Hello, for a bit more of context On Wed, Nov 03, 2021 at 12:39:52PM +0000, Eugen.Hristev@xxxxxxxxxxxxx wrote: > On 11/3/21 10:08 AM, Sakari Ailus wrote: > > Hi Eugen, > > > > Thanks for the patch. > > > > On Tue, Nov 02, 2021 at 05:30:08PM +0200, Eugen Hristev wrote: > >> Implement the get_mbus_config callback. > >> ov7740 is a parallel sensor, and according to datasheet, the register > >> REG12 controls the CCIR656 mode. This register is written to 0 in yuyv mode. > >> According to REG12[5] , CCIR656 mode, the behavior is: > >> CCIR656: disabled > >> REG28 controls the polarity of the signals. This register is unused. > >> The default behavior is then: > >> HSYNC polarity : positive > >> VSYNC polarity : positive > >> HREF polarity: positive > >> > > > > Doesn't the receiver driver get this information from DT? > > > > Hi Sakari, > > This patch comes as a result of my discussions with Jacopo, he advised > to get mbus configuration via the get_mbus_config . I agree that this That's where getting info at runtime was suggested https://patchwork.linuxtv.org/project/linux-media/patch/20200826065142.205000-1-eugen.hristev@xxxxxxxxxxxxx/#122336 > information can be taken from DT as you said. > In the end , my understanding is that get_mbus_config should be used > only for runtime configuration which can change. > Thus, if all this information is static, then, I will proceed with > obtaining it from DT, and you can disregard this patch, as it is not useful. And the latest comment where getting it from DTS was suggested https://patchwork.linuxtv.org/project/linux-media/patch/20211022075247.518880-4-eugen.hristev@xxxxxxxxxxxxx/#132605 Thanks j > > Thanks, > Eugen > > >> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> > >> --- > >> drivers/media/i2c/ov7740.c | 14 ++++++++++++++ > >> 1 file changed, 14 insertions(+) > >> > >> diff --git a/drivers/media/i2c/ov7740.c b/drivers/media/i2c/ov7740.c > >> index 2539cfee85c8..f8a717aecb6f 100644 > >> --- a/drivers/media/i2c/ov7740.c > >> +++ b/drivers/media/i2c/ov7740.c > >> @@ -873,12 +873,26 @@ static int ov7740_get_fmt(struct v4l2_subdev *sd, > >> return ret; > >> } > >> > >> +static int ov7740_get_mbus_config(struct v4l2_subdev *sd, > >> + unsigned int pad, > >> + struct v4l2_mbus_config *cfg) > >> +{ > >> + cfg->type = V4L2_MBUS_PARALLEL; > >> + cfg->flags = V4L2_MBUS_MASTER | V4L2_MBUS_HSYNC_ACTIVE_HIGH | > >> + V4L2_MBUS_VSYNC_ACTIVE_HIGH | > >> + V4L2_MBUS_PCLK_SAMPLE_RISING | > >> + V4L2_MBUS_FIELD_EVEN_LOW | V4L2_MBUS_DATA_ACTIVE_HIGH; > >> + > >> + return 0; > >> +} > >> + > >> static const struct v4l2_subdev_pad_ops ov7740_subdev_pad_ops = { > >> .enum_frame_interval = ov7740_enum_frame_interval, > >> .enum_frame_size = ov7740_enum_frame_size, > >> .enum_mbus_code = ov7740_enum_mbus_code, > >> .get_fmt = ov7740_get_fmt, > >> .set_fmt = ov7740_set_fmt, > >> + .get_mbus_config = ov7740_get_mbus_config, > >> }; > >> > >> static const struct v4l2_subdev_ops ov7740_subdev_ops = { > > > > -- > > Regards, > > > > Sakari Ailus > > >