[PATCH v2 0/6] Add display support on the stm32f746-disco board

[PATCH v2 0/6] Add display support on the stm32f746-disco board

[Dario Binacchi]

The series adds support for the display on the stm32f746-disco board,
along with a generic patch that adds the "bpp" parameter to the stm-drm
module. The intention is to allow users to size, within certain limits,
the memory footprint required by the framebuffer.

Changes in v2:
- Add 'Acked-by' tag of Conor Dooley.
- Fix build warning reported by kernel test robot.
- Add 'Reported-by' tag of kernel test robot.

Dario Binacchi (6):
  ARM: dts: stm32: add ltdc support on stm32f746 MCU
  ARM: dts: stm32: add pin map for LTDC on stm32f7
  ARM: dts: stm32: support display on stm32f746-disco board
  dt-bindings: display: simple: add Rocktech RK043FN48H
  drm/panel: simple: add support for Rocktech RK043FN48H panel
  drm/stm: add an option to change FB bpp

 .../bindings/display/panel/panel-simple.yaml  |  2 +
 arch/arm/boot/dts/stm32f7-pinctrl.dtsi        | 35 +++++++++++++
 arch/arm/boot/dts/stm32f746-disco.dts         | 51 +++++++++++++++++++
 arch/arm/boot/dts/stm32f746.dtsi              | 10 ++++
 drivers/gpu/drm/panel/panel-simple.c          | 29 +++++++++++
 drivers/gpu/drm/stm/drv.c                     |  8 ++-
 6 files changed, 134 insertions(+), 1 deletion(-)

-- 
2.32.0

[PATCH v2 1/6] ARM: dts: stm32: add ltdc support on stm32f746 MCU

[Dario Binacchi]

Add LTDC (Lcd-tft Display Controller) support.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

(no changes since v1)

 arch/arm/boot/dts/stm32f746.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/stm32f746.dtsi b/arch/arm/boot/dts/stm32f746.dtsi
index dc868e6da40e..9c4ba0b7f239 100644
--- a/arch/arm/boot/dts/stm32f746.dtsi
+++ b/arch/arm/boot/dts/stm32f746.dtsi
@@ -507,6 +507,16 @@ pwm {
 			};
 		};
 
+		ltdc: display-controller@40016800 {
+			compatible = "st,stm32-ltdc";
+			reg = <0x40016800 0x200>;
+			interrupts = <88>, <89>;
+			resets = <&rcc STM32F7_APB2_RESET(LTDC)>;
+			clocks = <&rcc 1 CLK_LCD>;
+			clock-names = "lcd";
+			status = "disabled";
+		};
+
 		pwrcfg: power-config@40007000 {
 			compatible = "st,stm32-power-config", "syscon";
 			reg = <0x40007000 0x400>;
-- 
2.32.0

[PATCH v2 2/6] ARM: dts: stm32: add pin map for LTDC on stm32f7

[Dario Binacchi]

Add pin configurations for using LTDC (LCD-tft Display Controller) on
stm32f746-disco board.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

(no changes since v1)

