diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 202 |
1 files changed, 155 insertions, 47 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 2b02655abb56..679ed764cb14 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -14,6 +14,7 @@ #include <linux/idr.h> #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/irqdesc.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/lockdep.h> @@ -23,7 +24,6 @@ #include <linux/pinctrl/consumer.h> #include <linux/seq_file.h> #include <linux/slab.h> -#include <linux/spinlock.h> #include <linux/srcu.h> #include <linux/string.h> @@ -713,6 +713,45 @@ bool gpiochip_line_is_valid(const struct gpio_chip *gc, } EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); +static void gpiod_free_irqs(struct gpio_desc *desc) +{ + int irq = gpiod_to_irq(desc); + struct irq_desc *irqd = irq_to_desc(irq); + void *cookie; + + for (;;) { + /* + * Make sure the action doesn't go away while we're + * dereferencing it. Retrieve and store the cookie value. + * If the irq is freed after we release the lock, that's + * alright - the underlying maple tree lookup will return NULL + * and nothing will happen in free_irq(). + */ + scoped_guard(mutex, &irqd->request_mutex) { + if (!irq_desc_has_action(irqd)) + return; + + cookie = irqd->action->dev_id; + } + + free_irq(irq, cookie); + } +} + +/* + * The chip is going away but there may be users who had requested interrupts + * on its GPIO lines who have no idea about its removal and have no way of + * being notified about it. We need to free any interrupts still in use here or + * we'll leak memory and resources (like procfs files). + */ +static void gpiochip_free_remaining_irqs(struct gpio_chip *gc) +{ + struct gpio_desc *desc; + + for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ) + gpiod_free_irqs(desc); +} + static void gpiodev_release(struct device *dev) { struct gpio_device *gdev = to_gpio_device(dev); @@ -986,10 +1025,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, } } - for (desc_index = 0; desc_index < gc->ngpio; desc_index++) - gdev->descs[desc_index].gdev = gdev; - - BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); + ATOMIC_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); ret = init_srcu_struct(&gdev->srcu); @@ -1018,6 +1054,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, for (desc_index = 0; desc_index < gc->ngpio; desc_index++) { struct gpio_desc *desc = &gdev->descs[desc_index]; + desc->gdev = gdev; + if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->get_direction(gc, desc_index)); @@ -1125,6 +1163,7 @@ void gpiochip_remove(struct gpio_chip *gc) /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); gpiochip_free_hogs(gc); + gpiochip_free_remaining_irqs(gc); scoped_guard(mutex, &gpio_devices_lock) list_del_rcu(&gdev->list); @@ -1183,11 +1222,6 @@ struct gpio_device *gpio_device_find(const void *data, struct gpio_device *gdev; struct gpio_chip *gc; - /* - * Not yet but in the future the spinlock below will become a mutex. - * Annotate this function before anyone tries to use it in interrupt - * context like it happened with gpiochip_find(). - */ might_sleep(); guard(srcu)(&gpio_devices_srcu); @@ -2392,8 +2426,10 @@ static void gpiod_free_commit(struct gpio_desc *desc) #endif desc_set_label(desc, NULL); WRITE_ONCE(desc->flags, flags); - - gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED); +#ifdef CONFIG_GPIO_CDEV + WRITE_ONCE(desc->debounce_period_us, 0); +#endif + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED); } } @@ -2492,6 +2528,8 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, return ERR_PTR(ret); } + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); + return desc; } EXPORT_SYMBOL_GPL(gpiochip_request_own_desc); @@ -2520,13 +2558,28 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); * rely on gpio_request() having been called beforehand. */ -static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset, - unsigned long config) +int gpio_do_set_config(struct gpio_desc *desc, unsigned long config) { - if (!gc->set_config) + int ret; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (!guard.gc->set_config) return -ENOTSUPP; - return gc->set_config(gc, offset, config); + ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config); +#ifdef CONFIG_GPIO_CDEV + /* + * Special case - if we're setting debounce period, we need to store + * it in the descriptor in case user-space wants to know it. + */ + if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE) + WRITE_ONCE(desc->debounce_period_us, + pinconf_to_config_argument(config)); +#endif + return ret; } static int gpio_set_config_with_argument(struct gpio_desc *desc, @@ -2535,12 +2588,8 @@ static int gpio_set_config_with_argument(struct gpio_desc *desc, { unsigned long config; - CLASS(gpio_chip_guard, guard)(desc); - if (!guard.gc) - return -ENODEV; - config = pinconf_to_config_packed(mode, argument); - return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config); + return gpio_do_set_config(desc, config); } static int gpio_set_config_with_argument_optional(struct gpio_desc *desc, @@ -2615,9 +2664,15 @@ static int gpio_set_bias(struct gpio_desc *desc) */ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) { - return gpio_set_config_with_argument_optional(desc, - PIN_CONFIG_INPUT_DEBOUNCE, - debounce); + int ret; + + ret = gpio_set_config_with_argument_optional(desc, + PIN_CONFIG_INPUT_DEBOUNCE, + debounce); + if (!ret) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; } /** @@ -2632,10 +2687,22 @@ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) */ int gpiod_direction_input(struct gpio_desc *desc) { - int ret = 0; + int ret; VALIDATE_DESC(desc); + ret = gpiod_direction_input_nonotify(desc); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; +} +EXPORT_SYMBOL_GPL(gpiod_direction_input); + +int gpiod_direction_input_nonotify(struct gpio_desc *desc) +{ + int ret = 0; + CLASS(gpio_chip_guard, guard)(desc); if (!guard.gc) return -ENODEV; @@ -2678,7 +2745,6 @@ int gpiod_direction_input(struct gpio_desc *desc) return ret; } -EXPORT_SYMBOL_GPL(gpiod_direction_input); static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { @@ -2740,8 +2806,15 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) */ int gpiod_direction_output_raw(struct gpio_desc *desc, int value) { + int ret; + VALIDATE_DESC(desc); - return gpiod_direction_output_raw_commit(desc, value); + + ret = gpiod_direction_output_raw_commit(desc, value); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; } EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); @@ -2760,11 +2833,23 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); */ int gpiod_direction_output(struct gpio_desc *desc, int value) { - unsigned long flags; int ret; VALIDATE_DESC(desc); + ret = gpiod_direction_output_nonotify(desc, value); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; +} +EXPORT_SYMBOL_GPL(gpiod_direction_output); + +int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value) +{ + unsigned long flags; + int ret; + flags = READ_ONCE(desc->flags); if (test_bit(FLAG_ACTIVE_LOW, &flags)) @@ -2788,7 +2873,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value) goto set_output_value; /* Emulate open drain by not actively driving the line high */ if (value) { - ret = gpiod_direction_input(desc); + ret = gpiod_direction_input_nonotify(desc); goto set_output_flag; } } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) { @@ -2797,7 +2882,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value) goto set_output_value; /* Emulate open source by not actively driving the line low */ if (!value) { - ret = gpiod_direction_input(desc); + ret = gpiod_direction_input_nonotify(desc); goto set_output_flag; } } else { @@ -2821,7 +2906,6 @@ set_output_flag: set_bit(FLAG_IS_OUT, &desc->flags); return ret; } -EXPORT_SYMBOL_GPL(gpiod_direction_output); /** * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds. @@ -2900,13 +2984,30 @@ EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns); */ int gpiod_set_config(struct gpio_desc *desc, unsigned long config) { + int ret; + VALIDATE_DESC(desc); - CLASS(gpio_chip_guard, guard)(desc); - if (!guard.gc) - return -ENODEV; + ret = gpio_do_set_config(desc, config); + if (!ret) { + /* These are the only options we notify the userspace about. */ + switch (pinconf_to_config_param(config)) { + case PIN_CONFIG_BIAS_DISABLE: + case PIN_CONFIG_BIAS_PULL_DOWN: + case PIN_CONFIG_BIAS_PULL_UP: + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + case PIN_CONFIG_DRIVE_OPEN_SOURCE: + case PIN_CONFIG_DRIVE_PUSH_PULL: + case PIN_CONFIG_INPUT_DEBOUNCE: + gpiod_line_state_notify(desc, + GPIO_V2_LINE_CHANGED_CONFIG); + break; + default: + break; + } + } - return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config); + return ret; } EXPORT_SYMBOL_GPL(gpiod_set_config); @@ -2973,6 +3074,7 @@ void gpiod_toggle_active_low(struct gpio_desc *desc) { VALIDATE_DESC_VOID(desc); change_bit(FLAG_ACTIVE_LOW, &desc->flags); + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); } EXPORT_SYMBOL_GPL(gpiod_toggle_active_low); @@ -3617,9 +3719,15 @@ EXPORT_SYMBOL_GPL(gpiod_cansleep); */ int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name) { + int ret; + VALIDATE_DESC(desc); - return desc_set_label(desc, name); + ret = desc_set_label(desc, name); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; } EXPORT_SYMBOL_GPL(gpiod_set_consumer_name); @@ -4047,8 +4155,8 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action) { - blocking_notifier_call_chain(&desc->gdev->line_state_notifier, - action, desc); + atomic_notifier_call_chain(&desc->gdev->line_state_notifier, + action, desc); } /** @@ -4325,7 +4433,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer, return ERR_PTR(ret); } - gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED); + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); return desc; } @@ -4497,10 +4605,10 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, /* Process flags */ if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) - ret = gpiod_direction_output(desc, + ret = gpiod_direction_output_nonotify(desc, !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL)); else - ret = gpiod_direction_input(desc); + ret = gpiod_direction_input_nonotify(desc); return ret; } @@ -4967,19 +5075,19 @@ static int gpiolib_seq_show(struct seq_file *s, void *v) struct gpio_chip *gc; struct device *parent; + if (priv->newline) + seq_putc(s, '\n'); + guard(srcu)(&gdev->srcu); gc = srcu_dereference(gdev->chip, &gdev->srcu); if (!gc) { - seq_printf(s, "%s%s: (dangling chip)\n", - priv->newline ? "\n" : "", - dev_name(&gdev->dev)); + seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev)); return 0; } - seq_printf(s, "%s%s: GPIOs %u-%u", priv->newline ? "\n" : "", - dev_name(&gdev->dev), - gdev->base, gdev->base + gdev->ngpio - 1); + seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base, + gdev->base + gdev->ngpio - 1); parent = gc->parent; if (parent) seq_printf(s, ", parent: %s/%s", |