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authorRabin Vincent <rabin@rab.in>2015-07-22 15:05:18 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-07-27 15:01:05 +0200
commit91492a44b998cf762150de8f1b40bda1902e8ea7 (patch)
tree31ca1c400a6e8d0921125fbe20b156eb35db25de /drivers/gpio/gpio-generic.c
parent1296fba1a397b173d45534885a0934a7c005d7e3 (diff)
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gpio: generic: support input-only chips
Allow chips to indicates that they are input-only and thus cannot set the output value. This will be used by the gpio-etraxfs driver. Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-generic.c')
-rw-r--r--drivers/gpio/gpio-generic.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c
index 802e6d2c64e9..a3f07537fe62 100644
--- a/drivers/gpio/gpio-generic.c
+++ b/drivers/gpio/gpio-generic.c
@@ -153,6 +153,10 @@ static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
return !!(bgc->read_reg(bgc->reg_dat) & bgc->pin2mask(bgc, gpio));
}
+static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+}
+
static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
@@ -279,6 +283,12 @@ static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
return 0;
}
+static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,
+ int val)
+{
+ return -EINVAL;
+}
+
static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,
int val)
{
@@ -460,6 +470,9 @@ static int bgpio_setup_io(struct bgpio_chip *bgc,
bgc->reg_set = set;
bgc->gc.set = bgpio_set_set;
bgc->gc.set_multiple = bgpio_set_multiple_set;
+ } else if (flags & BGPIOF_NO_OUTPUT) {
+ bgc->gc.set = bgpio_set_none;
+ bgc->gc.set_multiple = NULL;
} else {
bgc->gc.set = bgpio_set;
bgc->gc.set_multiple = bgpio_set_multiple;
@@ -476,7 +489,8 @@ static int bgpio_setup_io(struct bgpio_chip *bgc,
static int bgpio_setup_direction(struct bgpio_chip *bgc,
void __iomem *dirout,
- void __iomem *dirin)
+ void __iomem *dirin,
+ unsigned long flags)
{
if (dirout && dirin) {
return -EINVAL;
@@ -491,7 +505,10 @@ static int bgpio_setup_direction(struct bgpio_chip *bgc,
bgc->gc.direction_input = bgpio_dir_in_inv;
bgc->gc.get_direction = bgpio_get_dir_inv;
} else {
- bgc->gc.direction_output = bgpio_simple_dir_out;
+ if (flags & BGPIOF_NO_OUTPUT)
+ bgc->gc.direction_output = bgpio_dir_out_err;
+ else
+ bgc->gc.direction_output = bgpio_simple_dir_out;
bgc->gc.direction_input = bgpio_simple_dir_in;
}
@@ -543,7 +560,7 @@ int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
if (ret)
return ret;
- ret = bgpio_setup_direction(bgc, dirout, dirin);
+ ret = bgpio_setup_direction(bgc, dirout, dirin, flags);
if (ret)
return ret;