diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 759 |
1 files changed, 451 insertions, 308 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5359ca78130..4828fe7c66c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3,6 +3,7 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/spinlock.h> +#include <linux/list.h> #include <linux/device.h> #include <linux/err.h> #include <linux/debugfs.h> @@ -52,14 +53,13 @@ struct gpio_desc { /* flag symbols are bit numbers */ #define FLAG_REQUESTED 0 #define FLAG_IS_OUT 1 -#define FLAG_RESERVED 2 -#define FLAG_EXPORT 3 /* protected by sysfs_lock */ -#define FLAG_SYSFS 4 /* exported via /sys/class/gpio/control */ -#define FLAG_TRIG_FALL 5 /* trigger on falling edge */ -#define FLAG_TRIG_RISE 6 /* trigger on rising edge */ -#define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ -#define FLAG_OPEN_DRAIN 8 /* Gpio is open drain type */ -#define FLAG_OPEN_SOURCE 9 /* Gpio is open source type */ +#define FLAG_EXPORT 2 /* protected by sysfs_lock */ +#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ +#define FLAG_TRIG_FALL 4 /* trigger on falling edge */ +#define FLAG_TRIG_RISE 5 /* trigger on rising edge */ +#define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */ +#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ +#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ #define ID_SHIFT 16 /* add new flags before this one */ @@ -72,10 +72,36 @@ 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 static DEFINE_IDR(dirent_idr); #endif +/* + * Internal gpiod_* API using descriptors instead of the integer namespace. + * Most of this should eventually go public. + */ +static int gpiod_request(struct gpio_desc *desc, const char *label); +static void gpiod_free(struct gpio_desc *desc); +static int gpiod_direction_input(struct gpio_desc *desc); +static int gpiod_direction_output(struct gpio_desc *desc, int value); +static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); +static int gpiod_get_value_cansleep(struct gpio_desc *desc); +static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value); +static int gpiod_get_value(struct gpio_desc *desc); +static void gpiod_set_value(struct gpio_desc *desc, int value); +static int gpiod_cansleep(struct gpio_desc *desc); +static int gpiod_to_irq(struct gpio_desc *desc); +static int gpiod_export(struct gpio_desc *desc, bool direction_may_change); +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); +static void gpiod_unexport(struct gpio_desc *desc); + + static inline void desc_set_label(struct gpio_desc *d, const char *label) { #ifdef CONFIG_DEBUG_FS @@ -83,6 +109,36 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) #endif } +/* + * Return the GPIO number of the passed descriptor relative to its chip + */ +static int gpio_chip_hwgpio(const struct gpio_desc *desc) +{ + return desc - &desc->chip->desc[0]; +} + +/** + * Convert a GPIO number to its descriptor + */ +static struct gpio_desc *gpio_to_desc(unsigned gpio) +{ + if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio)) + return NULL; + else + return &gpio_desc[gpio]; +} + +/** + * Convert a GPIO descriptor to the integer namespace. + * This should disappear in the future but is needed since we still + * use GPIO numbers for error messages and sysfs nodes + */ +static int desc_to_gpio(const struct gpio_desc *desc) +{ + return desc->chip->base + gpio_chip_hwgpio(desc); +} + + /* Warn when drivers omit gpio_request() calls -- legal but ill-advised * when setting direction, and otherwise illegal. Until board setup code * and drivers use explicit requests everywhere (which won't happen when @@ -94,10 +150,10 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) * only "legal" in the sense that (old) code using it won't break yet, * but instead only triggers a WARN() stack dump. */ -static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) +static int gpio_ensure_requested(struct gpio_desc *desc) { const struct gpio_chip *chip = desc->chip; - const int gpio = chip->base + offset; + const int gpio = desc_to_gpio(desc); if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0, "autorequest GPIO-%d\n", gpio)) { @@ -116,95 +172,54 @@ static int gpio_ensure_requested(struct gpio_desc *desc, unsigned offset) } /* caller holds gpio_lock *OR* gpio is marked as requested */ +static struct gpio_chip *gpiod_to_chip(struct gpio_desc *desc) +{ + return desc->chip; +} + struct gpio_chip *gpio_to_chip(unsigned gpio) { - return gpio_desc[gpio].chip; + return gpiod_to_chip(gpio_to_desc(gpio)); } /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) { - int i; - int spare = 0; - int base = -ENOSPC; - - for (i = ARCH_NR_GPIOS - 1; i >= 0 ; i--) { - struct gpio_desc *desc = &gpio_desc[i]; - struct gpio_chip *chip = desc->chip; + struct gpio_chip *chip; + int base = ARCH_NR_GPIOS - ngpio; - if (!chip && !test_bit(FLAG_RESERVED, &desc->flags)) { - spare++; - if (spare == ngpio) { - base = i; - break; - } - } else { - spare = 0; - if (chip) - i -= chip->ngpio - 1; - } + list_for_each_entry_reverse(chip, &gpio_chips, list) { + /* found a free space? */ + if (chip->base + chip->ngpio <= base) + break; + else + /* nope, check the space right before the chip */ + base = chip->base - ngpio; } - if (gpio_is_valid(base)) + if (gpio_is_valid(base)) { pr_debug("%s: found new base at %d\n", __func__, base); - return base; -} - -/** - * gpiochip_reserve() - reserve range of gpios to use with platform code only - * @start: starting gpio number - * @ngpio: number of gpios to reserve - * Context: platform init, potentially before irqs or kmalloc will work - * - * Returns a negative errno if any gpio within the range is already reserved - * or registered, else returns zero as a success code. Use this function - * to mark a range of gpios as unavailable for dynamic gpio number allocation, - * for example because its driver support is not yet loaded. - */ -int __init gpiochip_reserve(int start, int ngpio) -{ - int ret = 0; - unsigned long flags; - int i; - - if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1)) - return -EINVAL; - - spin_lock_irqsave(&gpio_lock, flags); - - for (i = start; i < start + ngpio; i++) { - struct gpio_desc *desc = &gpio_desc[i]; - - if (desc->chip || test_bit(FLAG_RESERVED, &desc->flags)) { - ret = -EBUSY; - goto err; - } - - set_bit(FLAG_RESERVED, &desc->flags); + return base; + } else { + pr_err("%s: cannot find free range\n", __func__); + return -ENOSPC; } - - pr_debug("%s: reserved gpios from %d to %d\n", - __func__, start, start + ngpio - 1); -err: - spin_unlock_irqrestore(&gpio_lock, flags); - - return ret; } /* caller ensures gpio is valid and requested, chip->get_direction may sleep */ -static int gpio_get_direction(unsigned gpio) +static int gpiod_get_direction(struct gpio_desc *desc) { struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; + unsigned offset; int status = -EINVAL; - chip = gpio_to_chip(gpio); - gpio -= chip->base; + chip = gpiod_to_chip(desc); + offset = gpio_chip_hwgpio(desc); if (!chip->get_direction) return status; - status = chip->get_direction(chip, gpio); + status = chip->get_direction(chip, offset); if (status > 0) { /* GPIOF_DIR_IN, or other positive */ status = 1; @@ -248,19 +263,19 @@ static DEFINE_MUTEX(sysfs_lock); static ssize_t gpio_direction_show(struct device *dev, struct device_attribute *attr, char *buf) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); - if (!test_bit(FLAG_EXPORT, &desc->flags)) + if (!test_bit(FLAG_EXPORT, &desc->flags)) { status = -EIO; - else - gpio_get_direction(gpio); + } else { + gpiod_get_direction(desc); status = sprintf(buf, "%s\n", test_bit(FLAG_IS_OUT, &desc->flags) ? "out" : "in"); + } mutex_unlock(&sysfs_lock); return status; @@ -269,8 +284,7 @@ static ssize_t gpio_direction_show(struct device *dev, static ssize_t gpio_direction_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); @@ -278,11 +292,11 @@ static ssize_t gpio_direction_store(struct device *dev, if (!test_bit(FLAG_EXPORT, &desc->flags)) status = -EIO; else if (sysfs_streq(buf, "high")) - status = gpio_direction_output(gpio, 1); + status = gpiod_direction_output(desc, 1); else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low")) - status = gpio_direction_output(gpio, 0); + status = gpiod_direction_output(desc, 0); else if (sysfs_streq(buf, "in")) - status = gpio_direction_input(gpio); + status = gpiod_direction_input(desc); else status = -EINVAL; @@ -296,8 +310,7 @@ static /* const */ DEVICE_ATTR(direction, 0644, static ssize_t gpio_value_show(struct device *dev, struct device_attribute *attr, char *buf) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); @@ -307,7 +320,7 @@ static ssize_t gpio_value_show(struct device *dev, } else { int value; - value = !!gpio_get_value_cansleep(gpio); + value = !!gpiod_get_value_cansleep(desc); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; @@ -321,8 +334,7 @@ static ssize_t gpio_value_show(struct device *dev, static ssize_t gpio_value_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { - const struct gpio_desc *desc = dev_get_drvdata(dev); - unsigned gpio = desc - gpio_desc; + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); @@ -338,7 +350,7 @@ static ssize_t gpio_value_store(struct device *dev, if (status == 0) { if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; - gpio_set_value_cansleep(gpio, value != 0); + gpiod_set_value_cansleep(desc, value != 0); status = size; } } @@ -368,7 +380,7 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags) return 