#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
+#include <linux/acpi_gpio.h>
#include <linux/idr.h>
#include <linux/slab.h>
#define CREATE_TRACE_POINTS
#include <trace/events/gpio.h>
-/* Optional implementation infrastructure for GPIO interfaces.
+/* Implementation infrastructure for GPIO interfaces.
*
- * Platforms may want to use this if they tend to use very many GPIOs
- * that aren't part of a System-On-Chip core; or across I2C/SPI/etc.
- *
- * When kernel footprint or instruction count is an issue, simpler
- * implementations may be preferred. The GPIO programming interface
- * allows for inlining speed-critical get/set operations for common
- * cases, so that access to SOC-integrated GPIOs can sometimes cost
- * only an instruction or two per bit.
+ * The GPIO programming interface allows for inlining speed-critical
+ * get/set operations for common cases, so that access to SOC-integrated
+ * GPIOs can sometimes cost only an instruction or two per bit.
*/
#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
#define FLAG_TRIG_FALL 4 /* trigger on falling edge */
#define FLAG_TRIG_RISE 5 /* trigger on rising edge */
-#define FLAG_ACTIVE_LOW 6 /* sysfs value has active low */
+#define FLAG_ACTIVE_LOW 6 /* value has active low */
#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
+#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
#define ID_SHIFT 16 /* add new flags before this one */
#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
+static DEFINE_MUTEX(gpio_lookup_lock);
+static LIST_HEAD(gpio_lookup_list);
static LIST_HEAD(gpio_chips);
#ifdef CONFIG_GPIO_SYSFS
static DEFINE_IDR(dirent_idr);
#endif
-/*
- * Internal gpiod_* API using descriptors instead of the integer namespace.
- * Most of this should eventually go public.
- */
static int gpiod_request(struct gpio_desc *desc, const char *label);
static void gpiod_free(struct gpio_desc *desc);
-static int gpiod_direction_input(struct gpio_desc *desc);
-static int gpiod_direction_output(struct gpio_desc *desc, int value);
-static int gpiod_get_direction(const struct gpio_desc *desc);
-static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce);
-static int gpiod_get_value_cansleep(const struct gpio_desc *desc);
-static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value);
-static int gpiod_get_value(const struct gpio_desc *desc);
-static void gpiod_set_value(struct gpio_desc *desc, int value);
-static int gpiod_cansleep(const struct gpio_desc *desc);
-static int gpiod_to_irq(const struct gpio_desc *desc);
-static int gpiod_export(struct gpio_desc *desc, bool direction_may_change);
-static int gpiod_export_link(struct device *dev, const char *name,
- struct gpio_desc *desc);
-static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value);
-static void gpiod_unexport(struct gpio_desc *desc);
+#ifdef CONFIG_DEBUG_FS
+#define gpiod_emerg(desc, fmt, ...) \
+ pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#define gpiod_crit(desc, fmt, ...) \
+ pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#define gpiod_err(desc, fmt, ...) \
+ pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#define gpiod_warn(desc, fmt, ...) \
+ pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#define gpiod_info(desc, fmt, ...) \
+ pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#define gpiod_dbg(desc, fmt, ...) \
+ pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label, \
+ ##__VA_ARGS__)
+#else
+#define gpiod_emerg(desc, fmt, ...) \
+ pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_crit(desc, fmt, ...) \
+ pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_err(desc, fmt, ...) \
+ pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_warn(desc, fmt, ...) \
+ pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_info(desc, fmt, ...) \
+ pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#define gpiod_dbg(desc, fmt, ...) \
+ pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
+#endif
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
/**
* Convert a GPIO number to its descriptor
*/
-static struct gpio_desc *gpio_to_desc(unsigned gpio)
+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];
}
+EXPORT_SYMBOL_GPL(gpio_to_desc);
+
+/**
+ * Convert an offset on a certain chip to a corresponding descriptor
+ */
+static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ unsigned int gpio = chip->base + offset;
+
+ return gpio_to_desc(gpio);
+}
/**
* Convert a GPIO descriptor to the integer namespace.
