From: Marek Vasut marex@denx.de
[ Upstream commit 0b4c48f3e315d172e4cc06e10f2c8ba180788baf ]
The Refclk may be supplied by SoC clock output instead of crystal oscillator, make sure the clock are enabled before any other action is performed with the bridge chip, otherwise it may either fail to operate at all, or miss reset GPIO toggle.
Reviewed-by: Lucas Stach l.stach@pengutronix.de Fixes: 7caff0fc4296e ("drm/bridge: tc358767: Add DPI to eDP bridge driver") Signed-off-by: Marek Vasut marex@denx.de Cc: Jonas Karlman jonas@kwiboo.se Cc: Laurent Pinchart Laurent.pinchart@ideasonboard.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Marek Vasut marex@denx.de Cc: Maxime Ripard maxime@cerno.tech Cc: Neil Armstrong narmstrong@baylibre.com Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Reviewed-by: Maxime Ripard maxime@cerno.tech Link: https://patchwork.freedesktop.org/patch/msgid/20220520121543.11550-1-marex@d... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/bridge/tc358767.c | 32 ++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 835a146a0196..5a51c1699b29 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1576,6 +1576,13 @@ static int tc_probe_edp_bridge_endpoint(struct tc_data *tc) return ret; }
+static void tc_clk_disable(void *data) +{ + struct clk *refclk = data; + + clk_disable_unprepare(refclk); +} + static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; @@ -1592,6 +1599,24 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) if (ret) return ret;
+ tc->refclk = devm_clk_get(dev, "ref"); + if (IS_ERR(tc->refclk)) { + ret = PTR_ERR(tc->refclk); + dev_err(dev, "Failed to get refclk: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(tc->refclk); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, tc_clk_disable, tc->refclk); + if (ret) + return ret; + + /* tRSTW = 100 cycles , at 13 MHz that is ~7.69 us */ + usleep_range(10, 15); + /* Shut down GPIO is optional */ tc->sd_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH); if (IS_ERR(tc->sd_gpio)) @@ -1612,13 +1637,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) usleep_range(5000, 10000); }
- tc->refclk = devm_clk_get(dev, "ref"); - if (IS_ERR(tc->refclk)) { - ret = PTR_ERR(tc->refclk); - dev_err(dev, "Failed to get refclk: %d\n", ret); - return ret; - } - tc->regmap = devm_regmap_init_i2c(client, &tc_regmap_config); if (IS_ERR(tc->regmap)) { ret = PTR_ERR(tc->regmap);