When the sensor subdev registers and the ISC notifier completes, the scaler entity which was initialized at isc_probe() time is linked in between the ISC and the image sensor immutably. I think it is fine for now, but I wonder if you plan to plumb more components between the ISC video node and the sensor, if it's not worth changing the DT bindings and their parsing logic to separate the CSI-2 receiver from the ISC, whcih can create its media graph at probe time and have the CSI-2 receiver entity as downstream remote. I think I need to get to know the ISC better to really have an idea. For now, this seems ok to me, but please check with maintainers if this is fine with them. > + > diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h > index 5fbf52a9080b..c9234c90ae58 100644 > --- a/drivers/media/platform/atmel/atmel-isc.h > +++ b/drivers/media/platform/atmel/atmel-isc.h > @@ -183,6 +183,17 @@ struct isc_reg_offsets { > u32 his_entry; > }; > > +enum isc_mc_pads { > + ISC_PAD_SINK = 0, > + ISC_PADS_NUM = 1, > +}; > + > +enum isc_scaler_pads { > + ISC_SCALER_PAD_SINK = 0, > + ISC_SCALER_PAD_SOURCE = 1, > + ISC_SCALER_PADS_NUM = 2, > +}; > + > /* > * struct isc_device - ISC device driver data/config struct > * @regmap: Register map > @@ -257,6 +268,12 @@ struct isc_reg_offsets { > * be used as an input to the controller > * @controller_formats_size: size of controller_formats array > * @formats_list_size: size of formats_list array > + * @pads: media controller pads for isc video entity > + * @mdev: media device that is registered by the isc > + * @remote_pad: remote pad on the connected subdevice > + * @scaler_sd: subdevice for the scaler that isc registers > + * @scaler_pads: media controller pads for the scaler subdevice > + * @scaler_format: current format for the scaler subdevice > */ > struct isc_device { > struct regmap *regmap; > @@ -344,6 +361,19 @@ struct isc_device { > struct isc_format *formats_list; > u32 controller_formats_size; > u32 formats_list_size; > + > + struct { > + struct media_pad pads[ISC_PADS_NUM]; > + struct media_device mdev; > + > + u32 remote_pad; > + }; > + > + struct { > + struct v4l2_subdev scaler_sd; > + struct media_pad scaler_pads[ISC_SCALER_PADS_NUM]; > + struct v4l2_mbus_framefmt scaler_format; > + }; > }; > > extern const struct regmap_config isc_regmap_config; > @@ -355,4 +385,11 @@ int isc_clk_init(struct isc_device *isc); > void isc_subdev_cleanup(struct isc_device *isc); > void isc_clk_cleanup(struct isc_device *isc); > > +int isc_scaler_link(struct isc_device *isc); > +int isc_scaler_init(struct isc_device *isc); > +int isc_mc_init(struct isc_device *isc, u32 ver); > +void isc_mc_cleanup(struct isc_device *isc); > + > +struct isc_format *isc_find_format_by_code(struct isc_device *isc, > + unsigned int code, int *index); > #endif > diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c > index c5b9563e36cb..c244682ea22f 100644 > --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c > +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c > @@ -553,6 +553,12 @@ static int atmel_isc_probe(struct platform_device *pdev) > break; > } > > + regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver); I am surprised you can read a register before runtime_pm is intialized! Thanks j > + > + ret = isc_mc_init(isc, ver); > + if (ret < 0) > + goto isc_probe_mc_init_err; > + > pm_runtime_set_active(dev); > pm_runtime_enable(dev); > pm_request_idle(dev); > @@ -562,7 +568,7 @@ static int atmel_isc_probe(struct platform_device *pdev) > ret = clk_prepare_enable(isc->ispck); > if (ret) { > dev_err(dev, "failed to enable ispck: %d\n", ret); > - goto cleanup_subdev; > + goto isc_probe_mc_init_err; > } > > /* ispck should be greater or equal to hclock */ > @@ -572,7 +578,6 @@ static int atmel_isc_probe(struct platform_device *pdev) > goto unprepare_clk; > } > > - regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver); > dev_info(dev, "Microchip ISC version %x\n", ver); > > return 0; > @@ -580,6 +585,9 @@ static int atmel_isc_probe(struct platform_device *pdev) > unprepare_clk: > clk_disable_unprepare(isc->ispck); > > +isc_probe_mc_init_err: > + isc_mc_cleanup(isc); > + > cleanup_subdev: > isc_subdev_cleanup(isc); > > @@ -600,6 +608,8 @@ static int atmel_isc_remove(struct platform_device *pdev) > > pm_runtime_disable(&pdev->dev); > > + isc_mc_cleanup(isc); > + > isc_subdev_cleanup(isc); > > v4l2_device_unregister(&isc->v4l2_dev); > diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c > index 07a80b08bc54..9dc75eed0098 100644 > --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c > +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c > @@ -547,15 +547,23 @@ static int microchip_xisc_probe(struct platform_device *pdev) > break; > } > > + regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver); > + > + ret = isc_mc_init(isc, ver); > + if (ret < 0) > + goto isc_probe_mc_init_err; > + > pm_runtime_set_active(dev); > pm_runtime_enable(dev); > pm_request_idle(dev); > > - regmap_read(isc->regmap, ISC_VERSION + isc->offsets.version, &ver); > dev_info(dev, "Microchip XISC version %x\n", ver); > > return 0; > > +isc_probe_mc_init_err: > + isc_mc_cleanup(isc); > + > cleanup_subdev: > isc_subdev_cleanup(isc); > > @@ -576,6 +584,8 @@ static int microchip_xisc_remove(struct platform_device *pdev) > > pm_runtime_disable(&pdev->dev); > > + isc_mc_cleanup(isc); > + > isc_subdev_cleanup(isc); > > v4l2_device_unregister(&isc->v4l2_dev); > -- > 2.25.1 >