lkml.org 
[lkml]   [2011]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] pinctrl: indicate GPIO direction on single GPIO request
Date
From: Linus Walleij <linus.walleij@linaro.org>

When requesting a single GPIO pin to be muxed in, some controllers
will need to poke a different value into the control register
depending on whether the pin will be used for GPIO output or GPIO
input. So pass this info along for the gpio_request_enable()
function, we assume this is not needed for the gpio_free_disable()
function for the time being.

Suggested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/pinctrl/pinmux.c | 16 +++++++++++-----
include/linux/pinctrl/pinmux.h | 14 ++++++++++----
2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index d27b77d..ef2f812 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -100,10 +100,13 @@ struct pinmux_hog {
* means that you want to mux in the pin for use as GPIO number NN
* @gpio_range: the range matching the GPIO pin if this is a request for a
* single GPIO pin
+ * @gpio_direction: if the pin is muxed for GPIO, this provides the direction
+ * of the GPIO @true means output, @false means input
*/
static int pin_request(struct pinctrl_dev *pctldev,
int pin, const char *function,
- struct pinctrl_gpio_range *gpio_range)
+ struct pinctrl_gpio_range *gpio_range,
+ bool gpio_direction)
{
struct pin_desc *desc;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
@@ -148,7 +151,8 @@ static int pin_request(struct pinctrl_dev *pctldev,
*/
if (gpio_range && ops->gpio_request_enable)
/* This requests and enables a single GPIO pin */
- status = ops->gpio_request_enable(pctldev, gpio_range, pin);
+ status = ops->gpio_request_enable(pctldev, gpio_range, pin,
+ gpio_direction);
else if (ops->request)
status = ops->request(pctldev, pin);
else
@@ -218,8 +222,10 @@ static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
/**
* pinmux_request_gpio() - request a single pin to be muxed in as GPIO
* @gpio: the GPIO pin number from the GPIO subsystem number space
+ * @direction: the direction of the GPIO, @true means output, @false
+ * means input
*/
-int pinmux_request_gpio(unsigned gpio)
+int pinmux_request_gpio(unsigned gpio, bool direction)
{
char gpiostr[16];
const char *function;
@@ -242,7 +248,7 @@ int pinmux_request_gpio(unsigned gpio)
if (!function)
return -EINVAL;

- ret = pin_request(pctldev, pin, function, range);
+ ret = pin_request(pctldev, pin, function, range, direction);
if (ret < 0)
kfree(function);

@@ -360,7 +366,7 @@ static int acquire_pins(struct pinctrl_dev *pctldev,

/* Try to allocate all pins in this group, one by one */
for (i = 0; i < num_pins; i++) {
- ret = pin_request(pctldev, pins[i], func, NULL);
+ ret = pin_request(pctldev, pins[i], func, NULL, false);
if (ret) {
dev_err(&pctldev->dev,
"could not get pin %d for function %s "
diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h
index bb7a979..7d3841f 100644
--- a/include/linux/pinctrl/pinmux.h
+++ b/include/linux/pinctrl/pinmux.h
@@ -54,7 +54,12 @@ struct pinctrl_dev;
* Implement this only if you can mux every pin individually as GPIO. The
* affected GPIO range is passed along with an offset(pin number) into that
* specific GPIO range - function selectors and pin groups are orthogonal
- * to this, the core will however make sure the pins do not collide
+ * to this, the core will however make sure the pins do not collide. Since
+ * controllers may be needing different configurations depending on
+ * whether the GPIO is configured as input or output, a direction
+ * indicator is passed along
+ * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
+ * @gpio_request_enable
*/
struct pinmux_ops {
int (*request) (struct pinctrl_dev *pctldev, unsigned offset);
@@ -72,14 +77,15 @@ struct pinmux_ops {
unsigned group_selector);
int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
- unsigned offset);
+ unsigned offset,
+ bool direction);
void (*gpio_disable_free) (struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned offset);
};

/* External interface to pinmux */
-extern int pinmux_request_gpio(unsigned gpio);
+extern int pinmux_request_gpio(unsigned gpio, bool direction);
extern void pinmux_free_gpio(unsigned gpio);
extern struct pinmux * __must_check pinmux_get(struct device *dev, const char *name);
extern void pinmux_put(struct pinmux *pmx);
@@ -88,7 +94,7 @@ extern void pinmux_disable(struct pinmux *pmx);

#else /* !CONFIG_PINMUX */

-static inline int pinmux_request_gpio(unsigned gpio)
+static inline int pinmux_request_gpio(unsigned gpio, bool direction)
{
return 0;
}
--
1.7.3.2


\
 
 \ /
  Last update: 2011-11-14 10:13    [W:0.062 / U:27.444 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site