* This should disappear in the future but is needed since we still
* use GPIO numbers for error messages and sysfs nodes
*/
-static int desc_to_gpio(const struct gpio_desc *desc)
+int desc_to_gpio(const struct gpio_desc *desc)
{
return desc - &gpio_desc[0];
}
+EXPORT_SYMBOL_GPL(desc_to_gpio);
/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
return 0;
}
-static struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
+/**
+ * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
+ * @desc: descriptor to return the chip of
+ */
+struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
return desc ? desc->chip : NULL;
}
-
-/* caller holds gpio_lock *OR* gpio is marked as requested */
-struct gpio_chip *gpio_to_chip(unsigned gpio)
-{
- return gpiod_to_chip(gpio_to_desc(gpio));
-}
+EXPORT_SYMBOL_GPL(gpiod_to_chip);
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base(int ngpio)
}
}
-/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
-static int gpiod_get_direction(const struct gpio_desc *desc)
+/**
+ * gpiod_get_direction - return the current direction of a GPIO
+ * @desc: GPIO to get the direction of
+ *
+ * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
+ *
+ * This function may sleep if gpiod_cansleep() is true.
+ */
+int gpiod_get_direction(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
}
return status;
}
+EXPORT_SYMBOL_GPL(gpiod_get_direction);
#ifdef CONFIG_GPIO_SYSFS
mutex_lock(&sysfs_lock);
- if (!test_bit(FLAG_EXPORT, &desc->flags)) {
+ if (!test_bit(FLAG_EXPORT, &desc->flags))
status = -EIO;
- } else {
- int value;
-
- value = !!gpiod_get_value_cansleep(desc);
- if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
- value = !value;
-
- status = sprintf(buf, "%d\n", value);
- }
+ else
+ status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
mutex_unlock(&sysfs_lock);
return status;
status = kstrtol(buf, 0, &value);
if (status == 0) {
- if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
- value = !value;
- gpiod_set_value_cansleep(desc, value != 0);
+ gpiod_set_value_cansleep(desc, value);
status = size;
}
}
desc->flags &= ~GPIO_TRIGGER_MASK;
if (!gpio_flags) {
+ gpiod_unlock_as_irq(desc);
ret = 0;
goto free_id;
}
if (ret < 0)
goto free_id;
+ ret = gpiod_lock_as_irq(desc);
+ if (ret < 0) {
+ gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
+ goto free_id;
+ }
+
desc->flags |= gpio_flags;
return 0;
/**
- * gpio_export - export a GPIO through sysfs
+ * gpiod_export - export a GPIO through sysfs
* @gpio: gpio to make available, already requested
* @direction_may_change: true if userspace may change gpio direction
* Context: arch_initcall or later
*
* Returns zero on success, else an error.
*/
-static int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
+int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
{
unsigned long flags;
int status;
status);
return status;
}
-
-int gpio_export(unsigned gpio, bool direction_may_change)
-{
- return gpiod_export(gpio_to_desc(gpio), direction_may_change);
-}
-EXPORT_SYMBOL_GPL(gpio_export);
+EXPORT_SYMBOL_GPL(gpiod_export);
static int match_export(struct device *dev, const void *data)
{
}
/**
- * gpio_export_link - create a sysfs link to an exported GPIO node
+ * gpiod_export_link - create a sysfs link to an exported GPIO node
* @dev: device under which to create symlink
* @name: name of the symlink
* @gpio: gpio to create symlink to, already exported
*
* Returns zero on success, else an error.
*/
-static int gpiod_export_link(struct device *dev, const char *name,
- struct gpio_desc *desc)
+int gpiod_export_link(struct device *dev, const char *name,
+ struct gpio_desc *desc)
{
int status = -EINVAL;
return status;
}
-
-int gpio_export_link(struct device *dev, const char *name, unsigned gpio)
-{
- return gpiod_export_link(dev, name, gpio_to_desc(gpio));
-}
-EXPORT_SYMBOL_GPL(gpio_export_link);
+EXPORT_SYMBOL_GPL(gpiod_export_link);
/**
- * gpio_sysfs_set_active_low - set the polarity of gpio sysfs value
+ * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value
* @gpio: gpio to change
* @value: non-zero to use active low, i.e. inverted values
*
*
* Returns zero on success, else an error.
