Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penber...

[deliverable/linux.git] / drivers / gpio / gpiolib.c

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 17fdf4b6af93147428166e6ea595987b2ac59d02..5a75510d66bb14a2148c71432104fc7ac5f39d9b 100644 (file)
--- 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);