diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 2840 |
1 files changed, 2627 insertions, 213 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d8db2f8ee41..2ebc9071e35 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1,21 +1,30 @@ #include <linux/kernel.h> #include <linux/module.h> +#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> +#include <linux/seq_file.h> +#include <linux/gpio.h> +#include <linux/of_gpio.h> +#include <linux/idr.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/gpio/driver.h> -#include <asm/gpio.h> +#include "gpiolib.h" +#define CREATE_TRACE_POINTS +#include <trace/events/gpio.h> -/* Optional implementation infrastructure for GPIO interfaces. +/* 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. - * - * 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. */ @@ -43,6 +52,19 @@ struct gpio_desc { /* flag symbols are bit numbers */ #define FLAG_REQUESTED 0 #define FLAG_IS_OUT 1 +#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 */ + +#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) +#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) #ifdef CONFIG_DEBUG_FS const char *label; @@ -50,6 +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 @@ -57,24 +143,1019 @@ 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 * those calls have no teeth) we can't avoid autorequesting. This nag - * message should motivate switching to explicit requests... + * message should motivate switching to explicit requests... so should + * the weaker cleanup after faults, compared to gpio_request(). + * + * NOTE: the autorequest mechanism is going away; at this point it's + * only "legal" in the sense that (old) code using it won't break yet, + * but instead only triggers a WARN() stack dump. */ -static void gpio_ensure_requested(struct gpio_desc *desc) +static int gpio_ensure_requested(struct gpio_desc *desc) { - if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { - pr_warning("GPIO-%d autorequested\n", (int)(desc - gpio_desc)); + const struct gpio_chip *chip = desc->chip; + 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)) { + gpiod_err(desc, "%s: module can't be gotten\n", + __func__); + clear_bit(FLAG_REQUESTED, &desc->flags); + /* lose */ + return -EIO; + } desc_set_label(desc, "[auto]"); + /* caller must chip->request() w/o spinlock */ + if (chip->request) + return 1; + } + return 0; +} + +/** + * 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 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) +{ + struct gpio_chip *chip; + int base = ARCH_NR_GPIOS - ngpio; + + 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)) { + pr_debug("%s: found new base at %d\n", __func__, base); + return base; + } else { + pr_err("%s: cannot find free range\n", __func__); + return -ENOSPC; + } +} + +/** + * 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. + * + * This function may sleep if gpiod_cansleep() is true. + */ +int gpiod_get_direction(const struct gpio_desc *desc) +{ + struct gpio_chip *chip; + unsigned offset; + int status = -EINVAL; + + chip = gpiod_to_chip(desc); + offset = gpio_chip_hwgpio(desc); + + if (!chip->get_direction) + return status; + + 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); + } + 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 + +/* lock protects against unexport_gpio() being called while + * sysfs files are active. + */ +static DEFINE_MUTEX(sysfs_lock); + +/* + * /sys/class/gpio/gpioN... only for GPIOs that are exported + * /direction + * * MAY BE OMITTED if kernel won't allow direction changes + * * is read/write as "in" or "out" + * * may also be written as "high" or "low", initializing + * output value as specified ("out" implies "low") + * /value + * * always readable, subject to hardware behavior + * * may be writable, as zero/nonzero + * /edge + * * configures behavior of poll(2) on /value + * * available only if pin can generate IRQs on input + * * is read/write as "none", "falling", "rising", or "both" + * /active_low + * * configures polarity of /value + * * is read/write as zero/nonzero + * * also affects existing and subsequent "falling" and "rising" + * /edge configuration + */ + +static ssize_t gpio_direction_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) { + status = -EIO; + } 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; +} + +static ssize_t gpio_direction_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else