From fa7de9a76b91e1a2c4fe623e5b6fbbb704b76c5f Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Tue, 10 Nov 2020 11:21:56 +0000 Subject: [PATCH 0264/1002] 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(+) diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c index b2395e77e079..dae2ec2acd1f 100644 --- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c +++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c @@ -298,6 +298,7 @@ static int rpi_touchscreen_prepare(struct drm_panel *panel) 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) -- 2.44.0