Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755179Ab3JKSPB (ORCPT ); Fri, 11 Oct 2013 14:15:01 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:15708 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753172Ab3JKSOx (ORCPT ); Fri, 11 Oct 2013 14:14:53 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Fri, 11 Oct 2013 11:10:38 -0700 From: Alexandre Courbot To: Linus Walleij CC: Arnd Bergmann , Grant Likely , Mika Westerberg , , "Rafael J. Wysocki" , Mathias Nyman , , , , , Alexandre Courbot Subject: [PATCH v2 1/3] gpiolib: export descriptor-based GPIO interface Date: Fri, 11 Oct 2013 11:14:31 -0700 Message-ID: <1381515273-25466-2-git-send-email-acourbot@nvidia.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1381515273-25466-1-git-send-email-acourbot@nvidia.com> References: <1381515273-25466-1-git-send-email-acourbot@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 46036 Lines: 1426 This patch exports the gpiod_* family of API functions, a safer alternative to the legacy GPIO interface. Differences between the gpiod and legacy gpio APIs are: - gpio works with integers, whereas gpiod operates on opaque handlers which cannot be forged or used before proper acquisition - gpiod get/set functions are aware of the active low state of a GPIO - gpio consumers should now include to access the new interface, whereas chips drivers will use The legacy gpio API is now built as inline functions on top of gpiod. Signed-off-by: Alexandre Courbot --- drivers/gpio/gpiolib.c | 414 ++++++++++++++++++++++-------------------- include/asm-generic/gpio.h | 222 +++++++--------------- include/linux/gpio.h | 11 +- include/linux/gpio/consumer.h | 238 ++++++++++++++++++++++++ include/linux/gpio/driver.h | 124 +++++++++++++ 5 files changed, 651 insertions(+), 358 deletions(-) create mode 100644 include/linux/gpio/consumer.h create mode 100644 include/linux/gpio/driver.h diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 79ef3de..b2a7839 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -16,16 +16,11 @@ #define CREATE_TRACE_POINTS #include -/* 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. */ @@ -57,7 +52,7 @@ 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 */ @@ -80,27 +75,8 @@ static LIST_HEAD(gpio_chips); 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, ...) \ @@ -154,23 +130,25 @@ 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 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 @@ -205,16 +183,15 @@ 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) @@ -240,8 +217,15 @@ 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; @@ -267,6 +251,7 @@ static int gpiod_get_direction(const struct gpio_desc *desc) } return status; } +EXPORT_SYMBOL_GPL(gpiod_get_direction); #ifdef CONFIG_GPIO_SYSFS @@ -351,17 +336,10 @@ 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; @@ -384,9 +362,7 @@ 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; } } @@ -769,7 +745,7 @@ 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 @@ -783,7 +759,7 @@ 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; @@ -861,12 +837,7 @@ 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) { @@ -874,7 +845,7 @@ 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 @@ -884,8 +855,8 @@ 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; @@ -916,15 +887,10 @@ 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 * @@ -935,7 +901,7 @@ 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; @@ -966,20 +932,15 @@ 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; @@ -1012,12 +973,7 @@ 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) { @@ -1124,27 +1080,6 @@ 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 */ /* @@ -1656,7 +1591,16 @@ 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; @@ -1713,14 +1657,19 @@ fail: 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; @@ -1785,22 +1734,17 @@ fail: 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; @@ -1842,12 +1786,19 @@ fail: 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. @@ -1871,7 +1822,7 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce); * that the GPIO was actually requested. */ -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; @@ -1885,33 +1836,54 @@ static int _gpiod_get_value(const struct gpio_desc *desc) } /** - * __gpio_get_value() - return a gpio's value - * @gpio: gpio whose value will be returned - * Context: any + * gpiod_get_raw_value() - return a gpio's raw 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 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. */ -static int gpiod_get_value(const struct gpio_desc *desc) +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_value(desc); + return _gpiod_get_raw_value(desc); } +EXPORT_SYMBOL_GPL(gpiod_get_raw_value); -int __gpio_get_value(unsigned gpio) +/** + * 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) @@ -1937,9 +1909,8 @@ static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) } /* - * _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) @@ -1964,7 +1935,7 @@ static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) __func__, err); } -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; @@ -1979,62 +1950,70 @@ static void _gpiod_set_value(struct gpio_desc *desc, int 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. */ -static void gpiod_set_value(struct gpio_desc *desc, int value) +void gpiod_set_raw_value(struct gpio_desc *desc, int value) { - if (!desc) return; /* Should be using gpio_set_value_cansleep() */ WARN_ON(desc->chip->can_sleep); - _gpiod_set_value(desc, value); + _gpiod_set_raw_value(desc, value); } +EXPORT_SYMBOL_GPL(gpiod_set_raw_value); -void __gpio_set_value(unsigned gpio, int 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) { - 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); + 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. */ -static int gpiod_cansleep(const struct gpio_desc *desc) +int gpiod_cansleep(const struct gpio_desc *desc) { if (!desc) return 0; - /* only call this on GPIOs that are valid! */ return desc->chip->can_sleep; } - -int __gpio_cansleep(unsigned gpio) -{ - return gpiod_cansleep(gpio_to_desc(gpio)); -} -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; @@ -2045,45 +2024,92 @@ 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; } - -int __gpio_to_irq(unsigned gpio) -{ - return gpiod_to_irq(gpio_to_desc(gpio)); -} -EXPORT_SYMBOL_GPL(__gpio_to_irq); +EXPORT_SYMBOL_GPL(gpiod_to_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. */ - -static int gpiod_get_value_cansleep(const struct gpio_desc *desc) +int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) { might_sleep_if(extra_checks); if (!desc) return 0; - return _gpiod_get_value(desc); + 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) { - return gpiod_get_value_cansleep(gpio_to_desc(gpio)); + int value; + + might_sleep_if(extra_checks); + 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); -static void gpiod_set_value_cansleep(struct gpio_desc *desc, 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) { might_sleep_if(extra_checks); if (!desc) return; - _gpiod_set_value(desc, value); + _gpiod_set_raw_value(desc, value); } +EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); -void gpio_set_value_cansleep(unsigned gpio, 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) { - return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); + might_sleep_if(extra_checks); + 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); #ifdef CONFIG_DEBUG_FS diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index bde6469..725c997 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -10,6 +10,8 @@ #ifdef CONFIG_GPIOLIB #include +#include +#include /* Platforms may implement their GPIO interface with library code, * at a small performance cost for non-inlined operations and some @@ -49,122 +51,11 @@ struct module; struct device_node; struct gpio_desc; -/** - * struct gpio_chip - abstract a GPIO controller - * @label: for diagnostics - * @dev: optional device providing the GPIOs - * @owner: helps prevent removal of modules exporting active GPIOs - * @list: links gpio_chips together for traversal - * @request: optional hook for chip-specific activation, such as - * enabling module power and clock; may sleep - * @free: optional hook for chip-specific deactivation, such as - * disabling module power and clock; may sleep - * @get_direction: returns direction for signal "offset", 0=out, 1=in, - * (same as GPIOF_DIR_XXX), or negative error - * @direction_input: configures signal "offset" as input, or returns error - * @get: returns value for signal "offset"; for output signals this - * returns either the value