Commit a8972d5a authored by Hugo Villeneuve's avatar Hugo Villeneuve Committed by Neil Armstrong
Browse files

drm: panel: jd9365da-h3: fix reset signal polarity 



In jadard_prepare() a reset pulse is generated with the following
statements (delays ommited for clarity):

    gpiod_set_value(jadard->reset, 1); --> Deassert reset
    gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
    gpiod_set_value(jadard->reset, 1); --> Deassert reset

However, specifying second argument of "0" to gpiod_set_value() means to
deassert the GPIO, and "1" means to assert it. If the reset signal is
defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
incorrectly generate the reset pulse (inverted) and leave it asserted
(LOW) at the end of jadard_prepare().

Fix reset behavior by inverting gpiod_set_value() second argument
in jadard_prepare(). Also modify second argument to devm_gpiod_get()
in jadard_dsi_probe() to assert the reset when probing.

Do not modify it in jadard_unprepare() as it is already properly
asserted with "1", which seems to be the intended behavior.

Fixes: 6b818c53 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240927135306.857617-1-hugo@hugovil.com


Signed-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240927135306.857617-1-hugo@hugovil.com
parent e00a2e5d

drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c

+4 −4
Original line number Diff line number Diff line
@@ -109,13 +109,13 @@ static int jadard_prepare(struct drm_panel *panel) 
	if (jadard->desc->lp11_to_reset_delay_ms)

		msleep(jadard->desc->lp11_to_reset_delay_ms);



	gpiod_set_value(jadard->reset, 1);

	gpiod_set_value(jadard->reset, 0);

	msleep(5);



	gpiod_set_value(jadard->reset, 0);

	gpiod_set_value(jadard->reset, 1);

	msleep(10);



	gpiod_set_value(jadard->reset, 1);

	gpiod_set_value(jadard->reset, 0);

	msleep(130);



	ret = jadard->desc->init(jadard);
@@ -1130,7 +1130,7 @@ static int jadard_dsi_probe(struct mipi_dsi_device *dsi) 
	dsi->format = desc->format;

	dsi->lanes = desc->lanes;



	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);

	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);

	if (IS_ERR(jadard->reset)) {

		DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");

		return PTR_ERR(jadard->reset);