*/
-static int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
+int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
{
struct device *dev = NULL;
int status = -EINVAL;
return status;
}
-
-int gpio_sysfs_set_active_low(unsigned gpio, int value)
-{
- return gpiod_sysfs_set_active_low(gpio_to_desc(gpio), value);
-}
-EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
+EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
/**
- * gpio_unexport - reverse effect of gpio_export()
+ * gpiod_unexport - reverse effect of gpio_export()
* @gpio: gpio to make unavailable
*
* This is implicit on gpio_free().
*/
-static void gpiod_unexport(struct gpio_desc *desc)
+void gpiod_unexport(struct gpio_desc *desc)
{
int status = 0;
struct device *dev = NULL;
pr_debug("%s: gpio%d status %d\n", __func__, desc_to_gpio(desc),
status);
}
-
-void gpio_unexport(unsigned gpio)
-{
- gpiod_unexport(gpio_to_desc(gpio));
-}
-EXPORT_SYMBOL_GPL(gpio_unexport);
+EXPORT_SYMBOL_GPL(gpiod_unexport);
static int gpiochip_export(struct gpio_chip *chip)
{
{
}
-static inline int gpiod_export(struct gpio_desc *desc,
- bool direction_may_change)
-{
- return -ENOSYS;
-}
-
-static inline int gpiod_export_link(struct device *dev, const char *name,
- struct gpio_desc *desc)
-{
- return -ENOSYS;
-}
-
-static inline int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
-{
- return -ENOSYS;
-}
-
-static inline void gpiod_unexport(struct gpio_desc *desc)
-{
-}
-
#endif /* CONFIG_GPIO_SYSFS */
/*
* rely on gpio_request() having been called beforehand.
*/
-static int gpiod_direction_input(struct gpio_desc *desc)
+/**
+ * gpiod_direction_input - set the GPIO direction to input
+ * @desc: GPIO to set to input
+ *
+ * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
+ * be called safely on it.
+ *
+ * Return 0 in case of success, else an error code.
+ */
+int gpiod_direction_input(struct gpio_desc *desc)
{
unsigned long flags;
struct gpio_chip *chip;
chip = desc->chip;
if (!chip->get || !chip->direction_input) {
- pr_warn("%s: missing get() or direction_input() operations\n",
- __func__);
+ gpiod_warn(desc,
+ "%s: missing get() or direction_input() operations\n",
+ __func__);
return -EIO;
}
if (status) {
status = chip->request(chip, offset);
if (status < 0) {
- pr_debug("GPIO-%d: chip request fail, %d\n",
- desc_to_gpio(desc), status);
+ gpiod_dbg(desc, "chip request fail, %d\n", status);
/* and it's not available to anyone else ...
* gpio_request() is the fully clean solution.
*/
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
if (status)
- pr_debug("%s: gpio-%d status %d\n", __func__,
- desc_to_gpio(desc), status);
+ gpiod_dbg(desc, "%s status %d\n", __func__, status);
return status;
}
+EXPORT_SYMBOL_GPL(gpiod_direction_input);
-int gpio_direction_input(unsigned gpio)
-{
- return gpiod_direction_input(gpio_to_desc(gpio));
-}
-EXPORT_SYMBOL_GPL(gpio_direction_input);
-
-static int gpiod_direction_output(struct gpio_desc *desc, int value)
+/**
+ * gpiod_direction_output - set the GPIO direction to input
+ * @desc: GPIO to set to output
+ * @value: initial output value of the GPIO
+ *
+ * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
+ * be called safely on it. The initial value of the output must be specified.
+ *
+ * Return 0 in case of success, else an error code.
+ */
+int gpiod_direction_output(struct gpio_desc *desc, int value)
{
unsigned long flags;
struct gpio_chip *chip;
return -EINVAL;
}
+ /* GPIOs used for IRQs shall not be set as output */
+ if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
+ gpiod_err(desc,
+ "%s: tried to set a GPIO tied to an IRQ as output\n",
+ __func__);
+ return -EIO;
+ }
+
/* Open drain pin should not be driven to 1 */
if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
return gpiod_direction_input(desc);
chip = desc->chip;
if (!chip->set || !chip->direction_output) {
- pr_warn("%s: missing set() or direction_output() operations\n",
- __func__);
+ gpiod_warn(desc,
+ "%s: missing set() or direction_output() operations\n",
+ __func__);
return -EIO;
}
if (status) {
status = chip->request(chip, offset);
if (status < 0) {
- pr_debug("GPIO-%d: chip request fail, %d\n",
- desc_to_gpio(desc), status);
+ gpiod_dbg(desc, "chip request fail, %d\n", status);
/* and it's not available to anyone else ...