if (sysfs_streq(buf, "high")) + status = gpiod_direction_output_raw(desc, 1); + else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) + status = gpiod_direction_output_raw(desc, 0); + else if (sysfs_streq(buf, "in")) + status = gpiod_direction_input(desc); + else + status = -EINVAL; + + mutex_unlock(&sysfs_lock); + return status ? : size; +} + +static /* const */ DEVICE_ATTR(direction, 0644, + gpio_direction_show, gpio_direction_store); + +static ssize_t gpio_value_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else + status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc)); + + mutex_unlock(&sysfs_lock); + return status; +} + +static ssize_t gpio_value_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else if (!test_bit(FLAG_IS_OUT, &desc->flags)) + status = -EPERM; + else { + long value; + + status = kstrtol(buf, 0, &value); + if (status == 0) { + gpiod_set_value_cansleep(desc, value); + status = size; + } + } + + mutex_unlock(&sysfs_lock); + return status; +} + +static const DEVICE_ATTR(value, 0644, + gpio_value_show, gpio_value_store); + +static irqreturn_t gpio_sysfs_irq(int irq, void *priv) +{ + struct kernfs_node *value_sd = priv; + + sysfs_notify_dirent(value_sd); + return IRQ_HANDLED; +} + +static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, + unsigned long gpio_flags) +{ + struct kernfs_node *value_sd; + unsigned long irq_flags; + int ret, irq, id; + + if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) + return 0; + + irq = gpiod_to_irq(desc); + if (irq < 0) + return -EIO; + + id = desc->flags >> ID_SHIFT; + value_sd = idr_find(&dirent_idr, id); + if (value_sd) + free_irq(irq, value_sd); + + desc->flags &= ~GPIO_TRIGGER_MASK; + + if (!gpio_flags) { + gpiod_unlock_as_irq(desc); + ret = 0; + goto free_id; + } + + irq_flags = IRQF_SHARED; + if (test_bit(FLAG_TRIG_FALL, &gpio_flags)) + irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; + if (test_bit(FLAG_TRIG_RISE, &gpio_flags)) + irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; + + if (!value_sd) { + value_sd = sysfs_get_dirent(dev->kobj.sd, "value"); + if (!value_sd) { + ret = -ENODEV; + goto err_out; + } + + 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; + + if (desc->flags >> ID_SHIFT != id) { + ret = -ERANGE; + goto free_id; + } + } + + ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, + "gpiolib", value_sd); + 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; + +free_id: + idr_remove(&dirent_idr, id); + desc->flags &= GPIO_FLAGS_MASK; +free_sd: + if (value_sd) + sysfs_put(value_sd); +err_out: + return ret; +} + +static const struct { + const char *name; + unsigned long flags; +} trigger_types[] = { + { "none", 0 }, + { "falling", BIT(FLAG_TRIG_FALL) }, + { "rising", BIT(FLAG_TRIG_RISE) }, + { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) }, +}; + +static ssize_t gpio_edge_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else { + int i; + + status = 0; + for (i = 0; i < ARRAY_SIZE(trigger_types); i++) + if ((desc->flags & GPIO_TRIGGER_MASK) + == trigger_types[i].flags) { + status = sprintf(buf, "%s\n", + trigger_types[i].name); + break; + } + } + + mutex_unlock(&sysfs_lock); + return status; +} + +static ssize_t gpio_edge_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + int i; + + for (i = 0; i < ARRAY_SIZE(trigger_types); i++) + if (sysfs_streq(trigger_types[i].name, buf)) + goto found; + return -EINVAL; + +found: + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else { + status = gpio_setup_irq(desc, dev, trigger_types[i].flags); + if (!status) + status = size; + } + + mutex_unlock(&sysfs_lock); + + return status; +} + +static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); + +static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, + int value) +{ + int status = 0; + + if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value) + return 0; + + if (value) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + else + clear_bit(FLAG_ACTIVE_LOW, &desc->flags); + + /* reconfigure poll(2) support if enabled on one edge only */ + if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^ + !!test_bit(FLAG_TRIG_FALL, &desc->flags))) { + unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK; + + gpio_setup_irq(desc, dev, 0); + status = gpio_setup_irq(desc, dev, trigger_flags); + } + + return status; +} + +static ssize_t