On Thu, Jan 17, 2019 at 12:48 AM Maxime Ripard
<maxime.ripard@xxxxxxxxxxx> wrote:
>
> On Fri, Jan 11, 2019 at 11:54:12AM +0530, Jagan Teki wrote:
> > On Mon, Jan 7, 2019 at 6:59 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
> > > On Mon, Dec 24, 2018 at 08:57:48PM +0530, Jagan Teki wrote:
> > > > On Fri, Dec 21, 2018 at 6:30 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
> > > > >
> > > > > On Thu, Dec 20, 2018 at 06:24:34PM +0530, Jagan Teki wrote:
> > > > > > Unfortunately default CSI_SCLK rate cannot work properly to
> > > > > > drive the connected sensor interface, particularly on few
> > > > > > Allwinner SoC's like A64.
> > > > > >
> > > > > > So, add mod_rate quirk via driver data so-that the respective
> > > > > > SoC's which require to alter the default mod clock rate can assign
> > > > > > the operating clock rate.
> > > > > >
> > > > > > Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> > > > > > ---
> > > > > > .../platform/sunxi/sun6i-csi/sun6i_csi.c | 34 +++++++++++++++----
> > > > > > 1 file changed, 28 insertions(+), 6 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > > > > index ee882b66a5ea..fe002beae09c 100644
> > > > > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > > > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
> > > > > > @@ -15,6 +15,7 @@
> > > > > > #include <linux/ioctl.h>
> > > > > > #include <linux/module.h>
> > > > > > #include <linux/of.h>
> > > > > > +#include <linux/of_device.h>
> > > > > > #include <linux/platform_device.h>
> > > > > > #include <linux/pm_runtime.h>
> > > > > > #include <linux/regmap.h>
> > > > > > @@ -28,8 +29,13 @@
> > > > > >
> > > > > > #define MODULE_NAME "sun6i-csi"
> > > > > >
> > > > > > +struct sun6i_csi_variant {
> > > > > > + unsigned long mod_rate;
> > > > > > +};
> > > > > > +
> > > > > > struct sun6i_csi_dev {
> > > > > > struct sun6i_csi csi;
> > > > > > + const struct sun6i_csi_variant *variant;
> > > > > > struct device *dev;
> > > > > >
> > > > > > struct regmap *regmap;
> > > > > > @@ -822,33 +828,43 @@ static int sun6i_csi_resource_request(struct sun6i_csi_dev *sdev,
> > > > > > return PTR_ERR(sdev->clk_mod);
> > > > > > }
> > > > > >
> > > > > > + if (sdev->variant->mod_rate)
> > > > > > + clk_set_rate_exclusive(sdev->clk_mod, sdev->variant->mod_rate);
> > > > > > +
> > > > >
> > > > > It still doesn't make any sense to do it in the probe function...
> > > >
> > > > I'm not sure we discussed about the context wrt probe, we discussed
> > > > about exclusive put clock.
> > >
> > > https://lkml.org/lkml/2018/12/18/584
> > >
> > > "Doing it here is not really optimal either, since you'll put a
> > > constraint on the system (maintaining that clock at 300MHz), while
> > > it's not in use."
> >
> > But this constraint is only set, for SoC's who need mod_rate change
> > not for whole SoCs.
>
> Still, that constraint is there for the whole system on affected
> SoCs. Whether it applies to one SoC or not is not really relevant.
OK, please see this code change and let me know the comments.
https://gist.github.com/openedev/518b9e141f53814bb3adfac6f2bfd78c
