diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 2179 |
1 files changed, 1697 insertions, 482 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 21da9c19a0c..2ebc9071e35 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3,6 +3,7 @@ #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> @@ -11,18 +12,19 @@ #include <linux/of_gpio.h> #include <linux/idr.h> #include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/gpio/driver.h> +#include "gpiolib.h" -/* Optional implementation infrastructure for GPIO interfaces. - * - * Platforms may want to use this if they tend to use very many GPIOs - * that aren't part of a System-On-Chip core; or across I2C/SPI/etc. +#define CREATE_TRACE_POINTS +#include <trace/events/gpio.h> + +/* Implementation infrastructure for GPIO interfaces. * - * When kernel footprint or instruction count is an issue, simpler - * implementations may be preferred. 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. + * 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. */ @@ -50,12 +52,14 @@ struct gpio_desc { /* flag symbols are bit numbers */ #define FLAG_REQUESTED 0 #define FLAG_IS_OUT 1 -#define FLAG_RESERVED 2 -#define FLAG_EXPORT 3 /* protected by sysfs_lock */ -#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ -#define FLAG_TRIG_FALL 5 /* trigger on falling edge */ -#define FLAG_TRIG_RISE 6 /* trigger on rising edge */ -#define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ +#define FLAG_EXPORT 2 /* protected by sysfs_lock */ +#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ +#define FLAG_TRIG_FALL 4 /* trigger on falling edge */ +#define FLAG_TRIG_RISE 5 /* trigger on rising edge */ +#define FLAG_ACTIVE_LOW 6 /* value has active low */ +#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ +#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ +#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ #define ID_SHIFT 16 /* add new flags before this one */ @@ -68,10 +72,70 @@ struct gpio_desc { }; static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; +#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) + +static DEFINE_MUTEX(gpio_lookup_lock); +static LIST_HEAD(gpio_lookup_list); +static LIST_HEAD(gpio_chips); + #ifdef CONFIG_GPIO_SYSFS static DEFINE_IDR(dirent_idr); #endif +static int gpiod_request(struct gpio_desc *desc, const char *label); +static void gpiod_free(struct gpio_desc *desc); + +/* With descriptor prefix */ + +#ifdef CONFIG_DEBUG_FS +#define gpiod_emerg(desc, fmt, ...) \ + pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ + ##__VA_ARGS__) +#define gpiod_crit(desc, fmt, ...) \ + pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ + ##__VA_ARGS__) +#define gpiod_err(desc, fmt, ...) \ + pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ + ##__VA_ARGS__) +#define gpiod_warn(desc, fmt, ...) \ + pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ + ##__VA_ARGS__) +#define gpiod_info(desc, fmt, ...) \ + pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \ + ##__VA_ARGS__) +#define gpiod_dbg(desc, fmt, ...) \ + pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\ + ##__VA_ARGS__) +#else +#define gpiod_emerg(desc, fmt, ...) \ + pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#define gpiod_crit(desc, fmt, ...) \ + pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#define gpiod_err(desc, fmt, ...) \ + pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#define gpiod_warn(desc, fmt, ...) \ + pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#define gpiod_info(desc, fmt, ...) \ + pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#define gpiod_dbg(desc, fmt, ...) \ + pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__) +#endif + +/* With chip prefix */ + +#define chip_emerg(chip, fmt, ...) \ + pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) +#define chip_crit(chip, fmt, ...) \ + pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) +#define chip_err(chip, fmt, ...) \ + pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) +#define chip_warn(chip, fmt, ...) \ + pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) +#define chip_info(chip, fmt, ...) \ + pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) +#define chip_dbg(chip, fmt, ...) \ + pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__) + static inline void desc_set_label(struct gpio_desc *d, const char *label) { #ifdef CONFIG_DEBUG_FS @@ -79,6 +143,51 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) #endif } +/* + * Return the GPIO number of the passed descriptor relative to its chip + */ +static int gpio_chip_hwgpio(const struct gpio_desc *desc) +{ + return desc - &desc->chip->desc[0]; +} + +/** + * Convert a GPIO number to its descriptor + */ +struct gpio_desc *gpio_to_desc(unsigned gpio) +{ + if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) + return NULL; + else + return &gpio_desc[gpio]; +} +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) +{ + if (hwnum >= chip->ngpio) + return ERR_PTR(-EINVAL); + + return &chip->desc[hwnum]; +} +EXPORT_SYMBOL_GPL(gpiochip_get_desc); + +/** + * 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 - &gpio_desc[0]; +} +EXPORT_SYMBOL_GPL(desc_to_gpio); + + /* Warn when drivers omit gpio_request() calls -- legal but ill-advised * when setting direction, and otherwise illegal. Until board setup code * and drivers use explicit requests everywhere (which won't happen when @@ -90,15 +199,16 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) * only "legal" in the sense that (old) code using it won't break yet, * but instead only triggers a WARN() stack dump. */ -static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) +static int gpio_ensure_requested(struct gpio_desc *desc) { const struct gpio_chip *chip = desc->chip; - const int gpio = chip->base + offset; + const int gpio = desc_to_gpio(desc); if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, "autorequest GPIO-%d\n", gpio)) { if (!try_module_get(chip->owner)) { - pr_err("GPIO-%d: module can't be gotten \n", gpio); + gpiod_err(desc, "%s: module can't be gotten\n", + __func__); clear_bit(FLAG_REQUESTED, &desc->flags); /* lose */ return -EIO; @@ -111,81 +221,75 @@ static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) return 0; } -/* caller holds gpio_lock *OR* gpio is marked as requested */ -static inline struct gpio_chip *gpio_to_chip(unsigned 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) { - return gpio_desc[gpio].chip; + return desc ? desc->chip : NULL; } +EXPORT_SYMBOL_GPL(gpiod_to_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) { - int i; - int spare = 0; - int base = -ENOSPC; + struct gpio_chip *chip; + int base = ARCH_NR_GPIOS - ngpio; - for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { - struct gpio_desc *desc = &gpio_desc[i]; - struct gpio_chip *chip = desc->chip; - - if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { - spare++; - if (spare == ngpio) { - base = i; - break; - } - } else { - spare = 0; - if (chip) - i -= chip->ngpio - 1; - } + list_for_each_entry_reverse(chip, &gpio_chips, list) { + /* found