gpio_active_low_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) + status = -EIO; + else + status = sprintf(buf, "%d\n", + !!test_bit(FLAG_ACTIVE_LOW, &desc->flags)); + + mutex_unlock(&sysfs_lock); + + return status; +} + +static ssize_t gpio_active_low_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct gpio_desc *desc = dev_get_drvdata(dev); + ssize_t status; + + mutex_lock(&sysfs_lock); + + if (!test_bit(FLAG_EXPORT, &desc->flags)) { + status = -EIO; + } else { + long value; + + status = kstrtol(buf, 0, &value); + if (status == 0) + status = sysfs_set_active_low(desc, dev, value != 0); + } + + mutex_unlock(&sysfs_lock); + + return status ? : size; +} + +static const DEVICE_ATTR(active_low, 0644, + gpio_active_low_show, gpio_active_low_store); + +static const struct attribute *gpio_attrs[] = { + &dev_attr_value.attr, + &dev_attr_active_low.attr, + NULL, +}; + +static const struct attribute_group gpio_attr_group = { + .attrs = (struct attribute **) gpio_attrs, +}; + +/* + * /sys/class/gpio/gpiochipN/ + * /base ... matching gpio_chip.base (N) + * /label ... matching gpio_chip.label + * /ngpio ... matching gpio_chip.ngpio + */ + +static ssize_t chip_base_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", chip->base); +} +static DEVICE_ATTR(base, 0444, chip_base_show, NULL); + +static ssize_t chip_label_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", chip->label ? : ""); +} +static DEVICE_ATTR(label, 0444, chip_label_show, NULL); + +static ssize_t chip_ngpio_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct gpio_chip *chip = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", chip->ngpio); +} +static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL); + +static const struct attribute *gpiochip_attrs[] = { + &dev_attr_base.attr, + &dev_attr_label.attr, + &dev_attr_ngpio.attr, + NULL, +}; + +static const struct attribute_group gpiochip_attr_group = { + .attrs = (struct attribute **) gpiochip_attrs, +}; + +/* + * /sys/class/gpio/export ... write-only + * integer N ... number of GPIO to export (full access) + * /sys/class/gpio/unexport ... write-only + * integer N ... number of GPIO to unexport + */ +static ssize_t export_store(struct class *class, + struct class_attribute *attr, + const char *buf, size_t len) +{ + long gpio; + struct gpio_desc *desc; + int status; + + 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 = gpiod_request(desc, "sysfs"); + if (status < 0) { + if (status == -EPROBE_DEFER) + status = -ENODEV; + goto done; + } + status = gpiod_export(desc, true); + if (status < 0) + gpiod_free(desc); + else + set_bit(FLAG_SYSFS, &desc->flags); + +done: + if (status) + pr_debug("%s: status %d\n", __func__, status); + return status ? : len; +} + +static ssize_t unexport_store(struct class *class, + struct class_attribute *attr, + const char *buf, size_t len) +{ + long gpio; + struct gpio_desc *desc; + int status; + + status = kstrtol(buf, 0, &gpio); + if (status < 0) + goto done; + + desc = gpio_to_desc(gpio); + /* reject bogus commands (gpio_unexport ignores them) */ + 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, &desc->flags)) { + status = 0; + gpiod_free(desc); + } +done: + if (status) + pr_debug("%s: status %d\n", __func__, status); + return status ? : len; +} + +static struct class_attribute gpio_class_attrs[] = { + __ATTR(export, 0200, NULL, export_store), + __ATTR(unexport, 0200, NULL, unexport_store), + __ATTR_NULL, +}; + +static struct class gpio_class = { + .name = "gpio", + .owner = THIS_MODULE, + + .class_attrs = gpio_class_attrs, +}; + + +/** + * 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 + * + * When drivers want to make a GPIO accessible to userspace after they + * have requested it -- perhaps while debugging, or as part of their + * public interface -- they may use this routine. If the GPIO can + * change direction (some can't) and the caller allows it, userspace + * will see "direction" sysfs attribute which may be used to change + * the gpio's direction. A "value" attribute will always be provided. + * + * Returns zero on success, else an error. + */ +int gpiod_export(struct gpio_desc *desc, bool direction_may_change) +{ + unsigned long flags; + int status; + const char *ioname = NULL; + struct device *dev; + int offset; + + /* can't export until sysfs is available ... */ + if (!gpio_class.p) { + pr_debug("%s: called too early!