linux-kernel - [PATCH v4 4/8] media: adv7180: add power pin control

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Message-Id: <1470247430-11168-5-git-send-email-steve_longerbeam@mentor.com>
Date:	Wed,  3 Aug 2016 11:03:46 -0700
From:	Steve Longerbeam <slongerbeam@...il.com>
To:	lars@...afoo.de
Cc:	mchehab@...nel.org, linux-media@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Steve Longerbeam <steve_longerbeam@...tor.com>
Subject: [PATCH v4 4/8] media: adv7180: add power pin control

Some targets control the ADV7180 power pin via a gpio, so add
optional support for "powerdown" pin control.

Signed-off-by: Steve Longerbeam <steve_longerbeam@...tor.com>
Tested-by: Tim Harvey <tharvey@...eworks.com>
Acked-by: Tim Harvey <tharvey@...eworks.com>
Acked-by: Lars-Peter Clausen <lars@...afoo.de>

---

v4: no changes
v3: no changes

v2:
- placed call to gpiod_get inline in adv7180_probe().
- rename gpio pin to "powerdown".
- document optional powerdown-gpios property in
  Documentation/devicetree/bindings/media/i2c/adv7180.txt.
- include error number in error message on gpiod_get failure.
---
 .../devicetree/bindings/media/i2c/adv7180.txt      |  4 ++++
 drivers/media/i2c/Kconfig                          |  2 +-
 drivers/media/i2c/adv7180.c                        | 27 ++++++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/media/i2c/adv7180.txt b/Documentation/devicetree/bindings/media/i2c/adv7180.txt
index 6c175d2..ab9ef02 100644
--- a/Documentation/devicetree/bindings/media/i2c/adv7180.txt
+++ b/Documentation/devicetree/bindings/media/i2c/adv7180.txt
@@ -15,6 +15,10 @@ Required Properties :
 		"adi,adv7282"
 		"adi,adv7282-m"
 
+Optional Properties :
+- powerdown-gpios: reference to the GPIO connected to the powerdown pin,
+  if any.
+
 Optional Endpoint Properties :
 - newavmode: a boolean property to indicate the BT.656 bus is operating
   in Analog Device's NEWAVMODE. Valid for BT.656 busses only.
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index ce9006e..6769898 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -187,7 +187,7 @@ comment "Video decoders"
 
 config VIDEO_ADV7180
 	tristate "Analog Devices ADV7180 decoder"
-	depends on VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API
+	depends on GPIOLIB && VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API
 	---help---
 	  Support for the Analog Devices ADV7180 video decoder.
 
diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
index 467953e..b2df181 100644
--- a/drivers/media/i2c/adv7180.c
+++ b/drivers/media/i2c/adv7180.c
@@ -26,6 +26,7 @@
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/gpio/consumer.h>
 #include <linux/videodev2.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-event.h>
@@ -215,6 +216,7 @@ struct adv7180_state {
 	struct media_pad	pad;
 	struct mutex		mutex; /* mutual excl. when accessing chip */
 	int			irq;
+	struct gpio_desc	*pwdn_gpio;
 	v4l2_std_id		curr_norm;
 	bool			newavmode;
 	bool			powered;
@@ -466,6 +468,19 @@ static int adv7180_g_std(struct v4l2_subdev *sd, v4l2_std_id *norm)
 	return 0;
 }
 
+static void adv7180_set_power_pin(struct adv7180_state *state, bool on)
+{
+	if (!state->pwdn_gpio)
+		return;
+
+	if (on) {
+		gpiod_set_value_cansleep(state->pwdn_gpio, 0);
+		usleep_range(5000, 10000);
+	} else {
+		gpiod_set_value_cansleep(state->pwdn_gpio, 1);
+	}
+}
+
 static int adv7180_set_power(struct adv7180_state *state, bool on)
 {
 	u8 val;
@@ -1219,6 +1234,8 @@ static int init_device(struct adv7180_state *state)
 
 	mutex_lock(&state->mutex);
 
+	adv7180_set_power_pin(state, true);
+
 	adv7180_write(state, ADV7180_REG_PWR_MAN, ADV7180_PWR_MAN_RES);
 	usleep_range(5000, 10000);
 
@@ -1319,6 +1336,14 @@ static int adv7180_probe(struct i2c_client *client,
 
 	adv7180_of_parse(state);
 
+	state->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
+						   GPIOD_OUT_HIGH);
+	if (IS_ERR(state->pwdn_gpio)) {
+		ret = PTR_ERR(state->pwdn_gpio);
+		v4l_err(client, "request for power pin failed: %d\n", ret);
+		return ret;
+	}
+
 	if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2) {
 		state->csi_client = i2c_new_dummy(client->adapter,
 				ADV7180_DEFAULT_CSI_I2C_ADDR);
@@ -1410,6 +1435,8 @@ static int adv7180_remove(struct i2c_client *client)
 	if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2)
 		i2c_unregister_device(state->csi_client);
 
+	adv7180_set_power_pin(state, false);
+
 	mutex_destroy(&state->mutex);
 
 	return 0;
-- 
1.9.1