[PATCH 4/4] drm/panel: ilitek-ili9488: add the PocketGo S30 panel

[Romain TISSERAND <romain.tisserand@gmail.com>]

The PocketGo S30 handheld (Allwinner A33) has a 320x480 1-lane MIPI-DSI
panel built around an Ilitek ILI9488.

The init sequence is the stock kernel's, read back from the running
stock system. It differs from the E35GH-I-MW800CB sequence only in VCOM
(0x26 instead of 0x25), the display function control (2 parameters
instead of 3) and the position of the inversion command. As on stock,
the panel is set to the 18 bpp interface pixel format while the DSI link
carries RGB888, so the panel shows 6 bits per color.

Timings and video mode are from the stock configuration: 12 MHz pixel
clock, htotal 382, vtotal 524, active low sync (lcd_hv_sync_polarity 0),
non-burst video mode with sync pulses and without EoT packets.

Signed-off-by: Romain TISSERAND <romain.tisserand@gmail.com>
---
 drivers/gpu/drm/panel/panel-ilitek-ili9488.c | 55 ++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9488.c b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
index 6ab8ae72abbf..4be3d22360da 100644
--- a/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
@@ -86,6 +86,50 @@ static const struct drm_display_mode e35gh_i_mw800cb_display_mode = {
 	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
 };
 
+static void pocketgo_s30_init(struct mipi_dsi_multi_context *ctx)
+{
+	/* Gamma control 1,2 */
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xE0, 0x00, 0x10, 0x14, 0x01, 0x0E, 0x04, 0x33,
+				     0x56, 0x48, 0x03, 0x0C, 0x0B, 0x2B, 0x34, 0x0F);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xE1, 0x00, 0x12, 0x18, 0x05, 0x12, 0x06, 0x40,
+				     0x34, 0x57, 0x06, 0x10, 0x0C, 0x3B, 0x3F, 0x0F);
+	/* Power control 1,2 */
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xC0, 0x0F, 0x0C);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xC1, 0x41);
+	/* VCOM Control */
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xC5, 0x00, 0x26, 0x80);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0x36, 0x48);
+	/* Interface pixel format 18bpp */
+	mipi_dsi_dcs_write_seq_multi(ctx, 0x3A, 0x66);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xB0, 0x00);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xB1, 0xA0);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xB4, 0x02);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xB6, 0x02, 0x02);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xE9, 0x00);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0x21);
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xF7, 0xA9, 0x51, 0x2C, 0x82);
+}
+
+static const struct drm_display_mode pocketgo_s30_display_mode = {
+	.clock = 12000,
+
+	.hdisplay = 320,
+	.hsync_start = 320 + 22,
+	.hsync_end = 320 + 22 + 12,
+	.htotal = 320 + 22 + 12 + 28,
+
+	.vdisplay = 480,
+	.vsync_start = 480 + 22,
+	.vsync_end = 480 + 22 + 4,
+	.vtotal = 480 + 22 + 4 + 18,
+
+	.width_mm = 49,
+	.height_mm = 74,
+
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
 static inline struct ili9488 *panel_to_ili9488(struct drm_panel *panel)
 {
 	return container_of(panel, struct ili9488, panel);
@@ -269,8 +313,19 @@ static const struct ili9488_desc e35gh_i_mw800cb_desc = {
 	.bpc = 6,
 };
 
+static const struct ili9488_desc pocketgo_s30_desc = {
+	.init_sequence = pocketgo_s30_init,
+	.display_mode = &pocketgo_s30_display_mode,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+		      MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET,
+	.format = MIPI_DSI_FMT_RGB888,
+	.lanes = 1,
+	.bpc = 6,
+};
+
 static const struct of_device_id ili9488_of_match[] = {
 	{ .compatible = "focuslcds,e35gh-i-mw800cb", .data = &e35gh_i_mw800cb_desc },
+	{ .compatible = "pocketgo,s30-panel", .data = &pocketgo_s30_desc },
 	{ }
 };
 
-- 
2.43.0