From ee920bca27da6c33de6ee73de7b34dee0298f703 Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 8 Dec 2014 15:38:17 +0100
Subject: [PATCH] drm/panel: sharp: lq101r1sx01: Respect power timings
Before shutting down the display using the DCS display_off command, wait
for 4 frames according to the datasheet.
Furthermore, after enabling the power supply, the supply voltage needs
around 10 ms to settle. After that, another 120 ms is required before a
DCS exit_sleep_mode command can be sent.
While at it, no longer send the DCS soft_reset command. This is totally
unnecessary because we've just powered up the display, hence it will be
in a reset state already.
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
.../gpu/drm/panel/panel-sharp-lq101r1sx01.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c b/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c
index 8a11e83ab582..745ceb1ef36e 100644
--- a/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c
+++ b/drivers/gpu/drm/panel/panel-sharp-lq101r1sx01.c
@@ -116,6 +116,8 @@ static int sharp_panel_unprepare(struct drm_panel *panel)
if (!sharp->prepared)
return 0;
+ sharp_wait_frames(sharp, 4);
+
err = mipi_dsi_dcs_set_display_off(sharp->link1);
if (err < 0)
dev_err(panel->dev, "failed to set display off: %d\n", err);
@@ -180,15 +182,13 @@ static int sharp_panel_prepare(struct drm_panel *panel)
if (err < 0)
return err;
- usleep_range(10000, 20000);
-
- err = mipi_dsi_dcs_soft_reset(sharp->link1);
- if (err < 0) {
- dev_err(panel->dev, "soft reset failed: %d\n", err);
- goto poweroff;
- }
-
- msleep(120);
+ /*
+ * According to the datasheet, the panel needs around 10 ms to fully
+ * power up. At least another 120 ms is required before exiting sleep
+ * mode to make sure the panel is ready. Throw in another 20 ms for
+ * good measure.
+ */
+ msleep(150);
err = mipi_dsi_dcs_exit_sleep_mode(sharp->link1);
if (err < 0) {