diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 189 |
1 files changed, 163 insertions, 26 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5db344555..a3ad3bab2 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -15,6 +15,7 @@ #include <linux/acpi.h> #include <linux/gpio/driver.h> #include <linux/gpio/machine.h> +#include <linux/pinctrl/consumer.h> #include "gpiolib.h" @@ -47,8 +48,6 @@ */ DEFINE_SPINLOCK(gpio_lock); -#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) - static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); LIST_HEAD(gpio_chips); @@ -219,6 +218,68 @@ static int gpiochip_add_to_list(struct gpio_chip *chip) } /** + * Convert a GPIO name to its descriptor + */ +static struct gpio_desc *gpio_name_to_desc(const char * const name) +{ + struct gpio_chip *chip; + unsigned long flags; + + spin_lock_irqsave(&gpio_lock, flags); + + list_for_each_entry(chip, &gpio_chips, list) { + int i; + + for (i = 0; i != chip->ngpio; ++i) { + struct gpio_desc *gpio = &chip->desc[i]; + + if (!gpio->name || !name) + continue; + + if (!strcmp(gpio->name, name)) { + spin_unlock_irqrestore(&gpio_lock, flags); + return gpio; + } + } + } + + spin_unlock_irqrestore(&gpio_lock, flags); + + return NULL; +} + +/* + * Takes the names from gc->names and checks if they are all unique. If they + * are, they are assigned to their gpio descriptors. + * + * Returns -EEXIST if one of the names is already used for a different GPIO. + */ +static int gpiochip_set_desc_names(struct gpio_chip *gc) +{ + int i; + + if (!gc->names) + return 0; + + /* First check all names if they are unique */ + for (i = 0; i != gc->ngpio; ++i) { + struct gpio_desc *gpio; + + gpio = gpio_name_to_desc(gc->names[i]); + if (gpio) + dev_warn(gc->dev, "Detected name collision for " + "GPIO name '%s'\n", + gc->names[i]); + } + + /* Then add all names to the GPIO descriptors */ + for (i = 0; i != gc->ngpio; ++i) + gc->desc[i].name = gc->names[i]; + + return 0; +} + +/** * gpiochip_add() - register a gpio_chip * @chip: the chip to register, with chip->base initialized * Context: potentially before irqs will work @@ -290,6 +351,10 @@ int gpiochip_add(struct gpio_chip *chip) if (!chip->owner && chip->dev && chip->dev->driver) chip->owner = chip->dev->driver->owner; + status = gpiochip_set_desc_names(chip); + if (status) + goto err_remove_from_list; + status = of_gpiochip_add(chip); if (status) goto err_remove_chip; @@ -310,6 +375,7 @@ err_remove_chip: acpi_gpiochip_remove(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); +err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); list_del(&chip->list); spin_unlock_irqrestore(&gpio_lock, flags); @@ -680,6 +746,28 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {} #endif /* CONFIG_GPIOLIB_IRQCHIP */ +/** + * gpiochip_generic_request() - request the gpio function for a pin + * @chip: the gpiochip owning the GPIO + * @offset: the offset of the GPIO to request for GPIO function + */ +int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset) +{ + return pinctrl_request_gpio(chip->base + offset); +} +EXPORT_SYMBOL_GPL(gpiochip_generic_request); + +/** + * gpiochip_generic_free() - free the gpio function from a pin + * @chip: the gpiochip to request the gpio function for + * @offset: the offset of the GPIO to free from GPIO function + */ +void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset) +{ + pinctrl_free_gpio(chip->base + offset); +} +EXPORT_SYMBOL_GPL(gpiochip_generic_free); + #ifdef CONFIG_PINCTRL /** @@ -839,6 +927,14 @@ static int __gpiod_request(struct gpio_desc *desc, const char *label) spin_lock_irqsave(&gpio_lock, flags); } done: + if (status < 0) { + /* Clear flags that might have been set by the caller before + * requesting the GPIO. + */ + clear_bit(FLAG_ACTIVE_LOW, &desc->flags); + clear_bit(FLAG_OPEN_DRAIN, &desc->flags); + clear_bit(FLAG_OPEN_SOURCE, &desc->flags); + } spin_unlock_irqrestore(&gpio_lock, flags); return status; } @@ -928,7 +1024,7 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) { struct gpio_desc *desc; - if (!GPIO_OFFSET_VALID(chip, offset)) + if (offset >= chip->ngpio) return NULL; desc = &chip->desc[offset]; @@ -1183,7 +1279,13 @@ static int _gpiod_get_raw_value(const struct gpio_desc *desc) chip = desc->chip; offset = gpio_chip_hwgpio(desc); value = chip->get ? chip->get(chip, offset) : -EIO; - value = value < 0 ? value : !!value; + /* + * FIXME: fix all drivers to clamp to [0,1] or return negative, + * then change this to: + * value = value < 0 ? value : !!value; + * so we can properly propagate error codes. + */ + value = !!value; trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } @@ -1735,6 +1837,13 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, if (of_flags & OF_GPIO_ACTIVE_LOW) *flags |= GPIO_ACTIVE_LOW; + if (of_flags & OF_GPIO_SINGLE_ENDED) { + if (of_flags & OF_GPIO_ACTIVE_LOW) + *flags |= GPIO_OPEN_DRAIN; + else + *flags |= GPIO_OPEN_SOURCE; + } + return desc; } @@ -1765,6 +1874,9 