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drm/panel: st7703: Pick different reset sequence

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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
This commit is contained in:
Ondrej Jirman 2023-02-11 18:17:48 +01:00 committed by Guido Günther
parent a48e2cc928
commit d12d635bb0
1 changed files with 14 additions and 13 deletions
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27
drivers/gpu/drm/panel/panel-sitronix-st7703.c
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@ -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);
if (ret < 0) {
dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
return ret;
}
gpiod_set_value_cansleep(ctx->reset_gpio, 1);
ret = regulator_enable(ctx->iovcc);
if (ret < 0) {
dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
goto disable_vcc;
return ret;
}
gpiod_set_value_cansleep(ctx->reset_gpio, 1);
usleep_range(20, 40);
ret = regulator_enable(ctx->vcc);
if (ret < 0) {
dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
regulator_disable(ctx->iovcc);
return ret;
}
/* 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[] = {