[PATCH v3 1/3] dt-bindings: Add vendor prefix for Xinpeng Technology

[PATCH v3 1/3] dt-bindings: Add vendor prefix for Xinpeng Technology

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

Shenzhen Xinpeng Technology Co., Ltd produces for example display panels.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 6046f4555852..85e7c26a05c7 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1056,6 +1056,8 @@ patternProperties:
     description: Extreme Engineering Solutions (X-ES)
   "^xillybus,.*":
     description: Xillybus Ltd.
+  "^xinpeng,.*":
+    description: Shenzhen Xinpeng Technology Co., Ltd
   "^xlnx,.*":
     description: Xilinx
   "^xunlong,.*":
-- 
2.24.0

[PATCH v3 2/3] dt-bindings: display: panel: Add binding document for Xinpeng XPP055C272

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

The XPP055C272 is a 5.5" 720x1280 DSI display.

changes in v2:
- add size info into binding title (Sam)
- add more required properties (Sam)

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
 .../display/panel/xinpeng,xpp055c272.yaml     | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml

diff --git a/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
new file mode 100644
index 000000000000..2d0fc97d735c
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xinpeng XPP055C272 5.5in 720x1280 DSI panel
+
+maintainers:
+  - Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
+
+allOf:
+  - $ref: panel-common.yaml#
+
+properties:
+  compatible:
+    const: xinpeng,xpp055c272
+  reg: true
+  backlight: true
+  port: true
+  reset-gpios: true
+  iovcc-supply:
+     description: regulator that supplies the iovcc voltage
+  vci-supply:
+     description: regulator that supplies the vci voltage
+
+required:
+  - compatible
+  - reg
+  - backlight
+  - iovcc-supply
+  - vci-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    dsi@ff450000 {
+        panel@0 {
+            compatible = "xinpeng,xpp055c272";
+            reg = <0>;
+            backlight = <&backlight>;
+            iovcc-supply = <&vcc_1v8>;
+            vci-supply = <&vcc3v3_lcd>;
+        };
+    };
+
+...
-- 
2.24.0

Re: [PATCH v3 2/3] dt-bindings: display: panel: Add binding document for Xinpeng XPP055C272

[Maxime Ripard]

Hi,

On Tue, Dec 17, 2019 at 03:07:02PM +0100, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
>
> The XPP055C272 is a 5.5" 720x1280 DSI display.
>
> changes in v2:
> - add size info into binding title (Sam)
> - add more required properties (Sam)
>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> ---
>  .../display/panel/xinpeng,xpp055c272.yaml     | 48 +++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> new file mode 100644
> index 000000000000..2d0fc97d735c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> @@ -0,0 +1,48 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml#

The ID doesn't match the file name.

Did you run dt_bindings_check?

> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Xinpeng XPP055C272 5.5in 720x1280 DSI panel
> +
> +maintainers:
> +  - Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> +
> +allOf:
> +  - $ref: panel-common.yaml#
> +
> +properties:
> +  compatible:
> +    const: xinpeng,xpp055c272
> +  reg: true
> +  backlight: true
> +  port: true

What is the port supposed to be doing?

> +  reset-gpios: true
> +  iovcc-supply:
> +     description: regulator that supplies the iovcc voltage
> +  vci-supply:
> +     description: regulator that supplies the vci voltage
> +
> +required:
> +  - compatible
> +  - reg
> +  - backlight
> +  - iovcc-supply
> +  - vci-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    dsi@ff450000 {
> +        panel@0 {
> +            compatible = "xinpeng,xpp055c272";
> +            reg = <0>;
> +            backlight = <&backlight>;
> +            iovcc-supply = <&vcc_1v8>;
> +            vci-supply = <&vcc3v3_lcd>;
> +        };
> +    };
> +
> +...

