drm/bridge: anx7625: disable regulators when power off

When suspending the driver, anx7625_power_standby() will be called to
turn off reset-gpios and enable-gpios. However, power supplies are not
disabled. To save power, the driver can get the power supply regulators
and turn off them in anx7625_power_standby().

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210401053202.159302-2-hsinyi@chromium.org

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
@@ -875,12 +876,25 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
 static void anx7625_power_on(struct anx7625_data *ctx)
 {
 	struct device *dev = &ctx->client->dev;
+	int ret, i;
 
 	if (!ctx->pdata.low_power_mode) {
 		DRM_DEV_DEBUG_DRIVER(dev, "not low power mode!\n");
 		return;
 	}
 
+	for (i = 0; i < ARRAY_SIZE(ctx->pdata.supplies); i++) {
+		ret = regulator_enable(ctx->pdata.supplies[i].consumer);
+		if (ret < 0) {
+			DRM_DEV_DEBUG_DRIVER(dev, "cannot enable supply %d: %d\n",
+					     i, ret);
+			goto reg_err;
+		}
+		usleep_range(2000, 2100);
+	}
+
+	usleep_range(4000, 4100);
+
 	/* Power on pin enable */
 	gpiod_set_value(ctx->pdata.gpio_p_on, 1);
 	usleep_range(10000, 11000);
@@ -889,11 +903,16 @@ static void anx7625_power_on(struct anx7625_data *ctx)
 	usleep_range(10000, 11000);
 
 	DRM_DEV_DEBUG_DRIVER(dev, "power on !\n");
+	return;
+reg_err:
+	for (--i; i >= 0; i--)
+		regulator_disable(ctx->pdata.supplies[i].consumer);
 }
 
 static void anx7625_power_standby(struct anx7625_data *ctx)
 {
 	struct device *dev = &ctx->client->dev;
+	int ret;
 
 	if (!ctx->pdata.low_power_mode) {
 		DRM_DEV_DEBUG_DRIVER(dev, "not low power mode!\n");
@@ -904,6 +923,12 @@ static void anx7625_power_standby(struct anx7625_data *ctx)
 	usleep_range(1000, 1100);
 	gpiod_set_value(ctx->pdata.gpio_p_on, 0);
 	usleep_range(1000, 1100);
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->pdata.supplies),
+				     ctx->pdata.supplies);
+	if (ret < 0)
+		DRM_DEV_DEBUG_DRIVER(dev, "cannot disable supplies %d\n", ret);
+
 	DRM_DEV_DEBUG_DRIVER(dev, "power down\n");
 }
 
@@ -1742,6 +1767,15 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	platform->client = client;
 	i2c_set_clientdata(client, platform);
 
+	pdata->supplies[0].supply = "vdd10";
+	pdata->supplies[1].supply = "vdd18";
+	pdata->supplies[2].supply = "vdd33";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(pdata->supplies),
+				      pdata->supplies);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "fail to get power supplies: %d\n", ret);
+		return ret;
+	}
 	anx7625_init_gpio(platform);
 
 	atomic_set(&platform->power_status, 0);

drivers/gpu/drm/bridge/analogix/anx7625.h

@@ -350,6 +350,7 @@ struct s_edid_data {
 struct anx7625_platform_data {
 	struct gpio_desc *gpio_p_on;
 	struct gpio_desc *gpio_reset;
+	struct regulator_bulk_data supplies[3];
 	struct drm_bridge *panel_bridge;
 	int intp_irq;
 	u32 low_power_mode;