diff options
Diffstat (limited to 'drivers/pinctrl')
| -rw-r--r-- | drivers/pinctrl/Kconfig | 29 | ||||
| -rw-r--r-- | drivers/pinctrl/Makefile | 6 | ||||
| -rw-r--r-- | drivers/pinctrl/core.c | 599 | ||||
| -rw-r--r-- | drivers/pinctrl/core.h | 72 | ||||
| -rw-r--r-- | drivers/pinctrl/pinmux.c | 1180 | ||||
| -rw-r--r-- | drivers/pinctrl/pinmux.h | 47 |
6 files changed, 1933 insertions, 0 deletions
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig new file mode 100644 index 00000000000..02b4d4e92ff --- /dev/null +++ b/drivers/pinctrl/Kconfig @@ -0,0 +1,29 @@ +# +# PINCTRL infrastructure and drivers +# + +menuconfig PINCTRL + bool "PINCTRL Support" + depends on EXPERIMENTAL + help + This enables the PINCTRL subsystem for controlling pins + on chip packages, for example multiplexing pins on primarily + PGA and BGA packages for systems on chip. + + If unsure, say N. + +if PINCTRL + +config PINMUX + bool "Support pinmux controllers" + help + Say Y here if you want the pincontrol subsystem to handle pin + multiplexing drivers. + +config DEBUG_PINCTRL + bool "Debug PINCTRL calls" + depends on DEBUG_KERNEL + help + Say Y here to add some extra checks and diagnostics to PINCTRL calls. + +endif diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile new file mode 100644 index 00000000000..596ce9f2289 --- /dev/null +++ b/drivers/pinctrl/Makefile @@ -0,0 +1,6 @@ +# generic pinmux support + +ccflags-$(CONFIG_DEBUG_PINMUX) += -DDEBUG + +obj-$(CONFIG_PINCTRL) += core.o +obj-$(CONFIG_PINMUX) += pinmux.o diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c new file mode 100644 index 00000000000..b2eaf8d4412 --- /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/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 optional basic pin info */ + if (name) + strlcpy(pindesc->name, name, sizeof(pindesc->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) { + 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); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h new file mode 100644 index 00000000000..17e07772160 --- /dev/null +++ b/drivers/pinctrl/core.h @@ -0,0 +1,72 @@ +/* + * Core private header for the pin control subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ + +/** + * struct pinctrl_dev - pin control class device + * @node: node to include this pin controller in the global pin controller list + * @desc: the pin controller descriptor supplied when initializing this pin + * controller + * @pin_desc_tree: each pin descriptor for this pin controller is stored in + * this radix tree + * @pin_desc_tree_lock: lock for the descriptor tree + * @gpio_ranges: a list of GPIO ranges that is handled by this pin controller, + * ranges are added to this list at runtime + * @gpio_ranges_lock: lock for the GPIO ranges list + * @dev: the device entry for this pin controller + * @owner: module providing the pin controller, used for refcounting + * @driver_data: driver data for drivers registering to the pin controller + * subsystem + * @pinmux_hogs_lock: lock for the pinmux hog list + * @pinmux_hogs: list of pinmux maps hogged by this device + */ +struct pinctrl_dev { + struct list_head node; + struct pinctrl_desc *desc; + struct radix_tree_root pin_desc_tree; + spinlock_t pin_desc_tree_lock; + struct list_head gpio_ranges; + struct mutex gpio_ranges_lock; + struct device dev; + struct module *owner; + void *driver_data; +#ifdef CONFIG_PINMUX + struct mutex pinmux_hogs_lock; + struct list_head pinmux_hogs; +#endif +}; + +/** + * struct pin_desc - pin descriptor for each physical pin in the arch + * @pctldev: corresponding pin control device + * @name: a name for the pin, e.g. the name of the pin/pad/finger on a + * datasheet or such + * @lock: a lock to protect the descriptor structure + * @mux_requested: whether the pin is already requested