Message-ID: <19b7809a-db43-4134-bd81-2ace25907035@gmx.de>
Date: Fri, 2 May 2025 04:50:28 +0200
From: Armin Wolf <W_Armin@....de>
To: Pratap Nirujogi <pratap.nirujogi@....com>, ilpo.jarvinen@...ux.intel.com,
 hdegoede@...hat.com, mario.limonciello@....com
Cc: platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
 benjamin.chan@....com, bin.du@....com, gjorgji.rosikopulos@....com,
 king.li@....com, dantony@....com
Subject: Re: [PATCH v8] platform/x86: Add AMD ISP platform config for OV05C10

Am 30.04.25 um 19:11 schrieb Pratap Nirujogi:

> ISP device specific configuration is not available in ACPI. Add
> swnode graph to configure the missing device properties for the
> OV05C10 camera device supported on amdisp platform.
>
> Add support to create i2c-client dynamically when amdisp i2c
> adapter is available.
>
> Co-developed-by: Benjamin Chan <benjamin.chan@....com>
> Signed-off-by: Benjamin Chan <benjamin.chan@....com>
> Reviewed-by: Mario Limonciello <mario.limonciello@....com>
> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@....com>
> ---
> Changes v7 -> v8:
>
> * Create I2C client instance incase AMD ISP I2C device is registered
> prior to bus notifier registration.
> * Remove unused and duplicate variables in 'struct amdisp_platform'.
> * Remove global variable 'struct amdisp_platform amdisp_ov05c10_platform_config'.
> * Remove dependency on CONFIG_AMD_ISP4.
> * Call software_node_unregister_node_group() incase of amd_isp_probe() failures
> after prepare_amdisp_platform().
>
>   drivers/platform/x86/amd/Kconfig    |  11 ++
>   drivers/platform/x86/amd/Makefile   |   1 +
>   drivers/platform/x86/amd/amd_isp4.c | 275 ++++++++++++++++++++++++++++
>   3 files changed, 287 insertions(+)
>   create mode 100644 drivers/platform/x86/amd/amd_isp4.c
>
> diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig
> index c3e086ea64fc..152a68a470e8 100644
> --- a/drivers/platform/x86/amd/Kconfig
> +++ b/drivers/platform/x86/amd/Kconfig
> @@ -32,3 +32,14 @@ config AMD_WBRF
>   
>   	  This mechanism will only be activated on platforms that advertise a
>   	  need for it.
> +
> +config AMD_ISP_PLATFORM
> +	tristate "AMD ISP4 platform driver"
> +	depends on I2C && X86_64 && ACPI
> +	help
> +	  Platform driver for AMD platforms containing image signal processor
> +	  gen 4. Provides camera sensor module board information to allow
> +	  sensor and V4L drivers to work properly.
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called amd_isp4.
> diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile
> index c6c40bdcbded..b0e284b5d497 100644
> --- a/drivers/platform/x86/amd/Makefile
> +++ b/drivers/platform/x86/amd/Makefile
> @@ -10,3 +10,4 @@ obj-$(CONFIG_AMD_PMC)		+= pmc/
>   obj-$(CONFIG_AMD_HSMP)		+= hsmp/
>   obj-$(CONFIG_AMD_PMF)		+= pmf/
>   obj-$(CONFIG_AMD_WBRF)		+= wbrf.o
> +obj-$(CONFIG_AMD_ISP_PLATFORM)	+= amd_isp4.o
> diff --git a/drivers/platform/x86/amd/amd_isp4.c b/drivers/platform/x86/amd/amd_isp4.c
> new file mode 100644
> index 000000000000..6164915d8426
> --- /dev/null
> +++ b/drivers/platform/x86/amd/amd_isp4.c
> @@ -0,0 +1,275 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AMD ISP platform driver for sensor i2-client instantiation
> + *
> + * Copyright 2025 Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/units.h>
> +
> +#define AMDISP_OV05C10_I2C_ADDR		0x10
> +#define AMDISP_OV05C10_PLAT_NAME	"amdisp_ov05c10_platform"
> +#define AMDISP_OV05C10_HID		"OMNI5C10"
> +#define AMDISP_OV05C10_REMOTE_EP_NAME	"ov05c10_isp_4_1_1"
> +#define AMD_ISP_PLAT_DRV_NAME		"amd-isp4"
> +
> +/*
> + * AMD ISP platform definition to configure the device properties