actually sensed, or zero - * @direction_output: configures signal "offset" as output, or returns error - * @set_debounce: optional hook for setting debounce time for specified gpio in - * interrupt triggered gpio chips - * @set: assigns output value for signal "offset" - * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; - * implementation may not sleep - * @dbg_show: optional routine to show contents in debugfs; default code - * will be used when this is omitted, but custom code can show extra - * state (such as pullup/pulldown configuration). - * @base: identifies the first GPIO number handled by this chip; or, if - * negative during registration, requests dynamic ID allocation. - * @ngpio: the number of GPIOs handled by this controller; the last GPIO - * handled is (base + ngpio - 1). - * @desc: array of ngpio descriptors. Private. - * @can_sleep: flag must be set iff get()/set() methods sleep, as they - * must while accessing GPIO expander chips over I2C or SPI - * @names: if set, must be an array of strings to use as alternative - * names for the GPIOs in this chip. Any entry in the array - * may be NULL if there is no alias for the GPIO, however the - * array must be @ngpio entries long. A name can include a single printk - * format specifier for an unsigned int. It is substituted by the actual - * number of the gpio. - * - * A gpio_chip can help platforms abstract various sources of GPIOs so - * they can all be accessed through a common programing interface. - * Example sources would be SOC controllers, FPGAs, multifunction - * chips, dedicated GPIO expanders, and so on. - * - * Each chip controls a number of signals, identified in method calls - * by "offset" values in the range 0..(@ngpio - 1). When those signals - * are referenced through calls like gpio_get_value(gpio), the offset - * is calculated by subtracting @base from the gpio number. - */ -struct gpio_chip { - const char *label; - struct device *dev; - struct module *owner; - struct list_head list; - - int (*request)(struct gpio_chip *chip, - unsigned offset); - void (*free)(struct gpio_chip *chip, - unsigned offset); - int (*get_direction)(struct gpio_chip *chip, - unsigned offset); - int (*direction_input)(struct gpio_chip *chip, - unsigned offset); - int (*get)(struct gpio_chip *chip, - unsigned offset); - int (*direction_output)(struct gpio_chip *chip, - unsigned offset, int value); - int (*set_debounce)(struct gpio_chip *chip, - unsigned offset, unsigned debounce); - - void (*set)(struct gpio_chip *chip, - unsigned offset, int value); - - int (*to_irq)(struct gpio_chip *chip, - unsigned offset); - - void (*dbg_show)(struct seq_file *s, - struct gpio_chip *chip); - int base; - u16 ngpio; - struct gpio_desc *desc; - const char *const *names; - unsigned can_sleep:1; - unsigned exported:1; - -#if defined(CONFIG_OF_GPIO) - /* - * If CONFIG_OF is enabled, then all GPIO controllers described in the - * device tree automatically may have an OF translation - */ - struct device_node *of_node; - int of_gpio_n_cells; - int (*of_xlate)(struct gpio_chip *gc, - const struct of_phandle_args *gpiospec, u32 *flags); -#endif -#ifdef CONFIG_PINCTRL - /* - * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally - * describe the actual pin range which they serve in an SoC. This - * information would be used by pinctrl subsystem to configure - * corresponding pins for gpio usage. - */ - struct list_head pin_ranges; -#endif -}; - -extern const char *gpiochip_is_requested(struct gpio_chip *chip, - unsigned offset); -extern struct gpio_chip *gpio_to_chip(unsigned gpio); - -/* add/remove chips */ -extern int gpiochip_add(struct gpio_chip *chip); -extern int __must_check gpiochip_remove(struct gpio_chip *chip); -extern struct gpio_chip *gpiochip_find(void *data, - int (*match)(struct gpio_chip *chip, - void *data)); - +/* caller holds gpio_lock *OR* gpio is marked as requested */ +static inline struct gpio_chip *gpio_to_chip(unsigned gpio) +{ + return gpiod_to_chip(gpio_to_desc(gpio)); +} /* Always use the library code for GPIO management calls, * or when sleeping may be involved. @@ -172,43 +63,81 @@ extern struct gpio_chip *gpiochip_find(void *data, extern int gpio_request(unsigned gpio, const char *label); extern void gpio_free(unsigned gpio); -extern int gpio_direction_input(unsigned gpio); -extern int