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authorLinus Walleij <linus.walleij@linaro.org>2016-04-10 14:52:33 +0200
committerLinus Walleij <linus.walleij@linaro.org>2016-04-14 14:03:28 +0200
commit51c27da19d3dbf3219afb225e1626e193c5e1c72 (patch)
tree1029bdbda2edf550b6c6c448362ca849f1022d3f /drivers
parent640b9135c888f02afd058c213303ffbd10d3908d (diff)
downloadlinux-51c27da19d3dbf3219afb225e1626e193c5e1c72.tar.bz2
gpio: wm831x: use the new open drain callback
The WM831x GPIOs clearly have a dedicated open drain control register. Implement support for controlling this from GPIO descriptor tables or other hardware descriptions such as device tree by implementing the .set_single_ended() callback. Before this patch, lines requesting open drain will just be switched to input mode by the framework, thus emulating open drain. But the hardware can do the real thing, so let's support that. As part of this, rename the debugfs string for output mode from "CMOS" to "push-pull" because it is the term used in the framework to signify a tomem-pole CMOS output. Cc: patches@opensource.wolfsonmicro.com Cc: Mark Brown <broonie@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-wm831x.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-wm831x.c b/drivers/gpio/gpio-wm831x.c
index 18cb0f534b91..41ec7834059a 100644
--- a/drivers/gpio/gpio-wm831x.c
+++ b/drivers/gpio/gpio-wm831x.c
@@ -132,6 +132,28 @@ static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
}
+static int wm831x_set_single_ended(struct gpio_chip *chip,
+ unsigned int offset,
+ enum single_ended_mode mode)
+{
+ struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
+ struct wm831x *wm831x = wm831x_gpio->wm831x;
+ int reg = WM831X_GPIO1_CONTROL + offset;
+
+ switch (mode) {
+ case LINE_MODE_OPEN_DRAIN:
+ return wm831x_set_bits(wm831x, reg,
+ WM831X_GPN_OD_MASK, WM831X_GPN_OD);
+ case LINE_MODE_PUSH_PULL:
+ return wm831x_set_bits(wm831x, reg,
+ WM831X_GPN_OD_MASK, 0);
+ default:
+ break;
+ }
+
+ return -ENOTSUPP;
+}
+
#ifdef CONFIG_DEBUG_FS
static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
@@ -216,7 +238,7 @@ static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
pull,
powerdomain,
reg & WM831X_GPN_POL ? "" : " inverted",
- reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
+ reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
tristated ? " tristated" : "",
reg);
}
@@ -234,6 +256,7 @@ static struct gpio_chip template_chip = {
.set = wm831x_gpio_set,
.to_irq = wm831x_gpio_to_irq,
.set_debounce = wm831x_gpio_set_debounce,
+ .set_single_ended = wm831x_set_single_ended,
.dbg_show = wm831x_gpio_dbg_show,
.can_sleep = true,
};