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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.c98
1 files changed, 91 insertions, 7 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 17fdf4b..5a75510 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -58,6 +58,8 @@ struct gpio_desc {
#define FLAG_TRIG_FALL 5 /* trigger on falling edge */
#define FLAG_TRIG_RISE 6 /* trigger on rising edge */
#define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */
+#define FLAG_OPEN_DRAIN 8 /* Gpio is open drain type */
+#define FLAG_OPEN_SOURCE 9 /* Gpio is open source type */
#define ID_SHIFT 16 /* add new flags before this one */
@@ -873,6 +875,7 @@ void gpio_unexport(unsigned gpio)
{
struct gpio_desc *desc;
int status = 0;
+ struct device *dev = NULL;
if (!gpio_is_valid(gpio)) {
status = -EINVAL;
@@ -884,19 +887,20 @@ void gpio_unexport(unsigned gpio)
desc = &gpio_desc[gpio];
if (test_bit(FLAG_EXPORT, &desc->flags)) {
- struct device *dev = NULL;
dev = class_find_device(&gpio_class, NULL, desc, match_export);
if (dev) {
gpio_setup_irq(desc, dev, 0);
clear_bit(FLAG_EXPORT, &desc->flags);
- put_device(dev);
- device_unregister(dev);
} else
status = -ENODEV;
}
mutex_unlock(&sysfs_lock);
+ if (dev) {
+ device_unregister(dev);
+ put_device(dev);
+ }
done:
if (status)
pr_debug("%s: gpio%d status %d\n", __func__, gpio, status);
@@ -1150,8 +1154,9 @@ EXPORT_SYMBOL_GPL(gpiochip_remove);
* non-zero, this function will return to the caller and not iterate over any
* more gpio_chips.
*/
-struct gpio_chip *gpiochip_find(void *data,
- int (*match)(struct gpio_chip *chip, void *data))
+struct gpio_chip *gpiochip_find(const void *data,
+ int (*match)(struct gpio_chip *chip,
+ const void *data))
{
struct gpio_chip *chip = NULL;
unsigned long flags;
@@ -1261,6 +1266,8 @@ void gpio_free(unsigned gpio)
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);
@@ -1282,6 +1289,12 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
if (err)
return err;
+ if (flags & GPIOF_OPEN_DRAIN)
+ set_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags);
+
+ if (flags & GPIOF_OPEN_SOURCE)
+ set_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags);
+
if (flags & GPIOF_DIR_IN)
err = gpio_direction_input(gpio);
else
@@ -1431,6 +1444,14 @@ int gpio_direction_output(unsigned gpio, int value)
struct gpio_desc *desc = &gpio_desc[gpio];
int status = -EINVAL;
+ /* Open drain pin should not be driven to 1 */
+ if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+ return gpio_direction_input(gpio);
+
+ /* Open source pin should not be driven to 0 */
+ if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+ return gpio_direction_input(gpio);
+
spin_lock_irqsave(&gpio_lock, flags);
if (!gpio_is_valid(gpio))
@@ -1560,6 +1581,7 @@ int __gpio_get_value(unsigned gpio)
int value;
chip = gpio_to_chip(gpio);
+ /* Should be using gpio_get_value_cansleep() */
WARN_ON(chip->can_sleep);
value = chip->get ? chip->get(chip, gpio - chip->base) : 0;
trace_gpio_value(gpio, 1, value);
@@ -1567,6 +1589,57 @@ int __gpio_get_value(unsigned gpio)
}
EXPORT_SYMBOL_GPL(__gpio_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.
+ * @value: Non-zero for setting it HIGH otherise it will set to LOW.
+ */
+static void _gpio_set_open_drain_value(unsigned gpio,
+ struct gpio_chip *chip, int value)
+{
+ int err = 0;
+ if (value) {
+ err = chip->direction_input(chip, gpio - chip->base);
+ if (!err)
+ clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
+ } else {
+ err = chip->direction_output(chip, gpio - chip->base, 0);
+ if (!err)
+ set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
+ }
+ trace_gpio_direction(gpio, value, err);
+ if (err < 0)
+ pr_err("%s: Error in set_value for open drain gpio%d err %d\n",
+ __func__, gpio, err);
+}
+
+/*
+ * _gpio_set_open_source() - Set the open source gpio's value.
+ * @gpio: Gpio whose state need to be set.
+ * @chip: Gpio chip.
+ * @value: Non-zero for setting it HIGH otherise it will set to LOW.
+ */
+static void _gpio_set_open_source_value(unsigned gpio,
+ struct gpio_chip *chip, int value)
+{
+ int err = 0;
+ if (value) {
+ err = chip->direction_output(chip, gpio - chip->base, 1);
+ if (!err)
+ set_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
+ } else {
+ err = chip->direction_input(chip, gpio - chip->base);
+ if (!err)
+ clear_bit(FLAG_IS_OUT, &gpio_desc[gpio].flags);
+ }
+ trace_gpio_direction(gpio, !value, err);
+ if (err < 0)
+ pr_err("%s: Error in set_value for open source gpio%d err %d\n",
+ __func__, gpio, err);
+}
+
+
/**
* __gpio_set_value() - assign a gpio's value
* @gpio: gpio whose value will be assigned
@@ -1581,9 +1654,15 @@ void __gpio_set_value(unsigned gpio, int value)
struct gpio_chip *chip;
chip = gpio_to_chip(gpio);
+ /* Should be using gpio_set_value_cansleep() */
WARN_ON(chip->can_sleep);
trace_gpio_value(gpio, 0, value);
- chip->set(chip, gpio - chip->base, value);
+ if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags))
+ _gpio_set_open_drain_value(gpio, chip, value);
+ else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags))
+ _gpio_set_open_source_value(gpio, chip, value);
+ else
+ chip->set(chip, gpio - chip->base, value);
}
EXPORT_SYMBOL_GPL(__gpio_set_value);
@@ -1650,7 +1729,12 @@ void gpio_set_value_cansleep(unsigned gpio, int value)
might_sleep_if(extra_checks);
chip = gpio_to_chip(gpio);
trace_gpio_value(gpio, 0, value);
- chip->set(chip, gpio - chip->base, value);
+ if (test_bit(FLAG_OPEN_DRAIN, &gpio_desc[gpio].flags))
+ _gpio_set_open_drain_value(gpio, chip, value);
+ else if (test_bit(FLAG_OPEN_SOURCE, &gpio_desc[gpio].flags))
+ _gpio_set_open_source_value(gpio, chip, value);
+ else
+ chip->set(chip, gpio - chip->base, value);
}
EXPORT_SYMBOL_GPL(gpio_set_value_cansleep);
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