diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 156 |
1 files changed, 137 insertions, 19 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d8ccb500872f..e11a3bb03820 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -61,6 +61,11 @@ static struct bus_type gpio_bus_type = { .name = "gpio", }; +/* + * Number of GPIOs to use for the fast path in set array + */ +#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT + /* gpio_lock prevents conflicts during gpio_desc[] table updates. * While any GPIO is requested, its gpio_chip is not removable; * each GPIO's "requested" flag serves as a lock and refcount. @@ -71,6 +76,9 @@ static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); LIST_HEAD(gpio_devices); +static DEFINE_MUTEX(gpio_machine_hogs_mutex); +static LIST_HEAD(gpio_machine_hogs); + static void gpiochip_free_hogs(struct gpio_chip *chip); static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, struct lock_class_key *lock_key, @@ -450,12 +458,11 @@ static long linehandle_ioctl(struct file *filep, unsigned int cmd, vals[i] = !!ghd.values[i]; /* Reuse the array setting function */ - gpiod_set_array_value_complex(false, + return gpiod_set_array_value_complex(false, true, lh->numdescs, lh->descs, vals); - return 0; } return -EINVAL; } @@ -1172,6 +1179,41 @@ err_remove_device: return status; } +static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog) +{ + struct gpio_desc *desc; + int rv; + + desc = gpiochip_get_desc(chip, hog->chip_hwnum); + if (IS_ERR(desc)) { + pr_err("%s: unable to get GPIO desc: %ld\n", + __func__, PTR_ERR(desc)); + return; + } + + if (test_bit(FLAG_IS_HOGGED, &desc->flags)) + return; + + rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags); + if (rv) + pr_err("%s: unable to hog GPIO line (%s:%u): %d\n", + __func__, chip->label, hog->chip_hwnum, rv); +} + +static void machine_gpiochip_add(struct gpio_chip *chip) +{ + struct gpiod_hog *hog; + + mutex_lock(&gpio_machine_hogs_mutex); + + list_for_each_entry(hog, &gpio_machine_hogs, list) { + if (!strcmp(chip->label, hog->chip_label)) + gpiochip_machine_hog(chip, hog); + } + + mutex_unlock(&gpio_machine_hogs_mutex); +} + static void gpiochip_setup_devs(void) { struct gpio_device *gdev; @@ -1244,6 +1286,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, goto err_free_descs; } + if (chip->ngpio > FASTPATH_NGPIO) + chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n", + chip->ngpio, FASTPATH_NGPIO); + gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL); if (!gdev->label) { status = -ENOMEM; @@ -1327,6 +1373,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, acpi_gpiochip_add(chip); + machine_gpiochip_add(chip); + /* * By first adding the chardev, and then adding the device, * we get a device node entry in sysfs under @@ -2078,6 +2126,11 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_config); * @pctldev: the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_group: name of the pin group inside the pin controller + * + * Calling this function directly from a DeviceTree-supported + * pinctrl driver is DEPRECATED. Please see Section 2.1 of + * Documentation/devicetree/bindings/gpio/gpio.txt on how to + * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pingroup_range(struct gpio_chip *chip, struct pinctrl_dev *pctldev, @@ -2131,6 +2184,11 @@ EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); * * Returns: * 0 on success, or a negative error-code on failure. + * + * Calling this function directly from a DeviceTree-supported + * pinctrl driver is DEPRECATED. Please see Section 2.1 of + * Documentation/devicetree/bindings/gpio/gpio.txt on how to + * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, @@ -2719,16 +2777,28 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, while (i < array_size) { struct gpio_chip *chip = desc_array[i]->gdev->chip; - unsigned long mask[BITS_TO_LONGS(chip->ngpio)]; - unsigned long bits[BITS_TO_LONGS(chip->ngpio)]; + unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)]; + unsigned long *mask, *bits; int first, j, ret; + if (likely(chip->ngpio <= FASTPATH_NGPIO)) { + mask = fastpath; + } else { + mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio), + sizeof(*mask), + can_sleep ? GFP_KERNEL : GFP_ATOMIC); + if (!mask) + return -ENOMEM; + } + + bits = mask + BITS_TO_LONGS(chip->ngpio); + bitmap_zero(mask, chip->ngpio); + if (!can_sleep) WARN_ON(chip->can_sleep); /* collect all inputs belonging to the same chip */ first = i; - memset(mask, 0, sizeof(mask)); do { const struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); @@ -2739,8 +2809,11 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, (desc_array[i]->gdev->chip == chip)); ret = gpio_chip_get_multiple(chip, mask, bits); - if (ret) + if (ret) { + if (mask != fastpath) + kfree(mask); return ret; + } for (j = first; j < i; j++) { const struct gpio_desc *desc = desc_array[j]; @@ -2752,6 +2825,9 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, value_array[j] = value; trace_gpio_value(desc_to_gpio(desc), 1, value); } + + if (mask != fastpath) + kfree(mask); } return 0; } @@ -2935,7 +3011,7 @@ static void gpio_chip_set_multiple(struct gpio_chip *chip, } } -void gpiod_set_array_value_complex(bool raw, bool can_sleep, +int gpiod_set_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, int *value_array) @@ -2944,14 +3020,26 @@ void gpiod_set_array_value_complex(bool raw, bool can_sleep, while (i < array_size) { struct gpio_chip *chip = desc_array[i]->gdev->chip; - unsigned long mask[BITS_TO_LONGS(chip->ngpio)]; - unsigned long bits[BITS_TO_LONGS(chip->ngpio)]; + unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)]; + unsigned long *mask, *bits; int count = 0; + if (likely(chip->ngpio <= FASTPATH_NGPIO)) { + mask = fastpath; + } else { + mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio), + sizeof(*mask), + can_sleep ? GFP_KERNEL : GFP_ATOMIC); + if (!mask) + return -ENOMEM; + } + + bits = mask + BITS_TO_LONGS(chip->ngpio); + bitmap_zero(mask, chip->ngpio); + if (!can_sleep) WARN_ON(chip->can_sleep); - memset(mask, 0, sizeof(mask)); do { struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); @@ -2982,7 +3070,11 @@ void gpiod_set_array_value_complex(bool raw, bool can_sleep, /* push collected bits to outputs */ if (count != 0) gpio_chip_set_multiple(chip, mask, bits); + + if (mask != fastpath) + kfree(mask); } + return 0; } /** @@ -3057,13 +3149,13 @@ EXPORT_SYMBOL_GPL(gpiod_set_value); * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ -void gpiod_set_raw_array_value(unsigned int array_size, +int gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { if (!desc_array) - return; - gpiod_set_array_value_complex(true, false, array_size, desc_array, - value_array); + return -EINVAL; + return gpiod_set_array_value_complex(true, false, array_size, + desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value); @@ -3383,14 +3475,14 @@ EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); * * This function is to be called from contexts that can sleep. */ -void gpiod_set_raw_array_value_cansleep(unsigned int array_size, +int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, int *value_array) { might_sleep_if(extra_checks); if (!desc_array) - return; - gpiod_set_array_value_complex(true, true, array_size, desc_array, + return -EINVAL; + return gpiod_set_array_value_complex(true, true, array_size, desc_array, value_array); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep); @@ -3463,6 +3555,33 @@ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) } EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table); +/** + * gpiod_add_hogs() - register a set of GPIO hogs from machine code + * @hogs: table of gpio hog entries with a zeroed sentinel at the end + */ +void gpiod_add_hogs(struct gpiod_hog *hogs) +{ + struct gpio_chip *chip; + struct gpiod_hog *hog; + + mutex_lock(&gpio_machine_hogs_mutex); + + for (hog = &hogs[0]; hog->chip_label; hog++) { + list_add_tail(&hog->list, &gpio_machine_hogs); + + /* + * The chip may have been registered earlier, so check if it + * exists and, if so, try to hog the line now. + */ + chip = find_chip_by_name(hog->chip_label); + if (chip) + gpiochip_machine_hog(chip, hog); + } + + mutex_unlock(&gpio_machine_hogs_mutex); +} +EXPORT_SYMBOL_GPL(gpiod_add_hogs); + static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) { const char *dev_id = dev ? dev_name(dev) : NULL; @@ -4023,8 +4142,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, if (count < 0) return ERR_PTR(count); - descs = kzalloc(sizeof(*descs) + sizeof(descs->desc[0]) * count, - GFP_KERNEL); + descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL); if (!descs) return ERR_PTR(-ENOMEM); |