by pinmux or not + * @mux_function: a named muxing function for the pin that will be passed to + * subdrivers and shown in debugfs etc + */ +struct pin_desc { + struct pinctrl_dev *pctldev; + char name[16]; + spinlock_t lock; + /* These fields only added when supporting pinmux drivers */ +#ifdef CONFIG_PINMUX + bool mux_requested; + char mux_function[16]; +#endif +}; + +struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev, + const char *dev_name); +struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, int pin); +int pinctrl_get_device_gpio_range(unsigned gpio, + struct pinctrl_dev **outdev, + struct pinctrl_gpio_range **outrange); diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c new file mode 100644 index 00000000000..6544d98b2cf --- /dev/null +++ b/drivers/pinctrl/pinmux.c @@ -0,0 +1,1180 @@ +/* + * Core driver for the pin muxing portions of 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) "pinmux core: " fmt + +#include <linux/kernel.h> +#include <linux/module.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/machine.h> +#include <linux/pinctrl/pinmux.h> +#include "core.h" + +/* List of pinmuxes */ +static DEFINE_MUTEX(pinmux_list_mutex); +static LIST_HEAD(pinmux_list); + +/* List of pinmux hogs */ +static DEFINE_MUTEX(pinmux_hoglist_mutex); +static LIST_HEAD(pinmux_hoglist); + +/* Global pinmux maps, we allow one set only */ +static struct pinmux_map const *pinmux_maps; +static unsigned pinmux_maps_num; + +/** + * struct pinmux_group - group list item for pinmux groups + * @node: pinmux group list node + * @group_selector: the group selector for this group + */ +struct pinmux_group { + struct list_head node; + unsigned group_selector; +}; + +/** + * struct pinmux - per-device pinmux state holder + * @node: global list node + * @dev: the device using this pinmux + * @usecount: the number of active users of this mux setting, used to keep + * track of nested use cases + * @pins: an array of discrete physical pins used in this mapping, taken + * from the global pin enumeration space (copied from pinmux map) + * @num_pins: the number of pins in this mapping array, i.e. the number of + * elements in .pins so we can iterate over that array (copied from + * pinmux map) + * @pctldev: pin control device handling this pinmux + * @func_selector: the function selector for the pinmux device handling + * this pinmux + * @groups: the group selectors for the pinmux device and + * selector combination handling this pinmux, this is a list that + * will be traversed on all pinmux operations such as + * get/put/enable/disable + * @mutex: a lock for the pinmux state holder + */ +struct pinmux { + struct list_head node; + struct device *dev; + unsigned usecount; + struct pinctrl_dev *pctldev; + unsigned func_selector; + struct list_head groups; + struct mutex mutex; +}; + +/** + * struct pinmux_hog - a list item to stash mux hogs + * @node: pinmux hog list node + * @map: map entry responsible for this hogging + * @pmx: the pinmux hogged by this item + */ +struct pinmux_hog { + struct list_head node; + struct pinmux_map const *map; + struct pinmux *pmx; +}; + +/** + * pin_request() - request a single pin to be muxed in, typically for GPIO + * @pin: the pin number in the global pin space + * @function: a functional name to give to this pin, passed to the driver + * so it knows what function to mux in, e.g. the string "gpioNN" + * means that you want to mux in the pin for use as GPIO number NN + * @gpio: if this request concerns a single GPIO pin + * @gpio_range: the range matching the GPIO pin if this is a request for a + * single GPIO pin + */ +static int pin_request(struct pinctrl_dev *pctldev, + int pin, const char *function, bool gpio, + struct pinctrl_gpio_range *gpio_range) +{ + struct pin_desc *desc; + const struct pinmux_ops *ops = pctldev->desc->pmxops; + int status = -EINVAL; + + dev_dbg(&pctldev->dev, "request pin %d for %s\n", pin, function); + + if (!pin_is_valid(pctldev, pin)) { + dev_err(&pctldev->dev, "pin is invalid\n"); + return -EINVAL; + } + + if (!function) { + dev_err(&pctldev->dev, "no function name given\n"); + return -EINVAL; + } + + desc = pin_desc_get(pctldev, pin); + if (desc == NULL) { + dev_err(&pctldev->dev, + "pin is not registered so it cannot be requested\n"); + goto out; + } + + spin_lock(&desc->lock); + if (desc->mux_requested) { + spin_unlock(&desc->lock); + dev_err(&pctldev->dev, + "pin already requested\n"); + goto out; + } + desc->mux_requested = true; + strncpy(desc->mux_function, function, sizeof(desc->mux_function)); + spin_unlock(&desc->lock); + + /* Let each pin increase references to this module */ + if (!try_module_get(pctldev->owner)) { + dev_err(&pctldev->dev, + "could not increase module refcount for pin %d\n", + pin); + status = -EINVAL; + goto out_free_pin; + } + + /* + * If there is no kind of request function for the pin we just assume + * we got it by default and proceed. + */ + if (gpio && ops->gpio_request_enable) + /* This requests and enables a single GPIO pin */ + status = ops->gpio_request_enable(pctldev, gpio_range, pin); + else if (ops->request) + status = ops->request(pctldev, pin); + else + status = 0; + + if (status) + dev_err(&pctldev->dev, "->request on device %s failed " + "for pin %d\n", + pctldev->desc->name, pin); +out_free_pin: + if (status) { + spin_lock(&desc->lock); + desc->mux_requested = false; + desc->mux_function[0] = '\0'; + spin_unlock(&desc->lock); + } +out: + if (status) + dev_err(&pctldev->dev, "pin-%d (%s) status %d\n", + pin, function ? : "?", status); + + return status; +} + +/** + * pin_free() - release a single muxed in pin so something else can be muxed + * @pctldev: pin controller device handling this pin + * @pin: the pin to free + */ +static void pin_free(struct pinctrl_dev *pctldev, int pin) +{ + const struct pinmux_ops *ops = pctldev->desc->pmxops; + struct pin_desc *desc; + + desc = pin_desc_get(pctldev, pin); + if (desc == NULL) { + dev_err(&pctldev->dev, + "pin is not registered so it cannot be freed\n"); + return; + } + + if (ops->free) + ops->free(pctldev, pin); + + spin_lock(&desc->lock); + desc->mux_requested = false; + desc->mux_function[0] = '\0'; + spin_unlock(&desc->lock); + module_put(pctldev->owner); +} + +/** + * pinmux_request_gpio() - request a single pin to be muxed in as GPIO + * @gpio: the GPIO pin number from the GPIO subsystem number space + */ +int pinmux_request_gpio(unsigned gpio) +{ + char gpiostr[16]; + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range *range; + int ret; + int pin; + + ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range); + if (ret) + return -EINVAL; + + /* Convert to the pin controllers number space */ + pin = gpio - range->base; + + /* Conjure some name stating what chip and pin this is taken by */ + snprintf(gpiostr, 15, "%s:%d", range->name, gpio); + + return pin_request(pctldev, pin, gpiostr, true, range); +} +EXPORT_SYMBOL_GPL(pinmux_request_gpio); + +/** + * pinmux_free_gpio() - free a single pin, currently used as GPIO + * @gpio: the GPIO pin number from the GPIO subsystem number space + */ +void pinmux_free_gpio(unsigned gpio) +{ + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range *range; + int ret; + int pin; + + ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range); + if (ret) + return; + + /* Convert to the pin controllers number space */ + pin = gpio - range->base; + + pin_free(pctldev, pin); +} +EXPORT_SYMBOL_GPL(pinmux_free_gpio); + +/** + * pinmux_register_mappings() - register a set of pinmux mappings + * @maps: the pinmux mappings table to register + * @num_maps: the number of maps in the