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.
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);
>
