| Message ID | 1460446180-16397-1-git-send-email-linus.walleij@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Apr 12, 2016 at 09:29:40AM +0200, Linus Walleij wrote: > 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> > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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, };
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> 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-wm831x.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-)