Support Geekworm MZP280 Panel for Raspberry Pi

From: Chris Morgan <[email protected]>

This patch series is to add support for the MZP280 panel for the Raspberry Pi. This panel requires adding support for Mode 3 of the Raspberry Pi DPI connector, which necessitates a new media bus format.

This patch series has been tested on my Raspberry Pi 4 with version 1 of the panel in question.

Changes since V1:

- Added documentation for vendor string.

Chris Morgan (6):
dt-bindings: vendor-prefixes: Add Geekworm
media: uapi: Document format MEDIA_BUS_FMT_RGB565_1X24_CPADHI
media: uapi: add MEDIA_BUS_FMT_RGB565_1X24_CPADHI
dt-bindings: display: simple: add Geekworm MZP280 Panel drm/panel: simple: add Geekworm MZP280 Panel drm/vc4: dpi: Support DPI interface in mode3 for RGB565

 .../bindings/display/panel/panel-simple.yaml  |  2 +
 .../devicetree/bindings/vendor-prefixes.yaml  |  2 +
 .../media/v4l/subdev-formats.rst              | 37 +++++++++++++++++++
 drivers/gpu/drm/panel/panel-simple.c          | 29 +++++++++++++++
 drivers/gpu/drm/vc4/vc4_dpi.c                 |  4 ++
 include/uapi/linux/media-bus-format.h         |  3 +-
 6 files changed, 76 insertions(+), 1 deletion(-)

2.25.1

From: Chris Morgan <[email protected]>

Add vendor prefix for Geekworm (https://geekworm.com).

---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

index 294093d45..c0c7627c6 100644
@@ -455,6 +455,8 @@ patternProperties:
     description: General Electric Company
   "^geekbuying,.*":
     description: GeekBuying
+  "^geekworm,.*":
+    description: Geekworm
   "^gef,.*":
     description: GE Fanuc Intelligent Platforms Embedded Systems, Inc.
   "^GEFanuc,.*":

2.25.1

From: Chris Morgan <[email protected]>

Add support for MEDIA_BUS_FMT_RGB565_1X24_CPADHI. This format is used by the Geekworm MZP280 panel which interfaces with the Raspberry Pi.

---
 .../media/v4l/subdev-formats.rst              | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

index 0cbc045d5..e43e07634 100644
@@ -624,6 +624,43 @@ The following tables list existing packed RGB formats.
       - b\ :sub:`2`
       - b\ :sub:`1`
       - b\ :sub:`0`
+    * .. _MEDIA_BUS_FMT_RGB565_1X24_CPADHI:
+
+      - MEDIA_BUS_FMT_RGB565_1X24_CPADHI
+      - 0x101e
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      -
+      - 0
+      - 0
+      - 0
+      - r\ :sub:`4`
+      - r\ :sub:`3`
+      - r\ :sub:`2`
+      - r\ :sub:`1`
+      - r\ :sub:`0`
+      - 0
+      - 0
+      - g\ :sub:`5`
+      - g\ :sub:`4`
+      - g\ :sub:`3`
+      - g\ :sub:`2`
+      - g\ :sub:`1`
+      - g\ :sub:`0`
+      - 0
+      - 0
+      - 0
+      - b\ :sub:`4`
+      - b\ :sub:`3`
+      - b\ :sub:`2`
+      - b\ :sub:`1`
+      - b\ :sub:`0`
     * .. _MEDIA-BUS-FMT-BGR565-2X8-BE:
 
       - MEDIA_BUS_FMT_BGR565_2X8_BE

2.25.1

From: Chris Morgan <[email protected]>

Add the MEDIA_BUS_FMT_RGB565_1X24_CPADHI format used by the Geekworm MZP280 panel for the Raspberry Pi.

