diff mbox

[2/2] gpio: wm8994: use the new open drain callback

Message ID 1460446189-16444-1-git-send-email-linus.walleij@linaro.org
State New
Headers show

Commit Message

Linus Walleij April 12, 2016, 7:29 a.m. UTC
The WM8994 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>
Cc: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Use a switch() statement rather than if-constructions
---
 drivers/gpio/gpio-wm8994.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

Comments

Charles Keepax April 12, 2016, 8 a.m. UTC | #1
On Tue, Apr 12, 2016 at 09:29:49AM +0200, Linus Walleij wrote:
> The WM8994 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>
> Cc: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>

Thanks,
Charles
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diff mbox

Patch

diff --git a/drivers/gpio/gpio-wm8994.c b/drivers/gpio/gpio-wm8994.c
index b089df99a0d0..744af388c949 100644
--- a/drivers/gpio/gpio-wm8994.c
+++ b/drivers/gpio/gpio-wm8994.c
@@ -103,6 +103,28 @@  static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 	wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
 }
 
+static int wm8994_gpio_set_single_ended(struct gpio_chip *chip,
+					unsigned int offset,
+					enum single_ended_mode mode)
+{
+	struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
+	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
+
+	switch (mode) {
+	case LINE_MODE_OPEN_DRAIN:
+		return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
+				       WM8994_GPN_OP_CFG_MASK,
+				       WM8994_GPN_OP_CFG);
+	case LINE_MODE_PUSH_PULL:
+		return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
+				       WM8994_GPN_OP_CFG_MASK, 0);
+	default:
+		break;
+	}
+
+	return -ENOTSUPP;
+}
+
 static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct wm8994_gpio *wm8994_gpio = gpiochip_get_data(chip);
@@ -217,7 +239,7 @@  static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 		if (reg & WM8994_GPN_OP_CFG)
 			seq_printf(s, "open drain ");
 		else
-			seq_printf(s, "CMOS ");
+			seq_printf(s, "push-pull ");
 
 		seq_printf(s, "%s (%x)\n",
 			   wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), reg);
@@ -235,6 +257,7 @@  static struct gpio_chip template_chip = {
 	.get			= wm8994_gpio_get,
 	.direction_output	= wm8994_gpio_direction_out,
 	.set			= wm8994_gpio_set,
+	.set_single_ended	= wm8994_gpio_set_single_ended,
 	.to_irq			= wm8994_gpio_to_irq,
 	.dbg_show		= wm8994_gpio_dbg_show,
 	.can_sleep		= true,