diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 828 |
1 files changed, 594 insertions, 234 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4a34ca9c176..7dd44615029 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -10,22 +10,18 @@ #include <linux/seq_file.h> #include <linux/gpio.h> #include <linux/of_gpio.h> +#include <linux/acpi_gpio.h> #include <linux/idr.h> #include <linux/slab.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. */ @@ -57,9 +53,10 @@ struct gpio_desc { #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 /* sysfs value has active low */ +#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 */ @@ -74,34 +71,50 @@ 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 -/* - * Internal gpiod_* API using descriptors instead of the integer namespace. - * Most of this should eventually go public. - */ static int gpiod_request(struct gpio_desc *desc, const char *label); static void gpiod_free(struct gpio_desc *desc); -static int gpiod_direction_input(struct gpio_desc *desc); -static int gpiod_direction_output(struct gpio_desc *desc, int value); -static int gpiod_get_direction(const struct gpio_desc *desc); -static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); -static int gpiod_get_value_cansleep(const struct gpio_desc *desc); -static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); -static int gpiod_get_value(const struct gpio_desc *desc); -static void gpiod_set_value(struct gpio_desc *desc, int value); -static int gpiod_cansleep(const struct gpio_desc *desc); -static int gpiod_to_irq(const struct gpio_desc *desc); -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); -static int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc); -static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); -static void gpiod_unexport(struct gpio_desc *desc); +#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 static inline void desc_set_label(struct gpio_desc *d, const char *label) { @@ -121,23 +134,36 @@ static int gpio_chip_hwgpio(const struct gpio_desc *desc) /** * Convert a GPIO number to its descriptor */ -static struct gpio_desc *gpio_to_desc(unsigned gpio) +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); + +/** + * Convert an offset on a certain chip to a corresponding descriptor + */ +static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip, + unsigned int offset) +{ + unsigned int gpio = chip->base + offset; + + return gpio_to_desc(gpio); +} /** * 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 */ -static int desc_to_gpio(const struct gpio_desc *desc) +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 @@ -172,16 +198,15 @@ static int gpio_ensure_requested(struct gpio_desc *desc) return 0; } -static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) +/** + * 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; } - -/* caller holds gpio_lock *OR* gpio is marked as requested */ -struct gpio_chip *gpio_to_chip(unsigned gpio) -{ - return gpiod_to_chip(gpio_to_desc(gpio)); -} +EXPORT_SYMBOL_GPL(gpiod_to_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) @@ -207,8 +232,15 @@ static int gpiochip_find_base(int ngpio) } } -/* caller ensures gpio is valid and requested, chip->get_direction may sleep */ -static int gpiod_get_direction(const struct gpio_desc *desc) +/** + * 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; @@ -234,6 +266,7 @@ static int gpiod_get_direction(const struct gpio_desc *desc) } return status; } +EXPORT_SYMBOL_GPL(gpiod_get_direction); #ifdef CONFIG_GPIO_SYSFS @@ -318,17 +351,10 @@ static ssize_t gpio_value_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 { - int value; - - value = !!gpiod_get_value_cansleep(desc); - 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; @@ -351,9 +377,7 @@ static ssize_t gpio_value_store(struct device *dev, status = kstrtol(buf, 0, &value); if (status == 0) { - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - value = !value; - gpiod_set_value_cansleep(desc, value != 0); + gpiod_set_value_cansleep(desc, value); status = size; } } @@ -395,6 +419,7 @@ 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; } @@ -433,6 +458,12 @@ 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; @@ -736,7 +767,7 @@ 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 @@ -750,7 +781,7 @@ static struct class gpio_class = { * * Returns zero on success, else an error. */ -static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) +int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { unsigned long flags; int