[PATCH] GPIO: Add gpio_debounce and gpio_alt_func features to GPIOLIB

From: Alek Du
Date: Wed Jun 17 2009 - 02:50:51 EST


Add gpio_debounce and gpio_alt_func features to GPIOLIB:
* gpio_debounce is to adjust signal HW debounce value (need HW support)
* gpio_alt_func is to set GPIO as alternative function (need HW support)

Signed-off-by: Alek Du <alek.du@xxxxxxxxx>
---
drivers/gpio/gpiolib.c | 22 ++++++++++++++++++++++
include/asm-generic/gpio.h | 11 ++++++++++-
include/linux/gpio.h | 10 ++++++++++
3 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 51a8d41..6365038 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1066,6 +1066,28 @@ void __gpio_set_value(unsigned gpio, int value)
}
EXPORT_SYMBOL_GPL(__gpio_set_value);

+void gpio_debounce(unsigned gpio, int value)
+{
+ struct gpio_chip *chip;
+
+ chip = gpio_to_chip(gpio);
+ WARN_ON(extra_checks && chip->can_sleep);
+ if (chip->debounce)
+ chip->debounce(chip, gpio - chip->base, value);
+}
+EXPORT_SYMBOL_GPL(gpio_debounce);
+
+void gpio_alt_func(unsigned gpio, int value)
+{
+ struct gpio_chip *chip;
+
+ chip = gpio_to_chip(gpio);
+ WARN_ON(extra_checks && chip->can_sleep);
+ if (chip->alt_func)
+ chip->alt_func(chip, gpio - chip->base, value);
+}
+EXPORT_SYMBOL_GPL(gpio_alt_func);
+
/**
* __gpio_cansleep() - report whether gpio value access will sleep
* @gpio: gpio in question
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d6c379d..bc98c96 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -44,6 +44,8 @@ struct module;
* returns either the value actually sensed, or zero
* @direction_output: configures signal "offset" as output, or returns error
* @set: assigns output value for signal "offset"
+ * @debounce: Adjust signal hardware debounce level
+ * @alt_func: configures signal as GPIO or alternative function
* @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
* implementation may not sleep
* @dbg_show: optional routine to show contents in debugfs; default code
@@ -89,6 +91,12 @@ struct gpio_chip {
void (*set)(struct gpio_chip *chip,
unsigned offset, int value);

+ void (*debounce)(struct gpio_chip *chip,
+ unsigned offset,
+ int value);
+ void (*alt_func)(struct gpio_chip *chip,
+ unsigned offset, int value);
+
int (*to_irq)(struct gpio_chip *chip,
unsigned offset);

@@ -118,7 +126,8 @@ extern void gpio_free(unsigned gpio);

extern int gpio_direction_input(unsigned gpio);
extern int gpio_direction_output(unsigned gpio, int value);
-
+extern void gpio_debounce(unsigned gpio, int value);
+extern void gpio_alt_func(unsigned gpio, int value);
extern int gpio_get_value_cansleep(unsigned gpio);
extern void gpio_set_value_cansleep(unsigned gpio, int value);

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index e10c49a..cf005d5 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -82,6 +82,16 @@ static inline void gpio_set_value_cansleep(unsigned gpio, int value)
WARN_ON(1);
}

+static inline void gpio_debounce(unsigned gpio, int value)
+{
+ WARN_ON(1);
+}
+
+static inline void gpio_alt_func(unsigned gpio, int value)
+{
+ WARN_ON(1);
+}
+
static inline int gpio_export(unsigned gpio, bool direction_may_change)
{
/* GPIO can never have been requested or set as {in,out}put */
--
1.6.0.4
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