Hi Lubomir, On Tue, Nov 20, 2018 at 11:03:08AM +0100, Lubomir Rintel wrote: > The commit 71862f63f351 ("media: ov7670: Add the ov7670_s_power function") > added a power control routing. However, it was not good enough to use as > a s_power() callback: it merely flipped on the power GPIOs without > restoring the register settings. > > Fix this now and register an actual power callback. > > Signed-off-by: Lubomir Rintel <lkundrak@xxxxx> > > --- > Changes since v2: > - Restore the controls, format and frame rate on power on > > drivers/media/i2c/ov7670.c | 50 +++++++++++++++++++++++++++++++++----- > 1 file changed, 44 insertions(+), 6 deletions(-) > > diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c > index ead0c360df33..cbaab60aaaac 100644 > --- a/drivers/media/i2c/ov7670.c > +++ b/drivers/media/i2c/ov7670.c > @@ -242,6 +242,7 @@ struct ov7670_info { > struct ov7670_format_struct *fmt; /* Current format */ > struct ov7670_win_size *wsize; > struct clk *clk; > + int on; > struct gpio_desc *resetb_gpio; > struct gpio_desc *pwdn_gpio; > unsigned int mbus_config; /* Media bus configuration flags */ > @@ -1615,19 +1616,54 @@ 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) > +static void ov7670_power_on(struct v4l2_subdev *sd) > { > struct ov7670_info *info = to_state(sd); > > + if (info->on) > + return; > + > if (info->pwdn_gpio) > - gpiod_set_value(info->pwdn_gpio, !on); > - if (on && info->resetb_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); > } > > + info->on = true; > +} > + > +static void ov7670_power_off(struct v4l2_subdev *sd) > +{ > + struct ov7670_info *info = to_state(sd); > + > + if (!info->on) > + return; > + > + if (info->pwdn_gpio) > + gpiod_set_value(info->pwdn_gpio, 1); > + > + info->on = false; > +} > + > +static int ov7670_s_power(struct v4l2_subdev *sd, int on) > +{ > + struct ov7670_info *info = to_state(sd); > + > + if (info->on == on) > + return 0; > + > + if (on) { > + ov7670_power_on (sd); > + ov7670_apply_fmt(sd); > + ov7675_apply_framerate(sd); > + v4l2_ctrl_handler_setup(&info->hdl); > + } else { > + ov7670_power_off (sd); > + } > + > return 0; > } > > @@ -1660,6 +1696,7 @@ static int ov7670_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh) > static const struct v4l2_subdev_core_ops ov7670_core_ops = { > .reset = ov7670_reset, > .init = ov7670_init, > + .s_power = ov7670_s_power, > #ifdef CONFIG_VIDEO_ADV_DEBUG > .g_register = ov7670_g_register, > .s_register = ov7670_s_register, > @@ -1825,6 +1862,7 @@ static int ov7670_probe(struct i2c_client *client, > else > return ret; > } > + > if (info->clk) { > ret = clk_prepare_enable(info->clk); > if (ret) > @@ -1841,7 +1879,7 @@ static int ov7670_probe(struct i2c_client *client, > if (ret) > goto clk_disable; > > - ov7670_s_power(sd, 1); > + ov7670_power_on(sd); > > /* Make sure it's an ov7670 */ > ret = ov7670_detect(sd); > @@ -1929,7 +1967,7 @@ static int ov7670_probe(struct i2c_client *client, > hdl_free: > v4l2_ctrl_handler_free(&info->hdl); > power_off: > - ov7670_s_power(sd, 0); > + ov7670_power_off(sd); > clk_disable: > clk_disable_unprepare(info->clk); > return ret; > @@ -1945,7 +1983,7 @@ static int ov7670_remove(struct i2c_client *client) > v4l2_ctrl_handler_free(&info->hdl); > clk_disable_unprepare(info->clk); > media_entity_cleanup(&info->sd.entity); > - ov7670_s_power(sd, 0); > + ov7670_power_off(sd); > return 0; > } > Could you consider instead switching to runtime PM? A few drivers such as the ov2685 driver does that already. -- Kind regards, Sakari Ailus e-mail: sakari.ailus@xxxxxx