From b08ea35a3296ee25c4cb53a977b752266dafa2c2 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 3 Dec 2015 15:14:13 +0100 Subject: [PATCH] gpio: add a data pointer to gpio_chip This adds a void * pointer to gpio_chip so that driver can assign and retrieve some states. This is done to get rid of container_of() calls for gpio_chips embedded inside state containers, so we can remove the need to have the gpio_chip or later (planned) struct gpio_device be dynamically allocated at registration time, so that its struct device can be properly reference counted and not bound to its parent device (e.g. a platform_device) but instead live on after unregistration if it is opened by e.g. a char device or sysfs. The data is added with the new function gpiochip_add_data() and for compatibility we add static inline wrapper function gpiochip_add() that will call gpiochip_add_data() with NULL as argument. The latter will be removed once we have exorcised gpiochip_add() from the kernel. gpiochip_get_data() is added as a static inline accessor for drivers to quickly get their data out. Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 10 ++++++---- include/linux/gpio/driver.h | 14 +++++++++++++- 2 files changed, 19 insertions(+), 5 deletions(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -280,7 +280,7 @@ static int gpiochip_set_desc_names(struc } /** - * gpiochip_add() - register a gpio_chip + * gpiochip_add_data() - register a gpio_chip * @chip: the chip to register, with chip->base initialized * Context: potentially before irqs will work * @@ -288,7 +288,7 @@ static int gpiochip_set_desc_names(struc * because the chip->base is invalid or already associated with a * different chip. Otherwise it returns zero as a success code. * - * When gpiochip_add() is called very early during boot, so that GPIOs + * When gpiochip_add_data() is called very early during boot, so that GPIOs * can be freely used, the chip->dev device must be registered before * the gpio framework's arch_initcall(). Otherwise sysfs initialization * for GPIOs will fail rudely. @@ -296,7 +296,7 @@ static int gpiochip_set_desc_names(struc * If chip->base is negative, this requests dynamic assignment of * a range of valid GPIOs. */ -int gpiochip_add(struct gpio_chip *chip) +int gpiochip_add_data(struct gpio_chip *chip, void *data) { unsigned long flags; int status = 0; @@ -308,6 +308,8 @@ int gpiochip_add(struct gpio_chip *chip) if (!descs) return -ENOMEM; + chip->data = data; + spin_lock_irqsave(&gpio_lock, flags); if (base < 0) { @@ -389,7 +391,7 @@ err_free_descs: chip->label ? : "generic"); return status; } -EXPORT_SYMBOL_GPL(gpiochip_add); +EXPORT_SYMBOL_GPL(gpiochip_add_data); /** * gpiochip_remove() - unregister a gpio_chip --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -23,6 +23,7 @@ struct seq_file; * @dev: optional device providing the GPIOs * @cdev: class device used by sysfs interface (may be NULL) * @owner: helps prevent removal of modules exporting active GPIOs + * @data: per-instance data assigned by the driver * @list: links gpio_chips together for traversal * @request: optional hook for chip-specific activation, such as * enabling module power and clock; may sleep @@ -92,6 +93,7 @@ struct gpio_chip { struct device *dev; struct device *cdev; struct module *owner; + void *data; struct list_head list; int (*request)(struct gpio_chip *chip, @@ -166,7 +168,11 @@ extern const char *gpiochip_is_requested unsigned offset); /* add/remove chips */ -extern int gpiochip_add(struct gpio_chip *chip); +extern int gpiochip_add_data(struct gpio_chip *chip, void *data); +static inline int gpiochip_add(struct gpio_chip *chip) +{ + return gpiochip_add_data(chip, NULL); +} extern void gpiochip_remove(struct gpio_chip *chip); extern struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)); @@ -175,6 +181,12 @@ extern struct gpio_chip *gpiochip_find(v int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset); void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); +/* get driver data */ +static inline void *gpiochip_get_data(struct gpio_chip *chip) +{ + return chip->data; +} + struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc); #ifdef CONFIG_GPIOLIB_IRQCHIP