Add export possibility to sysfs with given name in device tree. Rebased from older unapplyed patch: [PATCH] owrt: GPIO: add gpio_export_with_name.
Signed-off-by: Jiri Prchal <[email protected]> --- Documentation/devicetree/bindings/gpio/gpio.txt | 61 +++++++++++++++++++++++ drivers/gpio/gpiolib-of.c | 61 +++++++++++++++++++++++ drivers/gpio/gpiolib.c | 27 ++++++---- include/asm-generic/gpio.h | 6 ++- include/linux/gpio.h | 23 ++++++++- 5 files changed, 166 insertions(+), 12 deletions(-) diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index 6cec6ff..03c4ef5 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -117,3 +117,64 @@ Example: Here, a single GPIO controller has GPIOs 0..9 routed to pin controller pinctrl1's pins 20..29, and GPIOs 10..19 routed to pin controller pinctrl2's pins 50..59. + + +3) gpio-export +-------------- + +gpio-export will allow you to automatically export gpio + +required properties: +- compatible: Should be "gpio-export" + +in each child node will reprensent a gpio or if no name is specified +a list of gpio to export + +required properties: +- gpios: gpio to export + +optional properties: + - gpio-export,name: export name + - gpio-export,output: to set the as output with default value + if no present gpio as input + - pio-export,direction_may_change: boolean to allow the direction to be controllable + +Example: + + +gpio_export { + compatible = "gpio-export"; + #size-cells = <0>; + + in { + gpio-export,name = "in"; + gpios = <&pioC 20 0>; + }; + + out { + gpio-export,name = "out"; + gpio-export,output = <1>; + gpio-export,direction_may_change; + gpios = <&pioC 21 0>; + }; + + in_out { + gpio-export,name = "in_out"; + gpio-export,direction_may_change; + gpios = <&pioC 21 0>; + }; + + gpios_in { + gpios = <&pioB 0 0 + &pioB 3 0 + &pioC 4 0>; + gpio-export,direction_may_change; + }; + + gpios_out { + gpios = <&pioB 1 0 + &pioB 2 0 + &pioC 3 0>; + gpio-export,output = <1>; + }; +}; \ No newline at end of file diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 0dfaf20..1a43d8b 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -21,6 +21,8 @@ #include <linux/of_gpio.h> #include <linux/pinctrl/pinctrl.h> #include <linux/slab.h> +#include <linux/init.h> +#include <linux/platform_device.h> /* Private data structure for of_gpiochip_find_and_xlate */ struct gg_data { @@ -243,3 +245,62 @@ void of_gpiochip_remove(struct gpio_chip *chip) if (chip->of_node) of_node_put(chip->of_node); } + +static struct of_device_id gpio_export_ids[] = { + { .compatible = "gpio-export" }, + { /* sentinel */ } +}; + +static int __init of_gpio_export_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device_node *cnp; + u32 val; + int nb = 0; + + for_each_child_of_node(np, cnp) { + const char *name = NULL; + int gpio; + bool dmc; + int max_gpio = 1; + int i; + + of_property_read_string(cnp, "gpio-export,name", &name); + + if (!name) + max_gpio = of_gpio_count(cnp); + + for (i = 0; i < max_gpio; i++) { + gpio = of_get_gpio(cnp, i); + if (devm_gpio_request(&pdev->dev, gpio, name ? name : of_node_full_name(np))) + continue; + + if (!of_property_read_u32(cnp, "gpio-export,output", &val)) + gpio_direction_output(gpio, val); + else + gpio_direction_input(gpio); + + dmc = of_property_read_bool(np, "gpio-export,direction_may_change"); + gpio_export_with_name(gpio, dmc, name); + nb++; + } + } + + dev_info(&pdev->dev, "%d gpio(s) exported\n", nb); + + return 0; +} + +static struct platform_driver gpio_export_driver = { + .driver = { + .name = "gpio-export", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(gpio_export_ids), + }, +}; + +static int __init of_gpio_export_init(void) +{ + return platform_driver_probe(&gpio_export_driver, of_gpio_export_probe); +} +device_initcall(of_gpio_export_init); \ No newline at end of file diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 86ef346..c7494d1 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -96,7 +96,8 @@ 