Thanks!
Maxime

Re: [PATCH v3 2/3] dt-bindings: display: panel: Add binding document for Xinpeng XPP055C272

[Heiko Stübner]

Am Dienstag, 17. Dezember 2019, 15:24:46 CET schrieb Maxime Ripard:
> Hi,
> 
> On Tue, Dec 17, 2019 at 03:07:02PM +0100, Heiko Stuebner wrote:
> > From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> >
> > The XPP055C272 is a 5.5" 720x1280 DSI display.
> >
> > changes in v2:
> > - add size info into binding title (Sam)
> > - add more required properties (Sam)
> >
> > Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> > ---
> >  .../display/panel/xinpeng,xpp055c272.yaml     | 48 +++++++++++++++++++
> >  1 file changed, 48 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > new file mode 100644
> > index 000000000000..2d0fc97d735c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > @@ -0,0 +1,48 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml#
> 
> The ID doesn't match the file name.
> 
> Did you run dt_bindings_check?

Thanks for that pointer ... I did run dtbs_check on the binding and was
sooo happy to not find any panel errors in the pages of other dt errors
but till now didn't realize that there's also a dtbinding_check.

Will keep that in mind for future bindings  - and of course fix things
in the next version.


> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Xinpeng XPP055C272 5.5in 720x1280 DSI panel
> > +
> > +maintainers:
> > +  - Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > +
> > +allOf:
> > +  - $ref: panel-common.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: xinpeng,xpp055c272
> > +  reg: true
> > +  backlight: true
> > +  port: true
> 
> What is the port supposed to be doing?

Hooking the display up to the dsi controller. But you're right,
works without port as well with these single-dsi displays.

I just remember needing one for the Gru-Scarlet display that needed
to connect to two dsi controllers.

So I'll drop the port node here and from my board devicetree.

Thanks for the review
Heiko


> 
> > +  reset-gpios: true
> > +  iovcc-supply:
> > +     description: regulator that supplies the iovcc voltage
> > +  vci-supply:
> > +     description: regulator that supplies the vci voltage
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - backlight
> > +  - iovcc-supply
> > +  - vci-supply
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    dsi@ff450000 {
> > +        panel@0 {
> > +            compatible = "xinpeng,xpp055c272";
> > +            reg = <0>;
> > +            backlight = <&backlight>;
> > +            iovcc-supply = <&vcc_1v8>;
> > +            vci-supply = <&vcc3v3_lcd>;
> > +        };
> > +    };
> > +
> > +...
> 
> Thanks!
> Maxime
> 

Re: [PATCH v3 2/3] dt-bindings: display: panel: Add binding document for Xinpeng XPP055C272

[Maxime Ripard]

On Tue, Dec 17, 2019 at 04:08:49PM +0100, Heiko Stübner wrote:
> Am Dienstag, 17. Dezember 2019, 15:24:46 CET schrieb Maxime Ripard:
> > Hi,
> >
> > On Tue, Dec 17, 2019 at 03:07:02PM +0100, Heiko Stuebner wrote:
> > > From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > >
> > > The XPP055C272 is a 5.5" 720x1280 DSI display.
> > >
> > > changes in v2:
> > > - add size info into binding title (Sam)
> > > - add more required properties (Sam)
> > >
> > > Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > > Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> > > ---
> > >  .../display/panel/xinpeng,xpp055c272.yaml     | 48 +++++++++++++++++++
> > >  1 file changed, 48 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > > new file mode 100644
> > > index 000000000000..2d0fc97d735c
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > > @@ -0,0 +1,48 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml#
> >
> > The ID doesn't match the file name.
> >
> > Did you run dt_bindings_check?
>
> Thanks for that pointer ... I did run dtbs_check on the binding and was
> sooo happy to not find any panel errors in the pages of other dt errors
> but till now didn't realize that there's also a dtbinding_check.

dt_bindings_check is a sanity check on the bindings
themselves. dtbs_check is using those bindings to check the device
trees.

dtbs_check used to have a dependency on dt_bindings_check, but it got
removed recently.

Maxime

>
> Will keep that in mind for future bindings  - and of course fix things
> in the next version.
>
>
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Xinpeng XPP055C272 5.5in 720x1280 DSI panel
> > > +
> > > +maintainers:
> > > +  - Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > > +
> > > +allOf:
> > > +  - $ref: panel-common.yaml#
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: xinpeng,xpp055c272
> > > +  reg: true
> > > +  backlight: true
> > > +  port: true
> >
> > What is the port supposed to be doing?
>
> Hooking the display up to the dsi controller. But you're right,
> works without port as well with these single-dsi displays.
>
> I just remember needing one for the Gru-Scarlet display that needed
> to connect to two dsi controllers.
>
> So I'll drop the port node here and from my board devicetree.

