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Message-ID: <20220221094420.5oqsydyjvub7d7h3@houat>
Date: Mon, 21 Feb 2022 10:44:20 +0100
From: Maxime Ripard <maxime@...no.tech>
To: Guillaume Ranquet <granquet@...libre.com>
Cc: chunkuang.hu@...nel.org, p.zabel@...gutronix.de, airlied@...ux.ie,
daniel@...ll.ch, robh+dt@...nel.org,
maarten.lankhorst@...ux.intel.com, tzimmermann@...e.de,
matthias.bgg@...il.com, chunfeng.yun@...iatek.com, kishon@...com,
vkoul@...nel.org, deller@....de, ck.hu@...iatek.com,
jitao.shi@...iatek.com, angelogioacchino.delregno@...labora.com,
dri-devel@...ts.freedesktop.org,
linux-mediatek@...ts.infradead.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-phy@...ts.infradead.org, linux-fbdev@...r.kernel.org,
Markus Schneider-Pargmann <msp@...libre.com>
Subject: Re: [PATCH v8 13/19] drm/mediatek: dpi: Add dpintf support
Hi
(Now I remember your series ;)
On Fri, Feb 18, 2022 at 03:54:31PM +0100, Guillaume Ranquet 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@...iatek.com>.
>
> Signed-off-by: Markus Schneider-Pargmann <msp@...libre.com>
> Signed-off-by: Guillaume Ranquet <granquet@...libre.com>
> ---
> drivers/gpu/drm/mediatek/mtk_dpi.c | 164 +++++++++++++++++---
> drivers/gpu/drm/mediatek/mtk_dpi_regs.h | 38 +++++
> drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 8 +
> drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 1 +
> drivers/gpu/drm/mediatek/mtk_drm_drv.c | 5 +-
> include/linux/soc/mediatek/mtk-mmsys.h | 2 +
> 6 files changed, 198 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index be99399faf1bb..c5639ada868f8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -63,6 +63,14 @@ enum mtk_dpi_out_color_format {
> MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL
> };
>
> +enum TVDPLL_CLK {
> + TVDPLL_PLL = 0,
> + TVDPLL_D2 = 2,
> + TVDPLL_D4 = 4,
> + TVDPLL_D8 = 8,
> + TVDPLL_D16 = 16,
> +};
> +
> struct mtk_dpi {
> struct drm_encoder encoder;
> struct drm_bridge bridge;
> @@ -71,8 +79,10 @@ struct mtk_dpi {
> void __iomem *regs;
> struct device *dev;
> struct clk *engine_clk;
> + struct clk *dpi_ck_cg;
> struct clk *pixel_clk;
> struct clk *tvd_clk;
> + struct clk *pclk_src[5];
> int irq;
> struct drm_display_mode mode;
> const struct mtk_dpi_conf *conf;
> @@ -126,6 +136,7 @@ struct mtk_dpi_conf {
> const u32 *output_fmts;
> u32 num_output_fmts;
> bool is_ck_de_pol;
> + bool is_dpintf;
> bool swap_input_support;
> // Mask used for HWIDTH, HPORCH, VSYNC_WIDTH and VSYNC_PORCH (no shift)
> u32 dimension_mask;
> @@ -384,6 +395,25 @@ static void mtk_dpi_config_disable_edge(struct mtk_dpi *dpi)
> mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, 0, EDGE_SEL_EN);
> }
>
> +static void mtk_dpi_matrix_sel(struct mtk_dpi *dpi, enum mtk_dpi_out_color_format format)
> +{
> + u32 matrix_sel = 0;
> +
> + switch (format) {
> + case MTK_DPI_COLOR_FORMAT_YCBCR_422:
> + case MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL:
> + case MTK_DPI_COLOR_FORMAT_YCBCR_444:
> + case MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL:
> + case MTK_DPI_COLOR_FORMAT_XV_YCC:
> + if (dpi->mode.hdisplay <= 720)
> + matrix_sel = 0x2;
> + break;
> + default:
> + break;
> + }
> + mtk_dpi_mask(dpi, DPI_MATRIX_SET, matrix_sel, INT_MATRIX_SEL_MASK);
> +}
> +
> static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> enum mtk_dpi_out_color_format format)
> {
> @@ -391,6 +421,7 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> (format == MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL)) {
> mtk_dpi_config_yuv422_enable(dpi, false);
> mtk_dpi_config_csc_enable(dpi, true);
> + mtk_dpi_matrix_sel(dpi, format);
> if (dpi->conf->swap_input_support)
> mtk_dpi_config_swap_input(dpi, false);
> mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_BGR);
> @@ -398,6 +429,7 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
> (format == MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL)) {
> mtk_dpi_config_yuv422_enable(dpi, true);
> mtk_dpi_config_csc_enable(dpi, true);
> + mtk_dpi_matrix_sel(dpi, format);
> if (dpi->conf->swap_input_support)
> mtk_dpi_config_swap_input(dpi, true);
> mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_RGB);
> @@ -438,6 +470,8 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
> mtk_dpi_disable(dpi);
> clk_disable_unprepare(dpi->pixel_clk);
> clk_disable_unprepare(dpi->engine_clk);
> + clk_disable_unprepare(dpi->dpi_ck_cg);
> + clk_disable_unprepare(dpi->tvd_clk);
> }
>
> static int mtk_dpi_power_on(struct mtk_dpi *dpi)
> @@ -447,12 +481,24 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
> if (++dpi->refcount != 1)
> return 0;
>
> + ret = clk_prepare_enable(dpi->tvd_clk);
> + if (ret) {
> + dev_err(dpi->dev, "Failed to enable tvd pll: %d\n", ret);
> + goto err_pixel;
> + }
> +
> ret = clk_prepare_enable(dpi->engine_clk);
> if (ret) {
> dev_err(dpi->dev, "Failed to enable engine clock: %d\n", ret);
> goto err_refcount;
> }
>
> + ret = clk_prepare_enable(dpi->dpi_ck_cg);
> + if (ret) {
> + dev_err(dpi->dev, "Failed to enable dpi_ck_cg clock: %d\n", ret);
> + goto err_ck_cg;
> + }
> +
> ret = clk_prepare_enable(dpi->pixel_clk);
> if (ret) {
> dev_err(dpi->dev, "Failed to enable pixel clock: %d\n", ret);
> @@ -462,10 +508,11 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
> if (dpi->pinctrl && dpi->pins_dpi)
> pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
>
> - mtk_dpi_enable(dpi);
> return 0;
>
> err_pixel:
> + clk_disable_unprepare(dpi->dpi_ck_cg);
> +err_ck_cg:
> clk_disable_unprepare(dpi->engine_clk);
> err_refcount:
> dpi->refcount--;
> @@ -497,12 +544,21 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> pll_rate = clk_get_rate(dpi->tvd_clk);
>
> vm.pixelclock = pll_rate / factor;
> - if ((dpi->output_fmt == MEDIA_BUS_FMT_RGB888_2X12_LE) ||
> - (dpi->output_fmt == MEDIA_BUS_FMT_RGB888_2X12_BE))
> + if (dpi->conf->is_dpintf) {
> + if (factor == 1)
> + clk_set_parent(dpi->pixel_clk, dpi->pclk_src[2]);
> + else if (factor == 2)
> + clk_set_parent(dpi->pixel_clk, dpi->pclk_src[3]);
> + else if (factor == 4)
> + clk_set_parent(dpi->pixel_clk, dpi->pclk_src[4]);
> + else
> + clk_set_parent(dpi->pixel_clk, dpi->pclk_src[2]);
You get a reference to these clocks using:
>
> + dpi->pclk_src[1] = devm_clk_get(dev, "TVDPLL_D2");
> + dpi->pclk_src[2] = devm_clk_get(dev, "TVDPLL_D4");
> + dpi->pclk_src[3] = devm_clk_get(dev, "TVDPLL_D8");
> + dpi->pclk_src[4] = devm_clk_get(dev, "TVDPLL_D16");
> +
So if the clock isn't there, you'll get an error pointer, won't check
it, but will dereference it.
If the clock is optional, you should use clk_get_optional, otherwise you
should check the error returned.
That clock setup is weird though. I don't have any knowledge about your
platform, but either the clock should be a single one if it has multiple
dividers, or the pixel_clk clock should behave as a mux and just pick
the best parent for the rate it's given.
Maxime
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