[PATCH v2 3/4] gpio: pca953x: Implement get_direction() hook

From: Peter Tyser
Date: Wed Feb 16 2011 - 19:58:06 EST


Adding the get_direction() function allows the accurate GPIO pin
direction data to be shown in sysfs. Previously, the direction was
was always initialized to 'unknown'.

Cc: Alek Du <alek.du@xxxxxxxxx>
Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Eric Miao <eric.y.miao@xxxxxxxxx>
Cc: Uwe Kleine-K?nig <u.kleine-koenig@xxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
Signed-off-by: Peter Tyser <ptyser@xxxxxxxxxxx>
---
Changes since v1:
- None

drivers/gpio/pca953x.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index b473429..66d36b1 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -168,6 +168,16 @@ exit:
return ret;
}

+static int pca953x_gpio_get_direction(struct gpio_chip *gc, unsigned off)
+{
+ struct pca953x_chip *chip;
+
+ chip = container_of(gc, struct pca953x_chip, gpio_chip);
+
+ /* return 0 if IO pin is input, 1 if its an output */
+ return chip->reg_direction & (1u << off) ? 0 : 1;
+}
+
static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
@@ -221,6 +231,7 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)

gc->direction_input = pca953x_gpio_direction_input;
gc->direction_output = pca953x_gpio_direction_output;
+ gc->get_direction = pca953x_gpio_get_direction;
gc->get = pca953x_gpio_get_value;
gc->set = pca953x_gpio_set_value;
gc->can_sleep = 1;
--
1.7.0.4

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