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Date: Tue, 7 Jan 2014 12:34:11 +0100
From: Philipp Zabel <p.zabel@...gutronix.de>
To: linux-gpio@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Linus Walleij <linus.walleij@...aro.org>,
Alexandre Courbot <gnurou@...il.com>,
Rob Landley <rob@...dley.net>, Arnd Bergmann <arnd@...db.de>,
Maxime Ripard <maxime.ripard@...e-electrons.com>,
kernel@...gutronix.de, Philipp Zabel <p.zabel@...gutronix.de>
Subject: [RFC PATCH] gpiolib: make gpiod_direction_output take a logical value, add gpiod_direction_output_raw
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@...gutronix.de>
---
Documentation/gpio/consumer.txt | 1 +
drivers/gpio/gpiolib.c | 67 +++++++++++++++++++++++++++++------------
include/asm-generic/gpio.h | 2 +-
include/linux/gpio/consumer.h | 7 +++++
4 files changed, 57 insertions(+), 20 deletions(-)
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index 07c74a3..4dc4809 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -150,6 +150,7 @@ 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 85f772c..f04f1e6 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -330,9 +330,9 @@ 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
@@ -1579,7 +1579,7 @@ 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)
@@ -1744,28 +1744,13 @@ 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,
@@ -1827,6 +1812,50 @@ 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 a5f56a0..23e3645 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 4d34dbb..3879943 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)
--
1.8.5.2
--
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