Re: [PATCH v5] platform/x86: Add AMD ISP platform config for OV05C10
From: Ilpo Järvinen
Date: Tue Apr 15 2025 - 11:43:03 EST
On Tue, 8 Apr 2025, Pratap Nirujogi wrote:
> 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@xxxxxxx>
> Signed-off-by: Benjamin Chan <benjamin.chan@xxxxxxx>
> Signed-off-by: Pratap Nirujogi <pratap.nirujogi@xxxxxxx>
> ---
> Changes v4 -> v5:
>
> * Avoid global variables and make driver reentrant following the
> state container design pattern.
>
> * Fix coding error referencing i2c_dev variable of amdisp_platform
> in instantiate_isp_i2c_client().
>
> * Remove i2c_put_adapter(). Not required as i2c_get_adapter() is not called.
>
> * Use i2c_board_info->swnode instead of fwnode to fix refcount imbalance
> warnings when module is removed.
>
> * Address review comments.
>
> drivers/platform/x86/amd/Kconfig | 11 ++
> drivers/platform/x86/amd/Makefile | 1 +
> drivers/platform/x86/amd/amd_isp4.c | 295 ++++++++++++++++++++++++++++
> 3 files changed, 307 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..ec755b5fc93c 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 && AMD_ISP4
> + 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..ad181ab96423
> --- /dev/null
> +++ b/drivers/platform/x86/amd/amd_isp4.c
> @@ -0,0 +1,295 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AMD ISP platform driver for sensor i2-client instantiation
> + *
> + * Copyright 2025 Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/device/bus.h>
> +#include <linux/dmi.h>
> +#include <linux/gpio/machine.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.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 {
> + const char *name;
> + u8 i2c_addr;
> + u8 max_num_swnodes;
> + struct i2c_board_info board_info;
> + struct notifier_block i2c_nb;
> + struct i2c_client *i2c_dev;
> + struct software_node **swnodes;
Can't this too be const struct so you can avoid a few casts below?
> +};
> +
> +/* 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
> +};
> +
> +/* OV05C10 specific AMD ISP platform configuration */
> +static const struct amdisp_platform amdisp_ov05c10_platform_config = {
> + .name = AMDISP_OV05C10_PLAT_NAME,
> + .board_info = {
> + .dev_name = "ov05c10",
> + I2C_BOARD_INFO("ov05c10", AMDISP_OV05C10_I2C_ADDR),
> + },
> + .i2c_addr = AMDISP_OV05C10_I2C_ADDR,
> + .max_num_swnodes = NUM_SW_NODES,
> + .swnodes = (struct software_node **)ov05c10_nodes,
> +};
> +
> +static const struct acpi_device_id amdisp_sensor_ids[] = {
> + { AMDISP_OV05C10_HID },
> + { }
> +};
> +MODULE_DEVICE_TABLE(acpi, amdisp_sensor_ids);
> +
> +static 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;
> +
> + if (!info->addr) {
> + dev_err(&adap->dev, "invalid i2c_addr 0x%x detected\n",
> + ov05c10->i2c_addr);
Put on a single line, you've longer lines already than what this is.
> + 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);
Ditto.
> + 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(const struct amdisp_platform *src)
> +{
> + struct amdisp_platform *isp_ov05c10;
> + const struct software_node **sw_nodes;
> + const struct software_node *sw_node;
> + struct i2c_board_info *info;
> + int ret;
> +
> + isp_ov05c10 = kmemdup(src, sizeof(*isp_ov05c10), GFP_KERNEL);
> + if (!isp_ov05c10)
> + return ERR_PTR(-ENOMEM);
> +
> + info = &isp_ov05c10->board_info;
> +
> + sw_nodes = (const struct software_node **)src->swnodes;
> + ret = software_node_register_node_group(sw_nodes);
> + if (ret)
> + goto error_unregister_sw_node;
> +
> + sw_node = (const struct software_node *)src->swnodes[0];
> + info->swnode = sw_node;
> +
> + return isp_ov05c10;
> +
> +error_unregister_sw_node:
> + software_node_unregister_node_group(sw_nodes);
If register failed, why you are calling unregister for it??
> + kfree(isp_ov05c10);
> + return ERR_PTR(ret);
> +}
> +
> +static int amd_isp_probe(struct platform_device *pdev)
> +{
> + struct amdisp_platform *ov05c10;
> + int ret;
> +
> + ov05c10 = prepare_amdisp_platform(&amdisp_ov05c10_platform_config);
> + if (IS_ERR(ov05c10))
> + return dev_err_probe(&pdev->dev, PTR_ERR(ov05c10),
> + "failed to prepare amdisp platform fw node\n");
fwnode
Please also capitalize properly as this is user visible message, AMD ISP ?
> +
> + ov05c10->i2c_nb.notifier_call = isp_i2c_bus_notify;
> +
> + ret = bus_register_notifier(&i2c_bus_type, &ov05c10->i2c_nb);
> + if (ret)
> + goto error_free_platform;
> +
> + platform_set_drvdata(pdev, ov05c10);
> + return ret;
return 0
> +
> +error_free_platform:
> + kfree(ov05c10);
> + return ret;
> +}
> +
> +static void amd_isp_remove(struct platform_device *pdev)
> +{
> + struct amdisp_platform *ov05c10 = platform_get_drvdata(pdev);
> +
> + if (IS_ERR_OR_NULL(ov05c10))
How can this happen??
> + return;
> +
> + bus_unregister_notifier(&i2c_bus_type, &ov05c10->i2c_nb);
> + i2c_unregister_device(ov05c10->i2c_dev);
> + software_node_unregister_node_group((const struct software_node **)
Unnecessary cast?
> + ov05c10->swnodes);
> + kfree(ov05c10);
> +}
> +
> +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@xxxxxxx>");
> +MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@xxxxxxx>");
> +MODULE_DESCRIPTION("AMD ISP4 Platform Driver");
> +MODULE_LICENSE("GPL");
>
--
i.