Re: [PATCH v3 8/8] media: qcom: camss: Decouple VFE from CSID

[Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>]

On 4/11/24 15:45, Gjorgji Rosikopulos wrote:
> From: Milen Mitkov <quic_mmitkov@xxxxxxxxxxx>
>
> Decouple the direct calls to VFE's vfe_get/put in the CSID subdev
> in order to prepare for the introduction of IFE subdev.
>
> Also decouple CSID base address from VFE since on the Titan platform
> CSID register base address resides within VFE's base address.
>
> Signed-off-by: Milen Mitkov <quic_mmitkov@xxxxxxxxxxx>
> Signed-off-by: Gjorgji Rosikopulos <quic_grosikop@xxxxxxxxxxx>
> ---
>   .../media/platform/qcom/camss/camss-csid.c    | 16 +++--
>   .../media/platform/qcom/camss/camss-csid.h    |  1 +
>   drivers/media/platform/qcom/camss/camss.c     | 69 +++++++++++++++++++
>   drivers/media/platform/qcom/camss/camss.h     |  8 +++
>   4 files changed, 89 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/camss/camss-csid.c b/drivers/media/platform/qcom/camss/camss-csid.c
> index 5b23f5b8746d..858db5d4ca75 100644
> --- a/drivers/media/platform/qcom/camss/camss-csid.c
> +++ b/drivers/media/platform/qcom/camss/camss-csid.c
> @@ -602,7 +602,6 @@ static int csid_set_power(struct v4l2_subdev *sd, int on)
>   	struct csid_device *csid = v4l2_get_subdevdata(sd);
>   	struct camss *camss = csid->camss;
>   	struct device *dev = camss->dev;
> -	struct vfe_device *vfe = &camss->vfe[csid->id];
>   	int ret = 0;
>   
>   	if (on) {
> @@ -611,7 +610,7 @@ static int csid_set_power(struct v4l2_subdev *sd, int on)
>   		 * switching on the CSID. Do so unconditionally, as there is no
>   		 * drawback in following the same powering order on older SoCs.
>   		 */
> -		ret = vfe_get(vfe);
> +		ret = csid->res->parent_dev_ops->get(camss, csid->id);
>   		if (ret < 0)
>   			return ret;
>   
> @@ -663,7 +662,7 @@ static int csid_set_power(struct v4l2_subdev *sd, int on)
>   		regulator_bulk_disable(csid->num_supplies,
>   				       csid->supplies);
>   		pm_runtime_put_sync(dev);
> -		vfe_put(vfe);
> +		csid->res->parent_dev_ops->put(camss, csid->id);
>   	}
>   
>   	return ret;
> @@ -1021,6 +1020,11 @@ int msm_csid_subdev_init(struct camss *camss, struct csid_device *csid,
>   	csid->id = id;
>   	csid->res = &res->csid;
>   
> +	if (dev_WARN_ONCE(dev, !csid->res->parent_dev_ops,

Please remove/replace dev_WARN_ONCE() to a lesser dev_warn_once(), wherever it's
possible please do not use/introduce WARN() type of writes to the kernel log buffer...