status; @@ -828,12 +859,7 @@ fail_unlock: status); return status; } - -int gpio_export(unsigned gpio, bool direction_may_change) -{ - return gpiod_export(gpio_to_desc(gpio), direction_may_change); -} -EXPORT_SYMBOL_GPL(gpio_export); +EXPORT_SYMBOL_GPL(gpiod_export); static int match_export(struct device *dev, const void *data) { @@ -841,7 +867,7 @@ static int match_export(struct device *dev, const void *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 @@ -851,8 +877,8 @@ static int match_export(struct device *dev, const void *data) * * Returns zero on success, else an error. */ -static int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc) +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) { int status = -EINVAL; @@ -883,15 +909,10 @@ static int gpiod_export_link(struct device *dev, const char *name, return status; } - -int gpio_export_link(struct device *dev, const char *name, unsigned gpio) -{ - return gpiod_export_link(dev, name, gpio_to_desc(gpio)); -} -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 * @@ -902,7 +923,7 @@ EXPORT_SYMBOL_GPL(gpio_export_link); * * Returns zero on success, else an error. */ -static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) { struct device *dev = NULL; int status = -EINVAL; @@ -933,20 +954,15 @@ unlock: return status; } - -int gpio_sysfs_set_active_low(unsigned gpio, int value) -{ - return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); -} -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(). */ -static void gpiod_unexport(struct gpio_desc *desc) +void gpiod_unexport(struct gpio_desc *desc) { int status = 0; struct device *dev = NULL; @@ -979,12 +995,7 @@ static void gpiod_unexport(struct gpio_desc *desc) pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), status); } - -void gpio_unexport(unsigned gpio) -{ - gpiod_unexport(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(gpio_unexport); +EXPORT_SYMBOL_GPL(gpiod_unexport); static int gpiochip_export(struct gpio_chip *chip) { @@ -1091,27 +1102,6 @@ static inline void gpiochip_unexport(struct gpio_chip *chip) { } -static inline int gpiod_export(struct gpio_desc *desc, - bool direction_may_change) -{ - return -ENOSYS; -} - -static inline int gpiod_export_link(struct device *dev, const char *name, - struct gpio_desc *desc) -{ - return -ENOSYS; -} - -static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) -{ - return -ENOSYS; -} - -static inline void gpiod_unexport(struct gpio_desc *desc) -{ -} - #endif /* CONFIG_GPIO_SYSFS */ /* @@ -1670,7 +1660,16 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested); * rely on gpio_request() having been called beforehand. */ -static int gpiod_direction_input(struct gpio_desc *desc) +/** + * 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; @@ -1684,8 +1683,9 @@ static int gpiod_direction_input(struct gpio_desc *desc) chip = desc->chip; if (!chip->get || !chip->direction_input) { - pr_warn("%s: missing get() or direction_input() operations\n", - __func__); + gpiod_warn(desc, + "%s: missing get() or direction_input() operations\n", + __func__); return -EIO; } @@ -1705,8 +1705,7 @@ static int gpiod_direction_input(struct gpio_desc *desc) if (status) { status = chip->request(chip, offset); if (status < 0) { - pr_debug("GPIO-%d: chip request fail, %d\n", - desc_to_gpio(desc), status); + gpiod_dbg(desc, "chip request fail, %d\n", status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1724,18 +1723,22 @@ lose: fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", __func__, - desc_to_gpio(desc), status); + gpiod_dbg(desc, "%s status %d\n", __func__, status); return status; } +EXPORT_SYMBOL_GPL(gpiod_direction_input); -int gpio_direction_input(unsigned gpio) -{ - return gpiod_direction_input(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(gpio_direction_input); - -static int gpiod_direction_output(struct gpio_desc *desc, int value) +/** + * gpiod_direction_output - set the GPIO direction to input + * @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. + * + * Return 0 in case of success, else an error code. + */ +int gpiod_direction_output(struct gpio_desc *desc, int value) { unsigned long flags; struct gpio_chip *chip; @@ -1747,6 +1750,14 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value) return -EINVAL; } + /* 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); @@ -1757,8 +1768,9 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value) chip = desc->chip; if (!chip->set || !chip->direction_output) { - pr_warn("%s: missing set() or