Re: [PATCH 3/4] drm/mediatek: fix the wrong pixel clock when resolution is 4K

From: CK Hu
Date: Wed Jul 20 2016 - 03:57:48 EST

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In reply to: Bibby Hsieh: "[PATCH 3/4] drm/mediatek: fix the wrong pixel clock when resolution is 4K"
Next in thread: Philipp Zabel: "Re: [PATCH 3/4] drm/mediatek: fix the wrong pixel clock when resolution is 4K"
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Hi, Bibby:

Some comments inline.

On Wed, 2016-07-20 at 12:03 +0800, Bibby Hsieh wrote:
> From: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>
>
> Pixel clock should be 297MHz when resolution is 4K.
>
> Signed-off-by: Junzhi Zhao <junzhi.zhao@xxxxxxxxxxxx>
> Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_dpi.c | 184 +++++++++++++++++++++++++-----------
> 1 file changed, 131 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index d05ca79..c0f04d2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -60,14 +60,35 @@ enum mtk_dpi_out_color_format {
> MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL
> };
>
> +enum mtk_dpi_clk_id {
> + MTK_DPI_CLK_DPI_ENGINE,
> + MTK_DPI_CLK_DPI_PIXEL,
> + MTK_DPI_CLK_TVD_PLL,
> + MTK_DPI_CLK_TVDPLL_MUX,
> + MTK_DPI_CLK_TVDPLL_D2,
> + MTK_DPI_CLK_TVDPLL_D4,
> + MTK_DPI_CLK_TVDPLL_D8,
> + MTK_DPI_CLK_TVDPLL_D16,
> + MTK_DPI_CLK_COUNT,
> +};
> +
> +static const char * const mtk_dpi_clk_names[MTK_DPI_CLK_COUNT] = {
> + [MTK_DPI_CLK_DPI_ENGINE] = "engine",
> + [MTK_DPI_CLK_DPI_PIXEL] = "pixel",
> + [MTK_DPI_CLK_TVD_PLL] = "pll",
> + [MTK_DPI_CLK_TVDPLL_MUX] = "tvdpll_mux",
> + [MTK_DPI_CLK_TVDPLL_D2] = "tvdpll_d2",
> + [MTK_DPI_CLK_TVDPLL_D4] = "tvdpll_d4",
> + [MTK_DPI_CLK_TVDPLL_D8] = "tvdpll_d8",
> + [MTK_DPI_CLK_TVDPLL_D16] = "tvdpll_d16",
> +};
> +
> struct mtk_dpi {
> struct mtk_ddp_comp ddp_comp;
> struct drm_encoder encoder;
> void __iomem *regs;
> struct device *dev;
> - struct clk *engine_clk;
> - struct clk *pixel_clk;
> - struct clk *tvd_clk;
> + struct clk *clk[MTK_DPI_CLK_COUNT];
> int irq;
> struct drm_display_mode mode;
> enum mtk_dpi_out_color_format color_format;
> @@ -76,6 +97,7 @@ struct mtk_dpi {
> enum mtk_dpi_out_channel_swap channel_swap;
> bool power_sta;
> u8 power_ctl;
> + void *data;
> };
>
> static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
> @@ -114,6 +136,11 @@ struct mtk_dpi_yc_limit {
> u16 c_bottom;
> };
>
> +struct mtk_dpi_conf {
> + int (*parse_clk_from_dt)(struct mtk_dpi *dpi, struct device_node *np);
> + int (*clk_config)(struct mtk_dpi *dpi, struct drm_display_mode *mode);
> +};
> +
> static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> {
> u32 tmp = readl(dpi->regs + offset) & ~mask;
> @@ -377,8 +404,8 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl)
> return;
>
> mtk_dpi_disable(dpi);
> - clk_disable_unprepare(dpi->pixel_clk);
> - clk_disable_unprepare(dpi->engine_clk);
> + clk_disable_unprepare(dpi->clk[MTK_DPI_CLK_DPI_PIXEL]);
> + clk_disable_unprepare(dpi->clk[MTK_DPI_CLK_DPI_ENGINE]);
> dpi->power_sta = false;
> }
>
> @@ -395,13 +422,13 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl)
> if (dpi->power_sta)
> return 0;
>
> - ret = clk_prepare_enable(dpi->engine_clk);
> + ret = clk_prepare_enable(dpi->clk[MTK_DPI_CLK_DPI_ENGINE]);
> if (ret) {
> dev_err(dpi->dev, "Failed to enable engine clock: %d\n", ret);
> goto err_eng;
> }
>
> - ret = clk_prepare_enable(dpi->pixel_clk);
> + ret = clk_prepare_enable(dpi->clk[MTK_DPI_CLK_DPI_PIXEL]);
> if (ret) {
> dev_err(dpi->dev, "Failed to enable pixel clock: %d\n", ret);
> goto err_pixel;
> @@ -412,7 +439,7 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi, enum mtk_dpi_power_ctl pctl)
> return 0;
>
> err_pixel:
> - clk_disable_unprepare(dpi->engine_clk);
> + clk_disable_unprepare(dpi->clk[MTK_DPI_CLK_DPI_ENGINE]);
> err_eng:
> dpi->power_ctl &= ~pctl;
> return ret;
> @@ -428,34 +455,16 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
> struct mtk_dpi_sync_param vsync_leven = { 0 };
> struct mtk_dpi_sync_param vsync_rodd = { 0 };
> struct mtk_dpi_sync_param vsync_reven = { 0 };
> - unsigned long pix_rate;
> - unsigned long pll_rate;
> - unsigned int factor;
> + struct mtk_dpi_conf *conf;
> + int ret;
>
> if (!dpi) {
> dev_err(dpi->dev, "invalid argument\n");
> return -EINVAL;
> }
>
> - pix_rate = 1000UL * mode->clock;
> - if (mode->clock <= 74000)
> - factor = 8 * 3;
> - else
> - factor = 4 * 3;
> - pll_rate = pix_rate * factor;
> -
> - dev_dbg(dpi->dev, "Want PLL %lu Hz, pixel clock %lu Hz\n",
> - pll_rate, pix_rate);
> -
> - clk_set_rate(dpi->tvd_clk, pll_rate);
> - pll_rate = clk_get_rate(dpi->tvd_clk);
> -
> - pix_rate = pll_rate / factor;
> - clk_set_rate(dpi->pixel_clk, pix_rate);
> - pix_rate = clk_get_rate(dpi->pixel_clk);
> -
> - dev_dbg(dpi->dev, "Got PLL %lu Hz, pixel clock %lu Hz\n",
> - pll_rate, pix_rate);
> + conf = (struct mtk_dpi_conf *)dpi->data;
> + ret = conf->clk_config(dpi, mode);

