Am Donnerstag, dem 19.05.2022 um 13:47 +0200 schrieb Marek Vasut:

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.

Fixes: 7caff0fc4296e ("drm/bridge: tc358767: Add DPI to eDP bridge driver") Signed-off-by: Marek Vasut marex@denx.de

Reviewed-by: Lucas Stach l.stach@pengutronix.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

---

V2: Use devm_add_action_or_reset() to add clock disable hook instead of wall of failpath

---

drivers/gpu/drm/bridge/tc358767.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 45ea829d56601..b2ef01303be23 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -2033,6 +2033,13 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc) return -EINVAL; }

+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; @@ -2049,6 +2056,22 @@ 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 = devm_add_action_or_reset(dev, tc_clk_disable, tc->refclk);
• if (ret)

• return ret;
  

• clk_prepare_enable(tc->refclk);
• /* 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))

@@ -2069,13 +2092,6 @@ 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);