Re: [PATCH v2 3/3] drm/panel: st7701: Add Anbernic RG28XX panel support

Neil Armstrong <neil.armstrong@xxxxxxxxxx> · Fri, 28 Jun 2024 10:22:42 +0200

On 28/06/2024 07:10, Hironori KIKUCHI wrote:
The Anbernic RG28XX is a handheld gaming device with a 2.8 inch 480x640
display. Add support for the display panel.

This panel is driven by a variant of ST7701 driver IC internally,
confirmed by dumping and analyzing its BSP initialization sequence
by using a logic analyzer. It is very similar to the existing
densitron,dmt028vghmcmi-1a panel, but differs in some unknown
register values. Besides, it is connected via SPI, so add a new entry
for the panel.

Signed-off-by: Hironori KIKUCHI <kikuchan98@xxxxxxxxx>
---
  drivers/gpu/drm/panel/panel-sitronix-st7701.c | 151 ++++++++++++++++++
  1 file changed, 151 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7701.c b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
index 07980f010bb..8450a4317c1 100644
--- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
@@ -471,6 +471,55 @@ static void rg_arc_gip_sequence(struct st7701 *st7701)
  	msleep(120);
  }
  
+static void rg28xx_gip_sequence(struct st7701 *st7701)
+{
+	st7701_switch_cmd_bkx(st7701, true, 3);
+	ST7701_WRITE(st7701, 0xEF, 0x08);
+
+	st7701_switch_cmd_bkx(st7701, true, 0);
+	ST7701_WRITE(st7701, 0xC3, 0x02, 0x10, 0x02);
+	ST7701_WRITE(st7701, 0xC7, 0x04);
+	ST7701_WRITE(st7701, 0xCC, 0x10);
+
+	st7701_switch_cmd_bkx(st7701, true, 1);
+	ST7701_WRITE(st7701, 0xEE, 0x42);
+	ST7701_WRITE(st7701, 0xE0, 0x00, 0x00, 0x02);
+
+	ST7701_WRITE(st7701, 0xE1, 0x04, 0xA0, 0x06, 0xA0, 0x05, 0xA0, 0x07, 0xA0,
+		   0x00, 0x44, 0x44);
+	ST7701_WRITE(st7701, 0xE2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		   0x00, 0x00, 0x00, 0x00);
+	ST7701_WRITE(st7701, 0xE3, 0x00, 0x00, 0x22, 0x22);
+	ST7701_WRITE(st7701, 0xE4, 0x44, 0x44);
+	ST7701_WRITE(st7701, 0xE5, 0x0C, 0x90, 0xA0, 0xA0, 0x0E, 0x92, 0xA0, 0xA0,
+		   0x08, 0x8C, 0xA0, 0xA0, 0x0A, 0x8E, 0xA0, 0xA0);
+	ST7701_WRITE(st7701, 0xE6, 0x00, 0x00, 0x22, 0x22);
+	ST7701_WRITE(st7701, 0xE7, 0x44, 0x44);
+	ST7701_WRITE(st7701, 0xE8, 0x0D, 0x91, 0xA0, 0xA0, 0x0F, 0x93, 0xA0, 0xA0,
+		   0x09, 0x8D, 0xA0, 0xA0, 0x0B, 0x8F, 0xA0, 0xA0);
+	ST7701_WRITE(st7701, 0xEB, 0x00, 0x00, 0xE4, 0xE4, 0x44, 0x00, 0x40);
+	ST7701_WRITE(st7701, 0xED, 0xFF, 0xF5, 0x47, 0x6F, 0x0B, 0xA1, 0xBA, 0xFF,
+		   0xFF, 0xAB, 0x1A, 0xB0, 0xF6, 0x74, 0x5F, 0xFF);
+	ST7701_WRITE(st7701, 0xEF, 0x08, 0x08, 0x08, 0x45, 0x3F, 0x54);
+
+	st7701_switch_cmd_bkx(st7701, false, 0);
+
+	st7701_switch_cmd_bkx(st7701, true, 3);
+	ST7701_WRITE(st7701, 0xE6, 0x16);
+	ST7701_WRITE(st7701, 0xE8, 0x00, 0x0E);
+
+	st7701_switch_cmd_bkx(st7701, false, 0);
+	ST7701_WRITE(st7701, MIPI_DCS_SET_ADDRESS_MODE, 0x10);
+	ST7701_WRITE(st7701, MIPI_DCS_EXIT_SLEEP_MODE);
+	msleep(120);
+
+	st7701_switch_cmd_bkx(st7701, true, 3);
+	ST7701_WRITE(st7701, 0xE8, 0x00, 0x0C);
+	msleep(10);
+	ST7701_WRITE(st7701, 0xE8, 0x00, 0x00);
+	st7701_switch_cmd_bkx(st7701, false, 0);
+}
+
  static int st7701_prepare(struct drm_panel *panel)
  {
  	struct st7701 *st7701 = panel_to_st7701(panel);
@@ -986,6 +1035,106 @@ static const struct st7701_panel_desc rg_arc_desc = {
  	.gip_sequence = rg_arc_gip_sequence,
  };
  