Nothing to do with return error?

>
> limit.c_bottom = 0x0010;
> limit.c_top = 0x0FE0;
> @@ -656,20 +665,109 @@ static const struct component_ops mtk_dpi_component_ops = {
> .unbind = mtk_dpi_unbind,
> };
>
> +static int mt8173_parse_clk_from_dt(struct mtk_dpi *dpi, struct device_node *np)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(mtk_dpi_clk_names); i++) {
> + dpi->clk[i] = of_clk_get_by_name(np,
> + mtk_dpi_clk_names[i]);
> + if (IS_ERR(dpi->clk[i]))
> + return PTR_ERR(dpi->clk[i]);
> + }
> + return 0;
> +}

I think parsing device tree is a pure SW behavior. Would this vary for
different MTK soc?

> +
> +static int mt8173_clk_config(struct mtk_dpi *dpi, struct drm_display_mode *mode)
> +{
> + unsigned long pix_rate;
> + unsigned long pll_rate;
> + unsigned int factor;
> + struct clk *parent;
> + int ret;
> +
> + if (mode->clock <= 27000) {
> + factor = 16 * 3;
> + parent = dpi->clk[MTK_DPI_CLK_TVDPLL_D16];
> + } else if (mode->clock <= 74250) {
> + factor = 8 * 3;
> + parent = dpi->clk[MTK_DPI_CLK_TVDPLL_D8];
> + } else if (mode->clock <= 167000) {
> + factor = 4 * 3;
> + parent = dpi->clk[MTK_DPI_CLK_TVDPLL_D4];
> + } else {
> + factor = 2 * 3;
> + parent = dpi->clk[MTK_DPI_CLK_TVDPLL_D2];
> + }
> +
> + pix_rate = 1000UL * mode->clock;
> + pll_rate = pix_rate * factor;
> +
> + dev_dbg(dpi->dev, "Want PLL %lu Hz, pixel clock %lu Hz\n",
> + pll_rate, pix_rate);
> +
> + ret = clk_prepare_enable(dpi->clk[MTK_DPI_CLK_TVDPLL_MUX]);
> + if (ret) {
> + dev_err(dpi->dev, "tvdpll_mux enable fail\n");
> + return ret;
> + }
> +
> + ret = clk_set_parent(dpi->clk[MTK_DPI_CLK_TVDPLL_MUX], parent);
> + if (ret) {
> + dev_err(dpi->dev, "tvdpll_mux set parent fail\n");

Before return, you may undo something.

> + return ret;
> + }
> + clk_disable_unprepare(dpi->clk[MTK_DPI_CLK_TVDPLL_MUX]);
> +
> + ret = clk_set_rate(dpi->clk[MTK_DPI_CLK_TVD_PLL], pll_rate);
> + if (ret) {
> + dev_err(dpi->dev, "dpi pll_rate set rate fail\n");
> + return ret;
> + }
> + pll_rate = clk_get_rate(dpi->clk[MTK_DPI_CLK_TVD_PLL]);
> + pix_rate = clk_get_rate(dpi->clk[MTK_DPI_CLK_DPI_PIXEL]);
> +
> + dev_dbg(dpi->dev, "Got PLL %lu Hz, pixel clock %lu Hz\n",
> + pll_rate, pix_rate);
> +
> + return 0;
> +}
> +
> +static const struct mtk_dpi_conf mt8173_conf = {
> + .parse_clk_from_dt = mt8173_parse_clk_from_dt,
> + .clk_config = mt8173_clk_config,
> +};
> +
> +static const struct of_device_id mtk_dpi_of_ids[] = {
> + { .compatible = "mediatek,mt8173-dpi",
> + .data = &mt8173_conf,
> + },
> + {}
> +};
> +
> static int mtk_dpi_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct mtk_dpi *dpi;
> struct resource *mem;
> + struct device_node *np = dev->of_node;
> struct device_node *ep, *bridge_node = NULL;
> int comp_id;
> + const struct of_device_id *match;
> + struct mtk_dpi_conf *conf;
> int ret;
>
> + match = of_match_node(mtk_dpi_of_ids, dev->of_node);
> + if (!match)
> + return -ENODEV;
> +
> dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
> if (!dpi)
> return -ENOMEM;
>
> dpi->dev = dev;
> + dpi->data = (void *)match->data;
> + conf = (struct mtk_dpi_conf *)match->data;
>
> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> dpi->regs = devm_ioremap_resource(dev, mem);
> @@ -679,24 +777,9 @@ static int mtk_dpi_probe(struct platform_device *pdev)
> return ret;
> }
>
> - dpi->engine_clk = devm_clk_get(dev, "engine");
> - if (IS_ERR(dpi->engine_clk)) {
> - ret = PTR_ERR(dpi->engine_clk);
> - dev_err(dev, "Failed to get engine clock: %d\n", ret);
> - return ret;
> - }
> -
> - dpi->pixel_clk = devm_clk_get(dev, "pixel");
> - if (IS_ERR(dpi->pixel_clk)) {
> - ret = PTR_ERR(dpi->pixel_clk);
> - dev_err(dev, "Failed to get pixel clock: %d\n", ret);
> - return ret;
> - }
> -
> - dpi->tvd_clk = devm_clk_get(dev, "pll");
> - if (IS_ERR(dpi->tvd_clk)) {
> - ret = PTR_ERR(dpi->tvd_clk);
> - dev_err(dev, "Failed to get tvdpll clock: %d\n", ret);
> + ret = conf->parse_clk_from_dt(dpi, np);
> + if (ret) {
> + dev_err(dev, "parse tvd div clk failed!");
> return ret;
> }
>
> @@ -754,11 +837,6 @@ static int mtk_dpi_remove(struct platform_device *pdev)
> return 0;
> }
>
> -static const struct of_device_id mtk_dpi_of_ids[] = {
> - { .compatible = "mediatek,mt8173-dpi", },
> - {}
> -};
> -
> struct platform_driver mtk_dpi_driver = {
> .probe = mtk_dpi_probe,
> .remove = mtk_dpi_remove,

Regards,
CK

Next message: Oliver Neukum: "Re: [PATCH net-next v3] cdc_ether: Improve ZTE MF823/831/910 handling"
Previous message: Enric Balletbo Serra: "Re: [PATCH 04/10] iio: cros_ec: Add common functions for cros_ec sensors."
In reply to: Bibby Hsieh: "[PATCH 3/4] drm/mediatek: fix the wrong pixel clock when resolution is 4K"
Next in thread: Philipp Zabel: "Re: [PATCH 3/4] drm/mediatek: fix the wrong pixel clock when resolution is 4K"
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