| Message ID | 20170918064514.6841-4-wenyou.yang@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sakari, On 2017/9/18 15:35, Sakari Ailus wrote: > Hi Wenyou, > > Thanks for the update. > > The driver exposes controls that are accessible through the sub-device node > even if the device hasn't been powered on. > > Many ISP and bridge drivers will also power the sensor down once the last > user of the user space device nodes disappears. You could keep the device > powered at all times or change the behaviour so that controls can be > accessed when the power is off. > > The best option would be to convert the driver to use runtime PM. Yes, I agree with you. I also noticed there are a lot of things needed to improve except for it, such as the platform data via device tree. I would like do it in another patch set. I will continue to work on it. > An example of this can be found in drivers/media/i2c/ov13858.c . A good example, thank you for your providing. > > On Mon, Sep 18, 2017 at 02:45:14PM +0800, Wenyou Yang wrote: >> 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@microchip.com> >> --- >> >> 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 >> Best Regards, Wenyou Yang
Hi Wenyou, On Mon, Sep 18, 2017 at 05:26:16PM +0800, Yang, Wenyou wrote: > Hi Sakari, > > > On 2017/9/18 15:35, Sakari Ailus wrote: > > Hi Wenyou, > > > > Thanks for the update. > > > > The driver exposes controls that are accessible through the sub-device node > > even if the device hasn't been powered on. > > > > Many ISP and bridge drivers will also power the sensor down once the last > > user of the user space device nodes disappears. You could keep the device > > powered at all times or change the behaviour so that controls can be > > accessed when the power is off. > > > > The best option would be to convert the driver to use runtime PM. > Yes, I agree with you. > I also noticed there are a lot of things needed to improve except for it, > such as the platform data via device tree. > I would like do it in another patch set. I will continue to work on it. Adding runtime PM support later on sound good to me. > > An example of this can be found in drivers/media/i2c/ov13858.c . > A good example, thank you for your providing.
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; }
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@microchip.com> --- 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(-)