned by dev_name(), this
* may be NULL but then dev needs to be defined instead
*
* Looks up a pin control device matching a certain device name or pure device
* pointer, the pure device pointer will take precedence.
*/
struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev,
const char *devname)
{
struct pinctrl_dev *pctldev = NULL;
bool found = false;
mutex_lock(&pinctrldev_list_mutex);
list_for_each_entry(pctldev, &pinctrldev_list, node) {
if (dev && &pctldev->dev == dev) {
/* Matched on device pointer */
found = true;
break;
}
if (devname &&
!strcmp(dev_name(&pctldev->dev), devname)) {
/* Matched on device name */
found = true;
break;
}
}
mutex_unlock(&pinctrldev_list_mutex);
return found ? pctldev : NULL;
}
struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, int pin)
{
struct pin_desc *pindesc;
unsigned long flags;
spin_lock_irqsave(&pctldev->pin_desc_tree_lock, flags);
pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, pin);
spin_unlock_irqrestore(&pctldev->pin_desc_tree_lock, flags);
return pindesc;
}
/**
* pin_is_valid() - check if pin exists on controller
* @pctldev: the pin control device to check the pin on
* @pin: pin to check, use the local pin controller index number
*
* This tells us whether a certain pin exist on a certain pin controller or
* not. Pin lists may be sparse, so some pins may not exist.
*/
bool pin_is_valid(struct pinctrl_dev *pctldev, int pin)
{
struct pin_desc *pindesc;
if (pin < 0)
return false;
pindesc = pin_desc_get(pctldev, pin);
if (pindesc == NULL)
return false;
return true;
}
EXPORT_SYMBOL_GPL(pin_is_valid);
/* Deletes a range of pin descriptors */
static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
const struct pinctrl_pin_desc *pins,
unsigned num_pins)
{
int i;
spin_lock(&pctldev->pin_desc_tree_lock);
for (i = 0; i < num_pins; i++) {
struct pin_desc *pindesc;
pindesc = radix_tree_lookup(&pctldev->pin_desc_tree,
pins[i].number);
if (pindesc != NULL) {
radix_tree_delete(&pctldev->pin_desc_tree,
pins[i].number);
}
kfree(pindesc);
}
spin_unlock(&pctldev->pin_desc_tree_lock);
}
static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
unsigned number, const char *name)
{
struct pin_desc *pindesc;
pindesc = pin_desc_get(pctldev, number);
if (pindesc != NULL) {
pr_err("pin %d already registered on %s\n", number,
pctldev->desc->name);
return -EINVAL;
}
pindesc = kzalloc(sizeof(*pindesc), GFP_KERNEL);
if (pindesc == NULL)
return -ENOMEM;
spin_lock_init(&pindesc->lock);
/* Set owner */
pindesc->pctldev = pctldev;
/* Copy basic pin info */
pindesc->name = name;
spin_lock(&pctldev->pin_desc_tree_lock);
radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc);
spin_unlock(&pctldev->pin_desc_tree_lock);
pr_debug("registered pin %d (%s) on %s\n",
number, name ? name : "(unnamed)", pctldev->desc->name);
return 0;
}
static int pinctrl_register_pins(struct pinctrl_dev *pctldev,
struct pinctrl_pin_desc const *pins,
unsigned num_descs)
{
unsigned i;
int ret = 0;
for (i = 0; i < num_descs; i++) {
ret = pinctrl_register_one_pin(pctldev,
pins[i].number, pins[i].name);
if (ret)
return ret;
}
return 0;
}
/**
* pinctrl_match_gpio_range() - check if a certain GPIO pin is in range
* @pctldev: pin controller device to check
* @gpio: gpio pin to check taken from the global GPIO pin space
*
* Tries to match a GPIO pin number to the ranges handled by a certain pin
* controller, return the range or NULL
*/
static struct pinctrl_gpio_range *
pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
{
struct pinctrl_gpio_range *range = NULL;
/* Loop over the ranges */
mutex_lock(&pctldev->gpio_ranges_lock);
list_for_each_entry(range, &pctldev->gpio_ranges, node) {
/* Check if we're in the valid range */
if (gpio >= range->base &&
gpio < range->base + range->npins) {
mutex_unlock(&pctldev->gpio_ranges_lock);
return range;
}
}
mutex_unlock(&pctldev->gpio_ranges_lock);
return NULL;
}
/**
* pinctrl_get_device_gpio_range() - find device for GPIO range
* @gpio: the pin to locate the pin controller for
* @outdev: the pin control device if found
* @outrange: the GPIO range if found
*
* Find the pin controller handling a certain GPIO pin from the pinspace of
* the GPIO subsystem, return the device and the matching GPIO range. Returns
* negative if the GPIO range could not be found in any device.
