diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r-- | drivers/gpio/gpiolib.c | 326 |
1 files changed, 293 insertions, 33 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e8e98ca25ec7..487afe6f22fc 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -47,8 +47,6 @@ */ DEFINE_SPINLOCK(gpio_lock); -static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; - #define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio) static DEFINE_MUTEX(gpio_lookup_lock); @@ -65,10 +63,24 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) */ 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]; + struct gpio_chip *chip; + unsigned long flags; + + spin_lock_irqsave(&gpio_lock, flags); + + list_for_each_entry(chip, &gpio_chips, list) { + if (chip->base <= gpio && chip->base + chip->ngpio > gpio) { + spin_unlock_irqrestore(&gpio_lock, flags); + return &chip->desc[gpio - chip->base]; + } + } + + spin_unlock_irqrestore(&gpio_lock, flags); + + if (!gpio_is_valid(gpio)) + WARN(1, "invalid GPIO %d\n", gpio); + + return NULL; } EXPORT_SYMBOL_GPL(gpio_to_desc); @@ -91,7 +103,7 @@ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, */ int desc_to_gpio(const struct gpio_desc *desc) { - return desc - &gpio_desc[0]; + return desc->chip->base + (desc - &desc->chip->desc[0]); } EXPORT_SYMBOL_GPL(desc_to_gpio); @@ -138,7 +150,7 @@ static int gpiochip_find_base(int ngpio) * * This function may sleep if gpiod_cansleep() is true. */ -int gpiod_get_direction(const struct gpio_desc *desc) +int gpiod_get_direction(struct gpio_desc *desc) { struct gpio_chip *chip; unsigned offset; @@ -154,13 +166,11 @@ int gpiod_get_direction(const struct gpio_desc *desc) if (status > 0) { /* GPIOF_DIR_IN, or other positive */ status = 1; - /* FLAG_IS_OUT is just a cache of the result of get_direction(), - * so it does not affect constness per se */ - clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); + clear_bit(FLAG_IS_OUT, &desc->flags); } if (status == 0) { /* GPIOF_DIR_OUT */ - set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); + set_bit(FLAG_IS_OUT, &desc->flags); } return status; } @@ -206,7 +216,7 @@ static int gpiochip_add_to_list(struct gpio_chip *chip) /** * gpiochip_add() - register a gpio_chip * @chip: the chip to register, with chip->base initialized - * Context: potentially before irqs or kmalloc will work + * Context: potentially before irqs will work * * Returns a negative errno if the chip can't be registered, such as * because the chip->base is invalid or already associated with a @@ -226,12 +236,11 @@ int gpiochip_add(struct gpio_chip *chip) int status = 0; unsigned id; int base = chip->base; + struct gpio_desc *descs; - if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1)) - && base >= 0) { - status = -EINVAL; - goto fail; - } + descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL); + if (!descs) + return -ENOMEM; spin_lock_irqsave(&gpio_lock, flags); @@ -247,10 +256,8 @@ int gpiochip_add(struct gpio_chip *chip) status = gpiochip_add_to_list(chip); if (status == 0) { - chip->desc = &gpio_desc[chip->base]; - for (id = 0; id < chip->ngpio; id++) { - struct gpio_desc *desc = &chip->desc[id]; + struct gpio_desc *desc = &descs[id]; desc->chip = chip; /* REVISIT: most hardware initializes GPIOs as @@ -266,6 +273,8 @@ int gpiochip_add(struct gpio_chip *chip) } } + chip->desc = descs; + spin_unlock_irqrestore(&gpio_lock, flags); #ifdef CONFIG_PINCTRL @@ -291,6 +300,9 @@ int gpiochip_add(struct gpio_chip *chip) unlock: spin_unlock_irqrestore(&gpio_lock, flags); fail: + kfree(descs); + chip->desc = NULL; + /* failures here can mean systems won't boot... */ pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__, chip->base, chip->base + chip->ngpio - 1, @@ -331,6 +343,9 @@ void gpiochip_remove(struct gpio_chip *chip) list_del(&chip->list); spin_unlock_irqrestore(&gpio_lock, flags); gpiochip_unexport(chip); + + kfree(chip->desc); + chip->desc = NULL; } EXPORT_SYMBOL_GPL(gpiochip_remove); @@ -495,7 +510,7 @@ static int gpiochip_irq_reqres(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); - if (gpio_lock_as_irq(chip, d->hwirq)) { + if (gpiochip_lock_as_irq(chip, d->hwirq)) { chip_err(chip, "unable to lock HW IRQ %lu for IRQ\n", d->hwirq); @@ -508,7 +523,7 @@ static void gpiochip_irq_relres(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); - gpio_unlock_as_irq(chip, d->hwirq); + gpiochip_unlock_as_irq(chip, d->hwirq); } static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) @@ -1254,6 +1269,88 @@ static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value) chip->set(chip, gpio_chip_hwgpio(desc), value); } +/* + * set multiple outputs on the same chip; + * use the chip's set_multiple function if available; + * otherwise set the outputs sequentially; + * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word + * defines which outputs are to be changed + * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word + * defines the values the outputs specified by mask are to be set to + */ +static void gpio_chip_set_multiple(struct gpio_chip *chip, + unsigned long *mask, unsigned long *bits) +{ + if (chip->set_multiple) { + chip->set_multiple(chip, mask, bits); + } else { + int i; + for (i = 0; i < chip->ngpio; i++) { + if (mask[BIT_WORD(i)] == 0) { + /* no more set bits in this mask word; + * skip ahead to the next word */ + i = (BIT_WORD(i) + 1) * BITS_PER_LONG - 1; + continue; + } + /* set outputs if the corresponding mask bit is set */ + if (__test_and_clear_bit(i, mask)) { + chip->set(chip, i, test_bit(i, bits)); + } + } + } +} + +static void gpiod_set_array_priv(bool raw, bool can_sleep, + unsigned int array_size, + struct gpio_desc **desc_array, + int *value_array) +{ + int i = 0; + + while (i < array_size) { + struct gpio_chip *chip = desc_array[i]->chip; + unsigned long mask[BITS_TO_LONGS(chip->ngpio)]; + unsigned long bits[BITS_TO_LONGS(chip->ngpio)]; + int count = 0; + + 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); + int value = value_array[i]; + + if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + value = !value; + trace_gpio_value(desc_to_gpio(desc), 0, value); + /* + * collect all normal outputs belonging to the same chip + * open drain and open source outputs are set individually + */ + 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 { + __set_bit(hwgpio, mask); + if (value) { + __set_bit(hwgpio, bits); + } else { + __clear_bit(hwgpio, bits); + } + count++; + } + i++; + } while ((i < array_size) && (desc_array[i]->chip == chip)); + /* push collected bits to outputs */ + if (count != 0) { + gpio_chip_set_multiple(chip, mask, bits); + } + } +} + /** * gpiod_set_raw_value() - assign a gpio's raw value * @desc: gpio whose value will be assigned @@ -1299,6 +1396,48 @@ void gpiod_set_value(struct gpio_desc *desc, int value) EXPORT_SYMBOL_GPL(gpiod_set_value); /** + * gpiod_set_raw_array() - assign values to an array of GPIOs + * @array_size: number of elements in the descriptor / value arrays + * @desc_array: array of GPIO descriptors whose values will be assigned + * @value_array: array of values to assign + * + * Set the raw values of the GPIOs, i.e. the values of the physical lines + * without regard for their ACTIVE_LOW status. + * + * 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(unsigned int array_size, + struct gpio_desc **desc_array, int *value_array) +{ + if (!desc_array) + return; + gpiod_set_array_priv(true, false, array_size, desc_array, value_array); +} +EXPORT_SYMBOL_GPL(gpiod_set_raw_array); + +/** + * gpiod_set_array() - assign values to an array of GPIOs + * @array_size: number of elements in the descriptor / value arrays + * @desc_array: array of GPIO descriptors whose values will be assigned + * @value_array: array of values to assign + * + * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status + * into account. + * + * This function should be called from contexts where we cannot sleep, and will + * complain if the GPIO chip functions potentially sleep. + */ +void gpiod_set_array(unsigned int array_size, + struct gpio_desc **desc_array, int *value_array) +{ + if (!desc_array) + return; + gpiod_set_array_priv(false, false, array_size, desc_array, value_array); +} +EXPORT_SYMBOL_GPL(gpiod_set_array); + +/** * gpiod_cansleep() - report whether gpio value access may sleep * @desc: gpio to check * @@ -1332,14 +1471,14 @@ int gpiod_to_irq(const struct gpio_desc *desc) EXPORT_SYMBOL_GPL(gpiod_to_irq); /** - * gpio_lock_as_irq() - lock a GPIO to be used as IRQ + * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ * @chip: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to lock down * a certain GPIO line to be used for IRQs. */ -int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) +int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return -EINVAL; @@ -1354,24 +1493,24 @@ int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) set_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags); return 0; } -EXPORT_SYMBOL_GPL(gpio_lock_as_irq); +EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); /** - * gpio_unlock_as_irq() - unlock