From b58262396fabd43dc869b576e3defdd23b32fe94 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Wed, 11 Apr 2018 17:31:35 +0200 Subject: drm/imx: imx-ldb: disable LDB on driver bind The LVDS signal integrity is only guaranteed when the correct enable sequence (first IPU DI, then LDB) is used. If the LDB display output was active before the imx-drm driver is loaded (like when a bootsplash was active) the DI will be disabled by the full IPU reset we do when loading the driver. The LDB control registers are not part of the IPU range and thus will remain unchanged. This leads to the LDB still being active when the DI is getting enabled, effectively reversing the required enable sequence. Fix this by also disabling the LDB on driver bind. Signed-off-by: Lucas Stach Signed-off-by: Philipp Zabel --- drivers/gpu/drm/imx/imx-ldb.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpu/drm/imx/imx-ldb.c') diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c index 56dd7a9a8e25..17974c0b4be8 100644 --- a/drivers/gpu/drm/imx/imx-ldb.c +++ b/drivers/gpu/drm/imx/imx-ldb.c @@ -612,6 +612,9 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data) return PTR_ERR(imx_ldb->regmap); } + /* disable LDB by resetting the control register to POR default */ + regmap_write(imx_ldb->regmap, IOMUXC_GPR2, 0); + imx_ldb->dev = dev; if (of_id) -- cgit v1.2.3 From c80d673b91a6c81d765864e10f2b15110ee900ad Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Wed, 11 Apr 2018 17:31:36 +0200 Subject: drm/imx: imx-ldb: check if channel is enabled before printing warning If the second LVDS channel has been disabled in the DT when using dual-channel mode we should not print a warning. Signed-off-by: Lucas Stach Signed-off-by: Philipp Zabel --- drivers/gpu/drm/imx/imx-ldb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/imx/imx-ldb.c') diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c index 17974c0b4be8..dd5312b02a8d 100644 --- a/drivers/gpu/drm/imx/imx-ldb.c +++ b/drivers/gpu/drm/imx/imx-ldb.c @@ -655,14 +655,14 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data) if (ret || i < 0 || i > 1) return -EINVAL; + if (!of_device_is_available(child)) + continue; + if (dual && i > 0) { dev_warn(dev, "dual-channel mode, ignoring second output\n"); continue; } - if (!of_device_is_available(child)) - continue; - channel = &imx_ldb->channel[i]; channel->ldb = imx_ldb; channel->chno = i; -- cgit v1.2.3