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[PATCH v7 07/43] drm/mediatek: mtk_dpi: Add support for DPI input clock from HDMI

AngeloGioacchino Del Regno posted 43 patches 10 months ago
[PATCH v7 07/43] drm/mediatek: mtk_dpi: Add support for DPI input clock from HDMI
Posted by AngeloGioacchino Del Regno 10 months ago 
On some SoCs, like MT8195 and MT8188, the DPI instance that is
reserved to the HDMI Transmitter uses a different clock topology.

In this case, the DPI is clocked by the HDMI IP, and this outputs
its clock to the MM input of dpi_pixel_clk, which is essential to
enable register access to the DPI IP.

Add a `clocked_by_hdmi` member to struct mtk_dpi_conf, and check
it to avoid enabling the DPI clocks in the mediatek-drm internal
.start() callback (and avoid disabing in the .stop() component
callback): this will make sure that the clock configuration
sequence is respected during display pipeline setup by following
the bridge ops between DPI and HDMI, where the HDMI driver is
expected to enable the clocks in the bridge's pre_enable(), and
DPI in the enable() cb.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 9a6c0f75f764..9f83e82437dd 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -145,6 +145,8 @@ struct mtk_dpi_factor {
                      If present, implies that the feature must be enabled.
  * @pixels_per_iter: Quantity of transferred pixels per iteration.
  * @edge_cfg_in_mmsys: If the edge configuration for DPI's output needs to be set in MMSYS.
+ * @clocked_by_hdmi: HDMI IP outputs clock to dpi_pixel_clk input clock, needed
+ *		     for DPI registers access.
  */
 struct mtk_dpi_conf {
 	const struct mtk_dpi_factor *dpi_factor;
@@ -165,6 +167,7 @@ struct mtk_dpi_conf {
 	u32 input_2p_en_bit;
 	u32 pixels_per_iter;
 	bool edge_cfg_in_mmsys;
+	bool clocked_by_hdmi;
 };
 
 static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -585,7 +588,9 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	struct videomode vm = { 0 };
 
 	drm_display_mode_to_videomode(mode, &vm);
-	mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
+
+	if (!dpi->conf->clocked_by_hdmi)
+		mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
 
 	dpi_pol.ck_pol = MTK_DPI_POLARITY_FALLING;
 	dpi_pol.de_pol = MTK_DPI_POLARITY_RISING;
@@ -920,14 +925,16 @@ void mtk_dpi_start(struct device *dev)
 {
 	struct mtk_dpi *dpi = dev_get_drvdata(dev);
 
-	mtk_dpi_power_on(dpi);
+	if (!dpi->conf->clocked_by_hdmi)
+		mtk_dpi_power_on(dpi);
 }
 
 void mtk_dpi_stop(struct device *dev)
 {
 	struct mtk_dpi *dpi = dev_get_drvdata(dev);
 
-	mtk_dpi_power_off(dpi);
+	if (!dpi->conf->clocked_by_hdmi)
+		mtk_dpi_power_off(dpi);
 }
 
 unsigned int mtk_dpi_encoder_index(struct device *dev)
-- 
2.48.1
Re: [PATCH v7 07/43] drm/mediatek: mtk_dpi: Add support for DPI input clock from HDMI
Posted by Chun-Kuang Hu 9 months, 2 weeks ago 
Hi, Angelo:

AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> 於
2025年2月17日 週一 下午11:49寫道：
>
> On some SoCs, like MT8195 and MT8188, the DPI instance that is
> reserved to the HDMI Transmitter uses a different clock topology.
>
> In this case, the DPI is clocked by the HDMI IP, and this outputs
> its clock to the MM input of dpi_pixel_clk, which is essential to
> enable register access to the DPI IP.
>
> Add a `clocked_by_hdmi` member to struct mtk_dpi_conf, and check
> it to avoid enabling the DPI clocks in the mediatek-drm internal
> .start() callback (and avoid disabing in the .stop() component
> callback): this will make sure that the clock configuration
> sequence is respected during display pipeline setup by following
> the bridge ops between DPI and HDMI, where the HDMI driver is
> expected to enable the clocks in the bridge's pre_enable(), and
> DPI in the enable() cb.

After fix conflicts, applied to mediatek-drm-next [1], thanks.

[1] https://web.git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
Chun-Kuang.