It's not really what I meant though :)

If it's needed then we should definitely have it, but we should
document our expectations here: is it the input port ? output? in
which case do we want to use it since it's optional, etc.

Maxime

Re: [PATCH v3 2/3] dt-bindings: display: panel: Add binding document for Xinpeng XPP055C272

[Heiko Stübner]

Hi Maxime,

Am Dienstag, 17. Dezember 2019, 17:01:22 CET schrieb Maxime Ripard:
> On Tue, Dec 17, 2019 at 04:08:49PM +0100, Heiko Stübner wrote:
> > Am Dienstag, 17. Dezember 2019, 15:24:46 CET schrieb Maxime Ripard:
> > > Hi,
> > >
> > > On Tue, Dec 17, 2019 at 03:07:02PM +0100, Heiko Stuebner wrote:
> > > > From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > > >
> > > > The XPP055C272 is a 5.5" 720x1280 DSI display.
> > > >
> > > > changes in v2:
> > > > - add size info into binding title (Sam)
> > > > - add more required properties (Sam)
> > > >
> > > > Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > > > Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> > > > ---
> > > >  .../display/panel/xinpeng,xpp055c272.yaml     | 48 +++++++++++++++++++
> > > >  1 file changed, 48 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > > > new file mode 100644
> > > > index 000000000000..2d0fc97d735c
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/display/panel/xinpeng,xpp055c272.yaml
> > > > @@ -0,0 +1,48 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/display/panel/sony,acx424akp.yaml#
> > >
> > > The ID doesn't match the file name.
> > >
> > > Did you run dt_bindings_check?
> >
> > Thanks for that pointer ... I did run dtbs_check on the binding and was
> > sooo happy to not find any panel errors in the pages of other dt errors
> > but till now didn't realize that there's also a dtbinding_check.
> 
> dt_bindings_check is a sanity check on the bindings
> themselves. dtbs_check is using those bindings to check the device
> trees.
> 
> dtbs_check used to have a dependency on dt_bindings_check, but it got
> removed recently.
> 
> Maxime
> 
> >
> > Will keep that in mind for future bindings  - and of course fix things
> > in the next version.
> >
> >
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: Xinpeng XPP055C272 5.5in 720x1280 DSI panel
> > > > +
> > > > +maintainers:
> > > > +  - Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> > > > +
> > > > +allOf:
> > > > +  - $ref: panel-common.yaml#
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    const: xinpeng,xpp055c272
> > > > +  reg: true
> > > > +  backlight: true
> > > > +  port: true
> > >
> > > What is the port supposed to be doing?
> >
> > Hooking the display up to the dsi controller. But you're right,
> > works without port as well with these single-dsi displays.
> >
> > I just remember needing one for the Gru-Scarlet display that needed
> > to connect to two dsi controllers.
> >
> > So I'll drop the port node here and from my board devicetree.
> 
> It's not really what I meant though :)
> 
> If it's needed then we should definitely have it, but we should
> document our expectations here: is it the input port ? output? in
> which case do we want to use it since it's optional, etc.

The port was actually unnecessary. As far as I understand dsi stuff,
the common case is the panel as subnode of the dsi controller and
the controller then finding the display itself automatically.

If you look at
	"drm/bridge/synopsys: dsi: use mipi_dsi_device to find panel or bridge" [0]
I just sent, you'll see that the dw-mipi-dsi used drm_of_find_panel_or_bridge
to find its panel/bridge thus requiring port connections in all cases where
it had the dsi-device available already, so wouldn't need to use ports for it.

