[PATCH 4/4] drm/panel: jh057n0090: Add regulator support

[Guido Günther <agx@xxxxxxxxxxx>]

Allow to specify regulators for vcc and iovcc. According to the data
sheet the panel wants vcc (2.8V) and iovcc (1.8V) and there's no startup
dependency between the two.

Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>
---
 .../drm/panel/panel-rocktech-jh057n00900.c    | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c b/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c
index b8a069055fbc..f8f6f087b9bc 100644
--- a/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c
+++ b/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c
@@ -15,6 +15,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/media-bus-format.h>
 #include <linux/module.h>
+#include <linux/regulator/consumer.h>
 #include <video/display_timing.h>
 #include <video/mipi_display.h>
 
@@ -47,6 +48,8 @@ struct jh057n {
 	struct drm_panel panel;
 	struct gpio_desc *reset_gpio;
 	struct backlight_device *backlight;
+	struct regulator *vcc;
+	struct regulator *iovcc;
 	bool prepared;
 
 	struct dentry *debugfs;
@@ -160,6 +163,8 @@ static int jh057n_unprepare(struct drm_panel *panel)
 		return 0;
 
 	mipi_dsi_dcs_set_display_off(dsi);
+	regulator_disable(ctx->iovcc);
+	regulator_disable(ctx->vcc);
 	ctx->prepared = false;
 
 	return 0;
@@ -174,6 +179,13 @@ static int jh057n_prepare(struct drm_panel *panel)
 		return 0;
 
 	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
+	ret = regulator_enable(ctx->vcc);
+	if (ret < 0)
+		return ret;
+	ret = regulator_enable(ctx->iovcc);
+	if (ret < 0)
+		return ret;
+
 	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 	usleep_range(20, 40);
 	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
@@ -301,6 +313,13 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 	if (IS_ERR(ctx->backlight))
 		return PTR_ERR(ctx->backlight);
 
+	ctx->vcc = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(ctx->vcc))
+		return PTR_ERR(ctx->vcc);
+	ctx->iovcc = devm_regulator_get(dev, "iovcc");
+	if (IS_ERR(ctx->iovcc))
+		return PTR_ERR(ctx->iovcc);
+
 	drm_panel_init(&ctx->panel);
 	ctx->panel.dev = dev;
 	ctx->panel.funcs = &jh057n_drm_funcs;
-- 
2.20.1