[PATCH 3/5] ov5670: Support probe whilst the device is off

[Sakari Ailus]

Tell ACPI device PM code that the driver supports the device being powered
off when the driver's probe function is entered.

Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
---
 drivers/media/i2c/ov5670.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index 041fcbb4eebdf..57e8b92f90e09 100644
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -2444,6 +2444,7 @@ static int ov5670_probe(struct i2c_client *client)
        struct ov5670 *ov5670;
        const char *err_msg;
        u32 input_clk = 0;
+       bool powered_off;
        int ret;
 
        device_property_read_u32(&client->dev, "clock-frequency", &input_clk);
@@ -2460,11 +2461,14 @@ static int ov5670_probe(struct i2c_client *client)
        /* Initialize subdev */
        v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);
 
-       /* Check module identity */
-       ret = ov5670_identify_module(ov5670);
-       if (ret) {
-               err_msg = "ov5670_identify_module() error";
-               goto error_print;
+       powered_off = acpi_dev_powered_off_for_probe(&client->dev);
+       if (!powered_off) {
+               /* Check module identity */
+               ret = ov5670_identify_module(ov5670);
+               if (ret) {
+                       err_msg = "ov5670_identify_module() error";
+                       goto error_print;
+               }
        }
 
        mutex_init(&ov5670->mutex);
@@ -2500,11 +2504,9 @@ static int ov5670_probe(struct i2c_client *client)
 
        ov5670->streaming = false;
 
-       /*
-        * 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);
+       /* Don't set the device's state to active if it's powered off. */
+       if (!powered_off)
+               pm_runtime_set_active(&client->dev);
        pm_runtime_enable(&client->dev);
        pm_runtime_idle(&client->dev);
 
@@ -2546,7 +2548,7 @@ static const struct dev_pm_ops ov5670_pm_ops = {
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id ov5670_acpi_ids[] = {
-       {"INT3479"},
+       { "INT3479" },
        { /* sentinel */ }
 };
 
@@ -2556,6 +2558,7 @@ MODULE_DEVICE_TABLE(acpi, ov5670_acpi_ids);
 static struct i2c_driver ov5670_i2c_driver = {
        .driver = {
                .name = "ov5670",
+               .probe_powered_off = true,
                .pm = &ov5670_pm_ops,
                .acpi_match_table = ACPI_PTR(ov5670_acpi_ids),
        },
-- 
2.11.0