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_with_name(struct gpio_desc *desc, + bool direction_may_change, const char *name); 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); @@ -674,7 +675,7 @@ static ssize_t export_store(struct class *class, status = -ENODEV; goto done; } - status = gpiod_export(desc, true); + status = gpiod_export_with_name(desc, true, NULL); if (status < 0) gpiod_free(desc); else @@ -736,9 +737,10 @@ static struct class gpio_class = { /** - * gpio_export - export a GPIO through sysfs + * gpiod_export_with_name - export a GPIO through sysfs * @gpio: gpio to make available, already requested * @direction_may_change: true if userspace may change gpio direction + * @name: gpio name * Context: arch_initcall or later * * When drivers want to make a GPIO accessible to userspace after they @@ -750,7 +752,8 @@ 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_with_name(struct gpio_desc *desc, bool direction_may_change, + const char *name) { unsigned long flags; int status; @@ -788,7 +791,9 @@ static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) spin_unlock_irqrestore(&gpio_lock, flags); offset = gpio_chip_hwgpio(desc); - if (desc->chip->names && desc->chip->names[offset]) + if (name) + ioname = name; + else if (desc->chip->names && desc->chip->names[offset]) ioname = desc->chip->names[offset]; dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), @@ -829,11 +834,13 @@ fail_unlock: return status; } -int gpio_export(unsigned gpio, bool direction_may_change) +int gpio_export_with_name(unsigned gpio, bool direction_may_change, + const char *name) { - return gpiod_export(gpio_to_desc(gpio), direction_may_change); + return gpiod_export_with_name(gpio_to_desc(gpio), direction_may_change, + name); } -EXPORT_SYMBOL_GPL(gpio_export); +EXPORT_SYMBOL_GPL(gpio_export_with_name); static int match_export(struct device *dev, const void *data) { @@ -1531,7 +1538,9 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) goto free_gpio; if (flags & GPIOF_EXPORT) { - err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); + err = gpiod_export_with_name(desc, + flags & GPIOF_EXPORT_CHANGEABLE, + NULL); if (err) goto free_gpio; } diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index bde6469..d0970e3 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -202,7 +202,8 @@ extern void gpio_free_array(const struct gpio *array, size_t num); * 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_with_name(unsigned gpio, bool direction_may_change, + const char *name); extern int gpio_export_link(struct device *dev, const char *name, unsigned gpio); extern int gpio_sysfs_set_active_low(unsigned gpio, int value); @@ -284,7 +285,8 @@ struct device; /* sysfs support is only available with gpiolib, where it's optional */ -static inline int gpio_export(unsigned gpio, bool direction_may_change) +static inline int gpio_export_with_name(unsigned gpio, bool direction_may_change, + const char *name) { return -ENOSYS; } diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 552e3f4..12a6cd2 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -169,7 +169,8 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value) WARN_ON(1); } -static inline int gpio_export(unsigned gpio, bool direction_may_change) +static inline int gpio_export_with_name(unsigned gpio, bool direction_may_change, + const char *name) { /* GPIO can never have been requested or set as {in,out}put */ WARN_ON(1); @@ -236,4 +237,24 @@ int devm_gpio_request_one(struct device *dev, unsigned gpio, unsigned long flags, const char *label); void devm_gpio_free(struct device *dev, unsigned int gpio); +/** + * gpio_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. + */ +static inline int gpio_export(unsigned gpio,bool direction_may_change) +{ + return gpio_export_with_name(gpio, direction_may_change, NULL); +} + #endif /* __LINUX_GPIO_H */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