gpio_direction_output(unsigned gpio, int value); +static inline int gpio_direction_input(unsigned gpio) +{ + return gpiod_direction_input(gpio_to_desc(gpio)); +} +static inline int gpio_direction_output(unsigned gpio, int value) +{ + return gpiod_direction_output(gpio_to_desc(gpio), value); +} -extern int gpio_set_debounce(unsigned gpio, unsigned debounce); +static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return gpiod_set_debounce(gpio_to_desc(gpio), debounce); +} -extern int gpio_get_value_cansleep(unsigned gpio); -extern void gpio_set_value_cansleep(unsigned gpio, int value); +static inline int gpio_get_value_cansleep(unsigned gpio) +{ + return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); +} +static inline void gpio_set_value_cansleep(unsigned gpio, int value) +{ + return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); +} /* A platform's code may want to inline the I/O calls when * the GPIO is constant and refers to some always-present controller, * giving direct access to chip registers and tight bitbanging loops. */ -extern int __gpio_get_value(unsigned gpio); -extern void __gpio_set_value(unsigned gpio, int value); +static inline int __gpio_get_value(unsigned gpio) +{ + return gpiod_get_raw_value(gpio_to_desc(gpio)); +} +static inline void __gpio_set_value(unsigned gpio, int value) +{ + return gpiod_set_raw_value(gpio_to_desc(gpio), value); +} -extern int __gpio_cansleep(unsigned gpio); +static inline int __gpio_cansleep(unsigned gpio) +{ + return gpiod_cansleep(gpio_to_desc(gpio)); +} -extern int __gpio_to_irq(unsigned gpio); +static inline int __gpio_to_irq(unsigned gpio) +{ + return gpiod_to_irq(gpio_to_desc(gpio)); +} extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); -#ifdef CONFIG_GPIO_SYSFS - /* * A sysfs interface can be exported by individual drivers if they want, * but more typically is configured entirely from userspace. */ -extern int gpio_export(unsigned gpio, bool direction_may_change); -extern int gpio_export_link(struct device *dev, const char *name, - unsigned gpio); -extern int gpio_sysfs_set_active_low(unsigned gpio, int value); -extern void gpio_unexport(unsigned gpio); +static inline int gpio_export(unsigned gpio, bool direction_may_change) +{ + return gpiod_export(gpio_to_desc(gpio), direction_may_change); +} -#endif /* CONFIG_GPIO_SYSFS */ +static inline int gpio_export_link(struct device *dev, const char *name, + unsigned gpio) +{ + return gpiod_export_link(dev, name, gpio_to_desc(gpio)); +} + +static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); +} + +static inline void gpio_unexport(unsigned gpio) +{ + gpiod_unexport(gpio_to_desc(gpio)); +} #ifdef CONFIG_PINCTRL @@ -278,31 +207,4 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) #endif /* !CONFIG_GPIOLIB */ -#ifndef CONFIG_GPIO_SYSFS - -struct device; - -/* sysfs support is only available with gpiolib, where it's optional */ - -static inline int gpio_export(unsigned gpio, bool direction_may_change) -{ - return -ENOSYS; -} - -static inline int gpio_export_link(struct device *dev, const char *name, - unsigned gpio) -{ - return -ENOSYS; -} - -static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) -{ - return -ENOSYS; -} - -static inline void gpio_unexport(unsigned gpio) -{ -} -#endif /* CONFIG_GPIO_SYSFS */ - #endif /* _ASM_GENERIC_GPIO_H */ diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 552e3f4..95717df 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -16,14 +16,17 @@ #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) +/* Gpio pin is active-low */ +#define GPIOF_ACTIVE_LOW (1 << 2) + /* Gpio pin is open drain */ -#define GPIOF_OPEN_DRAIN (1 << 2) +#define GPIOF_OPEN_DRAIN (1 << 3) /* Gpio pin is open source */ -#define GPIOF_OPEN_SOURCE (1 << 3) +#define GPIOF_OPEN_SOURCE (1 << 4) -#define GPIOF_EXPORT (1 << 4) -#define GPIOF_EXPORT_CHANGEABLE (1 << 5) +#define GPIOF_EXPORT (1 << 5) +#define GPIOF_EXPORT_CHANGEABLE (1 << 6) #define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT) #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE) diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h new file mode 100644 index 0000000..2088eb5 --- /dev/null +++ b/include/linux/gpio/consumer.h @@ -0,0 +1,238 @@ +#ifndef __LINUX_GPIO_CONSUMER_H +#define __LINUX_GPIO_CONSUMER_H + +#include +#include + +#ifdef CONFIG_GPIOLIB + +struct