From 959bc7b22bd25a3a907fbb9b26a1d0cbdf98ef40 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Tue, 7 Nov 2017 19:15:59 +0100 Subject: gpio: Automatically add lockdep keys In order to avoid lockdep boilerplate in individual drivers, turn the gpiochip_add_data() function into a macro that creates a unique class key for each driver. Note that this has the slight disadvantage of adding a key for each driver registered with the system. However, these keys are 8 bytes in size, which is negligible and a small price to pay for generic infrastructure. Suggested-by: Grygorii Strashko Signed-off-by: Thierry Reding Acked-by: Grygorii Strashko [renane __gpiochip_add_data() to gpiochip_add_data_with_key] Signed-off-by: Linus Walleij --- include/linux/gpio/driver.h | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index a77d4ada060c..8dd282c5167a 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -321,7 +321,41 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset); /* add/remove chips */ -extern int gpiochip_add_data(struct gpio_chip *chip, void *data); +extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, + struct lock_class_key *lock_key); + +/** + * gpiochip_add_data() - register a gpio_chip + * @chip: the chip to register, with chip->base initialized + * @data: driver-private data associated with this chip + * + * Context: potentially before irqs will work + * + * When gpiochip_add_data() is called very early during boot, so that GPIOs + * can be freely used, the chip->parent device must be registered before + * the gpio framework's arch_initcall(). Otherwise sysfs initialization + * for GPIOs will fail rudely. + * + * gpiochip_add_data() must only be called after gpiolib initialization, + * ie after core_initcall(). + * + * If chip->base is negative, this requests dynamic assignment of + * a range of valid GPIOs. + * + * Returns: + * A negative errno if the chip can't be registered, such as because the + * chip->base is invalid or already associated with a different chip. + * Otherwise it returns zero as a success code. + */ +#ifdef CONFIG_LOCKDEP +#define gpiochip_add_data(chip, data) ({ \ + static struct lock_class_key key; \ + gpiochip_add_data_with_key(chip, data, &key); \ + }) +#else +#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL) +#endif + static inline int gpiochip_add(struct gpio_chip *chip) { return gpiochip_add_data(chip, NULL); -- cgit v1.2.3-71-gd317