Or I'm completely wrong and port usage is better, we'll see :-D


Heiko


[0] https://patchwork.freedesktop.org/patch/345666/

[PATCH v3 3/3] drm/panel: add panel driver for Xinpeng XPP055C272 panels

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

Base on the somewhat similar Rocktech driver but adapted for
panel-specific init of the XPP055C272.

changes in v3:
- remove wrong negative sync flags from display-mode to fix a display
  artifact of the output getting move a tiny bit to the right
changes in v2:
- move to drm-panel-internal backlight handling (Sam)
- adapt to changes that happened to drm_panel structs+functions (Sam)
- sort includes (Sam)
- drop unnecessary DRV_NAME constant (Sam)
- do mipi_dsi_dcs_exit_sleep_mode and mipi_dsi_dcs_set_display_on
  in panel prepare (not init_sequence) to keep symmetric (Sam)

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
 drivers/gpu/drm/panel/Kconfig                 |  10 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../gpu/drm/panel/panel-xinpeng-xpp055c272.c  | 400 ++++++++++++++++++
 3 files changed, 411 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-xinpeng-xpp055c272.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index f152bc4eeb53..fb1ded47677e 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -355,4 +355,14 @@ config DRM_PANEL_TRULY_NT35597_WQXGA
 	help
 	  Say Y here if you want to enable support for Truly NT35597 WQXGA Dual DSI
 	  Video Mode panel
+
+config DRM_PANEL_XINPENG_XPP055C272
+	tristate "Xinpeng XPP055C272 panel driver"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for the Xinpeng
+	  XPP055C272 controller for 720x1280 LCD panels with MIPI/RGB/SPI
+	  system interfaces.
 endmenu
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index b6cd39fe0f20..71d7722146a7 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
 obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o
+obj-$(CONFIG_DRM_PANEL_XINPENG_XPP055C272) += panel-xinpeng-xpp055c272.o
diff --git a/drivers/gpu/drm/panel/panel-xinpeng-xpp055c272.c b/drivers/gpu/drm/panel/panel-xinpeng-xpp055c272.c
new file mode 100644
index 000000000000..1a7ded012344
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-xinpeng-xpp055c272.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xinpeng xpp055c272 5.5" MIPI-DSI panel driver
+ * Copyright (C) 2019 Theobroma Systems Design und Consulting GmbH
+ *
+ * based on
+ *
+ * Rockteck jh057n00900 5.5" MIPI-DSI panel driver
+ * Copyright (C) Purism SPC 2019
+ */
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+#include <video/display_timing.h>
+#include <video/mipi_display.h>
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+/* Manufacturer specific Commands send via DSI */
+#define XPP055C272_CMD_ALL_PIXEL_OFF	0x22
+#define XPP055C272_CMD_ALL_PIXEL_ON	0x23
+#define XPP055C272_CMD_SETDISP		0xb2
+#define XPP055C272_CMD_SETRGBIF		0xb3
+#define XPP055C272_CMD_SETCYC		0xb4
+#define XPP055C272_CMD_SETBGP		0xb5
+#define XPP055C272_CMD_SETVCOM		0xb6
+#define XPP055C272_CMD_SETOTP		0xb7
+#define XPP055C272_CMD_SETPOWER_EXT	0xb8
+#define XPP055C272_CMD_SETEXTC		0xb9
+#define XPP055C272_CMD_SETMIPI		0xbA
+#define XPP055C272_CMD_SETVDC		0xbc
+#define XPP055C272_CMD_SETPCR		0xbf
+#define XPP055C272_CMD_SETSCR		0xc0
+#define XPP055C272_CMD_SETPOWER		0xc1
+#define XPP055C272_CMD_SETECO		0xc6
+#define XPP055C272_CMD_SETPANEL		0xcc
+#define XPP055C272_CMD_SETGAMMA		0xe0
+#define XPP055C272_CMD_SETEQ		0xe3
+#define XPP055C272_CMD_SETGIP1		0xe9
+#define XPP055C272_CMD_SETGIP2		0xea
+
+struct xpp055c272 {
+	struct device *dev;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct regulator *vci;
+	struct regulator *iovcc;
+	bool prepared;
+};
+
+static inline struct xpp055c272 *panel_to_xpp055c272(struct drm_panel *panel)
+{
+	return container_of(panel, struct xpp055c272, panel);
+}
+
+#define dsi_generic_write_seq(dsi, cmd, seq...) do {			\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int xpp055c272_init_sequence(struct xpp055c272 *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	struct device *dev = ctx->dev;