direction_output() operations\n", - __func__); + gpiod_warn(desc, + "%s: missing set() or direction_output() operations\n", + __func__); return -EIO; } @@ -1778,8 +1790,7 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value) if (status) { status = chip->request(chip, offset); if (status < 0) { - pr_debug("GPIO-%d: chip request fail, %d\n", - desc_to_gpio(desc), status); + gpiod_dbg(desc, "chip request fail, %d\n", status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1797,26 +1808,20 @@ lose: fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", __func__, - desc_to_gpio(desc), status); + gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status); return status; } - -int gpio_direction_output(unsigned gpio, int value) -{ - return gpiod_direction_output(gpio_to_desc(gpio), value); -} -EXPORT_SYMBOL_GPL(gpio_direction_output); +EXPORT_SYMBOL_GPL(gpiod_direction_output); /** - * gpio_set_debounce - sets @debounce time for a @gpio + * 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. */ -static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { unsigned long flags; struct gpio_chip *chip; @@ -1830,8 +1835,9 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) chip = desc->chip; if (!chip->set || !chip->set_debounce) { - pr_debug("%s: missing set() or set_debounce() operations\n", - __func__); + gpiod_dbg(desc, + "%s: missing set() or set_debounce() operations\n", + __func__); return -ENOTSUPP; } @@ -1853,17 +1859,23 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) fail: spin_unlock_irqrestore(&gpio_lock, flags); if (status) - pr_debug("%s: gpio-%d status %d\n", __func__, - desc_to_gpio(desc), status); + gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } +EXPORT_SYMBOL_GPL(gpiod_set_debounce); -int gpio_set_debounce(unsigned gpio, unsigned 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 gpiod_set_debounce(gpio_to_desc(gpio), debounce); + return test_bit(FLAG_ACTIVE_LOW, &desc->flags); } -EXPORT_SYMBOL_GPL(gpio_set_debounce); +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. @@ -1887,42 +1899,68 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce); * that the GPIO was actually requested. */ -/** - * __gpio_get_value() - return a gpio's value - * @gpio: gpio whose value will be returned - * Context: any - * - * 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. - */ -static int gpiod_get_value(const struct gpio_desc *desc) +static int _gpiod_get_raw_value(const struct gpio_desc *desc) { struct gpio_chip *chip; int value; int offset; - if (!desc) - return 0; chip = desc->chip; offset = gpio_chip_hwgpio(desc); - /* Should be using gpio_get_value_cansleep() */ - WARN_ON(chip->can_sleep); value = chip->get ? chip->get(chip, offset) : 0; trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } -int __gpio_get_value(unsigned gpio) +/** + * 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); + +/** + * 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 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) { - return gpiod_get_value(gpio_to_desc(gpio)); + 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(__gpio_get_value); +EXPORT_SYMBOL_GPL(gpiod_get_value); /* * _gpio_set_open_drain_value() - Set the open drain gpio's value. - * @gpio: Gpio whose state need to be set. - * @chip: Gpio chip. + * @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, int value) @@ -1942,14 +1980,14 @@ static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) } trace_gpio_direction(desc_to_gpio(desc), value, err); if (err < 0) - pr_err("%s: Error in set_value for open drain gpio%d err %d\n", - __func__, desc_to_gpio(desc), err); + gpiod_err(desc, + "%s: Error in set_value for open drain err %d\n", + __func__, err); } /* - * _gpio_set_open_source() - Set the open source gpio's value. - * @gpio: Gpio whose state need to be set. - * @chip: Gpio chip. + * _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, int value) @@ -1969,28 +2007,16 @@ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) } trace_gpio_direction(desc_to_gpio(desc), !value, err); if (err < 0) - pr_err("%s: Error in set_value for open source gpio%d err %d\n", - __func__, desc_to_gpio(desc), err); + gpiod_err(desc, + "%s: Error in set_value for open source err %d\n", + __func__, err); } -/** - * __gpio_set_value() - assign a gpio's value - * @gpio: 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. - */ -static void gpiod_set_value(struct gpio_desc *desc, int value) +static void _gpiod_set_raw_value(struct gpio_desc *desc, int value) { struct