device; +struct gpio_chip; + +/** + * Opaque descriptor for a GPIO. These are obtained using gpiod_get() and are + * preferable to the old integer-based handles. + * + * Contrary to integers, a pointer to a gpio_desc is guaranteed to be valid + * until the GPIO is released. + */ +struct gpio_desc; + +int gpiod_get_direction(const struct gpio_desc *desc); +int gpiod_direction_input(struct gpio_desc *desc); +int gpiod_direction_output(struct gpio_desc *desc, int value); + +/* Value get/set from non-sleeping context */ +int gpiod_get_value(const struct gpio_desc *desc); +void gpiod_set_value(struct gpio_desc *desc, int value); +int gpiod_get_raw_value(const struct gpio_desc *desc); +void gpiod_set_raw_value(struct gpio_desc *desc, int value); + +/* Value get/set from sleeping context */ +int gpiod_get_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); +int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc); +void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value); + +int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); + +int gpiod_is_active_low(const struct gpio_desc *desc); +int gpiod_cansleep(const struct gpio_desc *desc); + +int gpiod_to_irq(const struct gpio_desc *desc); + +/* Convert between the old gpio_ and new gpiod_ interfaces */ +struct gpio_desc *gpio_to_desc(unsigned gpio); +int desc_to_gpio(const struct gpio_desc *desc); +struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB */ + +static inline struct gpio_desc *__must_check gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline struct gpio_desc *__must_check gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void gpiod_put(struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline struct gpio_desc *__must_check devm_gpiod_get(struct device *dev, + const char *con_id) +{ + return ERR_PTR(-ENOSYS); +} +static inline +struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev, + const char *con_id, + unsigned int idx) +{ + return ERR_PTR(-ENOSYS); +} +static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) +{ + might_sleep(); + + /* GPIO can never have been requested */ + WARN_ON(1); +} + + +static inline int gpiod_get_direction(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_input(struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} +static inline int gpiod_direction_output(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + + +static inline int gpiod_get_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_get_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} +static inline int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, + int value) +{ + /* GPIO can never have been requested */ + WARN_ON(1); +} + +static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + +static inline int gpiod_is_active_low(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} +static inline int gpiod_cansleep(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return 0; +} + +static inline int gpiod_to_irq(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} + +static inline struct gpio_desc *gpio_to_desc(unsigned gpio) +{ + return ERR_PTR(-EINVAL); +} +static inline int desc_to_gpio(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -EINVAL; +} +static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return ERR_PTR(-ENODEV); +} + + +#endif /* CONFIG_GPIOLIB */ + +#if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS) + +int gpiod_export(struct gpio_desc *desc, bool direction_may_change); +int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc); +int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); +void gpiod_unexport(struct gpio_desc *desc); + +#else /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ + +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_GPIOLIB && CONFIG_GPIO_SYSFS */ + +#endif diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h new file mode 100644 index 0000000..77eef93 --- /dev/null +++ b/include/linux/gpio/driver.h @@ -0,0 +1,124 @@ +#ifndef __LINUX_GPIO_DRIVER_H +#define __LINUX_GPIO_DRIVER_H + +#include + +struct device; +struct gpio_desc; + +/** + * struct gpio_chip - abstract a GPIO controller + * @label: for diagnostics + * @dev: optional device providing the GPIOs + * @owner: helps prevent removal of modules exporting active GPIOs + * @list: links gpio_chips together for traversal + * @request: optional