*/
int pinctrl_get_device_gpio_range(unsigned gpio,
struct pinctrl_dev **outdev,
struct pinctrl_gpio_range **outrange)
{
struct pinctrl_dev *pctldev = NULL;
/* Loop over the pin controllers */
mutex_lock(&pinctrldev_list_mutex);
list_for_each_entry(pctldev, &pinctrldev_list, node) {
struct pinctrl_gpio_range *range;
range = pinctrl_match_gpio_range(pctldev, gpio);
if (range != NULL) {
*outdev = pctldev;
*outrange = range;
mutex_unlock(&pinctrldev_list_mutex);
return 0;
}
}
mutex_unlock(&pinctrldev_list_mutex);
return -EINVAL;
}
/**
* pinctrl_add_gpio_range() - register a GPIO range for a controller
* @pctldev: pin controller device to add the range to
* @range: the GPIO range to add
*
* This adds a range of GPIOs to be handled by a certain pin controller. Call
* this to register handled ranges after registering your pin controller.
*/
void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range)
{
mutex_lock(&pctldev->gpio_ranges_lock);
list_add(&range->node, &pctldev->gpio_ranges);
mutex_unlock(&pctldev->gpio_ranges_lock);
}
/**
* pinctrl_remove_gpio_range() - remove a range of GPIOs fro a pin controller
* @pctldev: pin controller device to remove the range from
* @range: the GPIO range to remove
*/
void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range)
{
mutex_lock(&pctldev->gpio_ranges_lock);
list_del(&range->node);
mutex_unlock(&pctldev->gpio_ranges_lock);
}
#ifdef CONFIG_DEBUG_FS
static int pinctrl_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *ops = pctldev->desc->pctlops;
unsigned pin;
seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
seq_printf(s, "max pin number: %d\n", pctldev->desc->maxpin);
/* The highest pin number need to be included in the loop, thus <= */
for (pin = 0; pin <= pctldev->desc->maxpin; pin++) {
struct pin_desc *desc;
desc = pin_desc_get(pctldev, pin);
/* Pin space may be sparse */
if (desc == NULL)
continue;
seq_printf(s, "pin %d (%s) ", pin,
desc->name ? desc->name : "unnamed");
/* Driver-specific info per pin */
if (ops->pin_dbg_show)
ops->pin_dbg_show(pctldev, s, pin);
seq_puts(s, "\n");
}
return 0;
}
static int pinctrl_groups_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *ops = pctldev->desc->pctlops;
unsigned selector = 0;
/* No grouping */
if (!ops)
return 0;
seq_puts(s, "registered pin groups:\n");
while (ops->list_groups(pctldev, selector) >= 0) {
const unsigned *pins;
unsigned num_pins;
const char *gname = ops->get_group_name(pctldev, selector);
int ret;
int i;
ret = ops->get_group_pins(pctldev, selector,
&pins, &num_pins);
if (ret)
seq_printf(s, "%s [ERROR GETTING PINS]\n",
gname);
else {
seq_printf(s, "group: %s, pins = [ ", gname);
for (i = 0; i < num_pins; i++)
seq_printf(s, "%d ", pins[i]);
seq_puts(s, "]\n");
}
selector++;
}
return 0;
}
static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
struct pinctrl_gpio_range *range = NULL;
seq_puts(s, "GPIO ranges handled:\n");
/* Loop over the ranges */
mutex_lock(&pctldev->gpio_ranges_lock);
list_for_each_entry(range, &pctldev->gpio_ranges, node) {
seq_printf(s, "%u: %s [%u - %u]\n", range->id, range->name,
range->base, (range->base + range->npins - 1));
}
mutex_unlock(&pctldev->gpio_ranges_lock);
return 0;
}
static int pinctrl_devices_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev;
seq_puts(s, "name [pinmux]\n");
mutex_lock(&pinctrldev_list_mutex);
list_for_each_entry(pctldev, &pinctrldev_list, node) {
seq_printf(s, "%s ", pctldev->desc->name);
if (pctldev->desc->pmxops)
seq_puts(s, "yes");
else
seq_puts(s, "no");
seq_puts(s, "\n");
}
mutex_unlock(&pinctrldev_list_mutex);
return 0;
}
static int pinctrl_pins_open(struct inode *inode, struct file *file)
{
return single_open(file, pinctrl_pins_show, inode->i_private);
}
static int pinctrl_groups_open(struct inode *inode, struct file *file)
{
return single_open(file, pinctrl_groups_show, inode->i_private);
}
static int pinctrl_gpioranges_open(struct inode *inode, struct file *file)
{
return single_open(file, pinctrl_gpioranges_show, inode->i_private);
}
static int pinctrl_devices_open(struct inode *inode, struct file *file)
{
return single_open(file, pinctrl_devices_show, NULL);
}
static const struct file_operations pinctrl_pins_ops = {
.open = pinctrl_pins_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinctrl_groups_ops = {
