media: imx208: Support device probe in non-zero ACPI D state

Tell ACPI device PM code that the driver supports the device being in
non-zero ACPI D state when the driver's probe function is entered.

Also do identification on the first access of the device, whether in probe
or when starting streaming.

Signed-off-by: Bingbu Cao <bingbu.cao@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/imx208.c b/drivers/media/i2c/imx208.c
index 6f3d9c1b5879f942430d9e776ba0fc42ab342216..b9516b2f1c15e49a41f53db86d5dd6129ca21e79 100644 (file)
--- a/drivers/media/i2c/imx208.c
+++ b/drivers/media/i2c/imx208.c
@@ -296,6 +296,9 @@ struct imx208 {
        /* OTP data */
        bool otp_read;
        char otp_data[IMX208_OTP_SIZE];
+
+       /* True if the device has been identified */
+       bool identified;
 };
 
 static inline struct imx208 *to_imx208(struct v4l2_subdev *_sd)
@@ -619,6 +622,34 @@ static int imx208_set_pad_format(struct v4l2_subdev *sd,
        return 0;
 }
 
+static int imx208_identify_module(struct imx208 *imx208)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
+       int ret;
+       u32 val;
+
+       if (imx208->identified)
+               return 0;
+
+       ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
+                             2, &val);
+       if (ret) {
+               dev_err(&client->dev, "failed to read chip id %x\n",
+                       IMX208_CHIP_ID);
+               return ret;
+       }
+
+       if (val != IMX208_CHIP_ID) {
+               dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
+                       IMX208_CHIP_ID, val);
+               return -EIO;
+       }
+
+       imx208->identified = true;
+
+       return 0;
+}
+
 /* Start streaming */
 static int imx208_start_streaming(struct imx208 *imx208)
 {
@@ -626,6 +657,10 @@ static int imx208_start_streaming(struct imx208 *imx208)
        const struct imx208_reg_list *reg_list;
        int ret, link_freq_index;
 
+       ret = imx208_identify_module(imx208);
+       if (ret)
+               return ret;
+
        /* Setup PLL */
        link_freq_index = imx208->cur_mode->link_freq_index;
        reg_list = &link_freq_configs[link_freq_index].reg_list;
@@ -752,29 +787,6 @@ error:
 }
 
 /* Verify chip ID */
-static int imx208_identify_module(struct imx208 *imx208)
-{
-       struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
-       int ret;
-       u32 val;
-
-       ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
-                             2, &val);
-       if (ret) {
-               dev_err(&client->dev, "failed to read chip id %x\n",
-                       IMX208_CHIP_ID);
-               return ret;
-       }
-
-       if (val != IMX208_CHIP_ID) {
-               dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
-                       IMX208_CHIP_ID, val);
-               return -EIO;
-       }
-
-       return 0;
-}
-
 static const struct v4l2_subdev_video_ops imx208_video_ops = {
        .s_stream = imx208_set_stream,
 };
@@ -813,6 +825,10 @@ static int imx208_read_otp(struct imx208 *imx208)
                goto out_unlock;
        }
 
+       ret = imx208_identify_module(imx208);
+       if (ret)
+               goto out_pm_put;
+
        /* Write register address */
        msgs[0].addr = client->addr;
        msgs[0].flags = 0;
@@ -831,6 +847,7 @@ static int imx208_read_otp(struct imx208 *imx208)
                ret = 0;
        }
 
+out_pm_put:
        pm_runtime_put(&client->dev);
 
 out_unlock:
@@ -961,6 +978,7 @@ static int imx208_probe(struct i2c_client *client)
 {
        struct imx208 *imx208;
        int ret;
+       bool full_power;
        u32 val = 0;
 
        device_property_read_u32(&client->dev, "clock-frequency", &val);
@@ -978,11 +996,14 @@ static int imx208_probe(struct i2c_client *client)
        /* Initialize subdev */
        v4l2_i2c_subdev_init(&imx208->sd, client, &imx208_subdev_ops);
 
-       /* Check module identity */
-       ret = imx208_identify_module(imx208);
-       if (ret) {
-               dev_err(&client->dev, "failed to find sensor: %d", ret);
-               goto error_probe;
+       full_power = acpi_dev_state_d0(&client->dev);
+       if (full_power) {
+               /* Check module identity */
+               ret = imx208_identify_module(imx208);
+               if (ret) {
+                       dev_err(&client->dev, "failed to find sensor: %d", ret);
+                       goto error_probe;
+               }
        }
 
        /* Set default mode to max resolution */
@@ -1017,7 +1038,9 @@ static int imx208_probe(struct i2c_client *client)
                goto error_async_subdev;
        }
 
-       pm_runtime_set_active(&client->dev);
+       /* Set the device's state to active if it's in D0 state. */
+       if (full_power)
+               pm_runtime_set_active(&client->dev);
        pm_runtime_enable(&client->dev);
        pm_runtime_idle(&client->dev);
 
@@ -1077,6 +1100,7 @@ static struct i2c_driver imx208_i2c_driver = {
        },
        .probe_new = imx208_probe,
        .remove = imx208_remove,
+       .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(imx208_i2c_driver);