From ef2f2344f4c8421d9726e0fe204f2b5c01e8db05 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Fri, 15 Apr 2022 18:25:13 +0200
Subject: drm/panel/raspberrypi-touchscreen: Initialise the bridge in prepare
Git-commit: 5f18c0782b99e26121efa93d20b76c19e17aa1dd
Patch-mainline: v5.18-rc4
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

The panel has a prepare call which is before video starts, and an
enable call which is after.
The Toshiba bridge should be configured before video, so move
the relevant power and initialisation calls to prepare.

Fixes: 2f733d6194bd ("drm/panel: Add support for the Raspberry Pi 7" Touchscreen.")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415162513.42190-3-stefan.wahren@i2se.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
index 1f805eb8fdb5..145047e19394 100644
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -265,7 +265,7 @@ static int rpi_touchscreen_noop(struct drm_panel *panel)
 	return 0;
 }
 
-static int rpi_touchscreen_enable(struct drm_panel *panel)
+static int rpi_touchscreen_prepare(struct drm_panel *panel)
 {
 	struct rpi_touchscreen *ts = panel_to_ts(panel);
 	int i;
@@ -295,6 +295,13 @@ static int rpi_touchscreen_enable(struct drm_panel *panel)
 	rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 	msleep(100);
 
+	return 0;
+}
+
+static int rpi_touchscreen_enable(struct drm_panel *panel)
+{
+	struct rpi_touchscreen *ts = panel_to_ts(panel);
+
 	/* Turn on the backlight. */
 	rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 
@@ -349,7 +356,7 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel,
 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 	.disable = rpi_touchscreen_disable,
 	.unprepare = rpi_touchscreen_noop,
-	.prepare = rpi_touchscreen_noop,
+	.prepare = rpi_touchscreen_prepare,
 	.enable = rpi_touchscreen_enable,
 	.get_modes = rpi_touchscreen_get_modes,
 };
-- 
2.38.1