Hi,
On Tue, Aug 17, 2021 at 05:50:44PM +0800, CK Hu wrote:
> Hi, Markus:
>
> On Mon, 2021-08-16 at 21:25 +0200, Markus Schneider-Pargmann wrote:
> > dpintf is the displayport interface hardware unit. This unit is similar
> > to dpi and can reuse most of the code.
> >
> > This patch adds support for mt8195-dpintf to this dpi driver. Main
> > differences are:
> > - Some features/functional components are not available for dpintf
> > which are now excluded from code execution once is_dpintf is set
> > - dpintf can and needs to choose between different clockdividers based
> > on the clockspeed. This is done by choosing a different clock parent.
> > - There are two additional clocks that need to be managed. These are
> > only set for dpintf and will be set to NULL if not supplied. The
> > clk_* calls handle these as normal clocks then.
> > - Some register contents differ slightly between the two components. To
> > work around this I added register bits/masks with a DPINTF_ prefix
> > and use them where different.
> >
> > Based on a separate driver for dpintf created by
> > Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>.
> >
> > Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/mediatek/mtk_dpi.c | 282 ++++++++++++++++++++----
> > drivers/gpu/drm/mediatek/mtk_dpi_regs.h | 12 +
> > 2 files changed, 247 insertions(+), 47 deletions(-)
> >
>
> [snip]
>
> >
> > +static void mtk_dpi_set_pixel_clk_parent(struct mtk_dpi *dpi,
> > + unsigned int factor)
> > +{
> > + struct clk *new_parent;
> > +
> > + switch (factor) {
> > + case 16:
> > + new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D16].clk;
> > + break;
> > + case 8:
> > + new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D8].clk;
> > + break;
> > + case 4:
> > + new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D4].clk;
> > + break;
> > + case 2:
> > + new_parent = dpi->tvd_clks[MTK_DPI_TVDPLL_D2].clk;
> > + break;
> > + default:
> > + new_parent = NULL;
> > + }
> > + if (new_parent)
> > + clk_set_parent(dpi->pixel_clk, new_parent);
>
> I prefer that dpi->pixel_clk provide set_rate() interface, and let clock
> driver to control the parent of dpi->pixel_clk.
Good point, will do that, thanks.
Best,
Markus
>
> Regards,
> CK
>
> > +}
> > +
> > static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> > struct drm_display_mode *mode)
> > {
> > @@ -465,6 +568,8 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> > drm_display_mode_to_videomode(mode, &vm);
> > pll_rate = vm.pixelclock * factor;
> >
> > + mtk_dpi_set_pixel_clk_parent(dpi, factor);
> > +
> > dev_dbg(dpi->dev, "Want PLL %lu Hz, pixel clock %lu Hz\n",
> > pll_rate, vm.pixelclock);
> >
>
>