mapping table + * + * Only call this once during initialization of your machine, the function is + * tagged as __init and won't be callable after init has completed. The map + * passed into this function will be owned by the pinmux core and cannot be + * free:d. + */ +int __init pinmux_register_mappings(struct pinmux_map const *maps, + unsigned num_maps) +{ + int i; + + if (pinmux_maps != NULL) { + pr_err("pinmux mappings already registered, you can only " + "register one set of maps\n"); + return -EINVAL; + } + + pr_debug("add %d pinmux maps\n", num_maps); + for (i = 0; i < num_maps; i++) { + /* Sanity check the mapping */ + if (!maps[i].name) { + pr_err("failed to register map %d: " + "no map name given\n", i); + return -EINVAL; + } + if (!maps[i].ctrl_dev && !maps[i].ctrl_dev_name) { + pr_err("failed to register map %s (%d): " + "no pin control device given\n", + maps[i].name, i); + return -EINVAL; + } + if (!maps[i].function) { + pr_err("failed to register map %s (%d): " + "no function ID given\n", maps[i].name, i); + return -EINVAL; + } + + if (!maps[i].dev && !maps[i].dev_name) + pr_debug("add system map %s function %s with no device\n", + maps[i].name, + maps[i].function); + else + pr_debug("register map %s, function %s\n", + maps[i].name, + maps[i].function); + } + + pinmux_maps = maps; + pinmux_maps_num = num_maps; + + return 0; +} + +/** + * acquire_pins() - acquire all the pins for a certain funcion on a pinmux + * @pctldev: the device to take the pins on + * @func_selector: the function selector to acquire the pins for + * @group_selector: the group selector containing the pins to acquire + */ +static int acquire_pins(struct pinctrl_dev *pctldev, + unsigned func_selector, + unsigned group_selector) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + const struct pinmux_ops *pmxops = pctldev->desc->pmxops; + const char *func = pmxops->get_function_name(pctldev, + func_selector); + unsigned *pins; + unsigned num_pins; + int ret; + int i; + + ret = pctlops->get_group_pins(pctldev, group_selector, + &pins, &num_pins); + if (ret) + return ret; + + dev_dbg(&pctldev->dev, "requesting the %u pins from group %u\n", + num_pins, group_selector); + + /* Try to allocate all pins in this group, one by one */ + for (i = 0; i < num_pins; i++) { + ret = pin_request(pctldev, pins[i], func, false, NULL); + if (ret) { + dev_err(&pctldev->dev, + "could not get pin %d for function %s " + "on device %s - conflicting mux mappings?\n", + pins[i], func ? : "(undefined)", + pinctrl_dev_get_name(pctldev)); + /* On error release all taken pins */ + i--; /* this pin just failed */ + for (; i >= 0; i--) + pin_free(pctldev, pins[i]); + return -ENODEV; + } + } + return 0; +} + +/** + * release_pins() - release pins taken by earlier acquirement + * @pctldev: the device to free the pinx on + * @group_selector: the group selector containing the pins to free + */ +static void release_pins(struct pinctrl_dev *pctldev, + unsigned group_selector) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + unsigned *pins; + unsigned num_pins; + int ret; + int i; + + ret = pctlops->get_group_pins(pctldev, group_selector, + &pins, &num_pins); + if (ret) { + dev_err(&pctldev->dev, "could not get pins to release for " + "group selector %d\n", + group_selector); + return; + } + for (i = 0; i < num_pins; i++) + pin_free(pctldev, pins[i]); +} + +/** + * pinmux_get_group_selector() - returns the group selector for a group + * @pctldev: the pin controller handling the group + * @pin_group: the pin group to look up + */ +static int pinmux_get_group_selector(struct pinctrl_dev *pctldev, + const char *pin_group) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + unsigned group_selector = 0; + + while (pctlops->list_groups(pctldev, group_selector) >= 0) { + const char *gname = pctl |