diff mbox series

[v2,2/6] media: ov5647: Add support for PWDN GPIO.

Message ID a97c0faa973bc97099efddd89f7b9e5bacf06bd6.1589850165.git.roman.kovalivskyi@globallogic.com (mailing list archive)
State New
Delegated to: Kieran Bingham
Headers show
Series ov5647 driver improvement | expand

Commit Message

Roman Kovalivskyi May 19, 2020, 1:16 a.m. UTC 
From: Dave Stevenson <dave.stevenson@raspberrypi.org>

Add support for an optional GPIO connected to PWDN on the sensor. This
allows the use of hardware standby mode where internal device clock
and circuit activities are halted.

Please nothe that power is off when PWDN is high.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
---
 drivers/media/i2c/ov5647.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

Comments

Jacopo Mondi June 18, 2020, 3:54 p.m. UTC | #1 
Hi Roman,

On Tue, May 19, 2020 at 04:16:17AM +0300, Roman Kovalivskyi wrote:
> From: Dave Stevenson <dave.stevenson@raspberrypi.org>
>
> Add support for an optional GPIO connected to PWDN on the sensor. This
> allows the use of hardware standby mode where internal device clock
> and circuit activities are halted.
>
> Please nothe that power is off when PWDN is high.
>
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
> Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
> ---
>  drivers/media/i2c/ov5647.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
>
> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
> index 3e587eb0a30e..796cc80f8ee1 100644
> --- a/drivers/media/i2c/ov5647.c
> +++ b/drivers/media/i2c/ov5647.c
> @@ -21,6 +21,7 @@
>
>  #include <linux/clk.h>
>  #include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/i2c.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
> @@ -35,6 +36,13 @@
>
>  #define SENSOR_NAME "ov5647"
>
> +/*
> + * From the datasheet, "20ms after PWDN goes low or 20ms after RESETB goes
> + * high if reset is inserted after PWDN goes high, host can access sensor's
> + * SCCB to initialize sensor."
> + */
> +#define PWDN_ACTIVE_DELAY_MS	20
> +
>  #define MIPI_CTRL00_CLOCK_LANE_GATE		BIT(5)
>  #define MIPI_CTRL00_BUS_IDLE			BIT(2)
>  #define MIPI_CTRL00_CLOCK_LANE_DISABLE		BIT(0)
> @@ -86,6 +94,7 @@ struct ov5647 {
>  	unsigned int			height;
>  	int				power_count;
>  	struct clk			*xclk;
> +	struct gpio_desc		*pwdn;
>  };
>
>  static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
> @@ -93,6 +102,11 @@ static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
>  	return container_of(sd, struct ov5647, sd);
>  }
>
> +static inline void msleep_range(unsigned int delay_base)
> +{
> +	usleep_range(delay_base * 1000, delay_base * 1000 + 5000);
> +}
> +

I think I mis-lead you with the comment I gave on v1, as I just notice
the designated timeout is 20 msec, so msleep() is fine. Sorry about
this, I thought we were dealing with a shorter interval.

If that's ok with you I'll send a v3 of this series with Sakari's
comments addressed, rebased on top of the yaml version of the sensor
bindings I sent out a few hours ago.

Thanks
  j

>  static struct regval_list sensor_oe_disable_regs[] = {
>  	{0x3000, 0x00},
>  	{0x3001, 0x00},
> @@ -355,6 +369,11 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
>  	if (on && !ov5647->power_count)	{
>  		dev_dbg(&client->dev, "OV5647 power on\n");
>
> +		if (ov5647->pwdn) {
> +			gpiod_set_value(ov5647->pwdn, 0);
> +			msleep_range(PWDN_ACTIVE_DELAY_MS);
> +		}
> +
>  		ret = clk_prepare_enable(ov5647->xclk);
>  		if (ret < 0) {
>  			dev_err(&client->dev, "clk prepare enable failed\n");
> @@ -392,6 +411,8 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
>  			dev_dbg(&client->dev, "soft stby failed\n");
>
>  		clk_disable_unprepare(ov5647->xclk);
> +
> +		gpiod_set_value(ov5647->pwdn, 1);
>  	}
>
>  	/* Update the power count. */
> @@ -603,6 +624,10 @@ static int ov5647_probe(struct i2c_client *client)
>  		return -EINVAL;
>  	}
>
> +	/* Request the power down GPIO asserted */
> +	sensor->pwdn = devm_gpiod_get_optional(&client->dev, "pwdn",
> +					       GPIOD_OUT_HIGH);
> +
>  	mutex_init(&sensor->lock);
>
>  	sd = &sensor->sd;
> @@ -616,7 +641,15 @@ static int ov5647_probe(struct i2c_client *client)
>  	if (ret < 0)
>  		goto mutex_remove;
>
> +	if (sensor->pwdn) {
> +		gpiod_set_value(sensor->pwdn, 0);
> +		msleep_range(PWDN_ACTIVE_DELAY_MS);
> +	}
> +
>  	ret = ov5647_detect(sd);
> +
> +	gpiod_set_value(sensor->pwdn, 1);
> +
>  	if (ret < 0)
>  		goto error;
>
> --
> 2.17.1
>
diff mbox series