* gpio_request() is the fully clean solution.
*/
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
if (status)
- pr_debug("%s: gpio-%d status %d\n", __func__,
- desc_to_gpio(desc), status);
+ gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
return status;
}
-
-int gpio_direction_output(unsigned gpio, int value)
-{
- return gpiod_direction_output(gpio_to_desc(gpio), value);
-}
-EXPORT_SYMBOL_GPL(gpio_direction_output);
+EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
- * gpio_set_debounce - sets @debounce time for a @gpio
+ * gpiod_set_debounce - sets @debounce time for a @gpio
* @gpio: the gpio to set debounce time
* @debounce: debounce time is microseconds
*
* returns -ENOTSUPP if the controller does not support setting
* debounce.
*/
-static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
+int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
unsigned long flags;
struct gpio_chip *chip;
chip = desc->chip;
if (!chip->set || !chip->set_debounce) {
- pr_debug("%s: missing set() or set_debounce() operations\n",
- __func__);
+ gpiod_dbg(desc,
+ "%s: missing set() or set_debounce() operations\n",
+ __func__);
return -ENOTSUPP;
}
fail:
spin_unlock_irqrestore(&gpio_lock, flags);
if (status)
- pr_debug("%s: gpio-%d status %d\n", __func__,
- desc_to_gpio(desc), status);
+ gpiod_dbg(desc, "%s: status %d\n", __func__, status);
return status;
}
+EXPORT_SYMBOL_GPL(gpiod_set_debounce);
-int gpio_set_debounce(unsigned gpio, unsigned debounce)
+/**
+ * gpiod_is_active_low - test whether a GPIO is active-low or not
+ * @desc: the gpio descriptor to test
+ *
+ * Returns 1 if the GPIO is active-low, 0 otherwise.
+ */
+int gpiod_is_active_low(const struct gpio_desc *desc)
{
- return gpiod_set_debounce(gpio_to_desc(gpio), debounce);
+ return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
-EXPORT_SYMBOL_GPL(gpio_set_debounce);
+EXPORT_SYMBOL_GPL(gpiod_is_active_low);
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
* that the GPIO was actually requested.
*/
-/**
- * __gpio_get_value() - return a gpio's value
- * @gpio: gpio whose value will be returned
- * Context: any
- *
- * This is used directly or indirectly to implement gpio_get_value().
- * It returns the zero or nonzero value provided by the associated
- * gpio_chip.get() method; or zero if no such method is provided.
- */
-static int gpiod_get_value(const struct gpio_desc *desc)
+static int _gpiod_get_raw_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int value;
int offset;
- if (!desc)
- return 0;
chip = desc->chip;
offset = gpio_chip_hwgpio(desc);
- /* Should be using gpio_get_value_cansleep() */
- WARN_ON(chip->can_sleep);
value = chip->get ? chip->get(chip, offset) : 0;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}
-int __gpio_get_value(unsigned gpio)
+/**
+ * gpiod_get_raw_value() - return a gpio's raw value
+ * @desc: gpio whose value will be returned
+ *
+ * Return the GPIO's raw value, i.e. the value of the physical line disregarding
+ * its ACTIVE_LOW status.
+ *
+ * This function should be called from contexts where we cannot sleep, and will
+ * complain if the GPIO chip functions potentially sleep.
+ */
+int gpiod_get_raw_value(const struct gpio_desc *desc)
+{
+ if (!desc)
+ return 0;
+ /* Should be using gpio_get_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ return _gpiod_get_raw_value(desc);
+}
+EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
+
+/**
+ * gpiod_get_value() - return a gpio's value
+ * @desc: gpio whose value will be returned
+ *
+ * Return the GPIO's logical value, i.e. taking the 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.
