diff options
Diffstat (limited to 'drivers/pinctrl/core.c')
| -rw-r--r-- | drivers/pinctrl/core.c | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c new file mode 100644 index 000000000000..eadef9e191ea --- /dev/null +++ b/drivers/pinctrl/core.c @@ -0,0 +1,599 @@ +/* + * 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); |