From 907a9f57cd845d274e75e44540c667bcf69819be Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Tue, 10 Nov 2020 11:21:56 +0000 Subject: [PATCH] drm/panel/raspberrypi-ts: Insert delay before polling for startup state In switching to the hardware I2C controller there is an issue where we seem to not get back the correct state from the Pi touchscreen. Insert a delay before polling to avoid this condition. Signed-off-by: Dave Stevenson --- drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c @@ -300,6 +300,7 @@ static int rpi_touchscreen_prepare(struc int i; rpi_touchscreen_i2c_write(ts, REG_POWERON, 1); + usleep_range(20000, 25000); /* Wait for nPWRDWN to go low to indicate poweron is done. */ for (i = 0; i < 100; i++) { if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)