From: Eric Anholt <eric@anholt.net>
Date: Tue, 31 Oct 2017 12:32:58 -0700
Subject: drm/panel: Enable DSI transactions on the RPi panel.
Git-commit: 3481fe768faeae3f1d2a929e401748893460d82e
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
It turns out that I had just mistaken what type of write the register
writes were supposed to be, using DCS instead of generic long writes.
Switching to transactions instead of using the atmel as a bridge also
seems to resolve the sparkling pixels problem I've had.
Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 2f733d6194bd ("drm/panel: Add support for the Raspberry Pi 7" Touchscreen.")
Link: https://patchwork.freedesktop.org/patch/msgid/20171031193258.17373-2-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -238,12 +238,6 @@ static void rpi_touchscreen_i2c_write(st
static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
{
-#if 0
- /* The firmware uses LP DSI transactions like this to bring up
- * the hardware, which should be faster than using I2C to then
- * pass to the Toshiba. However, I was unable to get it to
- * work.
- */
u8 msg[] = {
reg,
reg >> 8,
@@ -253,13 +247,7 @@ static int rpi_touchscreen_write(struct
val >> 24,
};
- mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg));
-#else
- rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8);
- rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg);
- rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8);
- rpi_touchscreen_i2c_write(ts, REG_WRITEL, val);
-#endif
+ mipi_dsi_generic_write(ts->dsi, msg, sizeof(msg));
return 0;
}