> +			  "Error: CSID depends on VFE/IFE device ops!\n")) {
> +		return -EINVAL;
> +	}
> +
>   	csid->res->hw_ops->subdev_init(csid);
>   
>   	/* Memory */
> @@ -1031,9 +1035,11 @@ int msm_csid_subdev_init(struct camss *camss, struct csid_device *csid,
>   		 * VFE to be initialized before CSID
>   		 */
>   		if (id >= 2) /* VFE/CSID lite */
> -			csid->base = camss->vfe[id].base + VFE_480_LITE_CSID_OFFSET;
> +			csid->base = csid->res->parent_dev_ops->get_base_address(camss, id)
> +				+ VFE_480_LITE_CSID_OFFSET;
>   		else
> -			csid->base = camss->vfe[id].base + VFE_480_CSID_OFFSET;
> +			csid->base = csid->res->parent_dev_ops->get_base_address(camss, id)
> +				 + VFE_480_CSID_OFFSET;
>   	} else {
>   		csid->base = devm_platform_ioremap_resource_byname(pdev, res->reg[0]);
>   		if (IS_ERR(csid->base))
> diff --git a/drivers/media/platform/qcom/camss/camss-csid.h b/drivers/media/platform/qcom/camss/camss-csid.h
> index 0e385d17c250..8cdae98e4dca 100644
> --- a/drivers/media/platform/qcom/camss/camss-csid.h
> +++ b/drivers/media/platform/qcom/camss/camss-csid.h
> @@ -157,6 +157,7 @@ struct csid_hw_ops {
>   struct csid_subdev_resources {
>   	bool is_lite;
>   	const struct csid_hw_ops *hw_ops;
> +	const struct parent_dev_ops *parent_dev_ops;
>   	const struct csid_formats *formats;
>   };
>   
> diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
> index 37060eaa0ba5..4d625ef59cf7 100644
> --- a/drivers/media/platform/qcom/camss/camss.c
> +++ b/drivers/media/platform/qcom/camss/camss.c
> @@ -32,6 +32,8 @@
>   #define CAMSS_CLOCK_MARGIN_NUMERATOR 105
>   #define CAMSS_CLOCK_MARGIN_DENOMINATOR 100
>   
> +static const struct parent_dev_ops vfe_parent_dev_ops;
> +
>   static const struct camss_subdev_resources csiphy_res_8x16[] = {
>   	/* CSIPHY0 */
>   	{
> @@ -87,6 +89,7 @@ static const struct camss_subdev_resources csid_res_8x16[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_1,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_1
>   		}
>   	},
> @@ -109,6 +112,7 @@ static const struct camss_subdev_resources csid_res_8x16[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_1,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_1
>   		}
>   	},
> @@ -226,6 +230,7 @@ static const struct camss_subdev_resources csid_res_8x96[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -248,6 +253,7 @@ static const struct camss_subdev_resources csid_res_8x96[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -270,6 +276,7 @@ static const struct camss_subdev_resources csid_res_8x96[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -292,6 +299,7 @@ static const struct camss_subdev_resources csid_res_8x96[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	}
> @@ -445,6 +453,7 @@ static const struct camss_subdev_resources csid_res_660[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -470,6 +479,7 @@ static const struct camss_subdev_resources csid_res_660[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -495,6 +505,7 @@ static const struct camss_subdev_resources csid_res_660[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	},
> @@ -520,6 +531,7 @@ static const struct camss_subdev_resources csid_res_660[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_4_7,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_4_7
>   		}
>   	}
> @@ -714,6 +726,7 @@ static const struct camss_subdev_resources csid_res_845[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -739,6 +752,7 @@ static const struct camss_subdev_resources csid_res_845[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -765,6 +779,7 @@ static const struct camss_subdev_resources csid_res_845[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	}
> @@ -957,6 +972,7 @@ static const struct camss_subdev_resources csid_res_8250[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -974,6 +990,7 @@ static const struct camss_subdev_resources csid_res_8250[] = {
>   		.type = CAMSS_SUBDEV_TYPE_CSID,
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -991,6 +1008,7 @@ static const struct camss_subdev_resources csid_res_8250[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1008,6 +1026,7 @@ static const struct camss_subdev_resources csid_res_8250[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	}
> @@ -1212,6 +1231,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.interrupt = { "csid0" },
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1227,6 +1247,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.interrupt = { "csid1" },
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1242,6 +1263,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.interrupt = { "csid2" },
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1257,6 +1279,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.interrupt = { "csid3" },
>   		.csid = {
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1272,6 +1295,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1287,6 +1311,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1302,6 +1327,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	},
> @@ -1317,6 +1343,7 @@ static const struct camss_subdev_resources csid_res_sc8280xp[] = {
>   		.csid = {
>   			.is_lite = true,
>   			.hw_ops = &csid_ops_gen2,
> +			.parent_dev_ops = &vfe_parent_dev_ops,
>   			.formats = &csid_formats_gen2
>   		}
>   	}
> @@ -1661,6 +1688,48 @@ void camss_pm_domain_off(struct camss *camss, int id)
>   	}
>   }
>   
> +static int vfe_parent_dev_ops_get(struct camss *camss, int id)
> +{
> +	int ret = -EINVAL;
> +
> +	if (id < camss->res->vfe_num) {


if (id >= camss->res->vfe_num)
    return -EINVAL;

> +		struct vfe_device *vfe = &camss->vfe[id];
> +
> +		ret = vfe_get(vfe);
> +	}
> +
> +	return ret;
> +}
> +
> +static int vfe_parent_dev_ops_put(struct camss *camss, int id)
> +{
> +	if (id < camss->res->vfe_num) {
> +		struct vfe_device *vfe = &camss->vfe[id];
> +
> +		vfe_put(vfe);
> +	}
> +
> +	return 0;
> +}
> +
> +static void __iomem
> +*vfe_parent_dev_ops_get_base_address(struct camss *camss, int id)
> +{
> +	if (id < camss->res->vfe_num) {
> +		struct vfe_device *vfe = &camss->vfe[id];
> +
> +		return vfe->base;
> +	}
> +
> +	return NULL;

I can find code snippets above like

	if (IS_ERR(csid->base))
		...

So, is it really a good idea to return NULL on error? Probably it might be better
to return a reasonable error to the caller.

> +}
> +
> +static const struct parent_dev_ops vfe_parent_dev_ops = {
> +	.get = vfe_parent_dev_ops_get,
> +	.put = vfe_parent_dev_ops_put,
> +	.get_base_address = vfe_parent_dev_ops_get_base_address
> +};
> +
>   /*
>    * camss_of_parse_endpoint_node - Parse port endpoint node
>    * @dev: Device
> diff --git a/drivers/media/platform/qcom/camss/camss.h b/drivers/media/platform/qcom/camss/camss.h
> index a5be9e872992..b3c967bcf8a9 100644
> --- a/drivers/media/platform/qcom/camss/camss.h
> +++ b/drivers/media/platform/qcom/camss/camss.h
> @@ -143,6 +143,12 @@ struct camss_clock {
>   	u32 nfreqs;
>   };
>   
> +struct parent_dev_ops {
> +	int (*get)(struct camss *camss, int id);
> +	int (*put)(struct camss *camss, int id);
> +	void __iomem *(*get_base_address)(struct camss *camss, int id);
> +};
> +
>   void camss_add_clock_margin(u64 *rate);
>   int camss_enable_clocks(int nclocks, struct camss_clock *clock,
>   			struct device *dev);
> @@ -153,6 +159,8 @@ s64 camss_get_link_freq(struct media_entity *entity, unsigned int bpp,
>   int camss_get_pixel_clock(struct media_entity *entity, u64 *pixel_clock);
>   int camss_pm_domain_on(struct camss *camss, int id);
>   void camss_pm_domain_off(struct camss *camss, int id);
> +int camss_vfe_get(struct camss *camss, int id);
> +void camss_vfe_put(struct camss *camss, int id);
>   void camss_delete(struct camss *camss);
>   
>   #endif /* QC_MSM_CAMSS_H */

--
Best wishes,
Vladimir