\n", __func__); + return -ENOENT; + } + + if (!desc) { + pr_debug("%s: invalid gpio descriptor\n", __func__); + return -EINVAL; + } + + mutex_lock(&sysfs_lock); + + spin_lock_irqsave(&gpio_lock, flags); + 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); + + offset = gpio_chip_hwgpio(desc); + if (desc->chip->names && desc->chip->names[offset]) + ioname = desc->chip->names[offset]; + + 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; + } + + status = sysfs_create_group(&dev->kobj, &gpio_attr_group); + if (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(gpiod_export); -/* caller holds gpio_lock *OR* gpio is marked as requested */ -static inline struct gpio_chip *gpio_to_chip(unsigned gpio) +static int match_export(struct device *dev, const void *data) { - return gpio_desc[gpio].chip; + return dev_get_drvdata(dev) == data; +} + +/** + * 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 + * + * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN + * node. Caller is responsible for unlinking. + * + * Returns zero on success, else an error. + */ +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) +{ + int status = -EINVAL; + + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + + mutex_lock(&sysfs_lock); + + if (test_bit(FLAG_EXPORT, &desc->flags)) { + struct device *tdev; + + tdev = class_find_device(&gpio_class, NULL, desc, match_export); + if (tdev != NULL) { + status = sysfs_create_link(&dev->kobj, &tdev->kobj, + name); + } else { + status = -ENODEV; + } + } + + mutex_unlock(&sysfs_lock); + + if (status) + gpiod_dbg(desc, "%s: status %d\n", __func__, status); + + return status; +} +EXPORT_SYMBOL_GPL(gpiod_export_link); + +/** + * 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 + * + * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute. + * The GPIO does not have to be exported yet. If poll(2) support has + * been enabled for either rising or falling edge, it will be + * reconfigured to follow the new polarity. + * + * Returns zero on success, else an error. + */ +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +{ + struct device *dev = NULL; + int status = -EINVAL; + + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + + mutex_lock(&sysfs_lock); + + if (test_bit(FLAG_EXPORT, &desc->flags)) { + dev = class_find_device(&gpio_class, NULL, desc, match_export); + if (dev == NULL) { + status = -ENODEV; + goto unlock; + } + } + + status = sysfs_set_active_low(desc, dev, value); + +unlock: + mutex_unlock(&sysfs_lock); + + if (status) + gpiod_dbg(desc, "%s: status %d\n", __func__, status); + + return status; +} +EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low); + +/** + * gpiod_unexport - reverse effect of gpio_export() + * @gpio: gpio to make unavailable + * + * This is implicit on gpio_free(). + */ +void gpiod_unexport(struct gpio_desc *desc) +{ + int status = 0; + struct device *dev = NULL; + + if (!desc) { + pr_warn("%s: invalid GPIO\n", __func__); + return; + } + + mutex_lock(&sysfs_lock); + + if (test_bit(FLAG_EXPORT, &desc->flags)) { + + dev = class_find_device(&gpio_class, NULL, desc, match_export); + if (dev) { + gpio_setup_irq(desc, dev, 0); + clear_bit(FLAG_EXPORT, &desc->flags); + } else + status = -ENODEV; + } + + mutex_unlock(&sysfs_lock); + + if (dev) { + device_unregister(dev); + put_device(dev); + } + + if (status) + gpiod_dbg(desc, "%s: status %d\n", __func__, status); +} +EXPORT_SYMBOL_GPL(gpiod_unexport); + +static int gpiochip_export(struct gpio_chip *chip) +{ + int status; + struct device *dev; + + /* Many systems register gpio chips for SOC support very early, + * before driver model support is available. In those cases we + * export this later, in gpiolib_sysfs_init() ... here we just + * verify that _some_ field of gpio_class got initialized. + */ + if (!gpio_class.p) + return 0; + + /* use chip->base for the ID; it's already known to be unique */ + mutex_lock(&sysfs_lock); + dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip, + "gpiochip%d", chip->base); + if (!IS_ERR(dev)) { + status = sysfs_create_group(&dev->kobj, + &gpiochip_attr_group); + } else + status = PTR_ERR(dev); + chip->exported = (status == 0); + mutex_unlock(&sysfs_lock); + + if (status) { + unsigned long flags; + unsigned gpio; + + spin_lock_irqsave(&gpio_lock, flags); + gpio = 0; + while (gpio < chip->ngpio) + chip->desc[gpio++].chip = NULL; + spin_unlock_irqrestore(&gpio_lock, flags); + + chip_dbg(chip, "%s: status %d\n", __func__, status); + } + + return status; +} + +static void gpiochip_unexport(struct gpio_chip *chip) +{ + int status; + struct device *dev; + + mutex_lock(&sysfs_lock); + dev = class_find_device(&gpio_class, NULL, chip, match_export); + if (dev) { + put_device(dev); + device_unregister(dev); + chip->exported = false; + status = 0; + } else + status = -ENODEV; + mutex_unlock(&sysfs_lock); + + if (status) + chip_dbg(chip, "%s: status %d\n", __func__, status); +} + +static int __init gpiolib_sysfs_init(void) +{ + int status; + unsigned long flags; + struct gpio_chip *chip; + + status = class_register(&gpio_class); + if (status < 0) + return status; + + /* Scan and register the gpio_chips which registered very + * early (e.g. before the class_register above was called). + * + * We run before arch_initcall() so chip->dev nodes can have + * registered, and so arch_initcall() can always gpio_export(). + */ + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(chip, &gpio_chips, list) { + if (!chip || chip->exported) + continue; + + spin_unlock_irqrestore(&gpio_lock, flags); + status = gpiochip_export(chip); + spin_lock_irqsave(&gpio_lock, flags); + } + spin_unlock_irqrestore(&gpio_lock, flags); + + + return status; +} +postcore_initcall(gpiolib_sysfs_init); + +#else +static inline int gpiochip_export(struct gpio_chip *chip) +{ + return 0; +} + +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; } /** @@ -85,49 +1166,97 @@ static inline struct gpio_chip *gpio_to_chip(unsigned gpio) * Returns a negative errno if the chip can't be registered, such as * because the chip->base is invalid or already associated with a * different chip. Otherwise it returns zero as a success code. + * + * When gpiochip_add() is called very early during boot, so that GPIOs + * can be freely used, the chip->dev device must be registered before + * the gpio framework's arch_initcall(). Otherwise sysfs initialization + * for GPIOs will fail rudely. + * + * If chip->base is negative, this requests dynamic assignment of + * a range of valid GPIOs. */ int gpiochip_add(struct gpio_chip *chip) { unsigned long flags; int status = 0; unsigned id; + int base = chip->base; - /* NOTE chip->base negative is reserved to mean a request for - * dynamic allocation. We don't currently support that. - */ - - if (chip->base < 0 || (chip->base + chip->ngpio) >= ARCH_NR_GPIOS) { + if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) + && base >= 0) { status = -EINVAL; goto fail; } spin_lock_irqsave(&gpio_lock, flags); - /* these GPIO numbers must not be managed by another gpio_chip */ - for (id = chip->base; id < chip->base + chip->ngpio; id++) { - if (gpio_desc[id].chip != NULL) { - status = -EBUSY; - break; + if (base < 0) { + base = gpiochip_find_base(chip->ngpio); + if (base < 0) { + status = base; + goto unlock; } + chip->base = base; } + + status = gpiochip_add_to_list(chip); + if (status == 0) { - for (id = chip->base; id < chip->base + chip->ngpio; id++) { - gpio_desc[id].chip = chip; - gpio_desc[id].flags = 0; + 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. + */ + desc->flags = !chip->direction_input + ? (1 << FLAG_IS_OUT) + : 0; } } 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; + + status = gpiochip_export(chip); + 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... */ - if (status) - pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n", - chip->base, chip->base + chip->ngpio, - chip->label ? : "generic"); + 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 @@ -140,84 +1269,636 @@ int gpiochip_remove(struct gpio_chip *chip) int status = 0; unsigned id; + acpi_gpiochip_remove(chip); + spin_lock_irqsave(&gpio_lock, flags); - for (id = chip->base; id < chip->base + chip->ngpio; id++) { - if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { + gpiochip_irqchip_remove(chip); + gpiochip_remove_pin_ranges(chip); + of_gpiochip_remove(chip); + + 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); + + if (status == 0) + gpiochip_unexport(chip); + return status; } EXPORT_SYMBOL_GPL(gpiochip_remove); +/** + * gpiochip_find() - iterator for locating a specific gpio_chip + * @data: data to pass to match function + * @callback: Callback function to check gpio_chip + * + * Similar to bus_find_device. It returns a reference to a gpio_chip as + * determined by a user supplied @match