a free space? */ + if (chip->base + chip->ngpio <= base) + break; + else + /* nope, check the space right before the chip */ + base = chip->base - ngpio; } - if (gpio_is_valid(base)) + if (gpio_is_valid(base)) { pr_debug("%s: found new base at %d\n", __func__, base); - return base; + return base; + } else { + pr_err("%s: cannot find free range\n", __func__); + return -ENOSPC; + } } /** - * gpiochip_reserve() - reserve range of gpios to use with platform code only - * @start: starting gpio number - * @ngpio: number of gpios to reserve - * Context: platform init, potentially before irqs or kmalloc will work + * 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. * - * Returns a negative errno if any gpio within the range is already reserved - * or registered, else returns zero as a success code. Use this function - * to mark a range of gpios as unavailable for dynamic gpio number allocation, - * for example because its driver support is not yet loaded. + * This function may sleep if gpiod_cansleep() is true. */ -int __init gpiochip_reserve(int start, int ngpio) +int gpiod_get_direction(const struct gpio_desc *desc) { - int ret = 0; - unsigned long flags; - int i; - - if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) - return -EINVAL; - - spin_lock_irqsave(&gpio_lock, flags); + struct gpio_chip *chip; + unsigned offset; + int status = -EINVAL; - for (i = start; i < start + ngpio; i++) { - struct gpio_desc *desc = &gpio_desc[i]; + chip = gpiod_to_chip(desc); + offset = gpio_chip_hwgpio(desc); - if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { - ret = -EBUSY; - goto err; - } + if (!chip->get_direction) + return status; - set_bit(FLAG_RESERVED, &desc->flags); + status = chip->get_direction(chip, offset); + if (status > 0) { + /* GPIOF_DIR_IN, or other positive */ + status = 1; + /* FLAG_IS_OUT is just a cache of the result of get_direction(), + * so it does not affect constness per se */ + clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); } - - pr_debug("%s: reserved gpios from %d to %d\n", - __func__, start, start + ngpio - 1); -err: - spin_unlock_irqrestore(&gpio_lock, flags); - - return ret; + if (status == 0) { + /* GPIOF_DIR_OUT */ + set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); + } + return status; } +EXPORT_SYMBOL_GPL(gpiod_get_direction); #ifdef CONFIG_GPIO_SYSFS @@ -223,12 +327,14 @@ static ssize_t gpio_direction_show(struct device *dev, mutex_lock(&sysfs_lock); - if (!test_bit(FLAG_EXPORT, &desc->flags)) + if (!test_bit(FLAG_EXPORT, &desc->flags)) { status = -EIO; - else + } else { + gpiod_get_direction(desc); status = sprintf(buf, "%s\n", test_bit(FLAG_IS_OUT, &desc->flags) ? "out" : "in"); + } mutex_unlock(&sysfs_lock); return status; @@ -237,8 +343,7 @@ static ssize_t gpio_direction_show(struct device *dev, static ssize_t gpio_direction_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); @@ -246,11 +351,11 @@ static ssize_t gpio_direction_store(struct device *dev, if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; else if (sysfs_streq(buf, "high")) - status = gpio_direction_output(gpio, 1); + status = gpiod_direction_output_raw(desc, 1); else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) - status = gpio_direction_output(gpio, 0); + status = gpiod_direction_output_raw(desc, 0); else if (sysfs_streq(buf, "in")) - status = gpio_direction_input(gpio); + status = gpiod_direction_input(desc); else status = -EINVAL; @@ -264,23 +369,15 @@ static /* const */ DEVICE_ATTR(direction, 0644, static ssize_t gpio_value_show(struct device *dev, struct device_attribute *attr, char *buf) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); - if (!test_bit(FLAG_EXPORT, &desc->flags)) { + if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; - } else { - int value; - - value = !!gpio_get_value_cansleep(gpio); - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - value = !value; - - status = sprintf(buf, "%d\n", value); - } + else + status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc)); mutex_unlock(&sysfs_lock); return status; @@ -289,8 +386,7 @@ static ssize_t gpio_value_show(struct device *dev, static ssize_t gpio_value_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); @@ -302,11 +398,9 @@ static ssize_t gpio_value_store(struct device *dev, else { long value; - status = strict_strtol(buf, 0, &value); + status = kstrtol(buf, 0, &value); if (status == 0) { - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - value = !value; - gpio_set_value_cansleep(gpio, value != 0); + gpiod_set_value_cansleep(desc, value); status = size; } } @@ -320,7 +414,7 @@ static const DEVICE_ATTR(value, 0644, static irqreturn_t gpio_sysfs_irq(int irq, void *priv) { - struct sysfs_dirent *value_sd = priv; + struct kernfs_node *value_sd = priv; sysfs_notify_dirent(value_sd); return IRQ_HANDLED; @@ -329,14 +423,14 @@ static irqreturn_t gpio_sysfs_irq(int irq, void *priv) static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, unsigned long gpio_flags) { - struct sysfs_dirent *value_sd; + struct kernfs_node *value_sd; unsigned long irq_flags; int ret, irq, id; if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) return 0; - irq = gpio_to_irq(desc - gpio_desc); + irq = gpiod_to_irq(desc); if (irq < 0) return -EIO; @@ -348,6 +442,7 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, desc->flags &= ~GPIO_TRIGGER_MASK; if (!gpio_flags) { + gpiod_unlock_as_irq(desc); ret = 0; goto free_id; } @@ -361,21 +456,16 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; if (!value_sd) { - value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); + value_sd = sysfs_get_dirent(dev->kobj.sd, "value"); if (!value_sd) { ret = -ENODEV; goto err_out; } - do { - ret = -ENOMEM; - if (idr_pre_get(&dirent_idr, GFP_KERNEL)) - ret = idr_get_new_above(&dirent_idr, value_sd, - 1, &id); - } while (ret == -EAGAIN); - - if (ret) + ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL); + if (ret < 0) goto free_sd; + id = ret; desc->flags &= GPIO_FLAGS_MASK; desc->flags |= (unsigned long)id << ID_SHIFT; @@ -391,6 +481,12 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, if (ret < 0) goto free_id; + ret = gpiod_lock_as_irq(desc); + if (ret < 0) { + gpiod_warn(desc, "failed to flag the GPIO for IRQ\n"); + goto free_id; + } + desc->flags |= gpio_flags; return 0; @@ -528,7 +624,7 @@ static ssize_t gpio_active_low_store(struct device *dev, } else { long value; - status = strict_strtol(buf, 0, &value); + status = kstrtol(buf, 0, &value); if (status == 0) status = sysfs_set_active_low(desc, dev, value != 0); } @@ -606,27 +702,37 @@ static ssize_t export_store(struct class *class, struct class_attribute *attr, const char *buf, size_t len) { - long gpio; - int status; + long gpio; + struct gpio_desc *desc; + int status; - status = strict_strtol(buf, 0, &gpio); + status = kstrtol(buf, 0, &gpio); if (status < 0) goto done; + desc = gpio_to_desc(gpio); + /* reject invalid GPIOs */ + if (!desc) { + pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); + return -EINVAL; + } + /* No extra locking here; FLAG_SYSFS