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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.c210
1 files changed, 167 insertions, 43 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5d6c71edc739..199fca15f270 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -191,6 +191,32 @@ err:
return ret;
}
+/* caller ensures gpio is valid and requested, chip->get_direction may sleep */
+static int gpio_get_direction(unsigned gpio)
+{
+ struct gpio_chip *chip;
+ struct gpio_desc *desc = &gpio_desc[gpio];
+ int status = -EINVAL;
+
+ chip = gpio_to_chip(gpio);
+ gpio -= chip->base;
+
+ if (!chip->get_direction)
+ return status;
+
+ status = chip->get_direction(chip, gpio);
+ if (status > 0) {
+ /* GPIOF_DIR_IN, or other positive */
+ status = 1;
+ clear_bit(FLAG_IS_OUT, &desc->flags);
+ }
+ if (status == 0) {
+ /* GPIOF_DIR_OUT */
+ set_bit(FLAG_IS_OUT, &desc->flags);
+ }
+ return status;
+}
+
#ifdef CONFIG_GPIO_SYSFS
/* lock protects against unexport_gpio() being called while
@@ -223,6 +249,7 @@ static ssize_t gpio_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
const struct gpio_desc *desc = dev_get_drvdata(dev);
+ unsigned gpio = desc - gpio_desc;
ssize_t status;
mutex_lock(&sysfs_lock);
@@ -230,6 +257,7 @@ static ssize_t gpio_direction_show(struct device *dev,
if (!test_bit(FLAG_EXPORT, &desc->flags))
status = -EIO;
else
+ gpio_get_direction(gpio);
status = sprintf(buf, "%s\n",
test_bit(FLAG_IS_OUT, &desc->flags)
? "out" : "in");
@@ -623,9 +651,11 @@ static ssize_t export_store(struct class *class,
*/
status = gpio_request(gpio, "sysfs");
- if (status < 0)
+ if (status < 0) {
+ if (status == -EPROBE_DEFER)
+ status = -ENODEV;
goto done;
-
+ }
status = gpio_export(gpio, true);
if (status < 0)
gpio_free(gpio);
@@ -702,8 +732,9 @@ int gpio_export(unsigned gpio, bool direction_may_change)
{
unsigned long flags;
struct gpio_desc *desc;
- int status = -EINVAL;
+ int status;
const char *ioname = NULL;
+ struct device *dev;
/* can't export until sysfs is available ... */
if (!gpio_class.p) {
@@ -711,59 +742,66 @@ int gpio_export(unsigned gpio, bool direction_may_change)
return -ENOENT;
}
- if (!gpio_is_valid(gpio))
- goto done;
+ if (!gpio_is_valid(gpio)) {
+ pr_debug("%s: gpio %d is not valid\n", __func__, gpio);
+ return -EINVAL;
+ }
mutex_lock(&sysfs_lock);
spin_lock_irqsave(&gpio_lock, flags);
desc = &gpio_desc[gpio];
- if (test_bit(FLAG_REQUESTED, &desc->flags)
- && !test_bit(FLAG_EXPORT, &desc->flags)) {
- status = 0;
- if (!desc->chip->direction_input
- || !desc->chip->direction_output)
- direction_may_change = false;
+ if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+ test_bit(FLAG_EXPORT, &desc->flags)) {
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ pr_debug("%s: gpio %d unavailable (requested=%d, exported=%d)\n",
+ __func__, gpio,
+ test_bit(FLAG_REQUESTED, &desc->flags),
+ test_bit(FLAG_EXPORT, &desc->flags));
+ status = -EPERM;
+ goto fail_unlock;
}
+
+ if (!desc->chip->direction_input || !desc->chip->direction_output)
+ direction_may_change = false;
spin_unlock_irqrestore(&gpio_lock, flags);
if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
ioname = desc->chip->names[gpio - desc->chip->base];
- if (status == 0) {
- struct device *dev;
-
- dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
- desc, ioname ? ioname : "gpio%u", gpio);
- if (!IS_ERR(dev)) {
- status = sysfs_create_group(&dev->kobj,
- &gpio_attr_group);
-
- if (!status && direction_may_change)
- status = device_create_file(dev,
- &dev_attr_direction);
-
- if (!status && gpio_to_irq(gpio) >= 0
- && (direction_may_change
- || !test_bit(FLAG_IS_OUT,
- &desc->flags)))
- status = device_create_file(dev,
- &dev_attr_edge);
-
- if (status != 0)
- device_unregister(dev);
- } else
- status = PTR_ERR(dev);
- if (status == 0)
- set_bit(FLAG_EXPORT, &desc->flags);
+ dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
+ desc, ioname ? ioname : "gpio%u", gpio);
+ if (IS_ERR(dev)) {
+ status = PTR_ERR(dev);
+ goto fail_unlock;
}
- mutex_unlock(&sysfs_lock);
-
-done:
+ status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
if (status)
- pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
+ goto fail_unregister_device;
+
+ if (direction_may_change) {
+ status = device_create_file(dev, &dev_attr_direction);
+ if (status)
+ goto fail_unregister_device;
+ }
+
+ if (gpio_to_irq(gpio) >= 0 && (direction_may_change ||
+ !test_bit(FLAG_IS_OUT, &desc->flags))) {
+ status = device_create_file(dev, &dev_attr_edge);
+ if (status)
+ goto fail_unregister_device;
+ }
+ set_bit(FLAG_EXPORT, &desc->flags);
+ mutex_unlock(&sysfs_lock);
+ return 0;
+
+fail_unregister_device:
+ device_unregister(dev);
+fail_unlock:
+ mutex_unlock(&sysfs_lock);
+ pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
return status;
}
EXPORT_SYMBOL_GPL(gpio_export);
@@ -1073,6 +1111,7 @@ int gpiochip_add(struct gpio_chip *chip)
* inputs (often with pullups enabled) so power
* usage is minimized. Linux code should set the
* gpio direction first thing; but until it does,
+ * and in case chip->get_direction is not set,
* we may expose the wrong direction in sysfs.