hook for chip-specific activation, such as + * enabling module power and clock; may sleep + * @free: optional hook for chip-specific deactivation, such as + * disabling module power and clock; may sleep + * @get_direction: returns direction for signal "offset", 0=out, 1=in, + * (same as GPIOF_DIR_XXX), or negative error + * @direction_input: configures signal "offset" as input, or returns error + * @direction_output: configures signal "offset" as output, or returns error + * @get: returns value for signal "offset"; for output signals this + * returns either the value actually sensed, or zero + * @set: assigns output value for signal "offset" + * @set_debounce: optional hook for setting debounce time for specified gpio in + * interrupt triggered gpio chips + * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; + * implementation may not sleep + * @dbg_show: optional routine to show contents in debugfs; default code + * will be used when this is omitted, but custom code can show extra + * state (such as pullup/pulldown configuration). + * @base: identifies the first GPIO number handled by this chip; or, if + * negative during registration, requests dynamic ID allocation. + * @ngpio: the number of GPIOs handled by this controller; the last GPIO + * handled is (base + ngpio - 1). + * @desc: array of ngpio descriptors. Private. + * @can_sleep: flag must be set iff get()/set() methods sleep, as they + * must while accessing GPIO expander chips over I2C or SPI + * @names: if set, must be an array of strings to use as alternative + * names for the GPIOs in this chip. Any entry in the array + * may be NULL if there is no alias for the GPIO, however the + * array must be @ngpio entries long. A name can include a single printk + * format specifier for an unsigned int. It is substituted by the actual + * number of the gpio. + * + * A gpio_chip can help platforms abstract various sources of GPIOs so + * they can all be accessed through a common programing interface. + * Example sources would be SOC controllers, FPGAs, multifunction + * chips, dedicated GPIO expanders, and so on. + * + * Each chip controls a number of signals, identified in method calls + * by "offset" values in the range 0..(@ngpio - 1). When those signals + * are referenced through calls like gpio_get_value(gpio), the offset + * is calculated by subtracting @base from the gpio number. + */ +struct gpio_chip { + const char *label; + struct device *dev; + struct module *owner; + struct list_head list; + + int (*request)(struct gpio_chip *chip, + unsigned offset); + void (*free)(struct gpio_chip *chip, + unsigned offset); + int (*get_direction)(struct gpio_chip *chip, + unsigned offset); + int (*direction_input)(struct gpio_chip *chip, + unsigned offset); + int (*direction_output)(struct gpio_chip *chip, + unsigned offset, int value); + int (*get)(struct gpio_chip *chip, + unsigned offset); + void (*set)(struct gpio_chip *chip, + unsigned offset, int value); + int (*set_debounce)(struct gpio_chip *chip, + unsigned offset, + unsigned debounce); + + int (*to_irq)(struct gpio_chip *chip, + unsigned offset); + + void (*dbg_show)(struct seq_file *s, + struct gpio_chip *chip); + int base; + u16 ngpio; + struct gpio_desc *desc; + const char *const *names; + unsigned can_sleep:1; + unsigned exported:1; + +#if defined(CONFIG_OF_GPIO) + /* + * If CONFIG_OF is enabled, then all GPIO controllers described in the + * device tree automatically may have an OF translation + */ + struct device_node *of_node; + int of_gpio_n_cells; + int (*of_xlate)(struct gpio_chip *gc, + const struct of_phandle_args *gpiospec, u32 *flags); +#endif +#ifdef CONFIG_PINCTRL + /* + * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally + * describe the actual pin range which they serve in an SoC. This + * information would be used by pinctrl subsystem to configure + * corresponding pins for gpio usage. + */ + struct list_head pin_ranges; +#endif +}; + +extern const char *gpiochip_is_requested(struct gpio_chip *chip, + unsigned offset); + +/* add/remove chips */ +extern int gpiochip_add(struct gpio_chip *chip); +extern int __must_check gpiochip_remove(struct gpio_chip *chip); +extern struct gpio_chip *gpiochip_find(void *data, + int (*match)(struct gpio_chip *chip, void *data)); + + +#endif -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/