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, /* Then from plain _CRS GPIOs */ if (IS_ERR(desc)) { + if (!acpi_can_fallback_to_crs(adev, con_id)) + return ERR_PTR(-ENOENT); + desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info); if (IS_ERR(desc)) return desc; @@ -1953,13 +2065,28 @@ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, } EXPORT_SYMBOL_GPL(gpiod_get_optional); +/** + * gpiod_parse_flags - helper function to parse GPIO lookup flags + * @desc: gpio to be setup + * @lflags: gpio_lookup_flags - returned from of_find_gpio() or + * of_get_gpio_hog() + * + * Set the GPIO descriptor flags based on the given GPIO lookup flags. + */ +static void gpiod_parse_flags(struct gpio_desc *desc, unsigned long lflags) +{ + if (lflags & GPIO_ACTIVE_LOW) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + if (lflags & GPIO_OPEN_DRAIN) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + if (lflags & GPIO_OPEN_SOURCE) + set_bit(FLAG_OPEN_SOURCE, &desc->flags); +} /** * gpiod_configure_flags - helper function to configure a given GPIO * @desc: gpio whose value will be assigned * @con_id: function within the GPIO consumer - * @lflags: gpio_lookup_flags - returned from of_find_gpio() or - * of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags * * Return 0 on success, -ENOENT if no GPIO has been assigned to the @@ -1967,17 +2094,10 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional); * occurred while trying to acquire the GPIO. */ static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, - unsigned long lflags, enum gpiod_flags dflags) + enum gpiod_flags dflags) { int status; - if (lflags & GPIO_ACTIVE_LOW) - set_bit(FLAG_ACTIVE_LOW, &desc->flags); - if (lflags & GPIO_OPEN_DRAIN) - set_bit(FLAG_OPEN_DRAIN, &desc->flags); - if (lflags & GPIO_OPEN_SOURCE) - set_bit(FLAG_OPEN_SOURCE, &desc->flags); - /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { pr_debug("no flags found for %s\n", con_id); @@ -2044,11 +2164,13 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, return desc; } + gpiod_parse_flags(desc, lookupflags); + status = gpiod_request(desc, con_id); if (status < 0) return ERR_PTR(status); - status = gpiod_configure_flags(desc, con_id, lookupflags, flags); + status = gpiod_configure_flags(desc, con_id, flags); if (status < 0) { dev_dbg(dev, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); @@ -2078,6 +2200,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, { struct gpio_desc *desc = ERR_PTR(-ENODEV); bool active_low = false; + bool single_ended = false; int ret; if (!fwnode) @@ -2088,13 +2211,14 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0, &flags); - if (!IS_ERR(desc)) + if (!IS_ERR(desc)) { active_low = flags & OF_GPIO_ACTIVE_LOW; + single_ended = flags & OF_GPIO_SINGLE_ENDED; + } } else if (is_acpi_node(fwnode)) { struct acpi_gpio_info info; - desc = acpi_get_gpiod_by_index(to_acpi_node(fwnode), propname, 0, - &info); + desc = acpi_node_get_gpiod(fwnode, propname, 0, &info); if (!IS_ERR(desc)) active_low = info.active_low; } @@ -2102,14 +2226,20 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, if (IS_ERR(desc)) return desc; + if (active_low) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + + if (single_ended) { + if (active_low) + set_bit(FLAG_OPEN_DRAIN, &desc->flags); + else + set_bit(FLAG_OPEN_SOURCE, &desc->flags); + } + ret = gpiod_request(desc, NULL); if (ret) return ERR_PTR(ret); - /* Only value flag can be set from both DT and ACPI is active_low */ - if (active_low) - set_bit(FLAG_ACTIVE_LOW, &desc->flags); - return desc; } EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); @@ -2162,6 +2292,8 @@ int gpiod_hog(struct gpio_desc *desc, const char *name, chip = gpiod_to_chip(desc); hwnum = gpio_chip_hwgpio(desc); + gpiod_parse_flags(desc, lflags); + local_desc = gpiochip_request_own_desc(chip, hwnum, name); if (IS_ERR(local_desc)) { pr_err("requesting hog GPIO %s (chip %s, offset %d) failed\n", @@ -2169,7 +2301,7 @@ int gpiod_hog(struct gpio_desc *desc, const char *name, return PTR_ERR(local_desc); } - status = gpiod_configure_flags(desc, name, lflags, dflags); + status = gpiod_configure_flags(desc, name, dflags); if (status < 0) { pr_err("setup of hog GPIO %s (chip %s, offset %d) failed\n", name, chip->label, hwnum); @@ -2309,14 +2441,19 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) int is_irq; for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) { - if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) + if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) { + if (gdesc->name) { + seq_printf(s, " gpio-%-3d (%-20.20s)\n", + gpio, gdesc->name); + } continue; + } gpiod_get_direction(gdesc); is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); - seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s", - gpio, gdesc->label, + seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s", + gpio, gdesc->name ? gdesc->name : "", gdesc->label, is_out ? "out" : "in ", chip->get ? (chip->get(chip, i) ? "hi" : "lo") |