> + * missing in the ACPI table.
> + */
> +struct amdisp_platform {
> +	struct i2c_board_info board_info;
> +	struct notifier_block i2c_nb;
> +	struct i2c_client *i2c_dev;
> +};
> +
> +/* Top-level OV05C10 camera node property table */
> +static const struct property_entry ov05c10_camera_props[] = {
> +	PROPERTY_ENTRY_U32("clock-frequency", 24 * HZ_PER_MHZ),
> +	{ }
> +};
> +
> +/* Root AMD ISP OV05C10 camera node definition */
> +static const struct software_node camera_node = {
> +	.name = AMDISP_OV05C10_HID,
> +	.properties = ov05c10_camera_props,
> +};
> +
> +/*
> + * AMD ISP OV05C10 Ports node definition. No properties defined for
> + * ports node for OV05C10.
> + */
> +static const struct software_node ports = {
> +	.name = "ports",
> +	.parent = &camera_node,
> +};
> +
> +/*
> + * AMD ISP OV05C10 Port node definition. No properties defined for
> + * port node for OV05C10.
> + */
> +static const struct software_node port_node = {
> +	.name = "port@",
> +	.parent = &ports,
> +};
> +
> +/*
> + * Remote endpoint AMD ISP node definition. No properties defined for
> + * remote endpoint node for OV05C10.
> + */
> +static const struct software_node remote_ep_isp_node = {
> +	.name = AMDISP_OV05C10_REMOTE_EP_NAME,
> +};
> +
> +/*
> + * Remote endpoint reference for isp node included in the
> + * OV05C10 endpoint.
> + */
> +static const struct software_node_ref_args ov05c10_refs[] = {
> +	SOFTWARE_NODE_REFERENCE(&remote_ep_isp_node),
> +};
> +
> +/* OV05C supports one single link frequency */
> +static const u64 ov05c10_link_freqs[] = {
> +	925 * HZ_PER_MHZ,
> +};
> +
> +/* OV05C supports only 2-lane configuration */
> +static const u32 ov05c10_data_lanes[] = {
> +	1,
> +	2,
> +};
> +
> +/* OV05C10 endpoint node properties table */
> +static const struct property_entry ov05c10_endpoint_props[] = {
> +	PROPERTY_ENTRY_U32("bus-type", 4),
> +	PROPERTY_ENTRY_U32_ARRAY_LEN("data-lanes", ov05c10_data_lanes,
> +				     ARRAY_SIZE(ov05c10_data_lanes)),
> +	PROPERTY_ENTRY_U64_ARRAY_LEN("link-frequencies", ov05c10_link_freqs,
> +				     ARRAY_SIZE(ov05c10_link_freqs)),
> +	PROPERTY_ENTRY_REF_ARRAY("remote-endpoint", ov05c10_refs),
> +	{ }
> +};
> +
> +/* AMD ISP endpoint node definition */
> +static const struct software_node endpoint_node = {
> +	.name = "endpoint",
> +	.parent = &port_node,
> +	.properties = ov05c10_endpoint_props,
> +};
> +
> +/*
> + * AMD ISP swnode graph uses 5 nodes and also its relationship is
> + * fixed to align with the structure that v4l2 expects for successful
> + * endpoint fwnode parsing.
> + *
> + * It is only the node property_entries that will vary for each platform
> + * supporting different sensor modules.
> + */
> +#define NUM_SW_NODES 5
> +
> +static const struct software_node *ov05c10_nodes[NUM_SW_NODES + 1] = {
> +	&camera_node,
> +	&ports,
> +	&port_node,
> +	&endpoint_node,
> +	&remote_ep_isp_node,
> +	NULL
> +};
> +
> +static const struct acpi_device_id amdisp_sensor_ids[] = {
> +	{ AMDISP_OV05C10_HID },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, amdisp_sensor_ids);
> +
> +static inline bool is_isp_i2c_adapter(struct i2c_adapter *adap)
> +{
> +	return !strcmp(adap->owner->name, "i2c_designware_amdisp");
> +}
> +
> +static void instantiate_isp_i2c_client(struct amdisp_platform *ov05c10, struct i2c_adapter *adap)
> +{
> +	struct i2c_board_info *info = &ov05c10->board_info;
> +	struct i2c_client *i2c_dev;
> +
> +	if (ov05c10->i2c_dev)
> +		return;

Since this function can be called by the bus notifier and i2c_for_each_dev() you need to protect
the i2c client registration and the assignment of ov05c10->i2c_dev with a mutex.

