[PATCH v6 4/7] gpiolib: add support for biasing output lines

From: Kent Gibson <warthog618@gmail.com>
To: linux-gpio@vger.kernel.org, bgolaszewski@baylibre.com,
	linus.walleij@linaro.org, bamv2005@gmail.com
Cc: drew@pdp7.com, thomas.petazzoni@bootlin.com,
	Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v6 4/7] gpiolib: add support for biasing output lines
Date: Tue,  5 Nov 2019 10:04:26 +0800	[thread overview]
Message-ID: <20191105020429.18942-5-warthog618@gmail.com> (raw)
In-Reply-To: <20191105020429.18942-1-warthog618@gmail.com>

Allow pull up/down bias to be set on output lines.
Use case is for open source or open drain applications where
internal pull up/down may conflict with external biasing.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 drivers/gpio/gpiolib.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 0ac0a250b17a..f852ff60ae6e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -556,8 +556,9 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 	     (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
 		return -EINVAL;
 
-	/* Bias flags only allowed for input mode. */
-	if (!(lflags & GPIOHANDLE_REQUEST_INPUT) &&
+	/* Bias flags only allowed for input or output mode. */
+	if (!((lflags & GPIOHANDLE_REQUEST_INPUT) ||
+	      (lflags & GPIOHANDLE_REQUEST_OUTPUT)) &&
 	    ((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
 	     (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
 	     (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
@@ -3168,6 +3169,9 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
 	}
 
 set_output_value:
+	ret = gpio_set_bias(gc, desc);
+	if (ret)
+		return ret;
 	return gpiod_direction_output_raw_commit(desc, value);
 
 set_output_flag:
-- 
2.23.0