0; - irq = gpio_to_irq(desc - gpio_desc); + irq = gpiod_to_irq(desc); if (irq < 0) return -EIO; @@ -638,29 +650,32 @@ static ssize_t export_store(struct class *class, struct class_attribute *attr, const char *buf, size_t len) { - long gpio; - int status; + long gpio; + struct gpio_desc *desc; + int status; status = strict_strtol(buf, 0, &gpio); if (status < 0) goto done; + desc = gpio_to_desc(gpio); + /* No extra locking here; FLAG_SYSFS just signifies that the * request and export were done by on behalf of userspace, so * they may be undone on its behalf too. */ - status = gpio_request(gpio, "sysfs"); + status = gpiod_request(desc, "sysfs"); if (status < 0) { if (status == -EPROBE_DEFER) status = -ENODEV; goto done; } - status = gpio_export(gpio, true); + status = gpiod_export(desc, true); if (status < 0) - gpio_free(gpio); + gpiod_free(desc); else - set_bit(FLAG_SYSFS, &gpio_desc[gpio].flags); + set_bit(FLAG_SYSFS, &desc->flags); done: if (status) @@ -672,8 +687,9 @@ static ssize_t unexport_store(struct class *class, struct class_attribute *attr, const char *buf, size_t len) { - long gpio; - int status; + long gpio; + struct gpio_desc *desc; + int status; status = strict_strtol(buf, 0, &gpio); if (status < 0) @@ -681,17 +697,18 @@ static ssize_t unexport_store(struct class *class, status = -EINVAL; + desc = gpio_to_desc(gpio); /* reject bogus commands (gpio_unexport ignores them) */ - if (!gpio_is_valid(gpio)) + if (!desc) goto done; /* No extra locking here; FLAG_SYSFS just signifies that the * request and export were done by on behalf of userspace, so * they may be undone on its behalf too. */ - if (test_and_clear_bit(FLAG_SYSFS, &gpio_desc[gpio].flags)) { + if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) { status = 0; - gpio_free(gpio); + gpiod_free(desc); } done: if (status) @@ -728,13 +745,13 @@ static struct class gpio_class = { * * Returns zero on success, else an error. */ -int gpio_export(unsigned gpio, bool direction_may_change) +static int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { unsigned long flags; - struct gpio_desc *desc; int status; const char *ioname = NULL; struct device *dev; + int offset; /* can't export until sysfs is available ... */ if (!gpio_class.p) { @@ -742,20 +759,19 @@ int gpio_export(unsigned gpio, bool direction_may_change) return -ENOENT; } - if (!gpio_is_valid(gpio)) { - pr_debug("%s: gpio %d is not valid\n", __func__, gpio); + if (!desc) { + pr_debug("%s: invalid gpio descriptor\n", __func__); return -EINVAL; } mutex_lock(&sysfs_lock); spin_lock_irqsave(&gpio_lock, flags); - desc = &gpio_desc[gpio]; if (!test_bit(FLAG_REQUESTED, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags)) { spin_unlock_irqrestore(&gpio_lock, flags); pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n", - __func__, gpio, + __func__, desc_to_gpio(desc), test_bit(FLAG_REQUESTED, &desc->flags), test_bit(FLAG_EXPORT, &desc->flags)); status = -EPERM; @@ -766,11 +782,13 @@ int gpio_export(unsigned gpio, bool direction_may_change) direction_may_change = false; spin_unlock_irqrestore(&gpio_lock, flags); - if (desc->chip->names && desc->chip->names[gpio - desc->chip->base]) - ioname = desc->chip->names[gpio - desc->chip->base]; + offset = gpio_chip_hwgpio(desc); + if (desc->chip->names && desc->chip->names[offset]) + ioname = desc->chip->names[offset]; dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0), - desc, ioname ? ioname : "gpio%u", gpio); + desc, ioname ? ioname : "gpio%u", + desc_to_gpio(desc)); if (IS_ERR(dev)) { status = PTR_ERR(dev); goto fail_unlock; @@ -786,7 +804,7 @@ int gpio_export(unsigned gpio, bool direction_may_change) goto fail_unregister_device; } - if (gpio_to_irq(gpio) >= 0 && (direction_may_change || + if (gpiod_to_irq(desc) >= 0 && (direction_may_change || !test_bit(FLAG_IS_OUT, &desc->flags))) { status = device_create_file(dev, &dev_attr_edge); if (status) @@ -801,9 +819,15 @@ fail_unregister_device: device_unregister(dev); fail_unlock: mutex_unlock(&sysfs_lock); - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), + status); return status; } + +int gpio_export(unsigned gpio, bool direction_may_change) +{ + return gpiod_export(gpio_to_desc(gpio), direction_may_change); +} EXPORT_SYMBOL_GPL(gpio_export); static int match_export(struct device *dev, const void *data) @@ -822,18 +846,16 @@ static int match_export(struct device *dev, const void *data) * * Returns zero on success, else an error. */ -int gpio_export_link(struct device *dev, const char *name, unsigned gpio) +static int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) { - struct gpio_desc *desc; int status = -EINVAL; - if (!gpio_is_valid(gpio)) + if (!desc) goto done; mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { