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Commit 3481fe76 authored by Eric Anholt's avatar Eric Anholt
Browse files

drm/panel: Enable DSI transactions on the RPi panel. 



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: default avatarEric Anholt <eric@anholt.net>
Fixes: 2f733d61 ("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: default avatarBoris Brezillon <boris.brezillon@bootlin.com>
Acked-by: default avatarThierry Reding <treding@nvidia.com>
parent 1825067e

drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c

+1 −13
Original line number Diff line number Diff line
@@ -238,12 +238,6 @@ static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts, 


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 rpi_touchscreen *ts, u16 reg, u32 val) 
		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;

}