callback. The callback should return + * 0 if the device doesn't match and non-zero if it does. If the callback is + * non-zero, this function will return to the caller and not iterate over any + * more gpio_chips. + */ +struct gpio_chip *gpiochip_find(void *data, + int (*match)(struct gpio_chip *chip, + void *data)) +{ + struct gpio_chip *chip; + unsigned long flags; + + spin_lock_irqsave(&gpio_lock, flags); + 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; - int status = -EINVAL; + struct gpio_chip *chip = desc->chip; + int status; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - if (gpio >= ARCH_NR_GPIOS) - goto done; - desc = &gpio_desc[gpio]; - if (desc->chip == NULL) - goto done; - /* NOTE: gpio_request() can be called in early boot, - * before IRQs are enabled. + * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { desc_set_label(desc, label ? : "?"); status = 0; - } else + } else { status = -EBUSY; + goto done; + } + if (chip->request) { + /* chip->request may sleep */ + spin_unlock_irqrestore(&gpio_lock, flags); + status = chip->request(chip, gpio_chip_hwgpio(desc)); + spin_lock_irqsave(&gpio_lock, flags); + + if (status < 0) { + desc_set_label(desc, NULL); + 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: - if (status) - pr_debug("gpio_request: gpio-%d (%s) status %d\n", - gpio, label ? : "?", status); 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) + 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; - if (gpio >= ARCH_NR_GPIOS) { - WARN_ON(extra_checks); - return; - } + might_sleep(); + + gpiod_unexport(desc); spin_lock_irqsave(&gpio_lock, flags); - desc = &gpio_desc[gpio]; - if (desc->chip && test_and_clear_bit(FLAG_REQUESTED, &desc->flags)) + 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_hwgpio(desc)); + spin_lock_irqsave(&gpio_lock, flags); + } desc_set_label(desc, NULL); + clear_bit(FLAG_ACTIVE_LOW, &desc->flags); + clear_bit(FLAG_REQUESTED, &desc->flags); + 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); +} - spin_unlock_irqrestore(&gpio_lock, flags); +void gpio_free(unsigned gpio) +{ + gpiod_free(gpio_to_desc(gpio)); } EXPORT_SYMBOL_GPL(gpio_free); +/** + * gpio_request_one - request a single GPIO with initial configuration + * @gpio: the GPIO number + * @flags: GPIO configuration as specified by GPIOF_* + * @label: a literal description string of this GPIO + */ +int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) +{ + struct gpio_desc *desc; + int err; + + 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 = gpiod_direction_input(desc); + else + 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); + +/** + * gpio_request_array - request multiple GPIOs in a single call + * @array: array of the 'struct gpio' + * @num: how many GPIOs in the array + */ +int gpio_request_array(const struct gpio *array, size_t num) +{ + int i, err; + + for (i = 0; i < num; i++, array++) { + err = gpio_request_one(array->gpio, array->flags, array->label); + if (err) + goto err_free; + } + return 0; + +err_free: + while (i--) + gpio_free((--array)->gpio); + return err; +} +EXPORT_SYMBOL_GPL(gpio_request_array); + +/** + * gpio_free_array - release multiple GPIOs in a single call + * @array: array of the 'struct gpio' + * @num: how many GPIOs in the array + */ +void gpio_free_array(const struct gpio *array, size_t num) +{ + while (num--) + gpio_free((array++)->gpio); +} +EXPORT_SYMBOL_GPL(gpio_free_array); /** * gpiochip_is_requested - return string iff signal was requested @@ -234,20 +1915,54 @@ EXPORT_SYMBOL_GPL(gpio_free); */ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) { - unsigned gpio = chip->base + offset; + struct gpio_desc *desc; - if (gpio >= ARCH_NR_GPIOS || 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. @@ -258,82 +1973,253 @@ 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 >= ARCH_NR_GPIOS) - goto fail; chip = desc->chip; - if (!chip || !chip->get || !chip->direction_input) - goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) + 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; - gpio_ensure_requested(desc); /* now we know the gpio is valid and chip won't vanish */ spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); + + offset = gpio_chip_hwgpio(desc); + if (status) { + status = chip->request(chip, offset); + if (status < 0) { + 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. + */ + goto lose; + } + } - 