a GPIO used as IRQ + * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ * @chip: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to indicate * that a certain GPIO is no longer used exclusively for IRQ. */ -void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) +void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) { if (offset >= chip->ngpio) return; clear_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags); } -EXPORT_SYMBOL_GPL(gpio_unlock_as_irq); +EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); /** * gpiod_get_raw_value_cansleep() - return a gpio's raw value @@ -1458,6 +1597,50 @@ void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); /** + * gpiod_set_raw_array_cansleep() - assign values to an array of GPIOs + * @array_size: number of elements in the descriptor / value arrays + * @desc_array: array of GPIO descriptors whose values will be assigned + * @value_array: array of values to assign + * + * Set the raw values of the GPIOs, i.e. the values of the physical lines + * without regard for their ACTIVE_LOW status. + * + * This function is to be called from contexts that can sleep. + */ +void gpiod_set_raw_array_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_priv(true, true, array_size, desc_array, value_array); +} +EXPORT_SYMBOL_GPL(gpiod_set_raw_array_cansleep); + +/** + * gpiod_set_array_cansleep() - assign values to an array of GPIOs + * @array_size: number of elements in the descriptor / value arrays + * @desc_array: array of GPIO descriptors whose values will be assigned + * @value_array: array of values to assign + * + * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status + * into account. + * + * This function is to be called from contexts that can sleep. + */ +void gpiod_set_array_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_priv(false, true, array_size, desc_array, value_array); +} +EXPORT_SYMBOL_GPL(gpiod_set_array_cansleep); + +/** * gpiod_add_lookup_table() - register GPIO device consumers * @table: table of consumers to register */ @@ -1505,14 +1688,36 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) { + static const char * const suffixes[] = { "gpios", "gpio" }; + struct acpi_device *adev = ACPI_COMPANION(dev); struct acpi_gpio_info info; struct gpio_desc *desc; + char propname[32]; + int i; - desc = acpi_get_gpiod_by_index(dev, idx, &info); - if (IS_ERR(desc)) - return desc; + /* Try first from _DSD */ + for (i = 0; i < ARRAY_SIZE(suffixes); i++) { + if (con_id && strcmp(con_id, "gpios")) { + snprintf(propname, sizeof(propname), "%s-%s", + con_id, suffixes[i]); + } else { + snprintf(propname, sizeof(propname), "%s", + suffixes[i]); + } - if (info.gpioint && info.active_low) + desc = acpi_get_gpiod_by_index(adev, propname, idx, &info); + if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER)) + break; + } + + /* Then from plain _CRS GPIOs */ + if (IS_ERR(desc)) { + desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info); + if (IS_ERR(desc)) + return desc; + } + + if (info.active_low) *flags |= GPIO_ACTIVE_LOW; return desc; @@ -1713,6 +1918,61 @@ struct gpio_desc *__must_check __gpiod_get_index(struct device *dev, EXPORT_SYMBOL_GPL(__gpiod_get_index); /** + * fwnode_get_named_gpiod - obtain a GPIO from firmware node + * @fwnode: handle of the firmware node + * @propname: name of the firmware property representing the GPIO + * + * This function can be used for drivers that get their configuration + * from firmware. + * + * Function properly finds the corresponding GPIO using whatever is the + * underlying firmware interface and then makes sure that the GPIO + * descriptor is requested before it is returned to the caller. + * + * In case of error an ERR_PTR() is returned. + */ +struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, + const char *propname) +{ + struct gpio_desc *desc = ERR_PTR(-ENODEV); + bool active_low = false; + int ret; + + if (!fwnode) + return ERR_PTR(-EINVAL); + + if (is_of_node(fwnode)) { + enum of_gpio_flags flags; + + desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0, + &flags); + if (!IS_ERR(desc)) + active_low = flags & OF_GPIO_ACTIVE_LOW; + } else if (is_acpi_node(fwnode)) { + struct acpi_gpio_info info; + + desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0, + &info); + if (!IS_ERR(desc)) + active_low = info.active_low; + } + + if (IS_ERR(desc)) + return desc; + + 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); + +/** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs |