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);