struct device *tdev; @@ -850,12 +872,17 @@ int gpio_export_link(struct device *dev, const char *name, unsigned gpio) done: if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), + status); return status; } -EXPORT_SYMBOL_GPL(gpio_export_link); +int gpio_export_link(struct device *dev, const char *name, unsigned gpio) +{ + return gpiod_export_link(dev, name, gpio_to_desc(gpio)); +} +EXPORT_SYMBOL_GPL(gpio_export_link); /** * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value @@ -869,19 +896,16 @@ EXPORT_SYMBOL_GPL(gpio_export_link); * * Returns zero on success, else an error. */ -int gpio_sysfs_set_active_low(unsigned gpio, int value) +static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) { - struct gpio_desc *desc; struct device *dev = NULL; int status = -EINVAL; - if (!gpio_is_valid(gpio)) + if (!desc) goto done; mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { dev = class_find_device(&gpio_class, NULL, desc, match_export); if (dev == NULL) { @@ -897,10 +921,16 @@ unlock: done: if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), + status); return status; } + +int gpio_sysfs_set_active_low(unsigned gpio, int value) +{ + return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value); +} EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); /** @@ -909,21 +939,18 @@ EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low); * * This is implicit on gpio_free(). */ -void gpio_unexport(unsigned gpio) +static void gpiod_unexport(struct gpio_desc *desc) { - struct gpio_desc *desc; int status = 0; struct device *dev = NULL; - if (!gpio_is_valid(gpio)) { + if (!desc) { status = -EINVAL; goto done; } mutex_lock(&sysfs_lock); - desc = &gpio_desc[gpio]; - if (test_bit(FLAG_EXPORT, &desc->flags)) { dev = class_find_device(&gpio_class, NULL, desc, match_export); @@ -935,13 +962,20 @@ void gpio_unexport(unsigned gpio) } mutex_unlock(&sysfs_lock); + if (dev) { device_unregister(dev); put_device(dev); } done: if (status) - pr_debug("%s: gpio%d status %d\n", __func__, gpio, status); + pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc), + status); +} + +void gpio_unexport(unsigned gpio) +{ + gpiod_unexport(gpio_to_desc(gpio)); } EXPORT_SYMBOL_GPL(gpio_unexport); @@ -975,9 +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__, @@ -1012,7 +1046,7 @@ static int __init gpiolib_sysfs_init(void) { int status; unsigned long flags; - unsigned gpio; + struct gpio_chip *chip; status = class_register(&gpio_class); if (status < 0) @@ -1025,10 +1059,7 @@ static int __init gpiolib_sysfs_init(void) * registered, and so arch_initcall() can always gpio_export(). */ spin_lock_irqsave(&gpio_lock, flags); - for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) { - struct gpio_chip *chip; - - chip = gpio_desc[gpio].chip; + list_for_each_entry(chip, &gpio_chips, list) { if (!chip || chip->exported) continue; @@ -1053,8 +1084,66 @@ static inline void gpiochip_unexport(struct gpio_chip *chip) { } +static inline int gpiod_export(struct gpio_desc *desc, + bool direction_may_change) +{ + return -ENOSYS; +} + +static inline int gpiod_export_link(struct device *dev, const char *name, + struct gpio_desc *desc) +{ + return -ENOSYS; +} + +static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value) +{ + return -ENOSYS; +} + +static inline void gpiod_unexport(struct gpio_desc *desc) +{ +} + #endif /* CONFIG_GPIO_SYSFS */ +/* + * Add a new chip to the global chips list, keeping the list of chips sorted + * by base order. + * + * Return -EBUSY if the new chip overlaps with some other chip's integer + * space. + */ +static int gpiochip_add_to_list(struct gpio_chip *chip) +{ + struct list_head *pos = &gpio_chips; + struct gpio_chip *_chip; + int err = 0; + + /* find where to insert our chip */ + list_for_each(pos, &gpio_chips) { + _chip = list_entry(pos, struct gpio_chip, list); + /* shall we insert before _chip? */ + if (_chip->base >= chip->base + chip->ngpio) + break; + } + + /* are we stepping on the chip right before? */ + if (pos != &gpio_chips && pos->prev != &gpio_chips) { + _chip = list_entry(pos->prev, struct gpio_chip, list); + if (_chip->base + _chip->ngpio > chip->base) { + dev_err(chip->dev, + "GPIO integer space overlap, cannot add chip\n"); + err = -EBUSY; + } + } + + if (!err) + list_add_tail(&chip->list, pos); + + return err; +} + /** * gpiochip_add() - register a gpio_chip * @chip: the chip to register, with chip->base initialized @@ -1096,16 +1185,14 @@ int gpiochip_add(struct gpio_chip *chip) chip->base = base; } - /* these GPIO numbers must not be managed by another gpio_chip */ - for (id = base; id < base + chip->ngpio; id++) { - if (gpio_desc[id].chip != NULL) { - status = -EBUSY; - break; - } - } + 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 @@ -1114,7 +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; } @@ -1167,15 +1254,17 @@ 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); } spin_unlock_irqrestore(&gpio_lock, flags); @@ -1202,20 +1291,17 @@ struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)) { - struct gpio_chip *chip = NULL; + struct gpio_chip *chip; unsigned long flags; - int i; spin_lock_irqsave(&gpio_lock, flags); - for (i = 0; i < ARCH_NR_GPIOS; i++) { - if (!gpio_desc[i].chip) - continue; - - if (match(gpio_desc[i].chip, data)) { - chip = gpio_desc[i].chip; + list_for_each_entry(chip, &gpio_chips, list) + if (match(chip, data)) break; - } - } + + /* No match? */ + if (&chip->list == &gpio_chips) + chip = NULL; spin_unlock_irqrestore(&gpio_lock, flags); return chip; @@ -1297,20 +1383,18 @@ EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. */ -int gpio_request(unsigned gpio, const char *label) +static int gpiod_request(struct gpio_desc *desc, const char *label) { - struct gpio_desc *desc; struct gpio_chip *chip; int status = -EPROBE_DEFER; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - if (!gpio_is_valid(gpio)) { + if (!desc) { status = -EINVAL; goto done; } - desc = &gpio_desc[gpio]; chip = desc->chip; if (chip == NULL) goto done; @@ -1334,7 +1418,7 @@ int gpio_request(unsigned gpio, const char *label) if (chip->request) { /* chip->request may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); - status = chip->request(chip, gpio - chip->base); + status = chip->request(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); if (status < 0) { @@ -1347,42 +1431,46 @@ int gpio_request(unsigned gpio, const char *label) if (chip->get_direction) { /* chip->get_direction may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); - gpio_get_direction(gpio); + gpiod_get_direction(desc); spin_lock_irqsave(&gpio_lock, flags); } done: if (status) - pr_debug("gpio_request: gpio-%d (%s) status %d\n", - gpio, label ? : "?", status); + pr_debug("_gpio_request: gpio-%d (%s) status %d\n", + desc ? desc_to_gpio(desc) : -1, + label ? : "?", status); spin_unlock_irqrestore(&gpio_lock, flags); return status; } + +int gpio_request(unsigned gpio, const char *label) +{ + return gpiod_request(gpio_to_desc(gpio), label); +} EXPORT_SYMBOL_GPL(gpio_request); -void gpio_free(unsigned gpio) +static void gpiod_free(struct gpio_desc *desc) { unsigned long flags; - struct gpio_desc *desc; struct gpio_chip *chip; might_sleep(); - if (!gpio_is_valid(gpio)) { + if (!desc) { WARN_ON(extra_checks); return; } - gpio_unexport(gpio); + gpiod_unexport(desc); spin_lock_irqsave(&gpio_lock, flags); - desc = &gpio_desc[gpio]; chip = desc->chip; if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { if (chip->free) { spin_unlock_irqrestore(&gpio_lock, flags); might_sleep_if(chip->can_sleep); - chip->free(chip, gpio - chip->base); + chip->free(chip, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); } desc_set_label(desc, NULL); @@ -1396,6 +1484,11 @@ void gpio_free(unsigned gpio) spin_unlock_irqrestore(&gpio_lock, flags); } + +void gpio_free(unsigned gpio) +{ + gpiod_free(gpio_to_desc(gpio)); +} EXPORT_SYMBOL_GPL(gpio_free); /** @@ -1406,29 +1499,32 @@ EXPORT_SYMBOL_GPL(gpio_free); */ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) { + struct gpio_desc *desc; int err; - err = gpio_request(gpio, label); + desc = gpio_to_desc(gpio); + + err = gpiod_request(desc, label); if (err) return err; if (flags & GPIOF_OPEN_DRAIN) - set_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags); + set_bit(FLAG_OPEN_DRAIN, &desc->flags); if (flags & GPIOF_OPEN_SOURCE) - set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags); + set_bit(FLAG_OPEN_SOURCE, &desc->flags); if (flags & GPIOF_DIR_IN) - err = gpio_direction_input(gpio); + err = gpiod_direction_input(desc); else - err = gpio_direction_output(gpio, + err = gpiod_direction_output(desc, (flags & GPIOF_INIT_HIGH) ? 1 : 0); if (err) goto free_gpio; if (flags & GPIOF_EXPORT) { - err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE); + err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE); if (err) goto free_gpio; } @@ -1436,7 +1532,7 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) return 0; free_gpio: - gpio_free(gpio); + gpiod_free(desc); return err; } EXPORT_SYMBOL_GPL(gpio_request_one); @@ -1491,14 +1587,17 @@ 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; - if (!gpio_is_valid(gpio) || gpio_desc[gpio].chip != chip) + if (!GPIO_OFFSET_VALID(chip, offset)) return NULL; - if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0) + + desc = &chip->desc[offset]; + + if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) return NULL; #ifdef CONFIG_DEBUG_FS - return gpio_desc[gpio].label; + return desc->label; #else