From 16f77d4264c44d785a39d8dfa79007109c6536ba Mon Sep 17 00:00:00 2001 From: Ondrej Jirman Date: Sat, 11 Feb 2023 18:17:48 +0100 Subject: [PATCH] drm/panel: st7703: Pick different reset sequence MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit d12d635bb03c7cb4830acb641eb176ee9ff2aa89 ] 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 Signed-off-by: Frank Oltmanns Reported-by: Samuel Holland Reviewed-by: Guido Günther Tested-by: Guido Günther Signed-off-by: Guido Günther Link: https://patchwork.freedesktop.org/patch/msgid/20230211171748.36692-2-frank@oltmanns.dev Signed-off-by: Sasha Levin --- 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 3aa31f3d61574..687749bbec62c 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[] = { -- 2.47.2