From 065b2a4eb67ae5165e54dc4b3efd129c77c712db Mon Sep 17 00:00:00 2001
From: Ondrej Jirman <megi@xff.cz>
Date: Sat, 11 Feb 2023 18:17:48 +0100
Subject: drm/panel: st7703: Pick different reset sequence
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Git-commit: d12d635bb03c7cb4830acb641eb176ee9ff2aa89
Patch-mainline: v6.7-rc1
References: jsc#PED-3527 jsc#PED-5475 jsc#PED-6068 jsc#PED-6070 jsc#PED-6116 jsc#PED-6120 jsc#PED-5065 jsc#PED-5477 jsc#PED-5511 jsc#PED-6041 jsc#PED-6069 jsc#PED-6071
Switching to a different reset sequence, enabling IOVCC before enabling
VCC.
There also needs to be a delay after enabling the supplies and before
deasserting the reset. The datasheet specifies 1ms after the supplies
reach the required voltage. Use 10-20ms to also give the power supplies
some time to reach the required voltage, too.
This fixes intermittent panel initialization failures and screen
corruption during resume from sleep on panel xingbangda,xbd599 (e.g.
used in PinePhone).
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Reported-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Tested-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Guido Günther <agx@sigxcpu.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230211171748.36692-2-frank@oltmanns.dev
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/panel/panel-sitronix-st7703.c | 25 ++++++++++---------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
index 6a3945639535..7bb723d445ad 100644
--- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
@@ -506,29 +506,30 @@ static int st7703_prepare(struct drm_panel *panel)
return 0;
dev_dbg(ctx->dev, "Resetting the panel\n");
- ret = regulator_enable(ctx->vcc);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+ ret = regulator_enable(ctx->iovcc);
if (ret < 0) {
- dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
+ dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
return ret;
}
- ret = regulator_enable(ctx->iovcc);
+
+ ret = regulator_enable(ctx->vcc);
if (ret < 0) {
- dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
- goto disable_vcc;
+ dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
+ regulator_disable(ctx->iovcc);
+ return ret;
}
- gpiod_set_value_cansleep(ctx->reset_gpio, 1);
- usleep_range(20, 40);
+ /* Give power supplies time to stabilize before deasserting reset. */
+ usleep_range(10000, 20000);
+
gpiod_set_value_cansleep(ctx->reset_gpio, 0);
- msleep(20);
+ usleep_range(15000, 20000);
ctx->prepared = true;
return 0;
-
-disable_vcc:
- regulator_disable(ctx->vcc);
- return ret;
}
static const u32 mantix_bus_formats[] = {
--
2.43.0