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authorLucas Stach <l.stach@pengutronix.de>2018-04-11 18:31:35 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-05 10:20:00 +0300
commitcb94b5ea2455abc66740cf7b6e4b50e53254891a (patch)
treeba31ad3a92045e47d35d5ae49bc6e43c10055d75 /drivers/gpu
parent0a04fdb19d03408ad9bc7aecbbdb53667243ae35 (diff)
downloadlinux-cb94b5ea2455abc66740cf7b6e4b50e53254891a.tar.xz
drm/imx: imx-ldb: disable LDB on driver bind
[ Upstream commit b58262396fabd43dc869b576e3defdd23b32fe94 ] 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 <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/imx/imx-ldb.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index 3ce391c239b0..7c563b5f0683 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -634,6 +634,9 @@ 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)