media: ov8856: 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/ov8856.c b/drivers/media/i2c/ov8856.c
index c6c6050..8785764 100644 (file)
--- a/drivers/media/i2c/ov8856.c
+++ b/drivers/media/i2c/ov8856.c
@@ -1445,6 +1445,9 @@ struct ov8856 {
 
        const struct ov8856_lane_cfg *priv_lane;
        u8 modes_size;
+
+       /* True if the device has been identified */
+       bool identified;
 };
 
 struct ov8856_lane_cfg {
@@ -1685,6 +1688,71 @@ static int ov8856_write_reg_list(struct ov8856 *ov8856,
        return 0;
 }
 
+static int ov8856_identify_module(struct ov8856 *ov8856)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
+       int ret;
+       u32 val;
+
+       if (ov8856->identified)
+               return 0;
+
+       ret = ov8856_read_reg(ov8856, OV8856_REG_CHIP_ID,
+                             OV8856_REG_VALUE_24BIT, &val);
+       if (ret)
+               return ret;
+
+       if (val != OV8856_CHIP_ID) {
+               dev_err(&client->dev, "chip id mismatch: %x!=%x",
+                       OV8856_CHIP_ID, val);
+               return -ENXIO;
+       }
+
+       ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
+                              OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
+       if (ret)
+               return ret;
+
+       ret = ov8856_write_reg(ov8856, OV8856_OTP_MODE_CTRL,
+                              OV8856_REG_VALUE_08BIT, OV8856_OTP_MODE_AUTO);
+       if (ret) {
+               dev_err(&client->dev, "failed to set otp mode");
+               return ret;
+       }
+
+       ret = ov8856_write_reg(ov8856, OV8856_OTP_LOAD_CTRL,
+                              OV8856_REG_VALUE_08BIT,
+                              OV8856_OTP_LOAD_CTRL_ENABLE);
+       if (ret) {
+               dev_err(&client->dev, "failed to enable load control");
+               return ret;
+       }
+
+       ret = ov8856_read_reg(ov8856, OV8856_MODULE_REVISION,
+                             OV8856_REG_VALUE_08BIT, &val);
+       if (ret) {
+               dev_err(&client->dev, "failed to read module revision");
+               return ret;
+       }
+
+       dev_info(&client->dev, "OV8856 revision %x (%s) at address 0x%02x\n",
+                val,
+                val == OV8856_2A_MODULE ? "2A" :
+                val == OV8856_1B_MODULE ? "1B" : "unknown revision",
+                client->addr);
+
+       ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
+                              OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY);
+       if (ret) {
+               dev_err(&client->dev, "failed to exit streaming mode");
+               return ret;
+       }
+
+       ov8856->identified = true;
+
+       return 0;
+}
+
 static int ov8856_update_digital_gain(struct ov8856 *ov8856, u32 d_gain)
 {
        int ret;
@@ -1969,6 +2037,10 @@ static int ov8856_start_streaming(struct ov8856 *ov8856)
        const struct ov8856_reg_list *reg_list;
        int link_freq_index, ret;
 
+       ret = ov8856_identify_module(ov8856);
+       if (ret)
+               return ret;
+
        link_freq_index = ov8856->cur_mode->link_freq_index;
        reg_list = &ov8856->priv_lane->link_freq_configs[link_freq_index].reg_list;
 
@@ -2276,65 +2348,6 @@ static const struct v4l2_subdev_internal_ops ov8856_internal_ops = {
        .open = ov8856_open,
 };
 
-static int ov8856_identify_module(struct ov8856 *ov8856)
-{
-       struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
-       int ret;
-       u32 val;
-
-       ret = ov8856_read_reg(ov8856, OV8856_REG_CHIP_ID,
-                             OV8856_REG_VALUE_24BIT, &val);
-       if (ret)
-               return ret;
-
-       if (val != OV8856_CHIP_ID) {
-               dev_err(&client->dev, "chip id mismatch: %x!=%x",
-                       OV8856_CHIP_ID, val);
-               return -ENXIO;
-       }
-
-       ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
-                              OV8856_REG_VALUE_08BIT, OV8856_MODE_STREAMING);
-       if (ret)
-               return ret;
-
-       ret = ov8856_write_reg(ov8856, OV8856_OTP_MODE_CTRL,
-                              OV8856_REG_VALUE_08BIT, OV8856_OTP_MODE_AUTO);
-       if (ret) {
-               dev_err(&client->dev, "failed to set otp mode");
-               return ret;
-       }
-
-       ret = ov8856_write_reg(ov8856, OV8856_OTP_LOAD_CTRL,
-                              OV8856_REG_VALUE_08BIT,
-                              OV8856_OTP_LOAD_CTRL_ENABLE);
-       if (ret) {
-               dev_err(&client->dev, "failed to enable load control");
-               return ret;
-       }
-
-       ret = ov8856_read_reg(ov8856, OV8856_MODULE_REVISION,
-                             OV8856_REG_VALUE_08BIT, &val);
-       if (ret) {
-               dev_err(&client->dev, "failed to read module revision");
-               return ret;
-       }
-
-       dev_info(&client->dev, "OV8856 revision %x (%s) at address 0x%02x\n",
-                val,
-                val == OV8856_2A_MODULE ? "2A" :
-                val == OV8856_1B_MODULE ? "1B" : "unknown revision",
-                client->addr);
-
-       ret = ov8856_write_reg(ov8856, OV8856_REG_MODE_SELECT,
-                              OV8856_REG_VALUE_08BIT, OV8856_MODE_STANDBY);
-       if (ret) {
-               dev_err(&client->dev, "failed to exit streaming mode");
-               return ret;
-       }
-
-       return 0;
-}
 
 static int ov8856_get_hwcfg(struct ov8856 *ov8856, struct device *dev)
 {
@@ -2458,6 +2471,7 @@ static int ov8856_probe(struct i2c_client *client)
 {
        struct ov8856 *ov8856;
        int ret;
+       bool full_power;
 
        ov8856 = devm_kzalloc(&client->dev, sizeof(*ov8856), GFP_KERNEL);
        if (!ov8856)
@@ -2472,16 +2486,19 @@ static int ov8856_probe(struct i2c_client *client)
 
        v4l2_i2c_subdev_init(&ov8856->sd, client, &ov8856_subdev_ops);
 
-       ret = __ov8856_power_on(ov8856);
-       if (ret) {
-               dev_err(&client->dev, "failed to power on\n");
-               return ret;
-       }
+       full_power = acpi_dev_state_d0(&client->dev);
+       if (full_power) {
+               ret = __ov8856_power_on(ov8856);
+               if (ret) {
+                       dev_err(&client->dev, "failed to power on\n");
+                       return ret;
+               }
 
-       ret = ov8856_identify_module(ov8856);
-       if (ret) {
-               dev_err(&client->dev, "failed to find sensor: %d", ret);
-               goto probe_power_off;
+               ret = ov8856_identify_module(ov8856);
+               if (ret) {
+                       dev_err(&client->dev, "failed to find sensor: %d", ret);
+                       goto probe_power_off;
+               }
        }
 
        mutex_init(&ov8856->mutex);
@@ -2511,11 +2528,9 @@ static int ov8856_probe(struct i2c_client *client)
                goto probe_error_media_entity_cleanup;
        }
 
-       /*
-        * 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);
 
@@ -2562,6 +2577,7 @@ static struct i2c_driver ov8856_i2c_driver = {
        },
        .probe_new = ov8856_probe,
        .remove = ov8856_remove,
+       .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
 };
 
 module_i2c_driver(ov8856_i2c_driver);