 arch/arm/boot/dts/stm32f7-pinctrl.dtsi | 35 ++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/arch/arm/boot/dts/stm32f7-pinctrl.dtsi b/arch/arm/boot/dts/stm32f7-pinctrl.dtsi
index 9f65403295ca..f3f90b9bcd61 100644
--- a/arch/arm/boot/dts/stm32f7-pinctrl.dtsi
+++ b/arch/arm/boot/dts/stm32f7-pinctrl.dtsi
@@ -365,6 +365,41 @@ pins2 {
 					bias-pull-up;
 				};
 			};
+
+
+			ltdc_pins_a: ltdc-pins-a-0 {
+				pins {
+					pinmux = <STM32_PINMUX('E', 4, AF14)>, /* LCD_B0 */
+						 <STM32_PINMUX('G',12, AF9)>,  /* LCD_B4 */
+						 <STM32_PINMUX('I', 9, AF14)>, /* LCD_VSYNC */
+						 <STM32_PINMUX('I',10, AF14)>, /* LCD_HSYNC */
+						 <STM32_PINMUX('I',14, AF14)>, /* LCD_CLK */
+						 <STM32_PINMUX('I',15, AF14)>, /* LCD_R0 */
+						 <STM32_PINMUX('J', 0, AF14)>, /* LCD_R1 */
+						 <STM32_PINMUX('J', 1, AF14)>, /* LCD_R2 */
+						 <STM32_PINMUX('J', 2, AF14)>, /* LCD_R3 */
+						 <STM32_PINMUX('J', 3, AF14)>, /* LCD_R4 */
+						 <STM32_PINMUX('J', 4, AF14)>, /* LCD_R5 */
+						 <STM32_PINMUX('J', 5, AF14)>, /* LCD_R6 */
+						 <STM32_PINMUX('J', 6, AF14)>, /* LCD_R7 */
+						 <STM32_PINMUX('J', 7, AF14)>, /* LCD_G0 */
+						 <STM32_PINMUX('J', 8, AF14)>, /* LCD_G1 */
+						 <STM32_PINMUX('J', 9, AF14)>, /* LCD_G2 */
+						 <STM32_PINMUX('J',10, AF14)>, /* LCD_G3 */
+						 <STM32_PINMUX('J',11, AF14)>, /* LCD_G4 */
+						 <STM32_PINMUX('J',13, AF14)>, /* LCD_B1 */
+						 <STM32_PINMUX('J',14, AF14)>, /* LCD_B2 */
+						 <STM32_PINMUX('J',15, AF14)>, /* LCD_B3 */
+						 <STM32_PINMUX('K', 0, AF14)>, /* LCD_G5 */
+						 <STM32_PINMUX('K', 1, AF14)>, /* LCD_G6 */
+						 <STM32_PINMUX('K', 2, AF14)>, /* LCD_G7 */
+						 <STM32_PINMUX('K', 4, AF14)>, /* LCD_B5 */
+						 <STM32_PINMUX('K', 5, AF14)>, /* LCD_B6 */
+						 <STM32_PINMUX('K', 6, AF14)>, /* LCD_B7 */
+						 <STM32_PINMUX('K', 7, AF14)>; /* LCD_DE */
+					slew-rate = <2>;
+				};
+			};
 		};
 	};
 };
-- 
2.32.0

[PATCH v2 3/6] ARM: dts: stm32: support display on stm32f746-disco board

[Dario Binacchi]

Add support to Rocktech RK043FN48H display on stm32f746-disco board.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

(no changes since v1)

 arch/arm/boot/dts/stm32f746-disco.dts | 51 +++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/arch/arm/boot/dts/stm32f746-disco.dts b/arch/arm/boot/dts/stm32f746-disco.dts
index c11616ed5fc6..cda423b6a874 100644
--- a/arch/arm/boot/dts/stm32f746-disco.dts
+++ b/arch/arm/boot/dts/stm32f746-disco.dts
@@ -60,10 +60,41 @@ memory@c0000000 {
 		reg = <0xC0000000 0x800000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,cma {
+			compatible = "shared-dma-pool";
+			no-map;
+			size = <0x80000>;
+			linux,dma-default;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
 
+	backlight: backlight {
+		compatible = "gpio-backlight";
+		gpios = <&gpiok 3 GPIO_ACTIVE_HIGH>;
+		status = "okay";
+	};
+
+	panel_rgb: panel-rgb {
+		compatible = "rocktech,rk043fn48h";
+		backlight = <&backlight>;
+		enable-gpios = <&gpioi 12 GPIO_ACTIVE_HIGH>;
+		status = "okay";
+		port {
+			panel_in_rgb: endpoint {
+				remote-endpoint = <&ltdc_out_rgb>;
+			};
+		};
+	};
+
 	usbotg_hs_phy: usb-phy {
 		#phy-cells = <0>;
 		compatible = "usb-nop-xceiv";
@@ -99,6 +130,26 @@ &i2c1 {
 	status = "okay";
 };
 