Patch

diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
index 3e587eb0a30e..796cc80f8ee1 100644
--- a/drivers/media/i2c/ov5647.c
+++ b/drivers/media/i2c/ov5647.c
@@ -21,6 +21,7 @@ 
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -35,6 +36,13 @@ 
 
 #define SENSOR_NAME "ov5647"
 
+/*
+ * From the datasheet, "20ms after PWDN goes low or 20ms after RESETB goes
+ * high if reset is inserted after PWDN goes high, host can access sensor's
+ * SCCB to initialize sensor."
+ */
+#define PWDN_ACTIVE_DELAY_MS	20
+
 #define MIPI_CTRL00_CLOCK_LANE_GATE		BIT(5)
 #define MIPI_CTRL00_BUS_IDLE			BIT(2)
 #define MIPI_CTRL00_CLOCK_LANE_DISABLE		BIT(0)
@@ -86,6 +94,7 @@  struct ov5647 {
 	unsigned int			height;
 	int				power_count;
 	struct clk			*xclk;
+	struct gpio_desc		*pwdn;
 };
 
 static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
@@ -93,6 +102,11 @@  static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
 	return container_of(sd, struct ov5647, sd);
 }
 
+static inline void msleep_range(unsigned int delay_base)
+{
+	usleep_range(delay_base * 1000, delay_base * 1000 + 5000);
+}
+
 static struct regval_list sensor_oe_disable_regs[] = {
 	{0x3000, 0x00},
 	{0x3001, 0x00},
@@ -355,6 +369,11 @@  static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
 	if (on && !ov5647->power_count)	{
 		dev_dbg(&client->dev, "OV5647 power on\n");
 
+		if (ov5647->pwdn) {
+			gpiod_set_value(ov5647->pwdn, 0);
+			msleep_range(PWDN_ACTIVE_DELAY_MS);
+		}
+
 		ret = clk_prepare_enable(ov5647->xclk);
 		if (ret < 0) {
 			dev_err(&client->dev, "clk prepare enable failed\n");
@@ -392,6 +411,8 @@  static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)
 			dev_dbg(&client->dev, "soft stby failed\n");
 
 		clk_disable_unprepare(ov5647->xclk);
+
+		gpiod_set_value(ov5647->pwdn, 1);
 	}
 
 	/* Update the power count. */
@@ -603,6 +624,10 @@  static int ov5647_probe(struct i2c_client *client)
 		return -EINVAL;
 	}
 
+	/* Request the power down GPIO asserted */
+	sensor->pwdn = devm_gpiod_get_optional(&client->dev, "pwdn",
+					       GPIOD_OUT_HIGH);
+
 	mutex_init(&sensor->lock);
 
 	sd = &sensor->sd;
@@ -616,7 +641,15 @@  static int ov5647_probe(struct i2c_client *client)
 	if (ret < 0)
 		goto mutex_remove;
 
+	if (sensor->pwdn) {
+		gpiod_set_value(sensor->pwdn, 0);
+		msleep_range(PWDN_ACTIVE_DELAY_MS);
+	}
+
 	ret = ov5647_detect(sd);
+
+	gpiod_set_value(sensor->pwdn, 1);
+
 	if (ret < 0)
 		goto error;