From 6c0b4e6c85d085bd92966bc2b8da73e2d7f35929 Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Sun, 3 Feb 2013 01:29:30 +0900 Subject: [PATCH] gpiolib: let gpio_chip reference its descriptors Add a pointer to the gpio_chip structure that references the array of GPIO descriptors belonging to the chip, and update gpiolib code to use this pointer instead of the global gpio_desc[] array. This is another step towards the removal of the gpio_desc[] global array. Signed-off-by: Alexandre Courbot Reviewed-by: Linus Walleij Signed-off-by: Grant Likely --- drivers/gpio/gpiolib.c | 39 ++++++++++++++++++++++---------------- include/asm-generic/gpio.h | 3 +++ 2 files changed, 26 insertions(+), 16 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 866431f674c..5050693dcc3 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -72,6 +72,8 @@ struct gpio_desc { }; static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; +#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) + static LIST_HEAD(gpio_chips); #ifdef CONFIG_GPIO_SYSFS @@ -112,7 +114,7 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) */ static int gpio_chip_hwgpio(const struct gpio_desc *desc) { - return (desc - &gpio_desc[0]) - desc->chip->base; + return desc - &desc->chip->desc[0]; } /** @@ -133,7 +135,7 @@ static struct gpio_desc *gpio_to_desc(unsigned gpio) */ static int desc_to_gpio(const struct gpio_desc *desc) { - return desc - &gpio_desc[0]; + return desc->chip->base + gpio_chip_hwgpio(desc); } @@ -1007,9 +1009,9 @@ static int gpiochip_export(struct gpio_chip *chip) unsigned gpio; spin_lock_irqsave(&gpio_lock, flags); - gpio = chip->base; - while (gpio_desc[gpio].chip == chip) - gpio_desc[gpio++].chip = NULL; + gpio = 0; + while (gpio < chip->ngpio) + chip->desc[gpio++].chip = NULL; spin_unlock_irqrestore(&gpio_lock, flags); pr_debug("%s: chip %s status %d\n", __func__, @@ -1186,8 +1188,11 @@ int gpiochip_add(struct gpio_chip *chip) status = gpiochip_add_to_list(chip); if (status == 0) { - for (id = base; id < base + chip->ngpio; id++) { - gpio_desc[id].chip = chip; + chip->desc = &gpio_desc[chip->base]; + + for (id = 0; id < chip->ngpio; id++) { + struct gpio_desc *desc = &chip->desc[id]; + desc->chip = chip; /* REVISIT: most hardware initializes GPIOs as * inputs (often with pullups enabled) so power @@ -1196,7 +1201,7 @@ int gpiochip_add(struct gpio_chip *chip) * and in case chip->get_direction is not set, * we may expose the wrong direction in sysfs. */ - gpio_desc[id].flags = !chip->direction_input + desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0; } @@ -1249,15 +1254,15 @@ int gpiochip_remove(struct gpio_chip *chip) gpiochip_remove_pin_ranges(chip); of_gpiochip_remove(chip); - for (id = chip->base; id < chip->base + chip->ngpio; id++) { - if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) { + for (id = 0; id < chip->ngpio; id++) { + if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) { status = -EBUSY; break; } } if (status == 0) { - for (id = chip->base; id < chip->base + chip->ngpio; id++) - gpio_desc[id].chip = NULL; + for (id = 0; id < chip->ngpio; id++) + chip->desc[id].chip = NULL; list_del(&chip->list); } @@ -1582,11 +1587,13 @@ EXPORT_SYMBOL_GPL(gpio_free_array); */ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) { - unsigned gpio = chip->base + offset; - struct gpio_desc *desc = &gpio_desc[gpio]; + struct gpio_desc *desc; - if (!gpio_is_valid(gpio) || desc->chip != chip) + if (!GPIO_OFFSET_VALID(chip, offset)) return NULL; + + desc = &chip->desc[offset]; + if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) return NULL; #ifdef CONFIG_DEBUG_FS @@ -2025,7 +2032,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) { unsigned i; unsigned gpio = chip->base; - struct gpio_desc *gdesc = &gpio_desc[gpio]; + struct gpio_desc *gdesc = &chip->desc[0]; int is_out; for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h index b562f95cdc2..bde646995d1 100644 --- a/include/asm-generic/gpio.h +++ b/include/asm-generic/gpio.h @@ -47,6 +47,7 @@ struct gpio; struct seq_file; struct module; struct device_node; +struct gpio_desc; /** * struct gpio_chip - abstract a GPIO controller @@ -76,6 +77,7 @@ struct device_node; * 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 @@ -126,6 +128,7 @@ struct gpio_chip { struct gpio_chip *chip); int base; u16 ngpio; + struct gpio_desc *desc; const char *const *names; unsigned can_sleep:1; unsigned exported:1;