gpio: make gpiod_direction_output take a logical value

The documentation was not clear about whether
gpio_direction_output should take a logical value or the physical
level on the output line, i.e. whether the ACTIVE_LOW status
would be taken into account.

This converts gpiod_direction_output to use the logical level
and adds a new gpiod_direction_output_raw for the raw value.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 57 insertions, 20 deletions

diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index e42f77d8d4ca..09854fe59307 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -154,6 +154,7 @@ raw line value:
         void gpiod_set_raw_value(struct gpio_desc *desc, int value)
         int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
         void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
+        int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
 
 The active-low state of a GPIO can also be queried using the following call:
 
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 50c4922fe53a..80da9f1940c9 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -350,9 +350,9 @@ static ssize_t gpio_direction_store(struct device *dev,
         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
@@ -1590,7 +1590,7 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
         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)
@@ -1756,28 +1756,13 @@ fail:
 }
 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,
@@ -1840,6 +1825,50 @@ fail:
                 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 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
+ * 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);
 
 /**
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index a5f56a0213a7..23e364538ab5 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -69,7 +69,7 @@ static inline int gpio_direction_input(unsigned gpio)
 }
 static inline int gpio_direction_output(unsigned gpio, int value)
 {
-        return gpiod_direction_output(gpio_to_desc(gpio), value);
+        return gpiod_direction_output_raw(gpio_to_desc(gpio), value);
 }
 
 static inline int gpio_set_debounce(unsigned gpio, unsigned debounce)
diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 4d34dbbbad4d..387994325122 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -36,6 +36,7 @@ void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);
 int gpiod_get_direction(const struct gpio_desc *desc);
 int gpiod_direction_input(struct gpio_desc *desc);
 int gpiod_direction_output(struct gpio_desc *desc, int value);
+int gpiod_direction_output_raw(struct gpio_desc *desc, int value);
 
 /* Value get/set from non-sleeping context */
 int gpiod_get_value(const struct gpio_desc *desc);
@@ -121,6 +122,12 @@ static inline int gpiod_direction_output(struct gpio_desc *desc, int value)
         WARN_ON(1);
         return -ENOSYS;
 }
+static inline int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
+{
+        /* GPIO can never have been requested */
+        WARN_ON(1);
+        return -ENOSYS;
+}
 
 
 static inline int gpiod_get_value(const struct gpio_desc *desc)