drm/panel/panel-sitronix-st7701: Split GIP and init sequences

The ST7701 initialization sequence is well parametrized, split the GIP
programming sequence, which is fully custom completely undocumented
TFT matrix specific magic register programming sequence into separate
callback so other TFT matrix definitions can add their own GIP sequence.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Guido Günther <agx@sigxcpu.org>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220710194437.289042-9-marex@denx.de

drivers/gpu/drm/panel/panel-sitronix-st7701.c

@@ -107,6 +107,8 @@ enum op_bias {
 	OP_BIAS_MAX
 };
 
+struct st7701;
+
 struct st7701_panel_desc {
 	const struct drm_display_mode *mode;
 	unsigned int lanes;
@@ -129,6 +131,9 @@ struct st7701_panel_desc {
 	const u16	t2d_ns;		/* T2D in ns */
 	const u16	t3d_ns;		/* T3D in ns */
 	const bool	eot_en;
+
+	/* GIP sequence, fully custom and undocumented. */
+	void		(*gip_sequence)(struct st7701 *st7701);
 };
 
 struct st7701 {
@@ -297,7 +302,10 @@ static void st7701_init_sequence(struct st7701 *st7701)
 	ST7701_DSI(st7701, DSI_CMD2_BK1_MIPISET1,
 		   DSI_CMD2_BK1_MIPISET1_ONES |
 		   (desc->eot_en ? DSI_CMD2_BK1_MIPISET1_EOT_EN : 0));
+}
 
+static void ts8550b_gip_sequence(struct st7701 *st7701)
+{
 	/**
 	 * ST7701_SPEC_V1.2 is unable to provide enough information above this
 	 * specific command sequence, so grab the same from vendor BSP driver.
@@ -319,10 +327,6 @@ static void st7701_init_sequence(struct st7701 *st7701)
 	ST7701_DSI(st7701, 0xEC, 0x00, 0x00);
 	ST7701_DSI(st7701, 0xED, 0xFF, 0xF1, 0x04, 0x56, 0x72, 0x3F, 0xFF,
 		   0xFF, 0xFF, 0xFF, 0xF3, 0x27, 0x65, 0x40, 0x1F, 0xFF);
-
-	/* disable Command2 */
-	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
-		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BKX_SEL_NONE);
 }
 
 static int st7701_prepare(struct drm_panel *panel)
@@ -343,6 +347,13 @@ static int st7701_prepare(struct drm_panel *panel)
 
 	st7701_init_sequence(st7701);
 
+	if (st7701->desc->gip_sequence)
+		st7701->desc->gip_sequence(st7701);
+
+	/* Disable Command2 */
+	ST7701_DSI(st7701, DSI_CMD2BKX_SEL,
+		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BKX_SEL_NONE);
+
 	return 0;
 }
 
@@ -518,6 +529,7 @@ static const struct st7701_panel_desc ts8550b_desc = {
 	.t2d_ns = 1600,
 	.t3d_ns = 10400,
 	.eot_en = true,
+	.gip_sequence = ts8550b_gip_sequence,
 };
 
 static int st7701_dsi_probe(struct mipi_dsi_device *dsi)