[PATCH v5 3/6] ov5670: Support probe whilst the device is in a low power state

Sakari Ailus
2020-08-10T14:24:49Z

Tell ACPI device PM code that the driver supports the device being in a
low power state when the driver's probe function is entered.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/media/i2c/ov5670.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index f26252e35e08d..1f75b888d2a18 100644
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -2456,6 +2456,7 @@ static int ov5670_probe(struct i2c_client *client)
struct ov5670 *ov5670;
const char *err_msg;
u32 input_clk = 0;
+ bool low_power;
int ret;

device_property_read_u32(&client->dev, "clock-frequency", &input_clk);
@@ -2472,11 +2473,14 @@ 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;
+ low_power = acpi_dev_state_low_power(&client->dev);
+ if (!low_power) {
+ /* Check module identity */
+ ret = ov5670_identify_module(ov5670);
+ if (ret) {
+ err_msg = "ov5670_identify_module() error";
+ goto error_print;
+ }
}

mutex_init(&ov5670->mutex);
@@ -2513,10 +2517,10 @@ 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.
+ * Don't set the device's state to active if it's in a low power state.
*/
- pm_runtime_set_active(&client->dev);
+ if (!low_power)
+ pm_runtime_set_active(&client->dev);
pm_runtime_enable(&client->dev);
pm_runtime_idle(&client->dev);

@@ -2558,7 +2562,7 @@ static const struct dev_pm_ops ov5670_pm_ops = {

#ifdef CONFIG_ACPI
static const struct acpi_device_id ov5670_acpi_ids[] = {
- {"INT3479"},
+ { "INT3479" },
{ /* sentinel */ }
};

@@ -2573,6 +2577,7 @@ static struct i2c_driver ov5670_i2c_driver = {
},
.probe_new = ov5670_probe,
.remove = ov5670_remove,
+ .flags = I2C_DRV_FL_ALLOW_LOW_POWER_PROBE,
};

module_i2c_driver(ov5670_i2c_driver);
--
2.20.1