From 3355f4ee561da6065cc756bf54a3f8bb556889df Mon Sep 17 00:00:00 2001
From: Marek Vasut <marex@denx.de>
Date: Tue, 30 May 2023 21:28:05 +0200
Subject: [PATCH] drm/bridge: tc358762: Add reset GPIO support
Add reset GPIO support. The reset GPIO is cleared after supply regulator
was enabled, and set before supply regulator is disabled.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230530192805.648646-2-marex@denx.de
---
drivers/gpu/drm/bridge/tc358762.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/gpu/drm/bridge/tc358762.c b/drivers/gpu/drm/bridge/tc358762.c
index 77f7f7f547570..5641395fd310e 100644
--- a/drivers/gpu/drm/bridge/tc358762.c
+++ b/drivers/gpu/drm/bridge/tc358762.c
@@ -11,6 +11,7 @@
*/
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of_graph.h>
@@ -63,6 +64,7 @@ struct tc358762 {
struct drm_bridge bridge;
struct regulator *regulator;
struct drm_bridge *panel_bridge;
+ struct gpio_desc *reset_gpio;
bool pre_enabled;
int error;
};
@@ -138,6 +140,9 @@ static void tc358762_post_disable(struct drm_bridge *bridge)
ctx->pre_enabled = false;
+ if (ctx->reset_gpio)
+ gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+
ret = regulator_disable(ctx->regulator);
if (ret < 0)
dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
@@ -152,6 +157,11 @@ static void tc358762_pre_enable(struct drm_bridge *bridge)
if (ret < 0)
dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
+ if (ctx->reset_gpio) {
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ usleep_range(5000, 10000);
+ }
+
ret = tc358762_init(ctx);
if (ret < 0)
dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
@@ -185,6 +195,11 @@ static int tc358762_parse_dt(struct tc358762 *ctx)
ctx->panel_bridge = panel_bridge;
+ /* Reset GPIO is optional */
+ ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(ctx->reset_gpio))
+ return PTR_ERR(ctx->reset_gpio);
+
return 0;
}