Hi Bingbu,
On Tue, Nov 09, 2021 at 04:48:33PM +0800, Bingbu Cao wrote:
> 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@xxxxxxxxx>
> ---
> drivers/media/i2c/imx208.c | 77 +++++++++++++++++++++++++++++-----------------
> 1 file changed, 48 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/media/i2c/imx208.c b/drivers/media/i2c/imx208.c
> index 6f3d9c1b5879..b9f6d5f33b58 100644
> --- a/drivers/media/i2c/imx208.c
> +++ b/drivers/media/i2c/imx208.c
> @@ -296,6 +296,9 @@ struct imx208 {
> /* OTP data */
> bool otp_read;
> char otp_data[IMX208_OTP_SIZE];
> +
> + /* True if the device has been identified */
> + bool identified;
> };
>
> static inline struct imx208 *to_imx208(struct v4l2_subdev *_sd)
> @@ -619,6 +622,34 @@ static int imx208_set_pad_format(struct v4l2_subdev *sd,
> return 0;
> }
>
> +static int imx208_identify_module(struct imx208 *imx208)
> +{
> + struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
> + int ret;
> + u32 val;
> +
> + if (imx208->identified)
> + return 0;
Otp access requires this as well.
How about adding a runtime PM resume callback for this?
I guess it'd be better for the rest, too. Up to you.
> +
> + ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
> + 2, &val);
> + if (ret) {
> + dev_err(&client->dev, "failed to read chip id %x\n",
> + IMX208_CHIP_ID);
> + return ret;
> + }
> +
> + if (val != IMX208_CHIP_ID) {
> + dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
> + IMX208_CHIP_ID, val);
> + return -EIO;
> + }
> +
> + imx208->identified = true;
> +
> + return 0;
> +}
> +
> /* Start streaming */
> static int imx208_start_streaming(struct imx208 *imx208)
> {
> @@ -626,6 +657,10 @@ static int imx208_start_streaming(struct imx208 *imx208)
> const struct imx208_reg_list *reg_list;
> int ret, link_freq_index;
>
> + ret = imx208_identify_module(imx208);
> + if (ret)
> + return ret;
> +
> /* Setup PLL */
> link_freq_index = imx208->cur_mode->link_freq_index;
> reg_list = &link_freq_configs[link_freq_index].reg_list;
> @@ -752,29 +787,6 @@ static int __maybe_unused imx208_resume(struct device *dev)
> }
>
> /* Verify chip ID */
> -static int imx208_identify_module(struct imx208 *imx208)
> -{
> - struct i2c_client *client = v4l2_get_subdevdata(&imx208->sd);
> - int ret;
> - u32 val;
> -
> - ret = imx208_read_reg(imx208, IMX208_REG_CHIP_ID,
> - 2, &val);
> - if (ret) {
> - dev_err(&client->dev, "failed to read chip id %x\n",
> - IMX208_CHIP_ID);
> - return ret;
> - }
> -
> - if (val != IMX208_CHIP_ID) {
> - dev_err(&client->dev, "chip id mismatch: %x!=%x\n",
> - IMX208_CHIP_ID, val);
> - return -EIO;
> - }
> -
> - return 0;
> -}
> -
> static const struct v4l2_subdev_video_ops imx208_video_ops = {
> .s_stream = imx208_set_stream,
> };
> @@ -961,6 +973,7 @@ static int imx208_probe(struct i2c_client *client)
> {
> struct imx208 *imx208;
> int ret;
> + bool full_power;
> u32 val = 0;
>
> device_property_read_u32(&client->dev, "clock-frequency", &val);
> @@ -978,11 +991,14 @@ static int imx208_probe(struct i2c_client *client)
> /* Initialize subdev */
> v4l2_i2c_subdev_init(&imx208->sd, client, &imx208_subdev_ops);
>
> - /* Check module identity */
> - ret = imx208_identify_module(imx208);
> - if (ret) {
> - dev_err(&client->dev, "failed to find sensor: %d", ret);
> - goto error_probe;
> + full_power = acpi_dev_state_d0(&client->dev);
> + if (full_power) {
> + /* Check module identity */
> + ret = imx208_identify_module(imx208);
> + if (ret) {
> + dev_err(&client->dev, "failed to find sensor: %d", ret);
> + goto error_probe;
> + }
> }
>
> /* Set default mode to max resolution */
> @@ -1017,7 +1033,9 @@ static int imx208_probe(struct i2c_client *client)
> goto error_async_subdev;
> }
>
> - 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);
>
> @@ -1077,6 +1095,7 @@ static struct i2c_driver imx208_i2c_driver = {
> },
> .probe_new = imx208_probe,
> .remove = imx208_remove,
> + .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
> };
>
> module_i2c_driver(imx208_i2c_driver);
--
Regards,
Sakari Ailus
