EXPORT_SYMBOL_GPL(gpio_to_desc);
/**
- * Convert an offset on a certain chip to a corresponding descriptor
+ * Get the GPIO descriptor corresponding to the given hw number for this chip.
*/
-static struct gpio_desc *gpiochip_offset_to_desc(struct gpio_chip *chip,
- unsigned int offset)
+struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
+ u16 hwnum)
{
- if (offset >= chip->ngpio)
+ if (hwnum >= chip->ngpio)
return ERR_PTR(-EINVAL);
- return &chip->desc[offset];
+ return &chip->desc[hwnum];
}
+EXPORT_SYMBOL_GPL(gpiochip_get_desc);
/**
* Convert a GPIO descriptor to the integer namespace.
if (!test_bit(FLAG_EXPORT, &desc->flags))
status = -EIO;
else if (sysfs_streq(buf, "high"))
- status = gpiod_direction_output(desc, 1);
+ status = gpiod_direction_output_raw(desc, 1);
else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
- status = gpiod_direction_output(desc, 0);
+ status = gpiod_direction_output_raw(desc, 0);
else if (sysfs_streq(buf, "in"))
status = gpiod_direction_input(desc);
else
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
*/
-static int gpiod_request(struct gpio_desc *desc, const char *label)
+static int __gpiod_request(struct gpio_desc *desc, const char *label)
{
- struct gpio_chip *chip;
- int status = -EPROBE_DEFER;
+ struct gpio_chip *chip = desc->chip;
+ int status;
unsigned long flags;
- if (!desc) {
- pr_warn("%s: invalid GPIO\n", __func__);
- return -EINVAL;
- }
-
spin_lock_irqsave(&gpio_lock, flags);
- chip = desc->chip;
- if (chip == NULL)
- goto done;
-
- if (!try_module_get(chip->owner))
- goto done;
-
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
status = 0;
} else {
status = -EBUSY;
- module_put(chip->owner);
goto done;
}
if (status < 0) {
desc_set_label(desc, NULL);
- module_put(chip->owner);
clear_bit(FLAG_REQUESTED, &desc->flags);
goto done;
}
gpiod_get_direction(desc);
spin_lock_irqsave(&gpio_lock, flags);
}
+done:
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ return status;
+}
+
+static int gpiod_request(struct gpio_desc *desc, const char *label)
+{
+ int status = -EPROBE_DEFER;
+ struct gpio_chip *chip;
+
+ if (!desc) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+
+ chip = desc->chip;
+ if (!chip)
+ goto done;
+
+ if (try_module_get(chip->owner)) {
+ status = __gpiod_request(desc, label);
+ if (status < 0)
+ module_put(chip->owner);
+ }
+
done:
if (status)
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
- spin_unlock_irqrestore(&gpio_lock, flags);
+
return status;
}
}
EXPORT_SYMBOL_GPL(gpio_request);
-static void gpiod_free(struct gpio_desc *desc)
+static bool __gpiod_free(struct gpio_desc *desc)
{
+ bool ret = false;
unsigned long flags;
struct gpio_chip *chip;
might_sleep();
- if (!desc) {
- WARN_ON(extra_checks);
- return;
- }
-
gpiod_unexport(desc);
spin_lock_irqsave(&gpio_lock, flags);
spin_lock_irqsave(&gpio_lock, flags);
}
desc_set_label(desc, NULL);
- module_put(desc->chip->owner);
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_REQUESTED, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
- } else
- WARN_ON(extra_checks);
+ ret = true;
+ }
spin_unlock_irqrestore(&gpio_lock, flags);
+ return ret;
+}
+
+static void gpiod_free(struct gpio_desc *desc)
+{
+ if (desc && __gpiod_free(desc))
+ module_put(desc->chip->owner);
+ else
+ WARN_ON(extra_checks);
}
void gpio_free(unsigned gpio)
if (flags & GPIOF_DIR_IN)
err = gpiod_direction_input(desc);
else
- err = gpiod_direction_output(desc,
+ err = gpiod_direction_output_raw(desc,
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
if (err)
}
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
+/**
+ * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
+ * @desc: GPIO descriptor to request
+ * @label: label for the GPIO
+ *
+ * Function allows GPIO chip drivers to request and use their own GPIO
+ * descriptors via gpiolib API. Difference to gpiod_request() is that this
+ * function will not increase reference count of the GPIO chip module. This
+ * allows the GPIO chip module to be unloaded as needed (we assume that the
+ * GPIO chip driver handles freeing the GPIOs it has requested).
+ */
+int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
+{
+ if (!desc || !desc->chip)
+ return -EINVAL;
+
+ return __gpiod_request(desc, label);
+}
+
+/**
+ * gpiochip_free_own_desc - Free GPIO requested by the chip driver
+ * @desc: GPIO descriptor to free
+ *
+ * Function frees the given GPIO requested previously with
+ * gpiochip_request_own_desc().
+ */
+void gpiochip_free_own_desc(struct gpio_desc *desc)
+{
+ if (desc)
+ __gpiod_free(desc);
+}
/* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
}
EXPORT_SYMBOL_GPL(gpiod_direction_input);
-/**
- * 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)
+static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
unsigned long flags;
struct gpio_chip *chip;
int status = -EINVAL;
int offset;
- if (!desc || !desc->chip) {
- pr_warn("%s: invalid GPIO\n", __func__);
- return -EINVAL;
- }
-
/* GPIOs used for IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
gpiod_err(desc,
gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
return status;
}
+
+/**
+ * gpiod_direction_output_raw - set the GPIO direction to output
+ * @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
+ * as raw value on the physical line without regard for the ACTIVE_LOW status.
+ *
+ * Return 0 in case of success, else an error code.
+ */
+int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
+{
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+ return _gpiod_direction_output_raw(desc, value);
+}
+EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
+
+/**
+ * gpiod_direction_output - set the GPIO direction to output
+ * @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
+ * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
+ * account.
+ *
+ * Return 0 in case of success, else an error code.
+ */
+int gpiod_direction_output(struct gpio_desc *desc, int value)
+{
+ if (!desc || !desc->chip) {
+ pr_warn("%s: invalid GPIO\n", __func__);
+ return -EINVAL;
+ }
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ value = !value;
+ return _gpiod_direction_output_raw(desc, value);
+}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
* @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.
+ * a certain GPIO line to be used for IRQs.
*/
int gpiod_lock_as_irq(struct gpio_desc *desc)
{
int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
- return gpiod_lock_as_irq(gpiochip_offset_to_desc(chip, offset));
+ return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset));
}
EXPORT_SYMBOL_GPL(gpio_lock_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));
+ return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset));
}
EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
return ERR_PTR(-EINVAL);
}
- desc = gpiochip_offset_to_desc(chip, p->chip_hwnum);
+ desc = gpiochip_get_desc(chip, p->chip_hwnum);
*flags = p->flags;
return desc;
projects / firefly-linux-kernel-4.4.55.git / blobdiff