+ */
+int gpiod_get_value(const struct gpio_desc *desc)
{
- return gpiod_get_value(gpio_to_desc(gpio));
+ int value;
+ if (!desc)
+ return 0;
+ /* Should be using gpio_get_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+
+ value = _gpiod_get_raw_value(desc);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+
+ return value;
}
-EXPORT_SYMBOL_GPL(__gpio_get_value);
+EXPORT_SYMBOL_GPL(gpiod_get_value);
/*
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
- * @gpio: Gpio whose state need to be set.
- * @chip: Gpio chip.
+ * @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
*/
static void _gpio_set_open_drain_value(struct gpio_desc *desc, int value)
}
trace_gpio_direction(desc_to_gpio(desc), value, err);
if (err < 0)
- pr_err("%s: Error in set_value for open drain gpio%d err %d\n",
- __func__, desc_to_gpio(desc), err);
+ gpiod_err(desc,
+ "%s: Error in set_value for open drain err %d\n",
+ __func__, err);
}
/*
- * _gpio_set_open_source() - Set the open source gpio's value.
- * @gpio: Gpio whose state need to be set.
- * @chip: Gpio chip.
+ * _gpio_set_open_source_value() - Set the open source gpio's value.
+ * @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
*/
static void _gpio_set_open_source_value(struct gpio_desc *desc, int value)
}
trace_gpio_direction(desc_to_gpio(desc), !value, err);
if (err < 0)
- pr_err("%s: Error in set_value for open source gpio%d err %d\n",
- __func__, desc_to_gpio(desc), err);
+ gpiod_err(desc,
+ "%s: Error in set_value for open source err %d\n",
+ __func__, err);
}
-/**
- * __gpio_set_value() - assign a gpio's value
- * @gpio: gpio whose value will be assigned
- * @value: value to assign
- * Context: any
- *
- * This is used directly or indirectly to implement gpio_set_value().
- * It invokes the associated gpio_chip.set() method.
- */
-static void gpiod_set_value(struct gpio_desc *desc, int value)
+static void _gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
struct gpio_chip *chip;
- if (!desc)
- return;
chip = desc->chip;
- /* Should be using gpio_set_value_cansleep() */
- WARN_ON(chip->can_sleep);
trace_gpio_value(desc_to_gpio(desc), 0, value);
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
_gpio_set_open_drain_value(desc, value);
chip->set(chip, gpio_chip_hwgpio(desc), value);
}
-void __gpio_set_value(unsigned gpio, int value)
+/**
+ * gpiod_set_raw_value() - assign a gpio's raw value
+ * @desc: gpio whose value will be assigned
+ * @value: value to assign
+ *
+ * Set the raw value of the GPIO, i.e. the value of its physical line without
+ * regard for its 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_value(struct gpio_desc *desc, int value)
{
- return gpiod_set_value(gpio_to_desc(gpio), value);
+ if (!desc)
+ return;
+ /* Should be using gpio_set_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ _gpiod_set_raw_value(desc, value);
}
-EXPORT_SYMBOL_GPL(__gpio_set_value);
+EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
- * __gpio_cansleep() - report whether gpio value access will sleep
- * @gpio: gpio in question
- * Context: any
+ * gpiod_set_value() - assign a gpio's value
+ * @desc: gpio whose value will be assigned
+ * @value: value to assign
+ *
+ * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
+ * account
*
- * This is used directly or indirectly to implement gpio_cansleep(). It
- * returns nonzero if access reading or writing the GPIO value can sleep.
+ * This function should be called from contexts where we cannot sleep, and will
+ * complain if the GPIO chip functions potentially sleep.