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
+&ltdc {
+	pinctrl-0 = <&ltdc_pins_a>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	port {
+		ltdc_out_rgb: endpoint {
+			remote-endpoint = <&panel_in_rgb>;
+		};
+	};
+};
+
 &sdio1 {
 	status = "okay";
 	vmmc-supply = <&mmc_vcard>;
-- 
2.32.0

[PATCH v2 4/6] dt-bindings: display: simple: add Rocktech RK043FN48H

[Dario Binacchi]

Add compatible to panel-simple for Rocktech Displays Limited
RK043FN48H 4.3" 480x272 LCD-TFT panel.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>

---

Changes in v2:
- Add 'Acked-by' tag of Conor Dooley.

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

diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
index 01560fe226dd..bd6a92d2b41c 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
@@ -280,6 +280,8 @@ properties:
       - rocktech,rk101ii01d-ct
         # Rocktech Display Ltd. RK070ER9427 800(RGB)x480 TFT LCD panel
       - rocktech,rk070er9427
+        # Rocktech Display Ltd. RK043FN48H 4.3" 480x272 LCD-TFT panel
+      - rocktech,rk043fn48h
         # Samsung 13.3" FHD (1920x1080 pixels) eDP AMOLED panel
       - samsung,atna33xc20
         # Samsung 12.2" (2560x1600 pixels) TFT LCD panel
-- 
2.32.0

[PATCH v2 5/6] drm/panel: simple: add support for Rocktech RK043FN48H panel

[Dario Binacchi]

Add support for Rocktech RK043FN48H 4.3" (480x272) LCD-TFT panel.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306020343.jNTWeM0P-lkp@intel.com/

---

Changes in v2:
- Fix build warning reported by kernel test robot.
- Add 'Reported-by' tag of kernel test robot.

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

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 065f378bba9d..3b10e78d07d9 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -3188,6 +3188,32 @@ static const struct panel_desc qishenglong_gopher2b_lcd = {
 	.connector_type = DRM_MODE_CONNECTOR_DPI,
 };
 
+static const struct display_timing rocktech_rk043fn48h_timing = {
+	.pixelclock = { 6000000, 9000000, 12000000 },
+	.hactive = { 480, 480, 480 },
+	.hback_porch = { 8, 43, 43 },
+	.hfront_porch = { 2, 8, 8 },
+	.hsync_len = { 1, 1, 1 },
+	.vactive = { 272, 272, 272 },
+	.vback_porch = { 2, 12, 12 },
+	.vfront_porch = { 1, 4, 4 },
+	.vsync_len = { 1, 10, 10 },
+	.flags = DISPLAY_FLAGS_VSYNC_LOW | DISPLAY_FLAGS_HSYNC_LOW |
+		 DISPLAY_FLAGS_DE_HIGH | DISPLAY_FLAGS_PIXDATA_POSEDGE,
+};
+
+static const struct panel_desc rocktech_rk043fn48h = {
+	.timings = &rocktech_rk043fn48h_timing,
+	.num_timings = 1,
+	.bpc = 8,
+	.size = {
+		.width = 95,
+		.height = 54,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.connector_type = DRM_MODE_CONNECTOR_DPI,
+};
+
 static const struct display_timing rocktech_rk070er9427_timing = {
 	.pixelclock = { 26400000, 33300000, 46800000 },
 	.hactive = { 800, 800, 800 },
@@ -4218,6 +4244,9 @@ static const struct of_device_id platform_of_match[] = {
 	}, {
 		.compatible = "qishenglong,gopher2b-lcd",
 		.data = &qishenglong_gopher2b_lcd,
+	}, {
+		.compatible = "rocktech,rk043fn48h",
+		.data = &rocktech_rk043fn48h,
 	}, {
 		.compatible = "rocktech,rk070er9427",
 		.data = &rocktech_rk070er9427,
-- 
2.32.0