*/
gpio_desc[id].flags = !chip->direction_input
@@ -1081,6 +1120,10 @@ int gpiochip_add(struct gpio_chip *chip)
}
}
+#ifdef CONFIG_PINCTRL
+ INIT_LIST_HEAD(&chip->pin_ranges);
+#endif
+
of_gpiochip_add(chip);
unlock:
@@ -1121,6 +1164,7 @@ int gpiochip_remove(struct gpio_chip *chip)
spin_lock_irqsave(&gpio_lock, flags);
+ gpiochip_remove_pin_ranges(chip);
of_gpiochip_remove(chip);
for (id = chip->base; id < chip->base + chip->ngpio; id++) {
@@ -1178,6 +1222,77 @@ struct gpio_chip *gpiochip_find(void *data,
}
EXPORT_SYMBOL_GPL(gpiochip_find);
+#ifdef CONFIG_PINCTRL
+
+/**
+ * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl_name: the dev_name() of the pin controller to map to
+ * @gpio_offset: the start offset in the current gpio_chip number space
+ * @pin_offset: the start offset in the pin controller number space
+ * @npins: the number of pins from the offset of each pin space (GPIO and
+ * pin controller) to accumulate in this range
+ */
+int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
+ unsigned int gpio_offset, unsigned int pin_offset,
+ unsigned int npins)
+{
+ struct gpio_pin_range *pin_range;
+ int ret;
+
+ pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
+ if (!pin_range) {
+ pr_err("%s: GPIO chip: failed to allocate pin ranges\n",
+ chip->label);
+ return -ENOMEM;
+ }
+
+ /* Use local offset as range ID */
+ pin_range->range.id = gpio_offset;
+ pin_range->range.gc = chip;
+ pin_range->range.name = chip->label;
+ pin_range->range.base = chip->base + gpio_offset;
+ pin_range->range.pin_base = pin_offset;
+ pin_range->range.npins = npins;
+ pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
+ &pin_range->range);
+ if (IS_ERR(pin_range->pctldev)) {
+ ret = PTR_ERR(pin_range->pctldev);
+ pr_err("%s: GPIO chip: could not create pin range\n",
+ chip->label);
+ kfree(pin_range);
+ return ret;
+ }
+ pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PIN %d->%d\n",
+ chip->label, gpio_offset, gpio_offset + npins - 1,
+ pinctl_name,
+ pin_offset, pin_offset + npins - 1);
+
+ list_add_tail(&pin_range->node, &chip->pin_ranges);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
+
+/**
+ * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
+ * @chip: the chip to remove all the mappings for
+ */
+void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
+{
+ struct gpio_pin_range *pin_range, *tmp;
+
+ list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
+ list_del(&pin_range->node);
+ pinctrl_remove_gpio_range(pin_range->pctldev,
+ &pin_range->range);
+ kfree(pin_range);
+ }
+}
+EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
+
+#endif /* CONFIG_PINCTRL */
+
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
@@ -1191,8 +1306,10 @@ int gpio_request(unsigned gpio, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
- if (!gpio_is_valid(gpio))
+ if (!gpio_is_valid(gpio)) {
+ status = -EINVAL;
goto done;
+ }
desc = &gpio_desc[gpio];
chip = desc->chip;
if (chip == NULL)
@@ -1224,9 +1341,15 @@ int gpio_request(unsigned gpio, const char *label)
desc_set_label(desc, NULL);
module_put(chip->owner);
clear_bit(FLAG_REQUESTED, &desc->flags);
+ goto done;
}
}
-
+ if (chip->get_direction) {
+ /* chip->get_direction may sleep */
+ spin_unlock_irqrestore(&gpio_lock, flags);
+ gpio_get_direction(gpio);
+ spin_lock_irqsave(&gpio_lock, flags);
+ }
done:
if (status)
pr_debug("gpio_request: gpio-%d (%s) status %d\n",
@@ -1762,6 +1885,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
continue;
+ gpio_get_direction(gpio);
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
seq_printf(s, " gpio-%-3d (%-20.20s) %s %s",
gpio, gdesc->label,