gpio_chip *chip; - if (!desc) - return; chip = desc->chip; - /* Should be using gpio_set_value_cansleep() */ - WARN_ON(chip->can_sleep); trace_gpio_value(desc_to_gpio(desc), 0, value); if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) _gpio_set_open_drain_value(desc, value); @@ -2000,44 +2026,71 @@ static void gpiod_set_value(struct gpio_desc *desc, int value) chip->set(chip, gpio_chip_hwgpio(desc), value); } -void __gpio_set_value(unsigned gpio, int value) +/** + * gpiod_set_raw_value() - 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 should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. + */ +void gpiod_set_raw_value(struct gpio_desc *desc, int value) { - return gpiod_set_value(gpio_to_desc(gpio), value); + 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(__gpio_set_value); +EXPORT_SYMBOL_GPL(gpiod_set_raw_value); /** - * __gpio_cansleep() - report whether gpio value access will sleep - * @gpio: gpio in question - * Context: any + * 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 is used directly or indirectly to implement gpio_cansleep(). It - * returns nonzero if access reading or writing the GPIO value can sleep. + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. */ -static int gpiod_cansleep(const struct gpio_desc *desc) +void gpiod_set_value(struct gpio_desc *desc, int value) { if (!desc) - return 0; - /* only call this on GPIOs that are valid! */ - return desc->chip->can_sleep; + 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(gpiod_set_value); -int __gpio_cansleep(unsigned gpio) +/** + * gpiod_cansleep() - report whether gpio value access may sleep + * @desc: gpio to check + * + */ +int gpiod_cansleep(const struct gpio_desc *desc) { - return gpiod_cansleep(gpio_to_desc(gpio)); + if (!desc) + return 0; + return desc->chip->can_sleep; } -EXPORT_SYMBOL_GPL(__gpio_cansleep); +EXPORT_SYMBOL_GPL(gpiod_cansleep); /** - * __gpio_to_irq() - return the IRQ corresponding to a GPIO - * @gpio: gpio whose IRQ will be returned (already requested) - * Context: any + * gpiod_to_irq() - return the IRQ corresponding to a GPIO + * @desc: gpio whose IRQ will be returned (already requested) * - * 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. + * Return the IRQ corresponding to the passed GPIO, or an error code in case of + * error. */ -static int gpiod_to_irq(const struct gpio_desc *desc) +int gpiod_to_irq(const struct gpio_desc *desc) { struct gpio_chip *chip; int offset; @@ -2048,62 +2101,366 @@ static int gpiod_to_irq(const struct gpio_desc *desc) offset = gpio_chip_hwgpio(desc); return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; } +EXPORT_SYMBOL_GPL(gpiod_to_irq); + +/** + * 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 as IRQs, for example in the + * .to_irq() callback of their gpio_chip, or in the .irq_enable() + * of its irq_chip implementation if the GPIO is known from that + * code. + */ +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(gpiod_lock_as_irq); + +int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +{ + return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset)); +} +EXPORT_SYMBOL_GPL(gpio_lock_as_irq); -int __gpio_to_irq(unsigned gpio) +/** + * 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) { - return gpiod_to_irq(gpio_to_desc(gpio)); + if (!desc) + return; + + clear_bit(FLAG_USED_AS_IRQ, &desc->flags); } -EXPORT_SYMBOL_GPL(__gpio_to_irq); +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_offset_to_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); -static int gpiod_get_value_cansleep(const struct gpio_desc *desc) +/** + * 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; - int offset; might_sleep_if(extra_checks); if (!desc) return 0; - chip = desc->chip; - offset = gpio_chip_hwgpio(desc); - value = chip->get ? chip->get(chip, offset) : 0; - trace_gpio_value(desc_to_gpio(desc), 1, value); + + value = _gpiod_get_raw_value(desc); + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + return value; } +EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); -int gpio_get_value_cansleep(unsigned gpio) +/** + * 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) { - return gpiod_get_value_cansleep(gpio_to_desc(gpio)); + might_sleep_if(extra_checks); + if (!desc) + return; + _gpiod_set_raw_value(desc, value); } -EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); -static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +/** + * 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) { - struct gpio_chip *chip; - might_sleep_if(extra_checks); if (!desc) return; - 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); + + 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_table() - register GPIO device consumers + * @table: array of consumers to register + * @num: number of consumers in table + */ +void gpiod_add_table(struct gpiod_lookup *table, size_t size) +{ + mutex_lock(&gpio_lookup_lock); + + while (size--) { + list_add_tail(&table->list, &gpio_lookup_list); + table++; + } + + mutex_unlock(&gpio_lookup_lock); +} + +/* + * Caller must have a acquired gpio_lookup_lock + */ +static struct gpio_chip *find_chip_by_name(const char *name) +{ + struct gpio_chip *chip = NULL; + + list_for_each_entry(chip, &gpio_lookup_list, list) { + if (chip->label == NULL) + continue; + if (!strcmp(chip->label, name)) + break; + } + + return chip; +} + +#ifdef CONFIG_OF +static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, + unsigned int idx, unsigned long *flags) +{ + char prop_name[32]; /* 32 is max size of property name */ + enum of_gpio_flags of_flags; + struct gpio_desc *desc; + + if (con_id) + snprintf(prop_name, 32, "%s-gpios", con_id); else - chip->set(chip, gpio_chip_hwgpio(desc), value); + snprintf(prop_name, 32, "gpios"); + + desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, + &of_flags); + + if (IS_ERR(desc)) + return desc; + + if (of_flags & OF_GPIO_ACTIVE_LOW) + *flags |= GPIOF_ACTIVE_LOW; + + return desc; +} +#else +static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, + unsigned int idx, unsigned long *flags) +{ + return ERR_PTR(-ENODEV); +} +#endif + +static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, + unsigned int idx, unsigned long *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 |= GPIOF_ACTIVE_LOW; + + return desc; +} + +static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, + unsigned int idx, unsigned long *flags) +{ + const char *dev_id = dev ? dev_name(dev) : NULL; + struct gpio_desc *desc = ERR_PTR(-ENODEV); + unsigned int match, best = 0; + struct gpiod_lookup *p; + + mutex_lock(&gpio_lookup_lock); + + list_for_each_entry(p, &gpio_lookup_list, list) { + match = 0; + + if (p->dev_id) { + if (!dev_id || strcmp(p->dev_id, dev_id)) + continue; + + match += 2; + } + + if (p->con_id) { + if (!con_id || strcmp(p->con_id, con_id)) + continue; + + match += 1; + } + + if (p->idx != idx) + continue; + + if (match > best) { + struct gpio_chip *chip; + + chip = find_chip_by_name(p->chip_label); + + if (!chip) { + dev_warn(dev, "cannot find GPIO chip %s\n", + p->chip_label); + continue; + } + + if (chip->ngpio >= p->chip_hwnum) { + dev_warn(dev, "GPIO chip %s has %d GPIOs\n", + chip->label, chip->ngpio); + continue; + } + + desc = gpio_to_desc(chip->base + p->chip_hwnum); + *flags = p->flags; + + if (match != 3) + best = match; + else + break; + } + } + + mutex_unlock(&gpio_lookup_lock); + + return desc; +} + +/** + * gpio_get - obtain a GPIO for a given GPIO function + * @dev: GPIO consumer + * @con_id: function within the GPIO consumer + * + * Return the GPIO descriptor corresponding to the function con_id of device + * dev, or an IS_ERR() condition if an error occured. + */ +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_index - obtain a GPIO from a multi-index GPIO function + * @dev: GPIO consumer + * @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, or an IS_ERR() condition in case of error. + */ +struct gpio_desc *__must_check gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + struct gpio_desc *desc; + int status; + unsigned long 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); + } else { + dev_dbg(dev, "using lookup tables for GPIO lookup"); + desc = gpiod_find(dev, con_id, idx, &flags); + } + + if (IS_ERR(desc)) { + dev_warn(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 & GPIOF_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + + return desc; } +EXPORT_SYMBOL_GPL(gpiod_get_index); -void gpio_set_value_cansleep(unsigned gpio, int value) +/** + * 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) { - return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); + gpiod_free(desc); } -EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); +EXPORT_SYMBOL_GPL(gpiod_put); #ifdef CONFIG_DEBUG_FS @@ -2113,6 +2470,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) unsigned gpio = chip->base; 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)) @@ -2120,12 +2478,14 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) 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"); } } |