[PATCH v3 0/7] Add support to the mmsys driver to be a reset controller

[PATCH v3 0/7] Add support to the mmsys driver to be a reset controller

[Enric Balletbo i Serra]

Dear all,

The following patchset is a reimplementation of the patch sent by Jitao
Shi [1] some time ago. As suggested by Chun-Kuang Hu, this time the
reset is done using the reset API, where the mmsys driver is the reset
controller and the mtk_dsi driver is the reset consumer.

Note that the first patch is kind of unrelated change, it's just a
cleanup but is needed if you want to apply all the following patches
cleanly.

This patchset is important in order to have the DSI panel working on some
kukui MT8183 Chromebooks (i.e Lenovo IdeaPad Duet). Without it, you just
get a black screen.

Best regards,
  Enric

[1] https://lore.kernel.org/linux-arm-kernel/20210420132614.150242-4-jitao.shi@mediatek.com/


Changes in v3:
- Based on top of the patch that converts mmsys to schema
- Fix typo in the commit description

Changes in v2:
- Fix build test ERROR Reported-by: kernel test robot <lkp@intel.com>
- Added a new patch to describe the dsi reset optional property.

Enric Balletbo i Serra (7):
  arm64: dts: mediatek: Move reset controller constants into common
    location
  dt-bindings: mediatek: Add #reset-cells to mmsys system controller
  dt-bindings: display: mediatek: add dsi reset optional property
  arm64: dts: mt8173: Add the mmsys reset bit to reset the dsi0
  arm64: dts: mt8183: Add the mmsys reset bit to reset the dsi0
  soc: mediatek: mmsys: Add reset controller support
  drm/mediatek: mtk_dsi: Reset the dsi0 hardware

 .../bindings/arm/mediatek/mediatek,mmsys.yaml |  4 ++
 .../display/mediatek/mediatek,dsi.txt         |  6 ++
 arch/arm64/boot/dts/mediatek/mt8173.dtsi      |  2 +
 arch/arm64/boot/dts/mediatek/mt8183.dtsi      |  5 +-
 drivers/gpu/drm/mediatek/mtk_dsi.c            |  5 +-
 drivers/soc/mediatek/mtk-mmsys.c              | 69 +++++++++++++++++++
 drivers/soc/mediatek/mtk-mmsys.h              |  2 +
 drivers/watchdog/mtk_wdt.c                    |  6 +-
 .../mt2712-resets.h                           |  0
 include/dt-bindings/reset/mt8173-resets.h     |  2 +
 .../mt8183-resets.h                           |  3 +
 .../mt8192-resets.h                           |  0
 12 files changed, 98 insertions(+), 6 deletions(-)
 rename include/dt-bindings/{reset-controller => reset}/mt2712-resets.h (100%)
 rename include/dt-bindings/{reset-controller => reset}/mt8183-resets.h (98%)
 rename include/dt-bindings/{reset-controller => reset}/mt8192-resets.h (100%)

-- 
2.30.2

[PATCH v3 3/7] dt-bindings: display: mediatek: add dsi reset optional property

[Enric Balletbo i Serra]

Update device tree binding documentation for the dsi to add the optional
property to reset the dsi controller.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
---

(no changes since v2)

Changes in v2:
- Added a new patch to describe the dsi reset optional property.

 .../devicetree/bindings/display/mediatek/mediatek,dsi.txt   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
index 8238a86686be..3209b700ded6 100644
--- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
+++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
@@ -19,6 +19,11 @@ Required properties:
   Documentation/devicetree/bindings/graph.txt. This port should be connected
   to the input port of an attached DSI panel or DSI-to-eDP encoder chip.
 
+Optional properties:
+- resets: list of phandle + reset specifier pair, as described in [1].
+
+[1] Documentation/devicetree/bindings/reset/reset.txt
+
 MIPI TX Configuration Module
 ============================
 
@@ -45,6 +50,7 @@ dsi0: dsi@1401b000 {
 	clocks = <&mmsys MM_DSI0_ENGINE>, <&mmsys MM_DSI0_DIGITAL>,
 		 <&mipi_tx0>;
 	clock-names = "engine", "digital", "hs";
+	resets = <&mmsys MT8173_MMSYS_SW0_RST_B_DISP_DSI0>;
 	phys = <&mipi_tx0>;
 	phy-names = "dphy";
 
-- 
2.30.2

[PATCH v3 7/7] drm/mediatek: mtk_dsi: Reset the dsi0 hardware

[Enric Balletbo i Serra]

Reset dsi0 HW to default when power on. This prevents to have different
settingis between the bootloader and the kernel.

As not all Mediatek boards have the reset consumer configured in their
board description, also is not needed on all of them, the reset is optional,
so the change is compatible with all boards.

Cc: Jitao Shi <jitao.shi@mediatek.com>
Suggested-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
---

Changes in v3:
- Fix typo in the commit description

 drivers/gpu/drm/mediatek/mtk_dsi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index ae403c67cbd9..d8b81e2ab841 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -11,6 +11,7 @@
 #include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 
 #include <video/mipi_display.h>
 #include <video/videomode.h>
@@ -980,8 +981,10 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
 	ret = mtk_dsi_encoder_init(drm, dsi);
+	if (ret)
+		return ret;
 
-	return ret;
+	return device_reset_optional(dev);
 }
 
 static void mtk_dsi_unbind(struct device *dev, struct device *master,
-- 
2.30.2

Re: [PATCH v3 3/7] dt-bindings: display: mediatek: add dsi reset optional property

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2021年8月25日 週三 下午6:26寫道：
>
> Update device tree binding documentation for the dsi to add the optional
> property to reset the dsi controller.

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>
> (no changes since v2)
>
> Changes in v2:
> - Added a new patch to describe the dsi reset optional property.
>
>  .../devicetree/bindings/display/mediatek/mediatek,dsi.txt   | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> index 8238a86686be..3209b700ded6 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
> @@ -19,6 +19,11 @@ Required properties:
>    Documentation/devicetree/bindings/graph.txt. This port should be connected
>    to the input port of an attached DSI panel or DSI-to-eDP encoder chip.
>
> +Optional properties:
> +- resets: list of phandle + reset specifier pair, as described in [1].
> +
> +[1] Documentation/devicetree/bindings/reset/reset.txt
> +
>  MIPI TX Configuration Module
>  ============================
>
> @@ -45,6 +50,7 @@ dsi0: dsi@1401b000 {
>         clocks = <&mmsys MM_DSI0_ENGINE>, <&mmsys MM_DSI0_DIGITAL>,
>                  <&mipi_tx0>;
>         clock-names = "engine", "digital", "hs";
> +       resets = <&mmsys MT8173_MMSYS_SW0_RST_B_DISP_DSI0>;
>         phys = <&mipi_tx0>;
>         phy-names = "dphy";
>
> --
> 2.30.2
>