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>

diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index e42f77d8d4ca0f06278a09ba6d33108f526cfd75..09854fe59307874864b001f5f92e93519fc40faf 100644 (file)
--- 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 50c4922fe53abf8f51cf1d613d59a9d5207bc002..80da9f1940c9c11b611b3d84a265fab810392036 100644 (file)
--- 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 a5f56a0213a7e59ad3315fe8a8ddbaae1a402290..23e364538ab5926d372b95bca460e2cef253add2 100644 (file)
--- 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 4d34dbbbad4dde2ce2c1cd820320537661575450..3879943251221d9b916fbbb442e0a1c11c9286d5 100644 (file)
--- 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)