*/
-static int gpiod_cansleep(const struct gpio_desc *desc)
+void gpiod_set_value(struct gpio_desc *desc, int value)
{
if (!desc)
- return 0;
- /* only call this on GPIOs that are valid! */
- return desc->chip->can_sleep;
+ return;
+ /* Should be using gpio_set_value_cansleep() */
+ WARN_ON(desc->chip->can_sleep);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ _gpiod_set_raw_value(desc, value);
}
+EXPORT_SYMBOL_GPL(gpiod_set_value);
-int __gpio_cansleep(unsigned gpio)
+/**
+ * gpiod_cansleep() - report whether gpio value access may sleep
+ * @desc: gpio to check
+ *
+ */
+int gpiod_cansleep(const struct gpio_desc *desc)
{
- return gpiod_cansleep(gpio_to_desc(gpio));
+ if (!desc)
+ return 0;
+ return desc->chip->can_sleep;
}
-EXPORT_SYMBOL_GPL(__gpio_cansleep);
+EXPORT_SYMBOL_GPL(gpiod_cansleep);
/**
- * __gpio_to_irq() - return the IRQ corresponding to a GPIO
- * @gpio: gpio whose IRQ will be returned (already requested)
- * Context: any
+ * gpiod_to_irq() - return the IRQ corresponding to a GPIO
+ * @desc: gpio whose IRQ will be returned (already requested)
*
- * This is used directly or indirectly to implement gpio_to_irq().
- * It returns the number of the IRQ signaled by this (input) GPIO,
- * or a negative errno.
+ * Return the IRQ corresponding to the passed GPIO, or an error code in case of
+ * error.
*/
-static int gpiod_to_irq(const struct gpio_desc *desc)
+int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
offset = gpio_chip_hwgpio(desc);
return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
}
+EXPORT_SYMBOL_GPL(gpiod_to_irq);
+
+/**
+ * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
+ * @gpio: the GPIO line to lock as used for IRQ
+ *
+ * This is used directly by GPIO drivers that want to lock down
+ * a certain GPIO line to be used as IRQs, for example in the
+ * .to_irq() callback of their gpio_chip, or in the .irq_enable()
+ * of its irq_chip implementation if the GPIO is known from that
+ * code.
+ */
+int gpiod_lock_as_irq(struct gpio_desc *desc)
+{
+ if (!desc)
+ return -EINVAL;
+
+ if (test_bit(FLAG_IS_OUT, &desc->flags)) {
+ gpiod_err(desc,
+ "%s: tried to flag a GPIO set as output for IRQ\n",
+ __func__);
+ return -EIO;
+ }
+
+ set_bit(FLAG_USED_AS_IRQ, &desc->flags);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpiod_lock_as_irq);
+
+int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
+{
+ return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset));
+}
+EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
-int __gpio_to_irq(unsigned gpio)
+/**
+ * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
+ * @gpio: the GPIO line to unlock from IRQ usage
+ *
+ * This is used directly by GPIO drivers that want to indicate
+ * that a certain GPIO is no longer used exclusively for IRQ.
+ */
+void gpiod_unlock_as_irq(struct gpio_desc *desc)
{
- return gpiod_to_irq(gpio_to_desc(gpio));
+ if (!desc)
+ return;
+
+ clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
}
-EXPORT_SYMBOL_GPL(__gpio_to_irq);
+EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq);
+void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
+{
+ return gpiod_unlock_as_irq(gpiochip_offset_to_desc(chip, offset));
+}
+EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
-/* There's no value in making it easy to inline GPIO calls that may sleep.
- * Common examples include ones connected to I2C or SPI chips.
+/**
+ * gpiod_get_raw_value_cansleep() - return a gpio's raw value
+ * @desc: gpio whose value will be returned
+ *
+ * Return the GPIO's raw value, i.e. the value of the physical line disregarding
+ * its ACTIVE_LOW status.
+ *
+ * This function is to be called from contexts that can sleep.
*/
+int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
+{
+ might_sleep_if(extra_checks);
+ if (!desc)
+ return 0;
+ return _gpiod_get_raw_value(desc);
+}
+EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
-static int gpiod_get_value_cansleep(const struct gpio_desc *desc)
+/**
+ * gpiod_get_value_cansleep() - return a gpio's value
+ * @desc: gpio whose value will be returned
+ *
+ * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
+ * account.
+ *
+ * This function is to be called from contexts that can sleep.
