media: ov2740: 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/ov2740.c b/drivers/media/i2c/ov2740.c
index 934c9d65cb097217c596c865ff1e56f34a909377..bab720c7c1de1cf5efb7db1a6347d99afc73fe50 100644 (file)
--- a/drivers/media/i2c/ov2740.c
+++ b/drivers/media/i2c/ov2740.c
@@ -345,6 +345,9 @@ struct ov2740 {
 
        /* NVM data inforamtion */
        struct nvm_data *nvm;
+
+       /* True if the device has been identified */
+       bool identified;
 };
 
 static inline struct ov2740 *to_ov2740(struct v4l2_subdev *subdev)
@@ -440,6 +443,30 @@ static int ov2740_write_reg_list(struct ov2740 *ov2740,
        return 0;
 }
 
+static int ov2740_identify_module(struct ov2740 *ov2740)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&ov2740->sd);
+       int ret;
+       u32 val;
+
+       if (ov2740->identified)
+               return 0;
+
+       ret = ov2740_read_reg(ov2740, OV2740_REG_CHIP_ID, 3, &val);
+       if (ret)
+               return ret;
+
+       if (val != OV2740_CHIP_ID) {
+               dev_err(&client->dev, "chip id mismatch: %x!=%x",
+                       OV2740_CHIP_ID, val);
+               return -ENXIO;
+       }
+
+       ov2740->identified = true;
+
+       return 0;
+}
+
 static int ov2740_update_digital_gain(struct ov2740 *ov2740, u32 d_gain)
 {
        int ret = 0;
@@ -724,6 +751,10 @@ static int ov2740_start_streaming(struct ov2740 *ov2740)
        int link_freq_index;
        int ret = 0;
 
+       ret = ov2740_identify_module(ov2740);
+       if (ret)
+               return ret;
+
        ov2740_load_otp_data(nvm);
 
        link_freq_index = ov2740->cur_mode->link_freq_index;
@@ -956,25 +987,6 @@ static const struct v4l2_subdev_internal_ops ov2740_internal_ops = {
        .open = ov2740_open,
 };
 
-static int ov2740_identify_module(struct ov2740 *ov2740)
-{
-       struct i2c_client *client = v4l2_get_subdevdata(&ov2740->sd);
-       int ret;
-       u32 val;
-
-       ret = ov2740_read_reg(ov2740, OV2740_REG_CHIP_ID, 3, &val);
-       if (ret)
-               return ret;
-
-       if (val != OV2740_CHIP_ID) {
-               dev_err(&client->dev, "chip id mismatch: %x!=%x",
-                       OV2740_CHIP_ID, val);
-               return -ENXIO;
-       }
-
-       return 0;
-}
-
 static int ov2740_check_hwcfg(struct device *dev)
 {
        struct fwnode_handle *ep;
@@ -1137,6 +1149,7 @@ static int ov2740_probe(struct i2c_client *client)
 {
        struct ov2740 *ov2740;
        int ret = 0;
+       bool full_power;
 
        ret = ov2740_check_hwcfg(&client->dev);
        if (ret) {
@@ -1149,6 +1162,15 @@ static int ov2740_probe(struct i2c_client *client)
        if (!ov2740)
                return -ENOMEM;
 
+       full_power = acpi_dev_state_d0(&client->dev);
+       if (full_power) {
+               ret = ov2740_identify_module(ov2740);
+               if (ret) {
+                       dev_err(&client->dev, "failed to find sensor: %d", ret);
+                       return ret;
+               }
+       }
+
        v4l2_i2c_subdev_init(&ov2740->sd, client, &ov2740_subdev_ops);
        ret = ov2740_identify_module(ov2740);
        if (ret) {
@@ -1186,11 +1208,9 @@ static int ov2740_probe(struct i2c_client *client)
        if (ret)
                dev_warn(&client->dev, "register nvmem failed, ret %d\n", ret);
 
-       /*
-        * 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);
 
@@ -1225,6 +1245,7 @@ static struct i2c_driver ov2740_i2c_driver = {
        },
        .probe_new = ov2740_probe,
        .remove = ov2740_remove,
+       .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov2740_i2c_driver);