diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 150 |
1 files changed, 84 insertions, 66 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4c93cf73a826..75be4a3ca7f8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2,7 +2,6 @@ #include <linux/acpi.h> #include <linux/bitmap.h> -#include <linux/cleanup.h> #include <linux/compat.h> #include <linux/debugfs.h> #include <linux/device.h> @@ -16,7 +15,6 @@ #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> -#include <linux/mutex.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/seq_file.h> @@ -83,9 +81,7 @@ DEFINE_SPINLOCK(gpio_lock); static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); - LIST_HEAD(gpio_devices); -DECLARE_RWSEM(gpio_devices_sem); static DEFINE_MUTEX(gpio_machine_hogs_mutex); static LIST_HEAD(gpio_machine_hogs); @@ -117,15 +113,20 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) struct gpio_desc *gpio_to_desc(unsigned gpio) { struct gpio_device *gdev; + unsigned long flags; - scoped_guard(rwsem_read, &gpio_devices_sem) { - list_for_each_entry(gdev, &gpio_devices, list) { - if (gdev->base <= gpio && - gdev->base + gdev->ngpio > gpio) - return &gdev->descs[gpio - gdev->base]; + spin_lock_irqsave(&gpio_lock, flags); + + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->base <= gpio && + gdev->base + gdev->ngpio > gpio) { + spin_unlock_irqrestore(&gpio_lock, flags); + return &gdev->descs[gpio - gdev->base]; } } + spin_unlock_irqrestore(&gpio_lock, flags); + if (!gpio_is_valid(gpio)) pr_warn("invalid GPIO %d\n", gpio); @@ -398,21 +399,26 @@ static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev) static struct gpio_desc *gpio_name_to_desc(const char * const name) { struct gpio_device *gdev; + unsigned long flags; if (!name) return NULL; - guard(rwsem_read)(&gpio_devices_sem); + spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { struct gpio_desc *desc; for_each_gpio_desc(gdev->chip, desc) { - if (desc->name && !strcmp(desc->name, name)) + if (desc->name && !strcmp(desc->name, name)) { + spin_unlock_irqrestore(&gpio_lock, flags); return desc; + } } } + spin_unlock_irqrestore(&gpio_lock, flags); + return NULL; } @@ -807,6 +813,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *request_key) { struct gpio_device *gdev; + unsigned long flags; unsigned int i; int base = 0; int ret = 0; @@ -871,46 +878,49 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gdev->ngpio = gc->ngpio; - scoped_guard(rwsem_write, &gpio_devices_sem) { - /* - * TODO: this allocates a Linux GPIO number base in the global - * GPIO numberspace for this chip. In the long run we want to - * get *rid* of this numberspace and use only descriptors, but - * it may be a pipe dream. It will not happen before we get rid - * of the sysfs interface anyways. - */ - base = gc->base; + spin_lock_irqsave(&gpio_lock, flags); + /* + * TODO: this allocates a Linux GPIO number base in the global + * GPIO numberspace for this chip. In the long run we want to + * get *rid* of this numberspace and use only descriptors, but + * it may be a pipe dream. It will not happen before we get rid + * of the sysfs interface anyways. + */ + base = gc->base; + if (base < 0) { + base = gpiochip_find_base_unlocked(gc->ngpio); if (base < 0) { - base = gpiochip_find_base_unlocked(gc->ngpio); - if (base < 0) { - ret = base; - base = 0; - goto err_free_label; - } - /* - * TODO: it should not be necessary to reflect the assigned - * base outside of the GPIO subsystem. Go over drivers and - * see if anyone makes use of this, else drop this and assign - * a poison instead. - */ - gc->base = base; - } else { - dev_warn(&gdev->dev, - "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); - } - gdev->base = base; - - ret = gpiodev_add_to_list_unlocked(gdev); - if (ret) { - chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); + spin_unlock_irqrestore(&gpio_lock, flags); + ret = base; + base = 0; goto err_free_label; } + /* + * TODO: it should not be necessary to reflect the assigned + * base outside of the GPIO subsystem. Go over drivers and + * see if anyone makes use of this, else drop this and assign + * a poison instead. + */ + gc->base = base; + } else { + dev_warn(&gdev->dev, + "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); + } + gdev->base = base; - for (i = 0; i < gc->ngpio; i++) - gdev->descs[i].gdev = gdev; + ret = gpiodev_add_to_list_unlocked(gdev); + if (ret) { + spin_unlock_irqrestore(&gpio_lock, flags); + chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); + goto err_free_label; } + for (i = 0; i < gc->ngpio; i++) + gdev->descs[i].gdev = gdev; + + spin_unlock_irqrestore(&gpio_lock, flags); + BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); init_rwsem(&gdev->sem); @@ -958,11 +968,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, ret = gpiochip_irqchip_init_valid_mask(gc); if (ret) - goto err_remove_acpi_chip; + goto err_free_hogs; ret = gpiochip_irqchip_init_hw(gc); if (ret) - goto err_remove_acpi_chip; + goto err_remove_irqchip_mask; ret = gpiochip_add_irqchip(gc, lock_key, request_key); if (ret) @@ -987,22 +997,23 @@ err_remove_irqchip: gpiochip_irqchip_remove(gc); err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(gc); -err_remove_acpi_chip: +err_free_hogs: + gpiochip_free_hogs(gc); acpi_gpiochip_remove(gc); + gpiochip_remove_pin_ranges(gc); err_remove_of_chip: - gpiochip_free_hogs(gc); of_gpiochip_remove(gc); err_free_gpiochip_mask: - gpiochip_remove_pin_ranges(gc); gpiochip_free_valid_mask(gc); +err_remove_from_list: + spin_lock_irqsave(&gpio_lock, flags); + list_del(&gdev->list); + spin_unlock_irqrestore(&gpio_lock, flags); if (gdev->dev.release) { /* release() has been registered by gpiochip_setup_dev() */ gpio_device_put(gdev); goto err_print_message; } -err_remove_from_list: - scoped_guard(rwsem_write, &gpio_devices_sem) - list_del(&gdev->list); err_free_label: kfree_const(gdev->label); err_free_descs: @@ -1065,7 +1076,7 @@ void gpiochip_remove(struct gpio_chip *gc) dev_crit(&gdev->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); - scoped_guard(rwsem_write, &gpio_devices_sem) + scoped_guard(spinlock_irqsave, &gpio_lock) list_del(&gdev->list); /* @@ -1114,7 +1125,7 @@ struct gpio_device *gpio_device_find(void *data, */ might_sleep(); - guard(rwsem_read)(&gpio_devices_sem); + guard(spinlock_irqsave)(&gpio_lock); list_for_each_entry(gdev, &gpio_devices, list) { if (gdev->chip && match(gdev->chip, data)) @@ -2031,6 +2042,11 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_free); int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { +#ifdef CONFIG_PINCTRL + if (list_empty(&gc->gpiodev->pin_ranges)) + return -ENOTSUPP; +#endif + return pinctrl_gpio_set_config(gc, offset, config); } EXPORT_SYMBOL_GPL(gpiochip_generic_config); @@ -4725,33 +4741,35 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { + unsigned long flags; struct gpio_device *gdev = NULL; loff_t index = *pos; s->private = ""; - guard(rwsem_read)(&gpio_devices_sem); - - list_for_each_entry(gdev, &gpio_devices, list) { - if (index-- == 0) + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(gdev, &gpio_devices, list) + if (index-- == 0) { + spin_unlock_irqrestore(&gpio_lock, flags); return gdev; - } + } + spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { + unsigned long flags; struct gpio_device *gdev = v; void *ret = NULL; - scoped_guard(rwsem_read, &gpio_devices_sem) { - if (list_is_last(&gdev->list, &gpio_devices)) - ret = NULL; - else - ret = list_first_entry(&gdev->list, struct gpio_device, - list); - } + spin_lock_irqsave(&gpio_lock, flags); + if (list_is_last(&gdev->list, &gpio_devices)) + ret = NULL; + else + ret = list_first_entry(&gdev->list, struct gpio_device, list); + spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; |