Thanks,
Armin Wolf

> +
> +	if (!info->addr) {
> +		dev_err(&adap->dev, "invalid i2c_addr 0x%x detected\n", info->addr);
> +		return;
> +	}
> +
> +	i2c_dev = i2c_new_client_device(adap, info);
> +	if (IS_ERR(i2c_dev)) {
> +		dev_err(&adap->dev, "error %pe registering isp i2c_client\n", i2c_dev);
> +		return;
> +	}
> +	ov05c10->i2c_dev = i2c_dev;
> +}
> +
> +static int isp_i2c_bus_notify(struct notifier_block *nb,
> +			      unsigned long action, void *data)
> +{
> +	struct amdisp_platform *ov05c10 = container_of(nb, struct amdisp_platform, i2c_nb);
> +	struct device *dev = data;
> +	struct i2c_client *client;
> +	struct i2c_adapter *adap;
> +
> +	switch (action) {
> +	case BUS_NOTIFY_ADD_DEVICE:
> +		adap = i2c_verify_adapter(dev);
> +		if (!adap)
> +			break;
> +		if (is_isp_i2c_adapter(adap))
> +			instantiate_isp_i2c_client(ov05c10, adap);
> +		break;
> +	case BUS_NOTIFY_REMOVED_DEVICE:
> +		client = i2c_verify_client(dev);
> +		if (!client)
> +			break;
> +		if (ov05c10->i2c_dev == client) {
> +			dev_dbg(&client->adapter->dev, "amdisp i2c_client removed\n");
> +			ov05c10->i2c_dev = NULL;
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return NOTIFY_DONE;
> +}
> +
> +static struct amdisp_platform *prepare_amdisp_platform(struct device *dev)
> +{
> +	struct amdisp_platform *isp_ov05c10;
> +	int ret;
> +
> +	isp_ov05c10 = devm_kzalloc(dev, sizeof(*isp_ov05c10), GFP_KERNEL);
> +	if (!isp_ov05c10)
> +		return ERR_PTR(-ENOMEM);
> +
> +	isp_ov05c10->board_info.dev_name = "ov05c10";
> +	strscpy(isp_ov05c10->board_info.type, "ov05c10", I2C_NAME_SIZE);
> +	isp_ov05c10->board_info.addr = AMDISP_OV05C10_I2C_ADDR;
> +
> +	ret = software_node_register_node_group(ov05c10_nodes);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	isp_ov05c10->board_info.swnode = ov05c10_nodes[0];
> +
> +	return isp_ov05c10;
> +}
> +
> +static int try_to_instantiate_i2c_client(struct device *dev, void *data)
> +{
> +	struct amdisp_platform *ov05c10 = (struct amdisp_platform *)data;
> +	struct i2c_adapter *adap = i2c_verify_adapter(dev);
> +
> +	if (!ov05c10 || !adap)
> +		return 0;
> +	if (!adap->owner)
> +		return 0;
> +
> +	if (is_isp_i2c_adapter(adap))
> +		instantiate_isp_i2c_client(ov05c10, adap);
> +
> +	return 0;
> +}
> +
> +static int amd_isp_probe(struct platform_device *pdev)
> +{
> +	struct amdisp_platform *ov05c10;
> +	int ret;
> +
> +	ov05c10 = prepare_amdisp_platform(&pdev->dev);
> +	if (IS_ERR(ov05c10))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(ov05c10),
> +				     "failed to prepare AMD ISP platform fwnode\n");
> +
> +	ov05c10->i2c_nb.notifier_call = isp_i2c_bus_notify;
> +	ret = bus_register_notifier(&i2c_bus_type, &ov05c10->i2c_nb);
> +	if (ret)
> +		goto error_unregister_sw_node;
> +
> +	/* check if adapter is already registered and create i2c client instance */
> +	i2c_for_each_dev((void *)ov05c10, try_to_instantiate_i2c_client);
> +
> +	platform_set_drvdata(pdev, ov05c10);
> +	return 0;
> +
> +error_unregister_sw_node:
> +	software_node_unregister_node_group(ov05c10_nodes);
> +	return ret;
> +}
> +
> +static void amd_isp_remove(struct platform_device *pdev)
> +{
> +	struct amdisp_platform *ov05c10 = platform_get_drvdata(pdev);
> +
> +	bus_unregister_notifier(&i2c_bus_type, &ov05c10->i2c_nb);
> +	i2c_unregister_device(ov05c10->i2c_dev);
> +	software_node_unregister_node_group(ov05c10_nodes);
> +}
> +
> +static struct platform_driver amd_isp_platform_driver = {
> +	.driver	= {
> +		.name			= AMD_ISP_PLAT_DRV_NAME,
> +		.acpi_match_table	= amdisp_sensor_ids,
> +	},
> +	.probe	= amd_isp_probe,
> +	.remove	= amd_isp_remove,
> +};
> +
> +module_platform_driver(amd_isp_platform_driver);
> +
> +MODULE_AUTHOR("Benjamin Chan <benjamin.chan@....com>");
> +MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@....com>");
> +MODULE_DESCRIPTION("AMD ISP4 Platform Driver");
> +MODULE_LICENSE("GPL");

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