return "?"; #endif @@ -1515,24 +1614,21 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested); * rely on gpio_request() having been called beforehand. */ -int gpio_direction_input(unsigned gpio) +static int gpiod_direction_input(struct gpio_desc *desc) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; spin_lock_irqsave(&gpio_lock, flags); - if (!gpio_is_valid(gpio)) + if (!desc) goto fail; chip = desc->chip; if (!chip || !chip->get || !chip->direction_input) goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1542,11 +1638,12 @@ int gpio_direction_input(unsigned gpio) might_sleep_if(chip->can_sleep); + offset = gpio_chip_hwgpio(desc); if (status) { - status = chip->request(chip, gpio); + status = chip->request(chip, offset); if (status < 0) { pr_debug("GPIO-%d: chip request fail, %d\n", - chip->base + gpio, status); + desc_to_gpio(desc), status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1554,48 +1651,54 @@ int gpio_direction_input(unsigned gpio) } } - status = chip->direction_input(chip, gpio); + status = chip->direction_input(chip, offset); if (status == 0) clear_bit(FLAG_IS_OUT, &desc->flags); - trace_gpio_direction(chip->base + gpio, 1, status); + trace_gpio_direction(desc_to_gpio(desc), 1, status); lose: return status; fail: spin_unlock_irqrestore(&gpio_lock, flags); - if (status) + if (status) { + int gpio = -1; + if (desc) + gpio = desc_to_gpio(desc); pr_debug("%s: gpio-%d status %d\n", __func__, gpio, status); + } return status; } + +int gpio_direction_input(unsigned gpio) +{ + return gpiod_direction_input(gpio_to_desc(gpio)); +} EXPORT_SYMBOL_GPL(gpio_direction_input); -int gpio_direction_output(unsigned gpio, int value) +static int gpiod_direction_output(struct gpio_desc *desc, int value) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; /* Open drain pin should not be driven to 1 */ if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - return gpio_direction_input(gpio); + return gpiod_direction_input(desc); /* Open source pin should not be driven to 0 */ if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - return gpio_direction_input(gpio); + return gpiod_direction_input(desc); spin_lock_irqsave(&gpio_lock, flags); - if (!gpio_is_valid(gpio)) + if (!desc) goto fail; chip = desc->chip; if (!chip || !chip->set || !chip->direction_output) goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1605,11 +1708,12 @@ int gpio_direction_output(unsigned gpio, int value) might_sleep_if(chip->can_sleep); + offset = gpio_chip_hwgpio(desc); if (status) { - status = chip->request(chip, gpio); + status = chip->request(chip, offset); if (status < 0) { pr_debug("GPIO-%d: chip request fail, %d\n", - chip->base + gpio, status); + desc_to_gpio(desc), status); /* and it's not available to anyone else ... * gpio_request() is the fully clean solution. */ @@ -1617,20 +1721,29 @@ int gpio_direction_output(unsigned gpio, int value) } } - status = chip->direction_output(chip, gpio, value); + status = chip->direction_output(chip, offset, value); if (status == 0) set_bit(FLAG_IS_OUT, &desc->flags); - trace_gpio_value(chip->base + gpio, 0, value); - trace_gpio_direction(chip->base + gpio, 0, status); + trace_gpio_value(desc_to_gpio(desc), 0, value); + trace_gpio_direction(desc_to_gpio(desc), 0, status); lose: return status; fail: spin_unlock_irqrestore(&gpio_lock, flags); - if (status) + if (status) { + int gpio = -1; + if (desc) + gpio = desc_to_gpio(desc); pr_debug("%s: gpio-%d status %d\n", __func__, gpio, status); + } return status; } + +int gpio_direction_output(unsigned gpio, int value) +{ + return gpiod_direction_output(gpio_to_desc(gpio), value); +} EXPORT_SYMBOL_GPL(gpio_direction_output); /** @@ -1638,24 +1751,22 @@ EXPORT_SYMBOL_GPL(gpio_direction_output); * @gpio: the gpio to set debounce time * @debounce: debounce time is microseconds */ -int gpio_set_debounce(unsigned gpio, unsigned debounce) +static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { unsigned long flags; struct gpio_chip *chip; - struct gpio_desc *desc = &gpio_desc[gpio]; int status = -EINVAL; + int offset; spin_lock_irqsave(&gpio_lock, flags); - if (!gpio_is_valid(gpio)) + if (!desc) goto fail; chip = desc->chip; if (!chip || !chip->set || !chip->set_debounce) goto fail; - gpio -= chip->base; - if (gpio >= chip->ngpio) - goto fail; - status = gpio_ensure_requested(desc, gpio); + + status = gpio_ensure_requested(desc); if (status < 0) goto fail; @@ -1665,16 +1776,26 @@ int gpio_set_debounce(unsigned gpio, unsigned debounce) might_sleep_if(chip->can_sleep); - return chip->set_debounce(chip, gpio, debounce); + offset = gpio_chip_hwgpio(desc); + return chip->set_debounce(chip, offset, debounce); fail: spin_unlock_irqrestore(&gpio_lock, flags); - if (status) + if (status) { + int