[PATCH] drm: sun4i: exclusively set HDMI-related clocks for dw-hdmi

From: Icenowy Zheng
Date: Wed Aug 15 2018 - 08:09:00 EST


The glue in sun4i-drm of dw-hdmi currently doesn't set the clocks of
dw-hdmi exclusively, which will lead the display fails to initialize in
some situations.

Add the exclusivity to sun8i-dw-hdmi and sun8i-hdmi-phy.

Cc: stable@xxxxxxxxxxxxxxx # v4.17+
Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 11 ++++++++++-
drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 7 +++++--
2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 31875b636434..a10220518548 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -137,10 +137,16 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
goto err_assert_ctrl_reset;
}

+ ret = clk_rate_exclusive_get(hdmi->clk_tmds);
+ if (ret) {
+ dev_err(dev, "Could not get exclusivity over the tmds clock\n");
+ goto err_disable_clk_tmds;
+ }
+
phy_node = of_parse_phandle(dev->of_node, "phys", 0);
if (!phy_node) {
dev_err(dev, "Can't found PHY phandle\n");
- goto err_disable_clk_tmds;
+ goto err_put_clk_tmds_exclusivity;
}

ret = sun8i_hdmi_phy_probe(hdmi, phy_node);
@@ -179,6 +185,8 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
cleanup_encoder:
drm_encoder_cleanup(encoder);
sun8i_hdmi_phy_remove(hdmi);
+err_put_clk_tmds_exclusivity:
+ clk_rate_exclusive_put(hdmi->clk_tmds);
err_disable_clk_tmds:
clk_disable_unprepare(hdmi->clk_tmds);
err_assert_ctrl_reset:
@@ -194,6 +202,7 @@ static void sun8i_dw_hdmi_unbind(struct device *dev, struct device *master,

dw_hdmi_unbind(hdmi->hdmi);
sun8i_hdmi_phy_remove(hdmi);
+ clk_rate_exclusive_put(hdmi->clk_tmds);
clk_disable_unprepare(hdmi->clk_tmds);
reset_control_assert(hdmi->rst_ctrl);
}
diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
index 82502b351aec..1e0b1d9bc0fb 100644
--- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
+++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
@@ -511,13 +511,14 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
}

clk_prepare_enable(phy->clk_phy);
+ clk_rate_exclusive_get(phy->clk_phy);
}

phy->rst_phy = of_reset_control_get_shared(node, "phy");
if (IS_ERR(phy->rst_phy)) {
dev_err(dev, "Could not get phy reset control\n");
ret = PTR_ERR(phy->rst_phy);
- goto err_disable_clk_phy;
+ goto err_put_clk_phy_exclusivity;
}

ret = reset_control_deassert(phy->rst_phy);
@@ -548,7 +549,8 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
reset_control_assert(phy->rst_phy);
err_put_rst_phy:
reset_control_put(phy->rst_phy);
-err_disable_clk_phy:
+err_put_clk_phy_exclusivity:
+ clk_rate_exclusive_put(phy->clk_phy);
clk_disable_unprepare(phy->clk_phy);
err_put_clk_pll1:
clk_put(phy->clk_pll1);
@@ -568,6 +570,7 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi)

clk_disable_unprepare(phy->clk_mod);
clk_disable_unprepare(phy->clk_bus);
+ clk_rate_exclusive_put(phy->clk_phy);
clk_disable_unprepare(phy->clk_phy);

reset_control_assert(phy->rst_phy);
--
2.18.0