media: ov2740: Add regulator support

On some designs the regulators for the AVDD / DOVDD / DVDD power rails
are controlled by Linux.

Add support to the driver for getting regulators for these 3 rails and
for enabling these regulators when necessary.

The datasheet specifies a delay of 0ns between enabling the regulators,
IOW they can all 3 be enabled at the same time. This allows using the bulk
regulator API.

The regulator core will provide dummy regulators for the 3 power-rails
when necessary.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ricardo Ribalda <ribalda@chromium.org>
Tested-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
index 5ebee8d03e6700ae3e88f7801d78958a140db78c..9a5d118b87b0180f0813569b9f4cb35f25a4c58a 100644 (file)
--- a/drivers/media/i2c/ov2740.c
+++ b/drivers/media/i2c/ov2740.c
@@ -11,6 +11,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/nvmem-provider.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-fwnode.h>
@@ -76,6 +77,14 @@
 /* OTP registers from sensor */
 #define OV2740_REG_OTP_CUSTOMER                0x7010
 
+static const char * const ov2740_supply_name[] = {
+       "AVDD",
+       "DOVDD",
+       "DVDD",
+};
+
+#define OV2740_NUM_SUPPLIES ARRAY_SIZE(ov2740_supply_name)
+
 struct nvm_data {
        struct nvmem_device *nvmem;
        struct regmap *regmap;
@@ -523,10 +532,11 @@ struct ov2740 {
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *exposure;
 
-       /* GPIOs, clocks */
+       /* GPIOs, clocks, regulators */
        struct gpio_desc *reset_gpio;
        struct gpio_desc *powerdown_gpio;
        struct clk *clk;
+       struct regulator_bulk_data supplies[OV2740_NUM_SUPPLIES];
 
        /* Current mode */
        const struct ov2740_mode *cur_mode;
@@ -1309,6 +1319,7 @@ static int ov2740_suspend(struct device *dev)
        gpiod_set_value_cansleep(ov2740->reset_gpio, 1);
        gpiod_set_value_cansleep(ov2740->powerdown_gpio, 1);
        clk_disable_unprepare(ov2740->clk);
+       regulator_bulk_disable(OV2740_NUM_SUPPLIES, ov2740->supplies);
        return 0;
 }
 
@@ -1318,10 +1329,16 @@ static int ov2740_resume(struct device *dev)
        struct ov2740 *ov2740 = to_ov2740(sd);
        int ret;
 
-       ret = clk_prepare_enable(ov2740->clk);
+       ret = regulator_bulk_enable(OV2740_NUM_SUPPLIES, ov2740->supplies);
        if (ret)
                return ret;
 
+       ret = clk_prepare_enable(ov2740->clk);
+       if (ret) {
+               regulator_bulk_disable(OV2740_NUM_SUPPLIES, ov2740->supplies);
+               return ret;
+       }
+
        gpiod_set_value_cansleep(ov2740->powerdown_gpio, 0);
        gpiod_set_value_cansleep(ov2740->reset_gpio, 0);
        msleep(20);
@@ -1334,7 +1351,7 @@ static int ov2740_probe(struct i2c_client *client)
        struct device *dev = &client->dev;
        struct ov2740 *ov2740;
        bool full_power;
-       int ret;
+       int i, ret;
 
        ov2740 = devm_kzalloc(&client->dev, sizeof(*ov2740), GFP_KERNEL);
        if (!ov2740)
@@ -1372,6 +1389,13 @@ static int ov2740_probe(struct i2c_client *client)
                return dev_err_probe(dev, PTR_ERR(ov2740->clk),
                                     "failed to get clock\n");
 
+       for (i = 0; i < OV2740_NUM_SUPPLIES; i++)
+               ov2740->supplies[i].supply = ov2740_supply_name[i];
+
+       ret = devm_regulator_bulk_get(dev, OV2740_NUM_SUPPLIES, ov2740->supplies);
+       if (ret)
+               return dev_err_probe(dev, ret, "failed to get regulators\n");
+
        full_power = acpi_dev_state_d0(&client->dev);
        if (full_power) {
                /* ACPI does not always clear the reset GPIO / enable the clock */