Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

600 lines (510 sloc) 15.811 kb
/*
* 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);
Jump to Line
Something went wrong with that request. Please try again.