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Subject[PATCH v4 3/5] media: ov7670: control clock along with power
Date
This provides more power saving when the sensor is off.

While at that, do the delay on power/clock enable even if the sensor driver
itself doesn't control the GPIOs. This is required for the OLPC XO-1
platform, that lacks the proper power/reset properties in its DT, but
needs the delay after the sensor is clocked up.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/media/i2c/ov7670.c | 30 ++++++++++++++----------------
1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 4679aa9dc430..93c055502bb9 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1611,14 +1611,17 @@ static void ov7670_power_on(struct v4l2_subdev *sd)
if (info->on)
return;

+ clk_prepare_enable(info->clk);
+
if (info->pwdn_gpio)
gpiod_set_value(info->pwdn_gpio, 0);
if (info->resetb_gpio) {
gpiod_set_value(info->resetb_gpio, 1);
usleep_range(500, 1000);
gpiod_set_value(info->resetb_gpio, 0);
- usleep_range(3000, 5000);
}
+ if (info->pwdn_gpio || info->resetb_gpio || info->clk)
+ usleep_range(3000, 5000);

info->on = true;
}
@@ -1630,6 +1633,8 @@ static void ov7670_power_off(struct v4l2_subdev *sd)
if (!info->on)
return;

+ clk_disable_unprepare(info->clk);
+
if (info->pwdn_gpio)
gpiod_set_value(info->pwdn_gpio, 1);

@@ -1850,24 +1855,20 @@ static int ov7670_probe(struct i2c_client *client,
return ret;
}

- if (info->clk) {
- ret = clk_prepare_enable(info->clk);
- if (ret)
- return ret;
+ ret = ov7670_init_gpio(client, info);
+ if (ret)
+ return ret;

+ ov7670_power_on(sd);
+
+ if (info->clk) {
info->clock_speed = clk_get_rate(info->clk) / 1000000;
if (info->clock_speed < 10 || info->clock_speed > 48) {
ret = -EINVAL;
- goto clk_disable;
+ goto power_off;
}
}

- ret = ov7670_init_gpio(client, info);
- if (ret)
- goto clk_disable;
-
- ov7670_power_on(sd);
-
/* Make sure it's an ov7670 */
ret = ov7670_detect(sd);
if (ret) {
@@ -1946,6 +1947,7 @@ static int ov7670_probe(struct i2c_client *client,
if (ret < 0)
goto entity_cleanup;

+ ov7670_power_off(sd);
return 0;

entity_cleanup:
@@ -1954,12 +1956,9 @@ static int ov7670_probe(struct i2c_client *client,
v4l2_ctrl_handler_free(&info->hdl);
power_off:
ov7670_power_off(sd);
-clk_disable:
- clk_disable_unprepare(info->clk);
return ret;
}

-
static int ov7670_remove(struct i2c_client *client)
{
struct v4l2_subdev *sd = i2c_get_clientdata(client);
@@ -1967,7 +1966,6 @@ static int ov7670_remove(struct i2c_client *client)

v4l2_async_unregister_subdev(sd);
v4l2_ctrl_handler_free(&info->hdl);
- clk_disable_unprepare(info->clk);
media_entity_cleanup(&info->sd.entity);
ov7670_power_off(sd);
return 0;
--
2.20.1
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