media: ov13b10: 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: Arec Kao <arec.kao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/i2c/ov13b10.c b/drivers/media/i2c/ov13b10.c
index 549e5d9..722f490 100644 (file)
--- a/drivers/media/i2c/ov13b10.c
+++ b/drivers/media/i2c/ov13b10.c
@@ -589,6 +589,9 @@ struct ov13b10 {
 
        /* Streaming on/off */
        bool streaming;
+
+       /* True if the device has been identified */
+       bool identified;
 };
 
 #define to_ov13b10(_sd)        container_of(_sd, struct ov13b10, sd)
@@ -1023,12 +1026,42 @@ ov13b10_set_pad_format(struct v4l2_subdev *sd,
        return 0;
 }
 
+/* Verify chip ID */
+static int ov13b10_identify_module(struct ov13b10 *ov13b)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&ov13b->sd);
+       int ret;
+       u32 val;
+
+       if (ov13b->identified)
+               return 0;
+
+       ret = ov13b10_read_reg(ov13b, OV13B10_REG_CHIP_ID,
+                              OV13B10_REG_VALUE_24BIT, &val);
+       if (ret)
+               return ret;
+
+       if (val != OV13B10_CHIP_ID) {
+               dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
+                       OV13B10_CHIP_ID, val);
+               return -EIO;
+       }
+
+       ov13b->identified = true;
+
+       return 0;
+}
+
 static int ov13b10_start_streaming(struct ov13b10 *ov13b)
 {
        struct i2c_client *client = v4l2_get_subdevdata(&ov13b->sd);
        const struct ov13b10_reg_list *reg_list;
        int ret, link_freq_index;
 
+       ret = ov13b10_identify_module(ov13b);
+       if (ret)
+               return ret;
+
        /* Get out of from software reset */
        ret = ov13b10_write_reg(ov13b, OV13B10_REG_SOFTWARE_RST,
                                OV13B10_REG_VALUE_08BIT, OV13B10_SOFTWARE_RST);
@@ -1144,27 +1177,6 @@ error:
        return ret;
 }
 
-/* Verify chip ID */
-static int ov13b10_identify_module(struct ov13b10 *ov13b)
-{
-       struct i2c_client *client = v4l2_get_subdevdata(&ov13b->sd);
-       int ret;
-       u32 val;
-
-       ret = ov13b10_read_reg(ov13b, OV13B10_REG_CHIP_ID,
-                              OV13B10_REG_VALUE_24BIT, &val);
-       if (ret)
-               return ret;
-
-       if (val != OV13B10_CHIP_ID) {
-               dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
-                       OV13B10_CHIP_ID, val);
-               return -EIO;
-       }
-
-       return 0;
-}
-
 static const struct v4l2_subdev_video_ops ov13b10_video_ops = {
        .s_stream = ov13b10_set_stream,
 };
@@ -1379,6 +1391,7 @@ out_err:
 static int ov13b10_probe(struct i2c_client *client)
 {
        struct ov13b10 *ov13b;
+       bool full_power;
        int ret;
 
        /* Check HW config */
@@ -1395,11 +1408,14 @@ static int ov13b10_probe(struct i2c_client *client)
        /* Initialize subdev */
        v4l2_i2c_subdev_init(&ov13b->sd, client, &ov13b10_subdev_ops);
 
-       /* Check module identity */
-       ret = ov13b10_identify_module(ov13b);
-       if (ret) {
-               dev_err(&client->dev, "failed to find sensor: %d\n", ret);
-               return ret;
+       full_power = acpi_dev_state_d0(&client->dev);
+       if (full_power) {
+               /* Check module identity */
+               ret = ov13b10_identify_module(ov13b);
+               if (ret) {
+                       dev_err(&client->dev, "failed to find sensor: %d\n", ret);
+                       return ret;
+               }
        }
 
        /* Set default mode to max resolution */
@@ -1431,7 +1447,10 @@ static int ov13b10_probe(struct i2c_client *client)
         * Device is already turned on by i2c-core with ACPI domain PM.
         * Enable runtime PM and turn off the device.
         */
-       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);
 
@@ -1480,6 +1499,7 @@ static struct i2c_driver ov13b10_i2c_driver = {
        },
        .probe_new = ov13b10_probe,
        .remove = ov13b10_remove,
+       .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov13b10_i2c_driver);