gpio = -1; + if (desc) + gpio = desc_to_gpio(desc); pr_debug("%s: gpio-%d status %d\n", __func__, gpio, status); + } return status; } + +int gpio_set_debounce(unsigned gpio, unsigned debounce) +{ + return gpiod_set_debounce(gpio_to_desc(gpio), debounce); +} EXPORT_SYMBOL_GPL(gpio_set_debounce); /* I/O calls are only valid after configuration completed; the relevant @@ -1708,18 +1829,25 @@ EXPORT_SYMBOL_GPL(gpio_set_debounce); * It returns the zero or nonzero value provided by the associated * gpio_chip.get() method; or zero if no such method is provided. */ -int __gpio_get_value(unsigned gpio) +static int gpiod_get_value(struct gpio_desc *desc) { struct gpio_chip *chip; int value; + int offset; - chip = gpio_to_chip(gpio); + chip = desc->chip; + offset = gpio_chip_hwgpio(desc); /* Should be using gpio_get_value_cansleep() */ WARN_ON(chip->can_sleep); - value = chip->get ? chip->get(chip, gpio - chip->base) : 0; - trace_gpio_value(gpio, 1, value); + value = chip->get ? chip->get(chip, offset) : 0; + trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } + +int __gpio_get_value(unsigned gpio) +{ + return gpiod_get_value(gpio_to_desc(gpio)); +} EXPORT_SYMBOL_GPL(__gpio_get_value); /* @@ -1728,23 +1856,25 @@ EXPORT_SYMBOL_GPL(__gpio_get_value); * @chip: Gpio chip. * @value: Non-zero for setting it HIGH otherise it will set to LOW. */ -static void _gpio_set_open_drain_value(unsigned gpio, - struct gpio_chip *chip, int value) +static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value) { int err = 0; + struct gpio_chip *chip = desc->chip; + int offset = gpio_chip_hwgpio(desc); + if (value) { - err = chip->direction_input(chip, gpio - chip->base); + err = chip->direction_input(chip, offset); if (!err) - clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); + clear_bit(FLAG_IS_OUT, &desc->flags); } else { - err = chip->direction_output(chip, gpio - chip->base, 0); + err = chip->direction_output(chip, offset, 0); if (!err) - set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); + set_bit(FLAG_IS_OUT, &desc->flags); } - trace_gpio_direction(gpio, value, err); + trace_gpio_direction(desc_to_gpio(desc), value, err); if (err < 0) pr_err("%s: Error in set_value for open drain gpio%d err %d\n", - __func__, gpio, err); + __func__, desc_to_gpio(desc), err); } /* @@ -1753,26 +1883,27 @@ static void _gpio_set_open_drain_value(unsigned gpio, * @chip: Gpio chip. * @value: Non-zero for setting it HIGH otherise it will set to LOW. */ -static void _gpio_set_open_source_value(unsigned gpio, - struct gpio_chip *chip, int value) +static void _gpio_set_open_source_value(struct gpio_desc *desc, int value) { int err = 0; + struct gpio_chip *chip = desc->chip; + int offset = gpio_chip_hwgpio(desc); + if (value) { - err = chip->direction_output(chip, gpio - chip->base, 1); + err = chip->direction_output(chip, offset, 1); if (!err) - set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); + set_bit(FLAG_IS_OUT, &desc->flags); } else { - err = chip->direction_input(chip, gpio - chip->base); + err = chip->direction_input(chip, offset); if (!err) - clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags); + clear_bit(FLAG_IS_OUT, &desc->flags); } - trace_gpio_direction(gpio, !value, err); + trace_gpio_direction(desc_to_gpio(desc), !value, err); if (err < 0) pr_err("%s: Error in set_value for open source gpio%d err %d\n", - __func__, gpio, err); + __func__, desc_to_gpio(desc), err); } - /** * __gpio_set_value() - assign a gpio's value * @gpio: gpio whose value will be assigned @@ -1782,20 +1913,25 @@ static void _gpio_set_open_source_value(unsigned gpio, * This is used directly or indirectly to implement gpio_set_value(). * It invokes the associated gpio_chip.set() method. */ -void __gpio_set_value(unsigned gpio, int value) +static void gpiod_set_value(struct gpio_desc *desc, int value) { struct gpio_chip *chip; - chip = gpio_to_chip(gpio); + chip = desc->chip; /* Should be using gpio_set_value_cansleep() */ WARN_ON(chip->can_sleep); - trace_gpio_value(gpio, 0, value); - if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) - _gpio_set_open_drain_value(gpio, chip, value); - else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) - _gpio_set_open_source_value(gpio, chip, value); + trace_gpio_value(desc_to_gpio(desc), 0, value); + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) + _gpio_set_open_drain_value(desc, value); + else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) + _gpio_set_open_source_value(desc, value); else - chip->set(chip, gpio - chip->base, value); + chip->set(chip, gpio_chip_hwgpio(desc), value); +} + +void __gpio_set_value(unsigned gpio, int value) +{ + return gpiod_set_value(gpio_to_desc(gpio), value); } EXPORT_SYMBOL_GPL(__gpio_set_value); @@ -1807,14 +1943,15 @@ EXPORT_SYMBOL_GPL(__gpio_set_value); * This is used directly or indirectly to implement gpio_cansleep(). It * returns nonzero if access reading or writing the GPIO value can sleep. */ -int __gpio_cansleep(unsigned gpio) +static int gpiod_cansleep(struct gpio_desc *desc) { - struct gpio_chip *chip; - /* only call this on GPIOs that are valid! */ - chip = gpio_to_chip(gpio); + return desc->chip->can_sleep; +} - return chip->can_sleep; +int __gpio_cansleep(unsigned gpio) +{ + return gpiod_cansleep(gpio_to_desc(gpio)); } EXPORT_SYMBOL_GPL(__gpio_cansleep); @@ -1827,50 +1964,67 @@ EXPORT_SYMBOL_GPL(__gpio_cansleep); * It returns the number of the IRQ signaled by this (input) GPIO, * or a negative errno. */ -int __gpio_to_irq(unsigned gpio) +static int gpiod_to_irq(struct gpio_desc *desc) { struct gpio_chip *chip; + int offset; - chip = gpio_to_chip(gpio); - return chip->to_irq ? chip->to_irq(chip, gpio - chip->base) : -ENXIO; + chip = desc->chip; + offset = gpio_chip_hwgpio(desc); + return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; } -EXPORT_SYMBOL_GPL(__gpio_to_irq); +int __gpio_to_irq(unsigned gpio) +{ + return gpiod_to_irq(gpio_to_desc(gpio)); +} +EXPORT_SYMBOL_GPL(__gpio_to_irq); /* There's no value in making it easy to inline GPIO calls that may sleep. * Common examples include ones connected to I2C or SPI chips. */ -int gpio_get_value_cansleep(unsigned gpio) +static int gpiod_get_value_cansleep(struct gpio_desc *desc) { struct gpio_chip *chip; int value; + int offset; might_sleep_if(extra_checks); - chip = gpio_to_chip(gpio); - value = chip->get ? chip->get(chip, gpio - chip->base) : 0; - trace_gpio_value(gpio, 1, value); + chip = desc->chip; + offset = gpio_chip_hwgpio(desc); + value = chip->get ? chip->get(chip, offset) : 0; + trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } + +int gpio_get_value_cansleep(unsigned gpio) +{ + return gpiod_get_value_cansleep(gpio_to_desc(gpio)); +} EXPORT_SYMBOL_GPL(gpio_get_value_cansleep); -void gpio_set_value_cansleep(unsigned gpio, int value) +static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { struct gpio_chip *chip; might_sleep_if(extra_checks); - chip = gpio_to_chip(gpio); - trace_gpio_value(gpio, 0, value); - if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags)) - _gpio_set_open_drain_value(gpio, chip, value); - else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags)) - _gpio_set_open_source_value(gpio, chip, value); + chip = desc->chip; + trace_gpio_value(desc_to_gpio(desc), 0, value); + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) + _gpio_set_open_drain_value(desc, value); + else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) + _gpio_set_open_source_value(desc, value); else - chip->set(chip, gpio - chip->base, value); + chip->set(chip, gpio_chip_hwgpio(desc), value); } -EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); +void gpio_set_value_cansleep(unsigned gpio, int value) +{ + return gpiod_set_value_cansleep(gpio_to_desc(gpio), value); +} +EXPORT_SYMBOL_GPL(gpio_set_value_cansleep); #ifdef CONFIG_DEBUG_FS @@ -1878,14 +2032,14 @@ 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++) { if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) continue; - gpio_get_direction(gpio); + gpiod_get_direction(gdesc); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); seq_printf(s, " gpio-%-3d (%-20.20s) %s %s", gpio, gdesc->label, @@ -1899,46 +2053,35 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { + unsigned long flags; struct gpio_chip *chip = NULL; - unsigned int gpio; - void *ret = NULL; - loff_t index = 0; - - /* REVISIT this isn't locked against gpio_chip removal ... */ + loff_t index = *pos; - for (gpio = 0; gpio_is_valid(gpio); gpio++) { - if (gpio_desc[gpio].chip == chip) - continue; - - chip = gpio_desc[gpio].chip; - if (!chip) - continue; + s->private = ""; - if (index++ >= *pos) { - ret = chip; - break; + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(chip, &gpio_chips, list) + if (index-- == 0) { + spin_unlock_irqrestore(&gpio_lock, flags); + return chip; } - } - - s->private = ""; + spin_unlock_irqrestore(&gpio_lock, flags); - return ret; + return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { + unsigned long flags; struct gpio_chip *chip = v; - unsigned int gpio; void *ret = NULL; - /* skip GPIOs provided by the current chip */ - for (gpio = chip->base + chip->ngpio; gpio_is_valid(gpio); gpio++) { - chip = gpio_desc[gpio].chip; - if (chip) { - ret = chip; - break; - } - } + spin_lock_irqsave(&gpio_lock, flags); + if (list_is_last(&chip->list, &gpio_chips)) + ret = NULL; + else + ret = list_entry(chip->list.next, struct gpio_chip, list); + spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; |