Re: Re: [PATCH 16/19] media: i2c: imx290: Move registers with fixed value to init array

Dave Stevenson
2022-07-21T16:20:22Z

Hi Laurent and Alexander

On Thu, 21 Jul 2022 at 12:08, Alexander Stein
<alexander.stein@ew.tq-group.com> wrote:
>
> Hello Laurent,
>
> Am Donnerstag, 21. Juli 2022, 12:40:36 CEST schrieb Laurent Pinchart:
> > Hi Alexander,
> >
> > On Thu, Jul 21, 2022 at 12:08:50PM +0200, Alexander Stein wrote:
> > > Am Donnerstag, 21. Juli 2022, 10:35:37 CEST schrieb Laurent Pinchart:
> > > > Registers 0x3012, 0x3013 and 0x3480 are not documented and are set in
> > > > the per-mode register arrays with values indentical for all modes. Move
> > > > them to the common array.
> > > >
> > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > ---
> > > >
> > > > drivers/media/i2c/imx290.c | 8 ++------
> > > > 1 file changed, 2 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
> > > > index 78772c6327a2..fc6e87fada1c 100644
> > > > --- a/drivers/media/i2c/imx290.c
> > > > +++ b/drivers/media/i2c/imx290.c
> > > > @@ -192,6 +192,7 @@ static const struct imx290_regval
> > > > imx290_global_init_settings[] = { { IMX290_REG_8BIT(0x300f), 0x00 },
> > > >
> > > > { IMX290_REG_8BIT(0x3010), 0x21 },
> > > > { IMX290_REG_8BIT(0x3012), 0x64 },
> > > >
> > > > + { IMX290_REG_8BIT(0x3013), 0x00 },
> > > >
> > > > { IMX290_REG_8BIT(0x3016), 0x09 },
> > > > { IMX290_REG_8BIT(0x3070), 0x02 },
> > > > { IMX290_REG_8BIT(0x3071), 0x11 },
> > > >
> > > > @@ -230,6 +231,7 @@ static const struct imx290_regval
> > > > imx290_global_init_settings[] = { { IMX290_REG_8BIT(0x33b0), 0x50 },
> > > >
> > > > { IMX290_REG_8BIT(0x33b2), 0x1a },
> > > > { IMX290_REG_8BIT(0x33b3), 0x04 },
> > > >
> > > > + { IMX290_REG_8BIT(0x3480), 0x49 },
> > > >
> > > > };
> > > >
> > > > static const struct imx290_regval imx290_1080p_settings[] = {
> > > >
> > > > @@ -239,15 +241,12 @@ static const struct imx290_regval
> > > > imx290_1080p_settings[] = { { IMX290_OPB_SIZE_V, 10 },
> > > >
> > > > { IMX290_X_OUT_SIZE, 1920 },
> > > > { IMX290_Y_OUT_SIZE, 1080 },
> > > >
> > > > - { IMX290_REG_8BIT(0x3012), 0x64 },
> > > > - { IMX290_REG_8BIT(0x3013), 0x00 },
> > > >
> > > > { IMX290_INCKSEL1, 0x18 },
> > > > { IMX290_INCKSEL2, 0x03 },
> > > > { IMX290_INCKSEL3, 0x20 },
> > > > { IMX290_INCKSEL4, 0x01 },
> > > > { IMX290_INCKSEL5, 0x1a },
> > > > { IMX290_INCKSEL6, 0x1a },
> > > >
> > > > - { IMX290_REG_8BIT(0x3480), 0x49 },
> > > >
> > > > /* data rate settings */
> > > > { IMX290_REPETITION, 0x10 },
> > > > { IMX290_TCLKPOST, 87 },
> > > >
> > > > @@ -267,15 +266,12 @@ static const struct imx290_regval
> > > > imx290_720p_settings[] = { { IMX290_OPB_SIZE_V, 4 },
> > > >
> > > > { IMX290_X_OUT_SIZE, 1280 },
> > > > { IMX290_Y_OUT_SIZE, 720 },
> > > >
> > > > - { IMX290_REG_8BIT(0x3012), 0x64 },
> > > > - { IMX290_REG_8BIT(0x3013), 0x00 },
> > > >
> > > > { IMX290_INCKSEL1, 0x20 },
> > > > { IMX290_INCKSEL2, 0x00 },
> > > > { IMX290_INCKSEL3, 0x20 },
> > > > { IMX290_INCKSEL4, 0x01 },
> > > > { IMX290_INCKSEL5, 0x1a },
> > > > { IMX290_INCKSEL6, 0x1a },
> > > >
> > > > - { IMX290_REG_8BIT(0x3480), 0x49 },
> > > >
> > > > /* data rate settings */
> > > > { IMX290_REPETITION, 0x10 },
> > > > { IMX290_TCLKPOST, 79 },
> > >
> > > 0x3480 is INCKSEL7 for imx327, not sure if that should be set yet for
> > > imx290 (only) driver, without proper imx327 support.
> >
> > Do you mean the register doesn't exist on the IMX290 ? We could make it
> > conditional on the sensor model, but it's not added by this patch, it
> > has been there since the first version of the driver, so I'd rather do
> > that on top.
>
> As far as I know INCKSEL7 is only valid on imx327. On imx290 the whole
> 0x300-0x34ff range is reserved.

IMX290_CSI_LANE_MODE to select the number of CSI2 data lanes is
0x3443, so clearly the whole range is not reserved.

> I agree this should be conditional on the sensor model. If you want to keep
> it, because it is not new, I'm fine with that.

0x3840 is documented in my IMX290 datasheet as being INCKSEL7. 0x49
for 37.125MHz clock. 0x92 for 74.25MHz (default).
Removing it *will* break this driver for existing platforms as the
rest of the code configures a 37.125MHz clock.

See [1] for adding 74.25MHz clock support.

Dave

[1] https://github.com/raspberrypi/linux/commit/125f7e7ef1194d4849c74b25c87d18aea9de2de7