From cc809a441d8f2924f785eb863dfa6aef47a25b0b Mon Sep 17 00:00:00 2001 From: John Crispin Date: Tue, 12 Aug 2014 20:49:27 +0200 Subject: [PATCH 30/36] GPIO: add named gpio exports Signed-off-by: John Crispin --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include #include "gpiolib.h" #include "gpiolib-of.h" @@ -1030,3 +1032,100 @@ void of_gpio_dev_init(struct gpio_chip * else gc->of_node = gdev->dev.of_node; } + +#ifdef CONFIG_GPIO_SYSFS + +static struct of_device_id gpio_export_ids[] = { + { .compatible = "gpio-export" }, + { /* sentinel */ } +}; + +static int 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++) { + struct gpio_desc *desc; + unsigned flags = 0; + enum of_gpio_flags of_flags; + + gpio = of_get_gpio_flags(cnp, i, &of_flags); + if (!gpio_is_valid(gpio)) + return gpio; + + if (of_flags & OF_GPIO_ACTIVE_LOW) + flags |= GPIOF_ACTIVE_LOW; + + if (!of_property_read_u32(cnp, "gpio-export,output", &val)) { + if (of_flags & OF_GPIO_SINGLE_ENDED) { + /* + * As gpiod_direction_output_raw() is used, we + * need to emulate open drain or open source here. + */ + if (of_flags & OF_GPIO_OPEN_DRAIN) { + flags |= GPIOF_OPEN_DRAIN; + flags |= val ? GPIOF_IN : GPIOF_OUT_INIT_LOW; + } else { + flags |= GPIOF_OPEN_SOURCE; + flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_IN; + } + } else { + flags |= val ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; + } + } else { + flags |= GPIOF_IN; + } + + if (devm_gpio_request_one(&pdev->dev, gpio, flags, name ? name : of_node_full_name(np))) + continue; + + /* + * When emulating open-source or open-drain functionalities by not + * actively driving the line (setting mode to input) we still need to + * set the IS_OUT flag or otherwise we won't be able to set the line + * value anymore. + */ + if ((flags & GPIOF_IN) && + ((flags & GPIOF_OPEN_DRAIN) || (flags & GPIOF_OPEN_SOURCE))) { + desc = gpio_to_desc(gpio); + set_bit(FLAG_IS_OUT, &desc->flags); + } + + dmc = of_property_read_bool(cnp, "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), + }, + .probe = of_gpio_export_probe, +}; + +module_platform_driver(gpio_export_driver); + +#endif --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -125,6 +125,12 @@ static inline int gpio_export(unsigned g return gpiod_export(gpio_to_desc(gpio), direction_may_change); } +int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name); +static inline int gpio_export_with_name(unsigned gpio, bool direction_may_change, const char *name) +{ + return __gpiod_export(gpio_to_desc(gpio), direction_may_change, name); +} + static inline int gpio_export_link(struct device *dev, const char *name, unsigned gpio) { --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -715,6 +715,7 @@ static inline struct gpio_desc *acpi_get #if IS_ENABLED(CONFIG_GPIOLIB) && IS_ENABLED(CONFIG_GPIO_SYSFS) +int _gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name); 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); @@ -722,6 +723,13 @@ void gpiod_unexport(struct gpio_desc *de #else /* CONFIG_GPIOLIB && CONFIG_GPIO_SYSFS */ +static inline int _gpiod_export(struct gpio_desc *desc, + bool direction_may_change, + const char *name) +{ + return -ENOSYS; +} + static inline int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -544,7 +544,7 @@ static struct class gpio_class = { * * Returns zero on success, else an error. */ -int gpiod_export(struct gpio_desc *desc, bool direction_may_change) +int __gpiod_export(struct gpio_desc *desc, bool direction_may_change, const char *name) { struct gpio_chip *chip; struct gpio_device *gdev; @@ -606,6 +606,8 @@ int gpiod_export(struct gpio_desc *desc, offset = gpio_chip_hwgpio(desc); if (chip->names && chip->names[offset]) ioname = chip->names[offset]; + if (name) + ioname = name; dev = device_create_with_groups(&gpio_class, &gdev->dev, MKDEV(0, 0), data, gpio_groups, @@ -627,6 +629,12 @@ err_unlock: gpiod_dbg(desc, "%s: status %d\n", __func__, status); return status; } +EXPORT_SYMBOL_GPL(__gpiod_export); + +int gpiod_export(struct gpio_desc *desc, bool direction_may_change) +{ + return __gpiod_export(desc, direction_may_change, NULL); +} EXPORT_SYMBOL_GPL(gpiod_export); static int match_export(struct device *dev, const void *desc)