just signifies that the * request and export were done by on behalf of userspace, so * they may be undone on its behalf too. */ - status = gpio_request(gpio, "sysfs"); - if (status < 0) + status = gpiod_request(desc, "sysfs"); + if (status < 0) { + if (status == -EPROBE_DEFER) + status = -ENODEV; goto done; - - status = gpio_export(gpio, true); + } + status = gpiod_export(desc, true); if (status < 0) - gpio_free(gpio); + gpiod_free(desc); else - set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); + set_bit(FLAG_SYSFS, &desc->flags); done: if (status) @@ -638,26 +744,30 @@ static ssize_t unexport_store(struct class *class, struct class_attribute *attr, const char *buf, size_t len) { - long gpio; - int status; + long gpio; + struct gpio_desc *desc; + int status; - status = strict_strtol(buf, 0, &gpio); + status = kstrtol(buf, 0, &gpio); if (status < 0) goto done; - status = -EINVAL; - + desc = gpio_to_desc(gpio); /* reject bogus commands (gpio_unexport ignores them) */ - if (!gpio_is_valid(gpio)) - goto done; + if (!desc) { + pr_warn("%s: invalid GPIO %ld\n", __func__, gpio); + return -EINVAL; + } + + status = -EINVAL; /* No extra locking here; FLAG_SYSFS just signifies that the * request and export were done by on behalf of userspace, so * they may be undone on its behalf too. */ - if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { + if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { status = 0; - gpio_free(gpio); + gpiod_free(desc); } done: if (status) @@ -680,7 +790,7 @@ static struct class gpio_class = { /** - * gpio_export - export a GPIO through sysfs + * gpiod_export - export a GPIO through sysfs * @gpio: gpio to make available, already requested * @direction_may_change: true if userspace may change gpio direction * Context: arch_initcall or later @@ -694,12 +804,13 @@ static struct class gpio_class = { * * Returns zero on success, else an error. */ -int gpio_export(unsigned gpio, bool direction_may_change) +int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { unsigned long flags; - struct gpio_desc *desc; - int status = -EINVAL; + int status; const char *ioname = NULL; + struct device *dev; + int offset; /* can't export until sysfs is available ... */ if (!gpio_class.p) { @@ -707,70 +818,78 @@ int gpio_export(unsigned gpio, bool direction_may_change) return -ENOENT; } - if (!gpio_is_valid(gpio)) - goto done; + if (!desc) { + pr_debug("%s: invalid gpio descriptor\n", __func__); + return -EINVAL; + } mutex_lock(&sysfs_lock); spin_lock_irqsave(&gpio_lock, flags); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_REQUESTED, &desc->flags) - && !test_bit(FLAG_EXPORT, &desc->flags)) { - status = 0; - if (!desc->chip->direction_input - || !desc->chip->direction_output) - direction_may_change = false; + if (!test_bit(FLAG_REQUESTED, &desc->flags) || + test_bit(FLAG_EXPORT, &desc->flags)) { + spin_unlock_irqrestore(&gpio_lock, flags); + gpiod_dbg(desc, "%s: unavailable (requested=%d, exported=%d)\n", + __func__, + test_bit(FLAG_REQUESTED, &desc->flags), + test_bit(FLAG_EXPORT, &desc->flags)); + status = -EPERM; + goto fail_unlock; } + + if (!desc->chip->direction_input || !desc->chip->direction_output) + direction_may_change = false; spin_unlock_irqrestore(&gpio_lock, flags); - if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) - ioname = desc->chip->names[gpio - desc->chip->base]; + offset = gpio_chip_hwgpio(desc); + if (desc->chip->names && desc->chip->names[offset]) + ioname = desc->chip->names[offset]; - if (status == 0) { - struct device *dev; - - dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), - desc, ioname ? ioname : "gpio%u", gpio); - if (!IS_ERR(dev)) { - status = sysfs_create_group(&dev->kobj, - &gpio_attr_group); - - if (!status && direction_may_change) - status = device_create_file(dev, - &dev_attr_direction); - - if (!status && gpio_to_irq(gpio) >= 0 - && (direction_may_change - || !test_bit(FLAG_IS_OUT, - &desc->flags))) - status = device_create_file(dev, - &dev_attr_edge); - - if (status != 0) - device_unregister(dev); - } else - status = PTR_ERR(dev); - if (status == 0) - set_bit(FLAG_EXPORT, &desc->flags); + dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), + desc, ioname ? ioname : "gpio%u", + desc_to_gpio(desc)); + if (IS_ERR(dev)) { + status = PTR_ERR(dev); + goto fail_unlock; } - mutex_unlock(&sysfs_lock); - -done: + status = sysfs_create_group(&dev->kobj, &gpio_attr_group); if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + goto fail_unregister_device; + + if (direction_may_change) { + status = device_create_file(dev, &dev_attr_direction); + if (status) + goto fail_unregister_device; + } + + if (gpiod_to_irq(desc) >= 0 && (direction_may_change || + !test_bit(FLAG_IS_OUT, &desc->flags))) { + status = device_create_file(dev, &dev_attr_edge); + if (status) + goto fail_unregister_device; + } + + set_bit(FLAG_EXPORT, &desc->flags); + mutex_unlock(&sysfs_lock); + return 0; +fail_unregister_device: + device_unregister(dev); +fail_unlock: + mutex_unlock(&sysfs_lock); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_export); +EXPORT_SYMBOL_GPL(gpiod_export); -static int match_export(struct device *dev, void *data) +static int match_export(struct device *dev, const void *data) { return dev_get_drvdata(dev) == data; } /** - * gpio_export_link - create a sysfs link to an exported GPIO node + * gpiod_export_link - create a sysfs link to an exported GPIO node * @dev: device under which to create symlink * @name: name of the symlink * @gpio: gpio to create symlink to, already exported @@ -780,18 +899,18 @@ static int match_export(struct device *dev, void *data) * * Returns zero on success, else an error. */ -int gpio_export_link(struct device *dev, const char *name, unsigned gpio) +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) { - struct gpio_desc *desc; int status = -EINVAL; - if (!gpio_is_valid(gpio)) - goto done; + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { struct device *tdev; @@ -806,17 +925,15 @@ int gpio_export_link(struct device *dev, const char *name, unsigned gpio) mutex_unlock(&sysfs_lock); -done: if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_export_link); - +EXPORT_SYMBOL_GPL(gpiod_export_link); /** - * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value + * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value * @gpio: gpio to change * @value: non-zero to use active low, i.e. inverted values * @@ -827,19 +944,18 @@ EXPORT_SYMBOL_GPL(gpio_export_link); * * Returns zero on success, else an error. */ -int gpio_sysfs_set_active_low(unsigned gpio, int value) +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) { - struct gpio_desc *desc; struct device *dev = NULL; int status = -EINVAL; - if (!gpio_is_valid(gpio)) - goto done; + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { dev = class_find_device(&gpio_class, NULL, desc, match_export); if (dev == NULL) { @@ -853,53 +969,52 @@ int gpio_sysfs_set_active_low(unsigned gpio, int value) unlock: mutex_unlock(&sysfs_lock); -done: if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); +EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); /** - * gpio_unexport - reverse effect of gpio_export() + * gpiod_unexport - reverse effect of gpio_export() * @gpio: gpio to make unavailable * * This is implicit on gpio_free(). */ -void gpio_unexport(unsigned gpio) +void gpiod_unexport(struct gpio_desc *desc) { - struct gpio_desc *desc; int status = 0; + struct device *dev = NULL; - if (!gpio_is_valid(gpio)) { - status = -EINVAL; - goto done; + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return; } mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { - struct device *dev = NULL; dev = class_find_device(&gpio_class, NULL, desc, match_export); if (dev) { gpio_setup_irq(desc, dev, 0); clear_bit(FLAG_EXPORT, &desc->flags); - put_device(dev); - device_unregister(dev); } else status = -ENODEV; } mutex_unlock(&sysfs_lock); -done: + + if (dev) { + device_unregister(dev); + put_device(dev); + } + if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); } -EXPORT_SYMBOL_GPL(gpio_unexport); +EXPORT_SYMBOL_GPL(gpiod_unexport); static int gpiochip_export(struct gpio_chip *chip) { @@ -931,13 +1046,12 @@ static int gpiochip_export(struct gpio_chip *chip) unsigned gpio; spin_lock_irqsave(&gpio_lock, flags); - gpio = chip->base; - while (gpio_desc[gpio].chip == chip) - gpio_desc[gpio++].chip = NULL; + gpio = 0; + while (gpio < chip->ngpio) + chip->desc[gpio++].chip = NULL; spin_unlock_irqrestore(&gpio_lock, flags); - pr_debug("%s: chip %s status %d\n", __func__, - chip->label, status); + chip_dbg(chip, "%s: status %d\n", __func__, status); } return status; @@ -953,22 +1067,21 @@ static void gpiochip_unexport(struct gpio_chip *chip) if (dev) { put_device(dev); device_unregister(dev); - chip->exported = 0; + chip->exported = false; status = 0; } else status = -ENODEV; mutex_unlock(&sysfs_lock); if (status) - pr_debug("%s: chip %s status %d\n", __func__, - chip->label, status); + chip_dbg(chip, "%s: status %d\n", __func__, status); } static int __init gpiolib_sysfs_init(void) { int status; unsigned long flags; - unsigned gpio; + struct gpio_chip *chip; status = class_register(&gpio_class); if (status < 0) @@ -981,10 +1094,7 @@ static int __init gpiolib_sysfs_init(void) * registered, and so arch_initcall() can always gpio_export(). */ spin_lock_irqsave(&gpio_lock, flags); - for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { - struct gpio_chip *chip; - - chip = gpio_desc[gpio].chip; + list_for_each_entry(chip, &gpio_chips, list) { if (!chip || chip->exported) continue; @@ -1011,6 +1121,43 @@ static inline void gpiochip_unexport(struct gpio_chip *chip) #endif /* CONFIG_GPIO_SYSFS */ +/* + * Add a new chip to the global chips list, keeping the list of chips sorted + * by base order. + * + * Return -EBUSY if the new chip overlaps with some other chip's integer + * space. + */ +static int gpiochip_add_to_list(struct gpio_chip *chip) +{ + struct list_head *pos = &gpio_chips; + struct gpio_chip *_chip; + int err = 0; + + /* find where to insert our chip */ + list_for_each(pos, &gpio_chips) { + _chip = list_entry(pos, struct gpio_chip, list); + /* shall we insert before _chip? */ + if (_chip->base >= chip->base + chip->ngpio) + break; + } + + /* are we stepping on the chip right before? */ + if (pos != &gpio_chips && pos->prev != &gpio_chips) { + _chip = list_entry(pos->prev, struct gpio_chip, list); + if (_chip->base + _chip->ngpio > chip->base) { + dev_err(chip->dev, + "GPIO integer space overlap, cannot add chip\n"); + err = -EBUSY; + } + } + + if (!err) + list_add_tail(&chip->list, pos); + + return err; +} + /** * gpiochip_add() - register a gpio_chip * @chip: the chip to register, with chip->base initialized @@ -1052,34 +1199,37 @@ int gpiochip_add(struct gpio_chip *chip) chip->base = base; } - /* these GPIO numbers must not be managed by another gpio_chip */ - for (id = base; id < base + chip->ngpio; id++) { - if (gpio_desc[id].chip != NULL) { - status = -EBUSY; - break; - } - } + status = gpiochip_add_to_list(chip); + if (status == 0) { - for (id = base; id < base + chip->ngpio; id++) { - gpio_desc[id].chip = chip; + chip->desc = &gpio_desc[chip->base]; + + for (id = 0; id < chip->ngpio; id++) { + struct gpio_desc *desc = &chip->desc[id]; + desc->chip = chip; /* 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. */ - gpio_desc[id].flags = !chip->direction_input + desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0; } } - of_gpiochip_add(chip); - -unlock: spin_unlock_irqrestore(&gpio_lock, flags); +#ifdef CONFIG_PINCTRL + INIT_LIST_HEAD(&chip->pin_ranges); +#endif + + of_gpiochip_add(chip); + acpi_gpiochip_add(chip); + if (status) goto fail; @@ -1087,16 +1237,26 @@ unlock: if (status) goto fail; + pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__, + chip->base, chip->base + chip->ngpio - 1, + chip->label ? : "generic"); + return 0; + +unlock: + spin_unlock_irqrestore(&gpio_lock, flags); fail: /* failures here can mean systems won't boot... */ - pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n", + pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__, chip->base, chip->base + chip->ngpio - 1, chip->label ? : "generic"); return status; } EXPORT_SYMBOL_GPL(gpiochip_add); +/* Forward-declaration */ +static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); + /** * gpiochip_remove() - unregister a gpio_chip * @chip: the chip to unregister @@ -1109,19 +1269,25 @@ int gpiochip_remove(struct gpio_chip *chip) int status = 0; unsigned id; + acpi_gpiochip_remove(chip); + spin_lock_irqsave(&gpio_lock, flags); + gpiochip_irqchip_remove(chip); + gpiochip_remove_pin_ranges(chip); of_gpiochip_remove(chip); - for (id = chip->base; id < chip->base + chip->ngpio; id++) { - if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { + for (id = 0; id < chip->ngpio; id++) { + if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { status = -EBUSY; break; } } if (status == 0) { - for (id = chip->base; id < chip->base + chip->ngpio; id++) - gpio_desc[id].chip = NULL; + for (id = 0; id < chip->ngpio; id++) + chip->desc[id].chip = NULL; + + list_del(&chip->list); } spin_unlock_irqrestore(&gpio_lock, flags); @@ -1145,50 +1311,400 @@ EXPORT_SYMBOL_GPL(gpiochip_remove); * more gpio_chips. */ struct gpio_chip *gpiochip_find(void *data, - int (*match)(struct gpio_chip *chip, void *data)) + int (*match)(struct gpio_chip *chip, + void *data)) { - struct gpio_chip *chip = NULL; + struct gpio_chip *chip; unsigned long flags; - int i; spin_lock_irqsave(&gpio_lock, flags); - for (i = 0; i < ARCH_NR_GPIOS; i++) { - if (!gpio_desc[i].chip) - continue; - - if (match(gpio_desc[i].chip, data)) { - chip = gpio_desc[i].chip; + list_for_each_entry(chip, &gpio_chips, list) + if (match(chip, data)) break; - } - } + + /* No match? */ + if (&chip->list == &gpio_chips) + chip = NULL; 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_add_chained_irqchip() - adds a chained irqchip to a gpiochip + * @gpiochip: the gpiochip to add the irqchip to + * @irqchip: the irqchip to add 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 + */ +void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, + struct irq_chip *irqchip, + int parent_irq, + irq_flow_handler_t parent_handler) +{ + if (gpiochip->can_sleep) { + chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n"); + return; + } + + irq_set_chained_handler(parent_irq, parent_handler); + /* + * The parent irqchip is already using the chip_data for this + * irqchip, so our callbacks simply use the handler_data. + */ + irq_set_handler_data(parent_irq, gpiochip); +} +EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip); + +/* + * This lock class tells lockdep that GPIO irqs are in a different + * category than their parents, so it won't report false recursion. + */ +static struct lock_class_key gpiochip_irq_lock_class; + +/** + * 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); + irq_set_lockdep_class(irq, &gpiochip_irq_lock_class); + irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler); + /* Chips that can sleep need nested thread handlers */ + if (chip->can_sleep) + irq_set_nested_thread(irq, 1); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + /* + * 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; + +#ifdef CONFIG_ARM + set_irq_flags(irq, 0); +#endif + 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 (gpio_lock_as_irq(chip, d->hwirq)) { + chip_err(chip, + "unable to lock HW IRQ %lu for IRQ\n", + d->hwirq); + return -EINVAL; + } + return 0; +} + +static void gpiochip_irq_relres(struct irq_data *d) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(d); + + gpio_unlock_as_irq(chip, d->hwirq); +} + +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; + + /* Remove all IRQ mappings and delete the domain */ + if (gpiochip->irqdomain) { + for (offset = 0; offset < gpiochip->ngpio; offset++) + irq_dispose_mapping(gpiochip->irq_base + 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. + * + * 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 container_of() 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 device_node *of_node; + unsigned int offset; + unsigned irq_base = 0; + + if (!gpiochip || !irqchip) + return -EINVAL; + + if (!gpiochip->dev) { + pr_err("missing gpiochip .dev parent pointer\n"); + return -EINVAL; + } + of_node = gpiochip->dev->of_node; +#ifdef CONFIG_OF_GPIO + /* + * If the gpiochip has an assigned OF node this takes precendence + * FIXME: get rid of this and use gpiochip->dev->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->irqdomain = irq_domain_add_simple(of_node, + gpiochip->ngpio, first_irq, + &gpiochip_domain_ops, gpiochip); + if (!gpiochip->irqdomain) { + gpiochip->irqchip = NULL; + return -EINVAL; + } + 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; + } + + 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 */ + +#ifdef CONFIG_PINCTRL + +/** + * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping + * @chip: the gpiochip to add the range for + * @pinctrl: the dev_name() of 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; + 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 = chip->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, &chip->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; + 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 = chip->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, &chip->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; + + list_for_each_entry_safe(pin_range, tmp, &chip->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. */ -int gpio_request(unsigned gpio, const char *label) +static int __gpiod_request(struct gpio_desc *desc, const char *label) { - struct gpio_desc *desc; - struct gpio_chip *chip; - int status = -EINVAL; + struct gpio_chip *chip = desc->chip; + int status; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - if (!gpio_is_valid(gpio)) - goto done; - desc = &gpio_desc[gpio]; - chip = desc->chip; - if (chip == NULL) - goto done; - - if (!try_module_get(chip->owner)) - goto done; - /* NOTE: gpio_request() can be called in early boot, * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ @@ -1198,66 +1714,108 @@ int gpio_request(unsigned gpio, const char *label) status = 0; } else { status = -EBUSY; - module_put(chip->owner); goto done; } if (chip->request) { /* chip->request may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); - status = chip->request(chip, gpio - chip->base); + status = chip->request(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); if (status < 0) { desc_set_label(desc, NULL); - module_put(chip->owner); 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: + spin_unlock_irqrestore(&gpio_lock, flags); + return status; +} + +static int gpiod_request(struct gpio_desc *desc, const char *label) +{ + int status = -EPROBE_DEFER; + struct gpio_chip *chip; + + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + + chip = desc->chip; + if (!chip) + goto done; + + if (try_module_get(chip->owner)) { + status = __gpiod_request(desc, label); + if (status < 0) + module_put(chip->owner); + } done: if (status) - pr_debug("gpio_request: gpio-%d (%s) status %d\n", - gpio, label ? : "?", status); - spin_unlock_irqrestore(&gpio_lock, flags); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); + return status; } + +int gpio_request(unsigned gpio, const char *label) +{ + return gpiod_request(gpio_to_desc(gpio), label); +} EXPORT_SYMBOL_GPL(gpio_request); -void gpio_free(unsigned gpio) +static bool __gpiod_free(struct gpio_desc *desc) { + bool ret = false; unsigned long flags; - struct gpio_desc *desc; struct gpio_chip *chip; might_sleep(); - if (!gpio_is_valid(gpio)) { - WARN_ON(extra_checks); - return; - } - - gpio_unexport(gpio); + gpiod_unexport(desc); spin_lock_irqsave(&gpio_lock, flags); - desc = &gpio_desc[gpio]; chip = desc->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->base); + chip->free(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); } desc_set_label(desc, NULL); - module_put(desc->chip->owner); clear_bit(FLAG_ACTIVE_LOW, &desc->flags); clear_bit(FLAG_REQUESTED, &desc->flags); - } else - WARN_ON(extra_checks); + clear_bit(FLAG_OPEN_DRAIN, &desc->flags); + clear_bit(FLAG_OPEN_SOURCE, &desc->flags); + ret = true; + } spin_unlock_irqrestore(&gpio_lock, flags); + return ret; +} + +static void gpiod_free(struct gpio_desc *desc) +{ + if (desc && __gpiod_free(desc)) + module_put(desc->chip->owner); + else + WARN_ON(extra_checks); +} + +void gpio_free(unsigned gpio) +{ + gpiod_free(gpio_to_desc(gpio)); } EXPORT_SYMBOL_GPL(gpio_free); @@ -1269,18 +1827,40 @@ EXPORT_SYMBOL_GPL(gpio_free); */ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) { + struct gpio_desc *desc; int err; - err = gpio_request(gpio, label); + desc = gpio_to_desc(gpio); + + err = gpiod_request(desc, label); if (err) return err; + if (flags & GPIOF_OPEN_DRAIN) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + + if (flags & GPIOF_OPEN_SOURCE) + set_bit(FLAG_OPEN_SOURCE, &desc->flags); + if (flags & GPIOF_DIR_IN) - err = gpio_direction_input(gpio); + err = gpiod_direction_input(desc); else - err = gpio_direction_output(gpio, + err = gpiod_direction_output_raw(desc, (flags & GPIOF_INIT_HIGH) ? 