From 0b4c48f3e315d172e4cc06e10f2c8ba180788baf Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Fri, 20 May 2022 14:15:43 +0200 Subject: drm/bridge: tc358767: Make sure Refclk clock are enabled 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 Fixes: 7caff0fc4296e ("drm/bridge: tc358767: Add DPI to eDP bridge driver") Signed-off-by: Marek Vasut Cc: Jonas Karlman Cc: Laurent Pinchart Cc: Lucas Stach Cc: Marek Vasut Cc: Maxime Ripard Cc: Neil Armstrong Cc: Robert Foss Cc: Sam Ravnborg Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20220520121543.11550-1-marex@denx.de --- drivers/gpu/drm/bridge/tc358767.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 45ea829d5660..6c6177028742 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 +2056,24 @@ 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)) @@ -2069,13 +2094,6 @@ 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); -- cgit v1.2.3