+
+	/*
+	 * Init sequence was supplied by the panel vendor without much
+	 * documentation.
+	 */
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETEXTC, 0xf1, 0x12, 0x83);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETMIPI,
+			      0x33, 0x81, 0x05, 0xf9, 0x0e, 0x0e, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x44, 0x25,
+			      0x00, 0x91, 0x0a, 0x00, 0x00, 0x02, 0x4f, 0x01,
+			      0x00, 0x00, 0x37);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETPOWER_EXT, 0x25);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETPCR, 0x02, 0x11, 0x00);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETRGBIF,
+			      0x0c, 0x10, 0x0a, 0x50, 0x03, 0xff, 0x00, 0x00,
+			      0x00, 0x00);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETSCR,
+			      0x73, 0x73, 0x50, 0x50, 0x00, 0x00, 0x08, 0x70,
+			      0x00);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETVDC, 0x46);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETPANEL, 0x0b);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETCYC, 0x80);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETDISP, 0xc8, 0x12, 0x30);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETEQ,
+			      0x07, 0x07, 0x0B, 0x0B, 0x03, 0x0B, 0x00, 0x00,
+			      0x00, 0x00, 0xFF, 0x00, 0xC0, 0x10);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETPOWER,
+			      0x53, 0x00, 0x1e, 0x1e, 0x77, 0xe1, 0xcc, 0xdd,
+			      0x67, 0x77, 0x33, 0x33);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETECO, 0x00, 0x00, 0xff,
+			      0xff, 0x01, 0xff);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETBGP, 0x09, 0x09);
+	msleep(20);
+
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETVCOM, 0x87, 0x95);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETGIP1,
+			      0xc2, 0x10, 0x05, 0x05, 0x10, 0x05, 0xa0, 0x12,
+			      0x31, 0x23, 0x3f, 0x81, 0x0a, 0xa0, 0x37, 0x18,
+			      0x00, 0x80, 0x01, 0x00, 0x00, 0x00, 0x00, 0x80,
+			      0x01, 0x00, 0x00, 0x00, 0x48, 0xf8, 0x86, 0x42,
+			      0x08, 0x88, 0x88, 0x80, 0x88, 0x88, 0x88, 0x58,
+			      0xf8, 0x87, 0x53, 0x18, 0x88, 0x88, 0x81, 0x88,
+			      0x88, 0x88, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETGIP2,
+			      0x00, 0x1a, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x1f, 0x88, 0x81, 0x35,
+			      0x78, 0x88, 0x88, 0x85, 0x88, 0x88, 0x88, 0x0f,
+			      0x88, 0x80, 0x24, 0x68, 0x88, 0x88, 0x84, 0x88,
+			      0x88, 0x88, 0x23, 0x10, 0x00, 0x00, 0x1c, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x05,
+			      0xa0, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, XPP055C272_CMD_SETGAMMA,
+			      0x00, 0x06, 0x08, 0x2a, 0x31, 0x3f, 0x38, 0x36,
+			      0x07, 0x0c, 0x0d, 0x11, 0x13, 0x12, 0x13, 0x11,
+			      0x18, 0x00, 0x06, 0x08, 0x2a, 0x31, 0x3f, 0x38,
+			      0x36, 0x07, 0x0c, 0x0d, 0x11, 0x13, 0x12, 0x13,
+			      0x11, 0x18);
+
+	msleep(60);
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");
+	return 0;
+}
+
+static int xpp055c272_unprepare(struct drm_panel *panel)
+{
+	struct xpp055c272 *ctx = panel_to_xpp055c272(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (!ctx->prepared)
+		return 0;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(ctx->dev, "failed to set display off: %d\n",
+			      ret);
+
+	mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "failed to enter sleep mode: %d\n",
+			      ret);
+		return ret;
+	}
+
+	regulator_disable(ctx->iovcc);
+	regulator_disable(ctx->vci);
+
+	ctx->prepared = false;
+
+	return 0;
+}
+
+static int xpp055c272_prepare(struct drm_panel *panel)
+{
+	struct xpp055c272 *ctx = panel_to_xpp055c272(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
+	ret = regulator_enable(ctx->vci);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable vci supply: %d\n", ret);
+		return ret;
+	}
+	ret = regulator_enable(ctx->iovcc);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev,