1 : 0); + if (err) + goto free_gpio; + + if (flags & GPIOF_EXPORT) { + err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); + if (err) + goto free_gpio; + } + + return 0; + + free_gpio: + gpiod_free(desc); return err; } EXPORT_SYMBOL_GPL(gpio_request_one); @@ -1290,7 +1870,7 @@ EXPORT_SYMBOL_GPL(gpio_request_one); * @array: array of the 'struct gpio' * @num: how many GPIOs in the array */ -int gpio_request_array(struct gpio *array, size_t num) +int gpio_request_array(const struct gpio *array, size_t num) { int i, err; @@ -1313,7 +1893,7 @@ EXPORT_SYMBOL_GPL(gpio_request_array); * @array: array of the 'struct gpio' * @num: how many GPIOs in the array */ -void gpio_free_array(struct gpio *array, size_t num) +void gpio_free_array(const struct gpio *array, size_t num) { while (num--) gpio_free((array++)->gpio); @@ -1335,20 +1915,54 @@ EXPORT_SYMBOL_GPL(gpio_free_array); */ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) { - unsigned gpio = chip->base + offset; + struct gpio_desc *desc; - if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) + if (!GPIO_OFFSET_VALID(chip, offset)) return NULL; - if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) + + desc = &chip->desc[offset]; + + if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) return NULL; #ifdef CONFIG_DEBUG_FS - return gpio_desc[gpio].label; + return desc->label; #else return "?"; #endif } 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). + */ +int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label) +{ + if (!desc || !desc->chip) + return -EINVAL; + + return __gpiod_request(desc, label); +} + +/** + * 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); +} /* Drivers MUST set GPIO direction before making get/set calls. In * some cases this is done in early boot, before IRQs are enabled. @@ -1359,24 +1973,38 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested); * rely on gpio_request() having been called beforehand. */ -int gpio_direction_input(unsigned gpio) +/** + * 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) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; - spin_lock_irqsave(&gpio_lock, flags); + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } - if (!gpio_is_valid(gpio)) - goto fail; chip = desc->chip; - if (!chip || !chip->get || !chip->direction_input) - goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + if (!chip->get || !chip->direction_input) { + gpiod_warn(desc, + "%s: missing get() or direction_input() operations\n", + __func__); + return -EIO; + } + + spin_lock_irqsave(&gpio_lock, flags); + + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1386,11 +2014,12 @@ int gpio_direction_input(unsigned gpio) might_sleep_if(chip->can_sleep); + offset = gpio_chip_hwgpio(desc); if (status) { - status = chip->request(chip, gpio); + status = chip->request(chip, offset); if (status < 0) { - pr_debug("GPIO-%d: chip request fail, %d\n", - chip->base + gpio, status); + gpiod_dbg(desc, "%s: chip request fail, %d\n", + __func__, status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1398,38 +2027,55 @@ int gpio_direction_input(unsigned gpio) } } - status = chip->direction_input(chip, gpio); + status = chip->direction_input(chip, offset); if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags); + + trace_gpio_direction(desc_to_gpio(desc), 1, status); lose: return status; fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", - __func__, gpio, status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_direction_input); +EXPORT_SYMBOL_GPL(gpiod_direction_input); -int gpio_direction_output(unsigned gpio, int value) +static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; - spin_lock_irqsave(&gpio_lock, flags); + /* 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; + } + + /* Open drain pin should not be driven to 1 */ + if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) + return gpiod_direction_input(desc); + + /* Open source pin should not be driven to 0 */ + if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) + return gpiod_direction_input(desc); - if (!gpio_is_valid(gpio)) - goto fail; chip = desc->chip; - if (!chip || !chip->set || !chip->direction_output) - goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + if (!chip->set || !chip->direction_output) { + gpiod_warn(desc, + "%s: missing set() or direction_output() operations\n", + __func__); + return -EIO; + } + + spin_lock_irqsave(&gpio_lock, flags); + + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1439,11 +2085,12 @@ int gpio_direction_output(unsigned gpio, int value) might_sleep_if(chip->can_sleep); + offset = gpio_chip_hwgpio(desc); if (status) { - status = chip->request(chip, gpio); + status = chip->request(chip, offset); if (status < 0) { - pr_debug("GPIO-%d: chip request fail, %d\n", - chip->base + gpio, status); + gpiod_dbg(desc, "%s: chip request fail, %d\n", + __func__, status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1451,43 +2098,96 @@ int gpio_direction_output(unsigned gpio, int value) } } - status = chip->direction_output(chip, gpio, value); + status = chip->direction_output(chip, offset, value); if (status == 0) set_bit(FLAG_IS_OUT, &desc->flags); + trace_gpio_value(desc_to_gpio(desc), 0, value); + trace_gpio_direction(desc_to_gpio(desc), 0, status); lose: return status; fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", - __func__, gpio, status); + gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_direction_output); /** - * gpio_set_debounce - sets @debounce time for a @gpio + * 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) +{ + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + 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) +{ + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + 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 gpio_set_debounce(unsigned gpio, unsigned debounce) +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; - spin_lock_irqsave(&gpio_lock, flags); + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } - if (!gpio_is_valid(gpio)) - goto fail; chip = desc->chip; - if (!chip || !chip->set || !chip->set_debounce) - goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + if (!chip->set || !chip->set_debounce) { + gpiod_dbg(desc, + "%s: missing set() or set_debounce() operations\n", + __func__); + return -ENOTSUPP; + } + + spin_lock_irqsave(&gpio_lock, flags); + + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1497,17 +2197,29 @@ int gpio_set_debounce(unsigned gpio, unsigned debounce) might_sleep_if(chip->can_sleep); - return chip->set_debounce(chip, gpio, debounce); + offset = gpio_chip_hwgpio(desc); + return chip->set_debounce(chip, offset, debounce); fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", - __func__, gpio, status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } -EXPORT_SYMBOL_GPL(gpio_set_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) +{ + 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. @@ -1531,107 +2243,616 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce); * that