The patch titled
gpio-introduce-gpio_request_one-and-friends-update
has been added to the -mm tree. Its filename is
gpio-introduce-gpio_request_one-and-friends-update.patch
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------------------------------------------------------
Subject: gpio-introduce-gpio_request_one-and-friends-update
From: Eric Miao <eric.y.miao@xxxxxxxxx>
Signed-off-by: Eric Miao <eric.y.miao@xxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Ben Nizette <bn@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/gpio.txt | 64 +++++++++++++++++++++++++++++++++++
drivers/gpio/gpiolib.c | 16 ++++++++
include/asm-generic/gpio.h | 6 +++
3 files changed, 86 insertions(+)
diff -puN Documentation/gpio.txt~gpio-introduce-gpio_request_one-and-friends-update Documentation/gpio.txt
--- a/Documentation/gpio.txt~gpio-introduce-gpio_request_one-and-friends-update
+++ a/Documentation/gpio.txt
@@ -253,6 +253,70 @@ pin setup (e.g. controlling which pin th
Also note that it's your responsibility to have stopped using a GPIO
before you free it.
+Considering in most cases GPIOs are actually configured right after they
+are claimed, three additional calls are defined:
+
+ /* request a single GPIO, with initial configuration specified by
+ * 'flags', identical to gpio_request() wrt other arguments and
+ * return value
+ */
+ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
+
+ /* request multiple GPIOs in a single call
+ */
+ int gpio_request_array(struct gpio *array, size_t num);
+
+ /* release multiple GPIOs in a single call
+ */
+ void gpio_free_array(struct gpio *array, size_t num);
+
+where 'flags' is currently defined to specify the following properties:
+
+ * GPIOF_DIR_IN - to configure direction as input
+ * GPIOF_DIR_OUT - to configure direction as output
+
+ * GPIOF_INIT_LOW - as output, set initial level to LOW
+ * GPIOF_INIT_HIGH - as output, set initial level to HIGH
+
+since GPIOF_INIT_* are only valid when configured as output, so group valid
+combinations as:
+
+ * GPIOF_IN - configure as input
+ * GPIOF_OUT_INIT_LOW - configured as output, initial level LOW
+ * GPIOF_OUT_INIT_HIGH - configured as output, initial level HIGH
+
+In the future, these flags can be extended to support more properties such
+as open-drain status.
+
+Further more, to ease the claim/release of multiple GPIOs, 'struct gpio' is
+introduced to encapsulate all three fields as:
+
+ struct gpio {
+ unsigned gpio;
+ unsigned long flags;
+ const char *label;
+ };
+
+A typical example of usage:
+
+ static struct gpio leds_gpios[] = {
+ { 32, GPIOF_OUT_INIT_HIGH, "Power LED" }, /* default to ON */
+ { 33, GPIOF_OUT_INIT_LOW, "Green LED" }, /* default to OFF */
+ { 34, GPIOF_OUT_INIT_LOW, "Red LED" }, /* default to OFF */
+ { 35, GPIOF_OUT_INIT_LOW, "Blue LED" }, /* default to OFF */
+ { ... },
+ };
+
+ err = gpio_request_one(31, GPIOF_IN, "Reset Button");
+ if (err)
+ ...
+
+ err = gpio_request_array(leds_gpios, ARRAY_SIZE(leds_gpios));
+ if (err)
+ ...
+
+ gpio_free_array(leds_gpios, ARRAY_SIZE(leds_gpios));
+
GPIOs mapped to IRQs
--------------------
diff -puN drivers/gpio/gpiolib.c~gpio-introduce-gpio_request_one-and-friends-update drivers/gpio/gpiolib.c
--- a/drivers/gpio/gpiolib.c~gpio-introduce-gpio_request_one-and-friends-update
+++ a/drivers/gpio/gpiolib.c
@@ -1237,6 +1237,12 @@ void gpio_free(unsigned gpio)
}
EXPORT_SYMBOL_GPL(gpio_free);
+/**
+ * gpio_request_one - request a single GPIO with initial configuration
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
{
int err;
@@ -1255,6 +1261,11 @@ int gpio_request_one(unsigned gpio, unsi
}
EXPORT_SYMBOL_GPL(gpio_request_one);
+/**
+ * gpio_request_array - request multiple GPIOs in a single call
+ * @array: array of the 'struct gpio'
+ * @num: how many GPIOs in the array
+ */
int gpio_request_array(struct gpio *array, size_t num)
{
int i, err;
@@ -1273,6 +1284,11 @@ err_free:
}
EXPORT_SYMBOL_GPL(gpio_request_array);
+/**
+ * gpio_free_array - release multiple GPIOs in a single call
+ * @array: array of the 'struct gpio'
+ * @num: how many GPIOs in the array
+ */
void gpio_free_array(struct gpio *array, size_t num)
{
while (num--)
diff -puN include/asm-generic/gpio.h~gpio-introduce-gpio_request_one-and-friends-update include/asm-generic/gpio.h
--- a/include/asm-generic/gpio.h~gpio-introduce-gpio_request_one-and-friends-update
+++ a/include/asm-generic/gpio.h
@@ -146,6 +146,12 @@ extern int __gpio_to_irq(unsigned gpio);
#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
+/**
+ * struct gpio - a structure describing a GPIO with configuration
+ * @gpio: the GPIO number
+ * @flags: GPIO configuration as specified by GPIOF_*
+ * @label: a literal description string of this GPIO
+ */
struct gpio {
unsigned gpio;
unsigned long flags;
_
Patches currently in -mm which might be from eric.y.miao@xxxxxxxxx are
linux-next.patch
arch-arm-plat-pxa-dmac-correct-null-test.patch
genirq-warn-about-irqf_sharedirqf_disabled-at-the-right-place.patch
gpio-introduce-gpio_request_one-and-friends.patch
gpio-introduce-gpio_request_one-and-friends-update.patch
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