From: Michael Walle <mwalle@kernel.org>
To: Andrzej Hajda <andrzej.hajda@intel.com>,
Neil Armstrong <neil.armstrong@linaro.org>,
Robert Foss <rfoss@kernel.org>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Jonas Karlman <jonas@kwiboo.se>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>,
Daniel Vetter <daniel@ffwll.ch>,
Chun-Kuang Hu <chunkuang.hu@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
Sam Ravnborg <sam@ravnborg.org>,
Vinay Simha BN <simhavcs@gmail.com>,
Tony Lindgren <tony@atomide.com>
Cc: Daniel Semkowicz <dse@thaumatec.com>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
Michael Walle <mwalle@kernel.org>
Subject: [PATCH 18/20] drm/bridge: tc358775: fix the power-up/down delays
Date: Mon, 06 May 2024 15:34:47 +0200 [thread overview]
Message-ID: <20240506-tc358775-fix-powerup-v1-18-545dcf00b8dd@kernel.org> (raw)
In-Reply-To: <20240506-tc358775-fix-powerup-v1-0-545dcf00b8dd@kernel.org>
Implement the delays according to Figure 8-10 and 8-11 of the datasheet.
In particular, the datasheet states that the *maximum* time between
enabling the VDDIO and VDD is 10ms. Currently, as implemented this is
always violated. Of course, this is only a best effort because we cannot
be sure enabling of the two regulators will be that fast.
The time between releasing the stby GPIO and releasing the reset GPIO
must be at least 10us and not 10ms as it was before this patch. After
reset is released, there must be at least a delay of 200us until the
first HS clock is received.
Signed-off-by: Michael Walle <mwalle@kernel.org>
---
drivers/gpu/drm/bridge/tc358775.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c
index d5b3d691d2c1..99dbbb1fee78 100644
--- a/drivers/gpu/drm/bridge/tc358775.c
+++ b/drivers/gpu/drm/bridge/tc358775.c
@@ -242,18 +242,16 @@ static void tc358775_power_up(struct tc_data *tc)
ret = regulator_enable(tc->vddio);
if (ret < 0)
dev_err(dev, "regulator vddio enable failed, %d\n", ret);
- usleep_range(10000, 11000);
ret = regulator_enable(tc->vdd);
if (ret < 0)
dev_err(dev, "regulator vdd enable failed, %d\n", ret);
- usleep_range(10000, 11000);
gpiod_set_value(tc->stby_gpio, 0);
- usleep_range(10000, 11000);
+ usleep_range(10, 20);
gpiod_set_value(tc->reset_gpio, 0);
- usleep_range(10, 20);
+ usleep_range(200, 250);
}
static void tc358775_power_down(struct tc_data *tc)
@@ -265,17 +263,14 @@ static void tc358775_power_down(struct tc_data *tc)
usleep_range(10, 20);
gpiod_set_value(tc->stby_gpio, 1);
- usleep_range(10000, 11000);
ret = regulator_disable(tc->vdd);
if (ret < 0)
dev_err(dev, "regulator vdd disable failed, %d\n", ret);
- usleep_range(10000, 11000);
ret = regulator_disable(tc->vddio);
if (ret < 0)
dev_err(dev, "regulator vddio disable failed, %d\n", ret);
- usleep_range(10000, 11000);
}
static void tc_bridge_pre_enable(struct drm_bridge *bridge)
--
2.39.2
next prev parent reply other threads:[~2024-05-06 13:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 13:34 [PATCH 00/20] drm/bridge: tc358775: proper bridge bringup and code cleanup Michael Walle
2024-05-06 13:34 ` [PATCH 01/20] drm/bridge: add dsi_lp11_notify mechanism Michael Walle
2024-05-07 8:37 ` Alexander Stein
2024-05-07 13:39 ` Dmitry Baryshkov
2024-06-03 13:39 ` Michael Walle
2024-05-06 13:34 ` [PATCH 02/20] drm/mediatek: dsi: provide LP-11 mode during .pre_enable Michael Walle
2024-05-06 13:34 ` [PATCH 03/20] drm/mediatek: dsi: add support for .dsi_lp11_notity() Michael Walle
2024-05-06 13:34 ` [PATCH 04/20] drm/bridge: tc358775: fix regulator supply id Michael Walle
2024-05-06 13:34 ` [PATCH 05/20] drm/bridge: tc358775: add crtc modes fixup Michael Walle
2024-05-06 13:34 ` [PATCH 06/20] drm/bridge: tc358775: redefine LV_MX() Michael Walle
2024-05-06 13:34 ` [PATCH 07/20] drm/bridge: tc358775: use regmap instead of open coded access functions Michael Walle
2024-05-06 13:34 ` [PATCH 08/20] drm/bridge: tc358775: remove error message if regulator is missing Michael Walle
2024-05-06 13:34 ` [PATCH 09/20] drm/bridge: tc358775: remove complex vsdelay calculation Michael Walle
2024-05-06 13:34 ` [PATCH 10/20] drm/bridge: tc358775: simplify lvds_link property Michael Walle
2024-05-06 13:34 ` [PATCH 11/20] drm/bridge: tc358775: reformat weird indentation Michael Walle
2024-05-06 13:34 ` [PATCH 12/20] drm/bridge: tc358775: correctly configure LVDS clock Michael Walle
2024-05-06 13:34 ` [PATCH 13/20] drm/bridge: tc358775: split the init code Michael Walle
2024-05-06 13:34 ` [PATCH 14/20] drm/bridge: tc358775: configure PLL depending on the LVDS clock Michael Walle
2024-05-06 13:34 ` [PATCH 15/20] drm/bridge: tc358775: dynamically configure DSI link settings Michael Walle
2024-05-06 13:34 ` [PATCH 16/20] drm/bridge: tc358775: use proper defines to configure LVDS timings Michael Walle
2024-05-06 13:34 ` [PATCH 17/20] drm/bridge: tc358775: move bridge power up/down into functions Michael Walle
2024-05-06 13:34 ` Michael Walle [this message]
2024-05-06 13:34 ` [PATCH 19/20] drm/bridge: tc358775: fix power-up sequencing Michael Walle
2024-05-06 13:34 ` [PATCH 20/20] drm/bridge: tc358775: use devm_drm_bridge_add() Michael Walle
2024-06-03 11:47 ` [PATCH 00/20] drm/bridge: tc358775: proper bridge bringup and code cleanup Michael Walle
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