the GPIO was actually requested. */ +static bool _gpiod_get_raw_value(const struct gpio_desc *desc) +{ + struct gpio_chip *chip; + bool value; + int offset; + + chip = desc->chip; + offset = gpio_chip_hwgpio(desc); + value = chip->get ? chip->get(chip, offset) : false; + 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. + * + * 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) +{ + if (!desc) + return 0; + /* Should be using gpio_get_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + return _gpiod_get_raw_value(desc); +} +EXPORT_SYMBOL_GPL(gpiod_get_raw_value); + /** - * __gpio_get_value() - return a gpio's value - * @gpio: gpio whose value will be returned - * Context: any + * 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. * - * This is used directly or indirectly to implement gpio_get_value(). - * It returns the zero or nonzero value provided by the associated - * gpio_chip.get() method; or zero if no such method is provided. + * 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; + if (!desc) + return 0; + /* Should be using gpio_get_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + + value = _gpiod_get_raw_value(desc); + 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 otherise 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->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 otherise it will set to LOW. */ -int __gpio_get_value(unsigned gpio) +static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value) +{ + int err = 0; + struct gpio_chip *chip = desc->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 = gpio_to_chip(gpio); - WARN_ON(chip->can_sleep); - return chip->get ? chip->get(chip, gpio - chip->base) : 0; + chip = desc->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); } -EXPORT_SYMBOL_GPL(__gpio_get_value); /** - * __gpio_set_value() - assign a gpio's value - * @gpio: gpio whose value will be assigned + * gpiod_set_raw_value() - assign a gpio's raw value + * @desc: gpio whose value will be assigned * @value: value to assign - * Context: any * - * This is used directly or indirectly to implement gpio_set_value(). - * It invokes the associated gpio_chip.set() method. + * 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 __gpio_set_value(unsigned gpio, int value) +void gpiod_set_raw_value(struct gpio_desc *desc, int value) { - struct gpio_chip *chip; + if (!desc) + return; + /* Should be using gpio_set_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + _gpiod_set_raw_value(desc, value); +} +EXPORT_SYMBOL_GPL(gpiod_set_raw_value); - chip = gpio_to_chip(gpio); - WARN_ON(chip->can_sleep); - chip->set(chip, gpio - chip->base, 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) +{ + if (!desc) + return; + /* Should be using gpio_set_value_cansleep() */ + WARN_ON(desc->chip->can_sleep); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + _gpiod_set_raw_value(desc, value); } -EXPORT_SYMBOL_GPL(__gpio_set_value); +EXPORT_SYMBOL_GPL(gpiod_set_value); /** - * __gpio_cansleep() - report whether gpio value access will sleep - * @gpio: gpio in question - * Context: any + * gpiod_cansleep() - report whether gpio value access may sleep + * @desc: gpio to check * - * This is used directly or indirectly to implement gpio_cansleep(). It - * returns nonzero if access reading or writing the GPIO value can sleep. */ -int __gpio_cansleep(unsigned gpio) +int gpiod_cansleep(const struct gpio_desc *desc) { - struct gpio_chip *chip; + if (!desc) + return 0; + return desc->chip->can_sleep; +} +EXPORT_SYMBOL_GPL(gpiod_cansleep); - /* only call this on GPIOs that are valid! */ - chip = gpio_to_chip(gpio); +/** + * 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; - return chip->can_sleep; + if (!desc) + return -EINVAL; + chip = desc->chip; + offset = gpio_chip_hwgpio(desc); + return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; } -EXPORT_SYMBOL_GPL(__gpio_cansleep); +EXPORT_SYMBOL_GPL(gpiod_to_irq); /** - * __gpio_to_irq() - return the IRQ corresponding to a GPIO - * @gpio: gpio whose IRQ will be returned (already requested) - * Context: any + * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ + * @gpio: the GPIO line to lock as used for IRQ * - * This is used directly or indirectly to implement gpio_to_irq(). - * It returns the number of the IRQ signaled by this (input) GPIO, - * or a negative errno. + * This is used directly by GPIO drivers that want to lock down + * a certain GPIO line to be used for IRQs. */ -int __gpio_to_irq(unsigned gpio) +int gpiod_lock_as_irq(struct gpio_desc *desc) { - struct gpio_chip *chip; + if (!desc) + return -EINVAL; - chip = gpio_to_chip(gpio); - return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; + if (test_bit(FLAG_IS_OUT, &desc->flags)) { + gpiod_err(desc, + "%s: tried to flag a GPIO set as output for IRQ\n", + __func__); + return -EIO; + } + + set_bit(FLAG_USED_AS_IRQ, &desc->flags); + return 0; +} +EXPORT_SYMBOL_GPL(gpiod_lock_as_irq); + +int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset)); } -EXPORT_SYMBOL_GPL(__gpio_to_irq); +EXPORT_SYMBOL_GPL(gpio_lock_as_irq); + +/** + * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ + * @gpio: the GPIO line to unlock from IRQ usage + * + * This is used directly by GPIO drivers that want to indicate + * that a certain GPIO is no longer used exclusively for IRQ. + */ +void gpiod_unlock_as_irq(struct gpio_desc *desc) +{ + if (!desc) + return; + clear_bit(FLAG_USED_AS_IRQ, &desc->flags); +} +EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq); +void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset)); +} +EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); -/* There's no value in making it easy to inline GPIO calls that may sleep. - * Common examples include ones connected to I2C or SPI chips. +/** + * 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. + * + * 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); + if (!desc) + return 0; + return _gpiod_get_raw_value(desc); +} +EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); -int gpio_get_value_cansleep(unsigned gpio) +/** + * 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. + * + * This function is to be called from contexts that can sleep. + */ +int gpiod_get_value_cansleep(const struct gpio_desc *desc) { - struct gpio_chip *chip; + int value; might_sleep_if(extra_checks); - chip = gpio_to_chip(gpio); - return chip->get ? chip->get(chip, gpio - chip->base) : 0; + if (!desc) + return 0; + + value = _gpiod_get_raw_value(desc); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + + return value; } -EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); -void gpio_set_value_cansleep(unsigned gpio, int value) +/** + * 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) { - struct gpio_chip *chip; + might_sleep_if(extra_checks); + if (!desc) + return; + _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); - chip = gpio_to_chip(gpio); - chip->set(chip, gpio - chip->base, value); + if (!desc) + return; + + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + _gpiod_set_raw_value(desc, value); +} +EXPORT_SYMBOL_GPL(gpiod_set_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); +} + +static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, + unsigned int idx, + enum gpio_lookup_flags *flags) +{ + static const char *suffixes[] = { "gpios", "gpio" }; + 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(suffixes); i++) { + if (con_id) + snprintf(prop_name, 32, "%s-%s", con_id, suffixes[i]); + else + snprintf(prop_name, 32, "%s", 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; + + return desc; +} + +static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, + unsigned int idx, + enum gpio_lookup_flags *flags) +{ + struct acpi_gpio_info info; + struct gpio_desc *desc; + + desc = acpi_get_gpiod_by_index(dev, idx, &info); + if (IS_ERR(desc)) + return desc; + + if (info.gpioint && info.active_low) + *flags |= 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; +} + +/** + * 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 + * + * 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 occured while trying to acquire the GPIO. + */ +struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id) +{ + return gpiod_get_index(dev, con_id, 0); +} +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 + * + * 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) +{ + return gpiod_get_index_optional(dev, con_id, 0); +} +EXPORT_SYMBOL_GPL(gpiod_get_optional); + +/** + * 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 + * + * 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 + * occured while trying to acquire the GPIO. + */ +struct gpio_desc *__must_check gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + struct gpio_desc *desc = NULL; + int status; + enum gpio_lookup_flags flags = 0; + + dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); + + /* Using device tree? */ + if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { + dev_dbg(dev, "using device tree for GPIO lookup\n"); + desc = of_find_gpio(dev, con_id, idx, &flags); + } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { + dev_dbg(dev, "using ACPI for GPIO lookup\n"); + desc = acpi_find_gpio(dev, con_id, idx, &flags); + } + + /* + * 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"); + desc = gpiod_find(dev, con_id, idx, &flags); + } + + if (IS_ERR(desc)) { + dev_dbg(dev, "lookup for GPIO %s failed\n", con_id); + return desc; + } + + status = gpiod_request(desc, con_id); + + if (status < 0) + return ERR_PTR(status); + + if (flags & GPIO_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + if (flags & GPIO_OPEN_DRAIN) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + if (flags & GPIO_OPEN_SOURCE) + set_bit(FLAG_OPEN_SOURCE, &desc->flags); + + return desc; +} +EXPORT_SYMBOL_GPL(gpiod_get_index); + +/** + * 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 + * + * 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) +{ + struct gpio_desc *desc; + + desc = gpiod_get_index(dev, con_id, index); + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; } -EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_get_index_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); #ifdef CONFIG_DEBUG_FS @@ -1639,119 +2860,113 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) { unsigned i; unsigned gpio = chip->base; - struct gpio_desc *gdesc = &gpio_desc[gpio]; + struct gpio_desc *gdesc = &chip->desc[0]; int is_out; + int is_irq; for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) continue; + gpiod_get_direction(gdesc); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); - seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", + is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); + seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", gpio, gdesc->label, is_out ? "out" : "in ", chip->get ? (chip->get(chip, i) ? "hi" : "lo") - : "? "); + : "? ", + is_irq ? "IRQ" : " "); + seq_printf(s, "\n"); + } +} - if (!is_out) { - int irq = gpio_to_irq(gpio); - struct irq_desc *desc = irq_to_desc(irq); +static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) +{ + unsigned long flags; + struct gpio_chip *chip = NULL; + loff_t index = *pos; - /* This races with request_irq(), set_irq_type(), - * and set_irq_wake() ... but those are "rare". - * - * More significantly, trigger type flags aren't - * currently maintained by genirq. - */ - if (irq >= 0 && desc->action) { - char *trigger; - - switch (desc->status & IRQ_TYPE_SENSE_MASK) { - case IRQ_TYPE_NONE: - trigger = "(default)"; - break; - case IRQ_TYPE_EDGE_FALLING: - trigger = "edge-falling"; - break; - case IRQ_TYPE_EDGE_RISING: - trigger = "edge-rising"; - break; - case IRQ_TYPE_EDGE_BOTH: - trigger = "edge-both"; - break; - case IRQ_TYPE_LEVEL_HIGH: - trigger = "level-high"; - break; - case IRQ_TYPE_LEVEL_LOW: - trigger = "level-low"; - break; - default: - trigger = "?trigger?"; - break; - } - - seq_printf(s, " irq-%d %s%s", - irq, trigger, - (desc->status & IRQ_WAKEUP) - ? " wakeup" : ""); - } + s->private = ""; + + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(chip, &gpio_chips, list) + if (index-- == 0) { + spin_unlock_irqrestore(&gpio_lock, flags); + return chip; } + spin_unlock_irqrestore(&gpio_lock, flags); - seq_printf(s, "\n"); - } + return NULL; } -static int gpiolib_show(struct seq_file *s, void *unused) +static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { - struct gpio_chip *chip = NULL; - unsigned gpio; - int started = 0; + unsigned long flags; + struct gpio_chip *chip = v; + void *ret = NULL; - /* REVISIT this isn't locked against gpio_chip removal ... */ + spin_lock_irqsave(&gpio_lock, flags); + if (list_is_last(&chip->list, &gpio_chips)) + ret = NULL; + else + ret = list_entry(chip->list.next, struct gpio_chip, list); + spin_unlock_irqrestore(&gpio_lock, flags); - for (gpio = 0; gpio_is_valid(gpio); gpio++) { - struct device *dev; + s->private = "\n"; + ++*pos; - if (chip == gpio_desc[gpio].chip) - continue; - chip = gpio_desc[gpio].chip; - if (!chip) - continue; + 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_chip *chip = v; + struct device *dev; + + seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, + chip->base, chip->base + chip->ngpio - 1); + dev = chip->dev; + if (dev) + seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", + dev_name(dev)); + 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, chip); - seq_printf(s, "%sGPIOs %d-%d", - started ? "\n" : "", - chip->base, chip->base + chip->ngpio - 1); - dev = chip->dev; - if (dev) - seq_printf(s, ", %s/%s", - dev->bus ? dev->bus->name : "no-bus", - dev_name(dev)); - if (chip->label) - seq_printf(s, ", %s", chip->label); - if (chip->can_sleep) - seq_printf(s, ", can sleep"); - seq_printf(s, ":\n"); - - started = 1; - if (chip->dbg_show) - chip->dbg_show(s, chip); - else - gpiolib_dbg_show(s, chip); - } 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 single_open(file, gpiolib_show, NULL); + 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 = single_release, + .release = seq_release, }; static int __init gpiolib_debugfs_init(void) |