[PATCH v4 3/3] media: ov7670: Add the s_power operation

From: Wenyou Yang
Date: Mon Sep 18 2017 - 02:48:00 EST


Add the s_power operation which is responsible for manipulating the
power dowm mode through the PWDN pin and the reset operation through
the RESET pin.

Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
---

Changes in v4: None
Changes in v3: None
Changes in v2:
- Add the patch to support the get_fmt ops.
- Remove the redundant invoking ov7670_init_gpio().

drivers/media/i2c/ov7670.c | 32 +++++++++++++++++++++++++++-----
1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index 456f48057605..304abc769a67 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1542,6 +1542,22 @@ static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_regis
}
#endif

+static int ov7670_s_power(struct v4l2_subdev *sd, int on)
+{
+ struct ov7670_info *info = to_state(sd);
+
+ if (info->pwdn_gpio)
+ gpiod_direction_output(info->pwdn_gpio, !on);
+ if (on && 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);
+ }
+
+ return 0;
+}
+
static void ov7670_get_default_format(struct v4l2_subdev *sd,
struct v4l2_mbus_framefmt *format)
{
@@ -1575,6 +1591,7 @@ static const struct v4l2_subdev_core_ops ov7670_core_ops = {
.g_register = ov7670_g_register,
.s_register = ov7670_s_register,
#endif
+ .s_power = ov7670_s_power,
};

static const struct v4l2_subdev_video_ops ov7670_video_ops = {
@@ -1692,23 +1709,25 @@ static int ov7670_probe(struct i2c_client *client,
if (ret)
return ret;

- ret = ov7670_init_gpio(client, info);
- if (ret)
- goto clk_disable;
-
info->clock_speed = clk_get_rate(info->clk) / 1000000;
if (info->clock_speed < 10 || info->clock_speed > 48) {
ret = -EINVAL;
goto clk_disable;
}

+ ret = ov7670_init_gpio(client, info);
+ if (ret)
+ goto clk_disable;
+
+ ov7670_s_power(sd, 1);
+
/* Make sure it's an ov7670 */
ret = ov7670_detect(sd);
if (ret) {
v4l_dbg(1, debug, client,
"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
client->addr << 1, client->adapter->name);
- goto clk_disable;
+ goto power_off;
}
v4l_info(client, "chip found @ 0x%02x (%s)\n",
client->addr << 1, client->adapter->name);
@@ -1787,6 +1806,8 @@ static int ov7670_probe(struct i2c_client *client,
#endif
hdl_free:
v4l2_ctrl_handler_free(&info->hdl);
+power_off:
+ ov7670_s_power(sd, 0);
clk_disable:
clk_disable_unprepare(info->clk);
return ret;
@@ -1804,6 +1825,7 @@ static int ov7670_remove(struct i2c_client *client)
#if defined(CONFIG_MEDIA_CONTROLLER)
media_entity_cleanup(&info->sd.entity);
#endif
+ ov7670_s_power(sd, 0);
return 0;
}

--
2.13.0