+			      "Failed to enable iovcc supply: %d\n", ret);
+		goto disable_vci;
+	}
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	/* T6: 10us */
+	usleep_range(10, 20);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+
+	/* T8: 20ms */
+	msleep(20);
+
+	ret = xpp055c272_init_sequence(ctx);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
+			      ret);
+		goto disable_iovcc;
+	}
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	/* T9: 120ms */
+	msleep(120);
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to set display on: %d\n", ret);
+		goto disable_iovcc;
+	}
+
+	msleep(50);
+
+	ctx->prepared = true;
+
+	return 0;
+
+disable_iovcc:
+	regulator_disable(ctx->iovcc);
+disable_vci:
+	regulator_disable(ctx->vci);
+	return ret;
+}
+
+static const struct drm_display_mode default_mode = {
+	.hdisplay	= 720,
+	.hsync_start	= 720 + 40,
+	.hsync_end	= 720 + 40 + 10,
+	.htotal		= 720 + 40 + 10 + 40,
+	.vdisplay	= 1280,
+	.vsync_start	= 1280 + 22,
+	.vsync_end	= 1280 + 22 + 4,
+	.vtotal		= 1280 + 22 + 4 + 11,
+	.vrefresh	= 60,
+	.clock		= 64000,
+	.width_mm	= 68,
+	.height_mm	= 121,
+};
+
+static int xpp055c272_get_modes(struct drm_panel *panel,
+				struct drm_connector *connector)
+{
+	struct xpp055c272 *ctx = panel_to_xpp055c272(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, &default_mode);
+	if (!mode) {
+		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u\n",
+			      default_mode.hdisplay, default_mode.vdisplay,
+			      default_mode.vrefresh);
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs xpp055c272_funcs = {
+	.unprepare	= xpp055c272_unprepare,
+	.prepare	= xpp055c272_prepare,
+	.get_modes	= xpp055c272_get_modes,
+};
+
+static int xpp055c272_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct xpp055c272 *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	ctx->vci = devm_regulator_get(dev, "vci");
+	if (IS_ERR(ctx->vci)) {
+		ret = PTR_ERR(ctx->vci);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request vci regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	ctx->iovcc = devm_regulator_get(dev, "iovcc");
+	if (IS_ERR(ctx->iovcc)) {
+		ret = PTR_ERR(ctx->iovcc);
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev,
+				      "Failed to request iovcc regulator: %d\n",
+				      ret);
+		return ret;
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;
+
+	drm_panel_init(&ctx->panel, &dsi->dev, &xpp055c272_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "Failed to find backlight: %d\n", ret);
+		return ret;
+	}
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed: %d\n", ret);
+		drm_panel_remove(&ctx->panel);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void xpp055c272_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct xpp055c272 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = drm_panel_unprepare(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
+			      ret);
+
+	ret = drm_panel_disable(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
+			      ret);
+}
+
+static int xpp055c272_remove(struct mipi_dsi_device *dsi)
+{
+	struct xpp055c272 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	xpp055c272_shutdown(dsi);
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",
+			      ret);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct of_device_id xpp055c272_of_match[] = {
+	{ .compatible = "xinpeng,xpp055c272" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, xpp055c272_of_match);
+
+static struct mipi_dsi_driver xpp055c272_driver = {
+	.driver = {
+		.name = "panel-xinpeng-xpp055c272",
+		.of_match_table = xpp055c272_of_match,
+	},
+	.probe	= xpp055c272_probe,
+	.remove = xpp055c272_remove,
+	.shutdown = xpp055c272_shutdown,
+};
+module_mipi_dsi_driver(xpp055c272_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@theobroma-systems.com>");
+MODULE_DESCRIPTION("DRM driver for Xinpeng xpp055c272 MIPI DSI panel");
+MODULE_LICENSE("GPL v2");
-- 
2.24.0