+static const struct drm_display_mode rg28xx_mode = {
+	.clock		= 22325,
+
+	.hdisplay	= 480,
+	.hsync_start	= 480 + 40,
+	.hsync_end	= 480 + 40 + 4,
+	.htotal		= 480 + 40 + 4 + 20,
+
+	.vdisplay	= 640,
+	.vsync_start	= 640 + 2,
+	.vsync_end	= 640 + 2 + 40,
+	.vtotal		= 640 + 2 + 40 + 16,
+
+	.width_mm	= 44,
+	.height_mm	= 58,
+
+	.flags		= DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct st7701_panel_desc rg28xx_desc = {
+	.mode = &rg28xx_mode,
+
+	.panel_sleep_delay = 80,
+
+	.pv_gamma = {
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC0_MASK, 0),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC4_MASK, 0x10),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC8_MASK, 0x17),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC16_MASK, 0xd),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC24_MASK, 0x11),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC52_MASK, 0x6),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC80_MASK, 0x5),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC108_MASK, 0x8),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC147_MASK, 0x7),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC175_MASK, 0x1f),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC203_MASK, 0x4),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC231_MASK, 0x11),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC239_MASK, 0xe),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC247_MASK, 0x29),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC251_MASK, 0x30),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC255_MASK, 0x1f)
+	},
+	.nv_gamma = {
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC0_MASK, 0),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC4_MASK, 0xd),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC8_MASK, 0x14),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC16_MASK, 0xe),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC24_MASK, 0x11),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC52_MASK, 0x6),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC80_MASK, 0x4),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC108_MASK, 0x8),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC147_MASK, 0x8),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC175_MASK, 0x20),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC203_MASK, 0x5),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC231_MASK, 0x13),
+
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC239_MASK, 0x13),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC247_MASK, 0x26),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC251_MASK, 0x30),
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_AJ_MASK, 0) |
+		CFIELD_PREP(ST7701_CMD2_BK0_GAMCTRL_VC255_MASK, 0x1f)
+	},
+	.nlinv = 7,
+	.vop_uv = 4800000,
+	.vcom_uv = 1512500,
+	.vgh_mv = 15000,
+	.vgl_mv = -11730,
+	.avdd_mv = 6600,
+	.avcl_mv = -4400,
+	.gamma_op_bias = OP_BIAS_MIDDLE,
+	.input_op_bias = OP_BIAS_MIN,
+	.output_op_bias = OP_BIAS_MIN,
+	.t2d_ns = 1600,
+	.t3d_ns = 10400,
+	.eot_en = true,
+	.gip_sequence = rg28xx_gip_sequence,
+};
+
  static void st7701_cleanup(void *data)
  {
  	struct st7701 *st7701 = (struct st7701 *)data;
@@ -1120,11 +1269,13 @@ static const struct of_device_id st7701_dsi_of_match[] = {
  MODULE_DEVICE_TABLE(of, st7701_dsi_of_match);
  
  static const struct of_device_id st7701_spi_of_match[] = {
+	{ .compatible = "anbernic,rg28xx-panel", .data = &rg28xx_desc },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, st7701_spi_of_match);
  
  static const struct spi_device_id st7701_spi_ids[] = {
+	{ "rg28xx-panel" },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(spi, st7701_spi_ids);

Looks fine !

Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>

Thanks,
Neil






