linux-kernel - [PATCH v5 11/13] drm/panel: st7703: Assert reset prior to powering down the regulators

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Message-Id: <20200626005601.241022-12-megous@megous.com>
Date:   Fri, 26 Jun 2020 02:55:59 +0200
From:   Ondrej Jirman <megous@...ous.com>
To:     linux-sunxi@...glegroups.com,
        Thierry Reding <thierry.reding@...il.com>,
        Sam Ravnborg <sam@...nborg.org>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Guido Günther <agx@...xcpu.org>,
        Purism Kernel Team <kernel@...i.sm>,
        Rob Herring <robh+dt@...nel.org>,
        Maxime Ripard <mripard@...nel.org>,
        Chen-Yu Tsai <wens@...e.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Icenowy Zheng <icenowy@...c.io>
Cc:     Ondrej Jirman <megous@...ous.com>, dri-devel@...ts.freedesktop.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Samuel Holland <samuel@...lland.org>,
        Martijn Braam <martijn@...xit.nl>, Luca Weiss <luca@...tu.xyz>,
        Bhushan Shah <bshah@....org>
Subject: [PATCH v5 11/13] drm/panel: st7703: Assert reset prior to powering down the regulators

The reset pin is inverted, so if we don't assert reset, the actual gpio
will be high and may keep driving the IO port of the panel.

Signed-off-by: Ondrej Jirman <megous@...ous.com>
---
 drivers/gpu/drm/panel/panel-sitronix-st7703.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
index e771281eb547..92930e127559 100644
--- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
@@ -416,6 +416,7 @@ static int st7703_unprepare(struct drm_panel *panel)
 	if (!ctx->prepared)
 		return 0;
 
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 	regulator_disable(ctx->iovcc);
 	regulator_disable(ctx->vcc);
 	ctx->prepared = false;
-- 
2.27.0