+ */
+int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
- struct gpio_chip *chip;
int value;
- int offset;
might_sleep_if(extra_checks);
if (!desc)
return 0;
- chip = desc->chip;
- offset = gpio_chip_hwgpio(desc);
- value = chip->get ? chip->get(chip, offset) : 0;
- trace_gpio_value(desc_to_gpio(desc), 1, value);
+
+ value = _gpiod_get_raw_value(desc);
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+
return value;
}
+EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
-int gpio_get_value_cansleep(unsigned gpio)
+/**
+ * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
+ * @desc: gpio whose value will be assigned
+ * @value: value to assign
+ *
+ * Set the raw value of the GPIO, i.e. the value of its physical line without
+ * regard for its ACTIVE_LOW status.
+ *
+ * This function is to be called from contexts that can sleep.
+ */
+void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
{
- return gpiod_get_value_cansleep(gpio_to_desc(gpio));
+ might_sleep_if(extra_checks);
+ if (!desc)
+ return;
+ _gpiod_set_raw_value(desc, value);
}
-EXPORT_SYMBOL_GPL(gpio_get_value_cansleep);
+EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
-static void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
+/**
+ * gpiod_set_value_cansleep() - assign a gpio's value
+ * @desc: gpio whose value will be assigned
+ * @value: value to assign
+ *
+ * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
+ * account
+ *
+ * This function is to be called from contexts that can sleep.
+ */
+void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
- struct gpio_chip *chip;
-
might_sleep_if(extra_checks);
if (!desc)
return;
- chip = desc->chip;
- trace_gpio_value(desc_to_gpio(desc), 0, value);
- 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);
+
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ _gpiod_set_raw_value(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
+
+/**
+ * gpiod_add_table() - register GPIO device consumers
+ * @table: array of consumers to register
+ * @num: number of consumers in table
+ */
+void gpiod_add_table(struct gpiod_lookup *table, size_t size)
+{
+ mutex_lock(&gpio_lookup_lock);
+
+ while (size--) {
+ list_add_tail(&table->list, &gpio_lookup_list);
+ table++;
+ }
+
+ mutex_unlock(&gpio_lookup_lock);
+}
+
+/*
+ * Caller must have a acquired gpio_lookup_lock
+ */
+static struct gpio_chip *find_chip_by_name(const char *name)
+{
+ struct gpio_chip *chip = NULL;
+
+ list_for_each_entry(chip, &gpio_lookup_list, list) {
+ if (chip->label == NULL)
+ continue;
+ if (!strcmp(chip->label, name))
+ break;
+ }
+
+ return chip;
+}
+
+#ifdef CONFIG_OF
+static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx, unsigned long *flags)
+{
+ char prop_name[32]; /* 32 is max size of property name */
+ enum of_gpio_flags of_flags;
+ struct gpio_desc *desc;
+
+ if (con_id)
+ snprintf(prop_name, 32, "%s-gpios", con_id);
else
- chip->set(chip, gpio_chip_hwgpio(desc), value);
+ snprintf(prop_name, 32, "gpios");
+
+ desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
+ &of_flags);
+
+ if (IS_ERR(desc))
+ return desc;
+
+ if (of_flags & OF_GPIO_ACTIVE_LOW)
+ *flags |= GPIOF_ACTIVE_LOW;
+
+ return desc;
+}
+#else
+static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx, unsigned long *flags)
+{
+ return ERR_PTR(-ENODEV);
+}
+#endif
+
+static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
+ unsigned int idx, unsigned long *flags)
+{
+ struct acpi_gpio_info info;
+ struct gpio_desc *desc;
+
+ desc = acpi_get_gpiod_by_index(dev, idx, &info);
+ if (IS_ERR(desc))
+ return desc;
+
+ if (info.gpioint && info.active_low)
+ *flags |= GPIOF_ACTIVE_LOW;
+
+ return desc;
+}
+
+static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
+ unsigned int idx, unsigned long *flags)
+{
+ const char *dev_id = dev ? dev_name(dev) : NULL;