---
 include/uapi/linux/media-bus-format.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index 0dfc11ee2..a7b765498 100644
@@ -34,13 +34,14 @@
 
 #define MEDIA_BUS_FMT_FIXED			0x0001
 
-/* RGB - next is	0x101e */
+/* RGB - next is	0x101f */
 #define MEDIA_BUS_FMT_RGB444_1X12		0x1016
 #define MEDIA_BUS_FMT_RGB444_2X8_PADHI_BE	0x1001
 #define MEDIA_BUS_FMT_RGB444_2X8_PADHI_LE	0x1002
 #define MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE	0x1003
 #define MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE	0x1004
 #define MEDIA_BUS_FMT_RGB565_1X16		0x1017
+#define MEDIA_BUS_FMT_RGB565_1X24_CPADHI	0x101e
 #define MEDIA_BUS_FMT_BGR565_2X8_BE		0x1005
 #define MEDIA_BUS_FMT_BGR565_2X8_LE		0x1006
 #define MEDIA_BUS_FMT_RGB565_2X8_BE		0x1007

2.25.1

From: Chris Morgan <[email protected]>

The Geekworm MZP280 panel is a 480x640 (portrait) panel with a capacitive touch interface and a 40 pin header meant to interface directly with the Raspberry Pi. The screen is 2.8 inches diagonally, and there appear to be at least 4 distinct versions all with the same panel timings.

Timings were derived from drivers posted on the github located here:
https://github.com/tianyoujian/MZDPI/tree/master/vga

Additional details about this panel family can be found here:
https://wiki.geekworm.com/2.8_inch_Touch_Screen_for_Pi_zero

---
 .../devicetree/bindings/display/panel/panel-simple.yaml         | 2 ++
 1 file changed, 2 insertions(+)

index 62f5f050c..3d03d8276 100644
@@ -148,6 +148,8 @@ properties:
       - frida,frd350h54004
         # FriendlyELEC HD702E 800x1280 LCD panel
       - friendlyarm,hd702e
+        # Geekworm MZP280 2.8" 480x640 LCD panel with capacitive touch
+      - geekworm,mzp280
         # GiantPlus GPG48273QS5 4.3" (480x272) WQVGA TFT LCD panel
       - giantplus,gpg48273qs5
         # GiantPlus GPM940B0 3.0" QVGA TFT LCD panel

2.25.1

From: Chris Morgan <[email protected]>

Add support for the Geekworm MZP280 Panel

---
 drivers/gpu/drm/panel/panel-simple.c | 29 ++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

index 9e46db5e3..cbc1a4fd1 100644
@@ -1824,6 +1824,32 @@ static const struct panel_desc friendlyarm_hd702e = {
 	},
 };
 
+static const struct drm_display_mode geekworm_mzp280_mode = {
+	.clock = 32000,
+	.hdisplay = 480,
+	.hsync_start = 480 + 41,
+	.hsync_end = 480 + 41 + 20,
+	.htotal = 480 + 41 + 20 + 60,
+	.vdisplay = 640,
+	.vsync_start = 640 + 5,
+	.vsync_end = 640 + 5 + 10,
+	.vtotal = 640 + 5 + 10 + 10,
+	.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+};
+
+static const struct panel_desc geekworm_mzp280 = {
+	.modes = &geekworm_mzp280_mode,
+	.num_modes = 1,
+	.bpc = 6,
+	.size = {
+		.width = 47,
+		.height = 61,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB565_1X24_CPADHI,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
+	.connector_type = DRM_MODE_CONNECTOR_DPI,
+};
+
 static const struct drm_display_mode giantplus_gpg482739qs5_mode = {
 	.clock = 9000,
 	.hdisplay = 480,

@@ -3790,6 +3816,9 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "friendlyarm,hd702e",
 		.data = &friendlyarm_hd702e,
+	}, {
+		.compatible = "geekworm,mzp280",
+		.data = &geekworm_mzp280,
 	}, {
 		.compatible = "giantplus,gpg482739qs5",
 		.data = &giantplus_gpg482739qs5

2.25.1

From: Chris Morgan <[email protected]>

Add support for the VC4 DPI driver to utilize DPI mode 3. This is defined here as xxxRRRRRxxGGGGGGxxxBBBBB:
https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#parallel-display-interface-dpi

This mode is required to use the Geekworm MZP280 DPI display.

---
 drivers/gpu/drm/vc4/vc4_dpi.c | 4 ++++
 1 file changed, 4 insertions(+)

index c180eb60b..3c58ade25 100644
@@ -173,6 +173,10 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
 					       DPI_FORMAT);
 			break;
+		case MEDIA_BUS_FMT_RGB565_1X24_CPADHI:
+			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_2,
+					       DPI_FORMAT);
+			break;
 		default:
 			DRM_ERROR("Unknown media bus format %d\n", bus_format);
 			break;

2.25.1