.open = pinctrl_groups_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinctrl_gpioranges_ops = {
.open = pinctrl_gpioranges_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinctrl_devices_ops = {
.open = pinctrl_devices_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static struct dentry *debugfs_root;
static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
{
static struct dentry *device_root;
device_root = debugfs_create_dir(dev_name(&pctldev->dev),
debugfs_root);
if (IS_ERR(device_root) || !device_root) {
pr_warn("failed to create debugfs directory for %s\n",
dev_name(&pctldev->dev));
return;
}
debugfs_create_file("pins", S_IFREG | S_IRUGO,
device_root, pctldev, &pinctrl_pins_ops);
debugfs_create_file("pingroups", S_IFREG | S_IRUGO,
device_root, pctldev, &pinctrl_groups_ops);
debugfs_create_file("gpio-ranges", S_IFREG | S_IRUGO,
device_root, pctldev, &pinctrl_gpioranges_ops);
pinmux_init_device_debugfs(device_root, pctldev);
}
static void pinctrl_init_debugfs(void)
{
debugfs_root = debugfs_create_dir("pinctrl", NULL);
if (IS_ERR(debugfs_root) || !debugfs_root) {
pr_warn("failed to create debugfs directory\n");
debugfs_root = NULL;
return;
}
debugfs_create_file("pinctrl-devices", S_IFREG | S_IRUGO,
debugfs_root, NULL, &pinctrl_devices_ops);
pinmux_init_debugfs(debugfs_root);
}
#else /* CONFIG_DEBUG_FS */
static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
{
}
static void pinctrl_init_debugfs(void)
{
}
#endif
/**
* pinctrl_register() - register a pin controller device
* @pctldesc: descriptor for this pin controller
* @dev: parent device for this pin controller
* @driver_data: private pin controller data for this pin controller
*/
struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
struct device *dev, void *driver_data)
{
static atomic_t pinmux_no = ATOMIC_INIT(0);
struct pinctrl_dev *pctldev;
int ret;
if (pctldesc == NULL)
return NULL;
if (pctldesc->name == NULL)
return NULL;
/* If we're implementing pinmuxing, check the ops for sanity */
if (pctldesc->pmxops) {
ret = pinmux_check_ops(pctldesc->pmxops);
if (ret) {
pr_err("%s pinmux ops lacks necessary functions\n",
pctldesc->name);
return NULL;
}
}
pctldev = kzalloc(sizeof(struct pinctrl_dev), GFP_KERNEL);
if (pctldev == NULL)
return NULL;
/* Initialize pin control device struct */
pctldev->owner = pctldesc->owner;
pctldev->desc = pctldesc;
pctldev->driver_data = driver_data;
INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
spin_lock_init(&pctldev->pin_desc_tree_lock);
INIT_LIST_HEAD(&pctldev->gpio_ranges);
mutex_init(&pctldev->gpio_ranges_lock);
/* Register device */
pctldev->dev.parent = dev;
dev_set_name(&pctldev->dev, "pinctrl.%d",
atomic_inc_return(&pinmux_no) - 1);
pctldev->dev.release = pinctrl_dev_release;
ret = device_register(&pctldev->dev);
if (ret != 0) {
pr_err("error in device registration\n");
goto out_reg_dev_err;
}
dev_set_drvdata(&pctldev->dev, pctldev);
/* Register all the pins */
pr_debug("try to register %d pins on %s...\n",
pctldesc->npins, pctldesc->name);
ret = pinctrl_register_pins(pctldev, pctldesc->pins, pctldesc->npins);
if (ret) {
pr_err("error during pin registration\n");
pinctrl_free_pindescs(pctldev, pctldesc->pins,
pctldesc->npins);
goto out_reg_pins_err;
}
pinctrl_init_device_debugfs(pctldev);
mutex_lock(&pinctrldev_list_mutex);
list_add(&pctldev->node, &pinctrldev_list);
mutex_unlock(&pinctrldev_list_mutex);
pinmux_hog_maps(pctldev);
return pctldev;
out_reg_pins_err:
device_del(&pctldev->dev);
out_reg_dev_err:
put_device(&pctldev->dev);
return NULL;
}
EXPORT_SYMBOL_GPL(pinctrl_register);
/**
* pinctrl_unregister() - unregister pinmux
* @pctldev: pin controller to unregister
*
* Called by pinmux drivers to unregister a pinmux.
*/
void pinctrl_unregister(struct pinctrl_dev *pctldev)
{
if (pctldev == NULL)
return;
pinmux_unhog_maps(pctldev);
/* TODO: check that no pinmuxes are still active? */
mutex_lock(&pinctrldev_list_mutex);
list_del(&pctldev->node);
mutex_unlock(&pinctrldev_list_mutex);
/* Destroy descriptor tree */
pinctrl_free_pindescs(pctldev, pctldev->desc->pins,
pctldev->desc->npins);
device_unregister(&pctldev->dev);
}
EXPORT_SYMBOL_GPL(pinctrl_unregister);
static int __init pinctrl_init(void)
{
pr_info("initialized pinctrl subsystem\n");
pinctrl_init_debugfs();
return 0;
}
/* init early since many drivers really need to initialized pinmux early */
core_initcall(pinctrl_init);