+ struct gpio_desc *desc = ERR_PTR(-ENODEV);
+ unsigned int match, best = 0;
+ struct gpiod_lookup *p;
+
+ mutex_lock(&gpio_lookup_lock);
+
+ list_for_each_entry(p, &gpio_lookup_list, list) {
+ match = 0;
+
+ if (p->dev_id) {
+ if (!dev_id || strcmp(p->dev_id, dev_id))
+ continue;
+
+ match += 2;
+ }
+
+ if (p->con_id) {
+ if (!con_id || strcmp(p->con_id, con_id))
+ continue;
+
+ match += 1;
+ }
+
+ if (p->idx != idx)
+ continue;
+
+ if (match > best) {
+ struct gpio_chip *chip;
+
+ chip = find_chip_by_name(p->chip_label);
+
+ if (!chip) {
+ dev_warn(dev, "cannot find GPIO chip %s\n",
+ p->chip_label);
+ continue;
+ }
+
+ if (chip->ngpio >= p->chip_hwnum) {
+ dev_warn(dev, "GPIO chip %s has %d GPIOs\n",
+ chip->label, chip->ngpio);
+ continue;
+ }
+
+ desc = gpio_to_desc(chip->base + p->chip_hwnum);
+ *flags = p->flags;
+
+ if (match != 3)
+ best = match;
+ else
+ break;
+ }
+ }
+
+ mutex_unlock(&gpio_lookup_lock);
+
+ return desc;
+}
+
+/**
+ * gpio_get - obtain a GPIO for a given GPIO function
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ *
+ * Return the GPIO descriptor corresponding to the function con_id of device
+ * dev, or an IS_ERR() condition if an error occured.
+ */
+struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
+{
+ return gpiod_get_index(dev, con_id, 0);
+}
+EXPORT_SYMBOL_GPL(gpiod_get);
+
+/**
+ * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
+ * @dev: GPIO consumer
+ * @con_id: function within the GPIO consumer
+ * @idx: index of the GPIO to obtain in the consumer
+ *
+ * This variant of gpiod_get() allows to access GPIOs other than the first
+ * defined one for functions that define several GPIOs.
+ *
+ * Return a valid GPIO descriptor, or an IS_ERR() condition in case of error.
+ */
+struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
+ const char *con_id,
+ unsigned int idx)
+{
+ struct gpio_desc *desc;
+ int status;
+ unsigned long flags = 0;
+
+ dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
+
+ /* Using device tree? */
+ if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
+ dev_dbg(dev, "using device tree for GPIO lookup\n");
+ desc = of_find_gpio(dev, con_id, idx, &flags);
+ } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
+ dev_dbg(dev, "using ACPI for GPIO lookup\n");
+ desc = acpi_find_gpio(dev, con_id, idx, &flags);
+ } else {
+ dev_dbg(dev, "using lookup tables for GPIO lookup");
+ desc = gpiod_find(dev, con_id, idx, &flags);
+ }
+
+ if (IS_ERR(desc)) {
+ dev_warn(dev, "lookup for GPIO %s failed\n", con_id);
+ return desc;
+ }
+
+ status = gpiod_request(desc, con_id);
+
+ if (status < 0)
+ return ERR_PTR(status);
+
+ if (flags & GPIOF_ACTIVE_LOW)
+ set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+
+ return desc;
}
+EXPORT_SYMBOL_GPL(gpiod_get_index);
-void gpio_set_value_cansleep(unsigned gpio, int value)
+/**
+ * gpiod_put - dispose of a GPIO descriptor
+ * @desc: GPIO descriptor to dispose of
+ *
+ * No descriptor can be used after gpiod_put() has been called on it.
+ */
+void gpiod_put(struct gpio_desc *desc)
{
- return gpiod_set_value_cansleep(gpio_to_desc(gpio), value);
+ gpiod_free(desc);
}
-EXPORT_SYMBOL_GPL(gpio_set_value_cansleep);
+EXPORT_SYMBOL_GPL(gpiod_put);
#ifdef CONFIG_DEBUG_FS
unsigned gpio = chip->base;
struct gpio_desc *gdesc = &chip->desc[0];
int is_out;
+ int is_irq;
for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
gpiod_get_direction(gdesc);
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
- seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
+ is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
+ seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
gpio, gdesc->label,
is_out ? "out" : "in ",
chip->get
? (chip->get(chip, i) ? "hi" : "lo")
- : "? ");
+ : "? ",
+ is_irq ? "IRQ" : " ");
seq_printf(s, "\n");
}
}
projects / karo-tx-linux.git / blobdiff