Commit 0b4c48f3 authored by Marek Vasut's avatar Marek Vasut
Browse files

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: default avatarLucas Stach <l.stach@pengutronix.de>
Fixes: 7caff0fc ("drm/bridge: tc358767: Add DPI to eDP bridge driver")
Signed-off-by: default avatarMarek 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: default avatarMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220520121543.11550-1-marex@denx.de
parent c1de02bb

drivers/gpu/drm/bridge/tc358767.c

+25 −7
Original line number Diff line number Diff line
@@ -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);