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. Also do identification on the first access of the device, whether in probe or when starting streaming. Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> --- drivers/media/i2c/ov5670.c | 76 +++++++++++++++++++++++--------------- 1 file changed, 46 insertions(+), 30 deletions(-) diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c index 866c8c2e8f59a..eb0d599f3318b 100644 --- a/drivers/media/i2c/ov5670.c +++ b/drivers/media/i2c/ov5670.c @@ -1832,6 +1832,8 @@ struct ov5670 { /* Streaming on/off */ bool streaming; + /* True if the device has been identified */ + bool identified; }; #define to_ov5670(_sd) container_of(_sd, struct ov5670, sd) @@ -2271,6 +2273,32 @@ static int ov5670_get_skip_frames(struct v4l2_subdev *sd, u32 *frames) return 0; } +/* Verify chip ID */ +static int ov5670_identify_module(struct ov5670 *ov5670) +{ + struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd); + int ret; + u32 val; + + if (ov5670->identified) + return 0; + + ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID, + OV5670_REG_VALUE_24BIT, &val); + if (ret) + return ret; + + if (val != OV5670_CHIP_ID) { + dev_err(&client->dev, "chip id mismatch: %x!=%x\n", + OV5670_CHIP_ID, val); + return -ENXIO; + } + + ov5670->identified = true; + + return 0; +} + /* Prepare streaming by writing default values and customized values */ static int ov5670_start_streaming(struct ov5670 *ov5670) { @@ -2279,6 +2307,10 @@ static int ov5670_start_streaming(struct ov5670 *ov5670) int link_freq_index; int ret; + ret = ov5670_identify_module(ov5670); + if (ret) + return ret; + /* Get out of from software reset */ ret = ov5670_write_reg(ov5670, OV5670_REG_SOFTWARE_RST, OV5670_REG_VALUE_08BIT, OV5670_SOFTWARE_RST); @@ -2400,27 +2432,6 @@ static int __maybe_unused ov5670_resume(struct device *dev) return 0; } -/* Verify chip ID */ -static int ov5670_identify_module(struct ov5670 *ov5670) -{ - struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd); - int ret; - u32 val; - - ret = ov5670_read_reg(ov5670, OV5670_REG_CHIP_ID, - OV5670_REG_VALUE_24BIT, &val); - if (ret) - return ret; - - if (val != OV5670_CHIP_ID) { - dev_err(&client->dev, "chip id mismatch: %x!=%x\n", - OV5670_CHIP_ID, val); - return -ENXIO; - } - - return 0; -} - static const struct v4l2_subdev_video_ops ov5670_video_ops = { .s_stream = ov5670_set_stream, }; @@ -2455,6 +2466,7 @@ 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); @@ -2471,11 +2483,14 @@ 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); @@ -2512,10 +2527,10 @@ 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); @@ -2557,7 +2572,7 @@ static const struct dev_pm_ops ov5670_pm_ops = { #ifdef CONFIG_ACPI static const struct acpi_device_id ov5670_acpi_ids[] = { - {"INT3479"}, + { "INT3479" }, { /* sentinel */ } }; @@ -2572,6 +2587,7 @@ 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