[PATCH v2 3/6] drm/bridge: ti-sn65dsi86: Add some 100 us delays

From: Douglas Anderson
Date: Fri Jul 30 2021 - 11:46:55 EST


The manual has always said that we need 100 us delays in a few
places. Though it hasn't seemed to be a big deal to skip these, let's
add them in case it makes something happier.

NOTE: this fixes no known issues but it seems good to make it right.

Fixes: a095f15c00e2 ("drm/bridge: add support for sn65dsi86 bridge driver")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Acked-by: Robert Foss <robert.foss@xxxxxxxxxx>
Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
---

Changes in v2:
- Added Fixes tag as requested by Sam.

drivers/gpu/drm/bridge/ti-sn65dsi86.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index 5e932070a1c3..cd0fccdd8dfd 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -307,6 +307,9 @@ static int __maybe_unused ti_sn65dsi86_resume(struct device *dev)
return ret;
}

+ /* td2: min 100 us after regulators before enabling the GPIO */
+ usleep_range(100, 110);
+
gpiod_set_value(pdata->enable_gpio, 1);

/*
@@ -1096,6 +1099,9 @@ static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)

if (!pdata->refclk)
ti_sn65dsi86_enable_comms(pdata);
+
+ /* td7: min 100 us after enable before DSI data */
+ usleep_range(100, 110);
}

static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
--
2.32.0.554.ge1b32706d8-goog