[PATCH v2 0/7] Add support to the mmsys driver to be a reset controller

[PATCH v2 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 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.txt  |  2 +
 .../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, 96 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 v2 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>
---

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

Re: [PATCH v2 3/7] dt-bindings: display: mediatek: add dsi reset optional property

[Rob Herring]

On Wed, 14 Jul 2021 12:11:37 +0200, Enric Balletbo i Serra wrote:
> 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>
> ---
> 
> 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(+)
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v2 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
settingbetween 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>
---

(no changes since v1)

 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 v2 7/7] drm/mediatek: mtk_dsi: Reset the dsi0 hardware

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2021年7月14日 週三 下午6:12寫道：
>
> Reset dsi0 HW to default when power on. This prevents to have different
> settingbetween 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.

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

>
> 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>
> ---
>
> (no changes since v1)
>
>  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 v2 7/7] drm/mediatek: mtk_dsi: Reset the dsi0 hardware

[Matthias Brugger]

On 14/07/2021 12:11, Enric Balletbo i Serra wrote:
> Reset dsi0 HW to default when power on. This prevents to have different
> settingbetween the bootloader and the kernel.

settings between the...

> 
> 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>

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>

> ---
> 
> (no changes since v1)
> 
>  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,
>