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", - __FUNCTION__, 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; + + /* 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; + } - spin_lock_irqsave(&gpio_lock, flags); + /* 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 >= ARCH_NR_GPIOS) - goto fail; chip = desc->chip; - if (!chip || !chip->set || !chip->direction_output) - goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) + 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; - gpio_ensure_requested(desc); /* now we know the gpio is valid and chip won't vanish */ spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); + + offset = gpio_chip_hwgpio(desc); + if (status) { + status = chip->request(chip, offset); + if (status < 0) { + 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. + */ + goto lose; + } + } - 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", - __FUNCTION__, gpio, status); + gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); + return status; +} + +/** + * 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 gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +{ + unsigned long flags; + struct gpio_chip *chip; + int status = -EINVAL; + int offset; + + if (!desc || !desc->chip) { + pr_warn("%s: invalid GPIO\n", __func__); + return -EINVAL; + } + + chip = desc->chip; + 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; + + /* now we know the gpio is valid and chip won't vanish */ + + spin_unlock_irqrestore(&gpio_lock, flags); + + might_sleep_if(chip->can_sleep); + + offset = gpio_chip_hwgpio(desc); + return chip->set_debounce(chip, offset, debounce); + +fail: + spin_unlock_irqrestore(&gpio_lock, flags); + if (status) + gpiod_dbg(desc, "%s: status %d\n", __func__, status); + return status; } -EXPORT_SYMBOL_GPL(gpio_direction_output); +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. @@ -357,202 +2243,730 @@ EXPORT_SYMBOL_GPL(gpio_direction_output); * 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 * - * 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. + * Return the GPIO's logical value, i.e. taking the 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. + */ +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. */ -int __gpio_get_value(unsigned gpio) +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. + */ +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(extra_checks && 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(extra_checks && 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) +{ + if (!desc) + return 0; + return desc->chip->can_sleep; +} +EXPORT_SYMBOL_GPL(gpiod_cansleep); + +/** + * 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; - /* only call this on GPIOs that are valid! */ - chip = gpio_to_chip(gpio); + 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(gpiod_to_irq); - return chip->can_sleep; +/** + * 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 by GPIO drivers that want to lock down + * a certain GPIO line to be used for IRQs. + */ +int gpiod_lock_as_irq(struct gpio_desc *desc) +{ + if (!desc) + return -EINVAL; + + 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(__gpio_cansleep); +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_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, gpio - chip->base); + 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(gpio_set_value_cansleep); +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); -#ifdef CONFIG_DEBUG_FS + list_add_tail(&table->list, &gpio_lookup_list); -#include <linux/debugfs.h> -#include <linux/seq_file.h> + 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(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 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 (%-12s) %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_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 < ARCH_NR_GPIOS; gpio++) { - if (chip == gpio_desc[gpio].chip) - continue; - chip = gpio_desc[gpio].chip; - if (!chip) - continue; + s->private = "\n"; + ++*pos; + + 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, %s%s:\n", - started ? "\n" : "", - chip->base, chip->base + chip->ngpio - 1, - chip->label ? : "generic", - chip->can_sleep ? ", can sleep" : ""); - 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 struct file_operations gpiolib_operations = { +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) |