drm/imx: imx-ldb: reset display clock input when disabling LVDS
The LDB driver changes the attached display interface's input clock mux
to the LDB_DI clock reference. Change it back again when disabling the
LVDS display. Changing back to the PLL5 for example allows to configure
the same DI for HDMI output later.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index 4286399..544282b 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -77,6 +77,7 @@
struct imx_ldb_channel channel[2];
struct clk *clk[2]; /* our own clock */
struct clk *clk_sel[4]; /* parent of display clock */
+ struct clk *clk_parent[4]; /* original parent of clk_sel */
struct clk *clk_pll[2]; /* upstream clock we can adjust */
u32 ldb_ctrl;
const struct bus_mux *lvds_mux;
@@ -287,6 +288,7 @@
{
struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
struct imx_ldb *ldb = imx_ldb_ch->ldb;
+ int mux, ret;
/*
* imx_ldb_encoder_disable is called by
@@ -314,6 +316,28 @@
clk_disable_unprepare(ldb->clk[1]);
}
+ if (ldb->lvds_mux) {
+ const struct bus_mux *lvds_mux = NULL;
+
+ if (imx_ldb_ch == &ldb->channel[0])
+ lvds_mux = &ldb->lvds_mux[0];
+ else if (imx_ldb_ch == &ldb->channel[1])
+ lvds_mux = &ldb->lvds_mux[1];
+
+ regmap_read(ldb->regmap, lvds_mux->reg, &mux);
+ mux &= lvds_mux->mask;
+ mux >>= lvds_mux->shift;
+ } else {
+ mux = (imx_ldb_ch == &ldb->channel[0]) ? 0 : 1;
+ }
+
+ /* set display clock mux back to original input clock */
+ ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk_parent[mux]);
+ if (ret)
+ dev_err(ldb->dev,
+ "unable to set di%d parent clock to original parent\n",
+ mux);
+
drm_panel_unprepare(imx_ldb_ch->panel);
}
@@ -499,6 +523,8 @@
imx_ldb->clk_sel[i] = NULL;
break;
}
+
+ imx_ldb->clk_parent[i] = clk_get_parent(imx_ldb->clk_sel[i]);
}
if (i == 0)
return ret;