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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c326
1 files changed, 293 insertions, 33 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e8e98ca25ec..487afe6f22f 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