>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 9a6c0f75f764..9f83e82437dd 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -145,6 +145,8 @@ struct mtk_dpi_factor {
>                       If present, implies that the feature must be enabled.
>   * @pixels_per_iter: Quantity of transferred pixels per iteration.
>   * @edge_cfg_in_mmsys: If the edge configuration for DPI's output needs to be set in MMSYS.
> + * @clocked_by_hdmi: HDMI IP outputs clock to dpi_pixel_clk input clock, needed
> + *                  for DPI registers access.
>   */
>  struct mtk_dpi_conf {
>         const struct mtk_dpi_factor *dpi_factor;
> @@ -165,6 +167,7 @@ struct mtk_dpi_conf {
>         u32 input_2p_en_bit;
>         u32 pixels_per_iter;
>         bool edge_cfg_in_mmsys;
> +       bool clocked_by_hdmi;
>  };
>
>  static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> @@ -585,7 +588,9 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>         struct videomode vm = { 0 };
>
>         drm_display_mode_to_videomode(mode, &vm);
> -       mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
> +
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
>
>         dpi_pol.ck_pol = MTK_DPI_POLARITY_FALLING;
>         dpi_pol.de_pol = MTK_DPI_POLARITY_RISING;
> @@ -920,14 +925,16 @@ void mtk_dpi_start(struct device *dev)
>  {
>         struct mtk_dpi *dpi = dev_get_drvdata(dev);
>
> -       mtk_dpi_power_on(dpi);
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_power_on(dpi);
>  }
>
>  void mtk_dpi_stop(struct device *dev)
>  {
>         struct mtk_dpi *dpi = dev_get_drvdata(dev);
>
> -       mtk_dpi_power_off(dpi);
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_power_off(dpi);
>  }
>
>  unsigned int mtk_dpi_encoder_index(struct device *dev)
> --
> 2.48.1
>
Re: [PATCH v7 07/43] drm/mediatek: mtk_dpi: Add support for DPI input clock from HDMI
Posted by CK Hu (胡俊光) 9 months, 3 weeks ago 
On Mon, 2025-02-17 at 16:48 +0100, AngeloGioacchino Del Regno wrote:
> External email : Please do not click links or open attachments until you have verified the sender or the content.
> 
> 
> On some SoCs, like MT8195 and MT8188, the DPI instance that is
> reserved to the HDMI Transmitter uses a different clock topology.
> 
> In this case, the DPI is clocked by the HDMI IP, and this outputs
> its clock to the MM input of dpi_pixel_clk, which is essential to
> enable register access to the DPI IP.
> 
> Add a `clocked_by_hdmi` member to struct mtk_dpi_conf, and check
> it to avoid enabling the DPI clocks in the mediatek-drm internal
> .start() callback (and avoid disabing in the .stop() component
> callback): this will make sure that the clock configuration
> sequence is respected during display pipeline setup by following
> the bridge ops between DPI and HDMI, where the HDMI driver is
> expected to enable the clocks in the bridge's pre_enable(), and
> DPI in the enable() cb.

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 9a6c0f75f764..9f83e82437dd 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -145,6 +145,8 @@ struct mtk_dpi_factor {
>                       If present, implies that the feature must be enabled.
>   * @pixels_per_iter: Quantity of transferred pixels per iteration.
>   * @edge_cfg_in_mmsys: If the edge configuration for DPI's output needs to be set in MMSYS.
> + * @clocked_by_hdmi: HDMI IP outputs clock to dpi_pixel_clk input clock, needed
> + *                  for DPI registers access.
>   */
>  struct mtk_dpi_conf {
>         const struct mtk_dpi_factor *dpi_factor;
> @@ -165,6 +167,7 @@ struct mtk_dpi_conf {
>         u32 input_2p_en_bit;
>         u32 pixels_per_iter;
>         bool edge_cfg_in_mmsys;
> +       bool clocked_by_hdmi;
>  };
> 
>  static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> @@ -585,7 +588,9 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>         struct videomode vm = { 0 };
> 
>         drm_display_mode_to_videomode(mode, &vm);
> -       mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
> +
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_set_pixel_clk(dpi, &vm, mode->clock);
> 
>         dpi_pol.ck_pol = MTK_DPI_POLARITY_FALLING;
>         dpi_pol.de_pol = MTK_DPI_POLARITY_RISING;
> @@ -920,14 +925,16 @@ void mtk_dpi_start(struct device *dev)
>  {
>         struct mtk_dpi *dpi = dev_get_drvdata(dev);
> 
> -       mtk_dpi_power_on(dpi);
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_power_on(dpi);
>  }
> 
>  void mtk_dpi_stop(struct device *dev)
>  {
>         struct mtk_dpi *dpi = dev_get_drvdata(dev);
> 
> -       mtk_dpi_power_off(dpi);
> +       if (!dpi->conf->clocked_by_hdmi)
> +               mtk_dpi_power_off(dpi);
>  }
> 
>  unsigned int mtk_dpi_encoder_index(struct device *dev)
> --
> 2.48.1
>

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