[PATCH v2 6/6] drm/stm: add an option to change FB bpp

[Dario Binacchi]

Boards that use the STM32F{4,7} series have limited amounts of RAM. The
added parameter allows users to size, within certain limits, the memory
footprint required by the framebuffer.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

(no changes since v1)

 drivers/gpu/drm/stm/drv.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
index 422220df7d8c..65be2b442a6a 100644
--- a/drivers/gpu/drm/stm/drv.c
+++ b/drivers/gpu/drm/stm/drv.c
@@ -30,6 +30,11 @@
 #define STM_MAX_FB_WIDTH	2048
 #define STM_MAX_FB_HEIGHT	2048 /* same as width to handle orientation */
 
+static uint stm_bpp = 16;
+
+MODULE_PARM_DESC(bpp, "bits-per-pixel (default: 16)");
+module_param_named(bpp, stm_bpp, uint, 0644);
+
 static const struct drm_mode_config_funcs drv_mode_config_funcs = {
 	.fb_create = drm_gem_fb_create,
 	.atomic_check = drm_atomic_helper_check,
@@ -93,6 +98,7 @@ static int drv_load(struct drm_device *ddev)
 	ddev->mode_config.min_height = 0;
 	ddev->mode_config.max_width = STM_MAX_FB_WIDTH;
 	ddev->mode_config.max_height = STM_MAX_FB_HEIGHT;
+	ddev->mode_config.preferred_depth = stm_bpp;
 	ddev->mode_config.funcs = &drv_mode_config_funcs;
 	ddev->mode_config.normalize_zpos = true;
 
@@ -203,7 +209,7 @@ static int stm_drm_platform_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_put;
 
-	drm_fbdev_dma_setup(ddev, 16);
+	drm_fbdev_dma_setup(ddev, stm_bpp);
 
 	return 0;
 
-- 
2.32.0

Re: [PATCH v2 0/6] Add display support on the stm32f746-disco board

[Raphael Gallais-Pou]

Hi Dario,


Thanks for this serie. I'll look at it shortly.

In the meantime, would it be possible to send it again as I think it is not
complete.

patchwork and lore.kernel.org both prompt incomplete parts of your serie.

https://patchwork.freedesktop.org/series/118814/?_sm_au_=iVVrkQQkv5r1r0rQcLpsvK618Vf61

https://lore.kernel.org/dri-devel/20230602102123.3345587-1-dario.binacchi@amarulasolutions.com/


Thanks,

Raphaël

On 6/2/23 12:21, Dario Binacchi wrote:
> The series adds support for the display on the stm32f746-disco board,
> along with a generic patch that adds the "bpp" parameter to the stm-drm
> module. The intention is to allow users to size, within certain limits,
> the memory footprint required by the framebuffer.
>
> Changes in v2:
> - Add 'Acked-by' tag of Conor Dooley.
> - Fix build warning reported by kernel test robot.
> - Add 'Reported-by' tag of kernel test robot.
>
> Dario Binacchi (6):
>   ARM: dts: stm32: add ltdc support on stm32f746 MCU
>   ARM: dts: stm32: add pin map for LTDC on stm32f7
>   ARM: dts: stm32: support display on stm32f746-disco board
>   dt-bindings: display: simple: add Rocktech RK043FN48H
>   drm/panel: simple: add support for Rocktech RK043FN48H panel
>   drm/stm: add an option to change FB bpp
>
>  .../bindings/display/panel/panel-simple.yaml  |  2 +
>  arch/arm/boot/dts/stm32f7-pinctrl.dtsi        | 35 +++++++++++++
>  arch/arm/boot/dts/stm32f746-disco.dts         | 51 +++++++++++++++++++
>  arch/arm/boot/dts/stm32f746.dtsi              | 10 ++++
>  drivers/gpu/drm/panel/panel-simple.c          | 29 +++++++++++
>  drivers/gpu/drm/stm/drv.c                     |  8 ++-
>  6 files changed, 134 insertions(+), 1 deletion(-)
>