// SPDX-License-Identifier: GPL-2.0+
/*
 * AMD ISP platform driver for sensor i2-client instantiation
 *
 * Copyright 2025 Advanced Micro Devices, Inc.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/soc/amd/isp4_misc.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/units.h>

#define AMDISP_OV05C10_I2C_ADDR         0x10
#define AMDISP_OV05C10_HID              "OMNI5C10"
#define AMDISP_OV05C10_REMOTE_EP_NAME   "ov05c10_isp_4_1_1"
#define AMD_ISP_PLAT_DRV_NAME           "amd-isp4"

static const struct software_node isp4_mipi1_endpoint_node;
static const struct software_node ov05c10_endpoint_node;

/*
 * AMD ISP platform info definition to initialize sensor
 * specific platform configuration to prepare the amdisp
 * platform.
 */
struct amdisp_platform_info {
        struct i2c_board_info board_info;
        const struct software_node **swnodes;
};

/*
 * AMD ISP platform definition to configure the device properties
 * missing in the ACPI table.
 */
struct amdisp_platform {
        const struct amdisp_platform_info *pinfo;
        struct i2c_board_info board_info;
        struct notifier_block i2c_nb;
        struct i2c_client *i2c_dev;
        struct mutex lock;      /* protects i2c client creation */
};

/* Root AMD CAMERA SWNODE */

/* Root amd camera node definition */
static const struct software_node amd_camera_node = {
        .name = "amd_camera",
};

/* ISP4 SWNODE */

/* ISP4 OV05C10 camera node definition */
static const struct software_node isp4_node = {
        .name = "isp4",
        .parent = &amd_camera_node,
};

/*
 * ISP4 Ports node definition. No properties defined for
 * ports node.
 */
static const struct software_node isp4_ports = {
        .name = "ports",
        .parent = &isp4_node,
};

/*
 * ISP4 Port node definition. No properties defined for
 * port node.
 */
static const struct software_node isp4_port_node = {
        .name = "port@0",
        .parent = &isp4_ports,
};

/*
 * ISP4 MIPI1 remote endpoint points to OV05C10 endpoint
 * node.
 */
static const struct software_node_ref_args isp4_refs[] = {
        SOFTWARE_NODE_REFERENCE(&ov05c10_endpoint_node),
};

/* ISP4 MIPI1 endpoint node properties table */
static const struct property_entry isp4_mipi1_endpoint_props[] = {
        PROPERTY_ENTRY_REF_ARRAY("remote-endpoint", isp4_refs),
        { }
};

/* ISP4 MIPI1 endpoint node definition */
static const struct software_node isp4_mipi1_endpoint_node = {
        .name = "endpoint",
        .parent = &isp4_port_node,
        .properties = isp4_mipi1_endpoint_props,
};

/* I2C1 SWNODE */

/* I2C1 camera node property table */
static const struct property_entry i2c1_camera_props[] = {
        PROPERTY_ENTRY_U32("clock-frequency", 1 * HZ_PER_MHZ),
        { }
};

/* I2C1 camera node definition */
static const struct software_node i2c1_node = {
        .name = "i2c1",
        .parent = &amd_camera_node,
        .properties = i2c1_camera_props,
};

/* I2C1 camera node property table */
static const struct property_entry ov05c10_camera_props[] = {
        PROPERTY_ENTRY_U32("clock-frequency", 24 * HZ_PER_MHZ),
        { }
};

/* OV05C10 camera node definition */
static const struct software_node ov05c10_camera_node = {
        .name = AMDISP_OV05C10_HID,
        .parent = &i2c1_node,
        .properties = ov05c10_camera_props,
};

/*
 * OV05C10 Ports node definition. No properties defined for
 * ports node for OV05C10.
 */
static const struct software_node ov05c10_ports = {
        .name = "ports",
        .parent = &ov05c10_camera_node,
};

/*
 * OV05C10 Port node definition.
 */
static const struct software_node ov05c10_port_node = {
        .name = "port@0",
        .parent = &ov05c10_ports,
};

/*
 * OV05C10 remote endpoint points to ISP4 MIPI1 endpoint
 * node.
 */
static const struct software_node_ref_args ov05c10_refs[] = {
        SOFTWARE_NODE_REFERENCE(&isp4_mipi1_endpoint_node),
};

/* OV05C10 supports one single link frequency */
static const u64 ov05c10_link_freqs[] = {
        900 * HZ_PER_MHZ,
};

/* OV05C10 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),
        { }
};

/* OV05C10 endpoint node definition */
static const struct software_node ov05c10_endpoint_node = {
        .name = "endpoint",
        .parent = &ov05c10_port_node,
        .properties = ov05c10_endpoint_props,
};

/*
 * AMD Camera swnode graph uses 10 nodes and also its relationship is
 * fixed to align with the structure that v4l2 and i2c frameworks expects
 * for successful parsing of fwnodes and its properties with standard names.
 *
 * It is only the node property_entries that will vary for each platform
 * supporting different sensor modules.
 *
 * AMD ISP4 SWNODE GRAPH Structure
 *
 * amd_camera {
 *  isp4 {
 *        ports {
 *                port@0 {
 *                        isp4_mipi1_ep: endpoint {
 *                                        remote-endpoint = &OMNI5C10_ep;
 *                        };
 *                };
 *        };
 *  };
 *
 *  i2c1 {
 *        clock-frequency = 1 MHz;
 *        OMNI5C10 {
 *                clock-frequency = 24MHz;
 *                ports {
 *                        port@0 {
 *                                OMNI5C10_ep: endpoint {
 *                                        bus-type = 4;
 *                                        data-lanes = <1 2>;
 *                                        link-frequencies = 900MHz;
 *                                        remote-endpoint = &isp4_mipi1;
 *                                };
 *                        };
 *                };
 *        };
 *      };
 * };
 *
 */
static const struct software_node *amd_isp4_nodes[] = {
        &amd_camera_node,
        &isp4_node,
        &isp4_ports,
        &isp4_port_node,
        &isp4_mipi1_endpoint_node,
        &i2c1_node,
        &ov05c10_camera_node,
        &ov05c10_ports,
        &ov05c10_port_node,
        &ov05c10_endpoint_node,
        NULL
};

/* OV05C10 specific AMD ISP platform configuration */
static const struct amdisp_platform_info ov05c10_platform_config = {
        .board_info = {
                .dev_name = "ov05c10",
                I2C_BOARD_INFO("ov05c10", AMDISP_OV05C10_I2C_ADDR),
        },
        .swnodes = amd_isp4_nodes,
};

static const struct acpi_device_id amdisp_sensor_ids[] = {
        { AMDISP_OV05C10_HID, (kernel_ulong_t)&ov05c10_platform_config },
        { }
};
MODULE_DEVICE_TABLE(acpi, amdisp_sensor_ids);

static inline bool is_isp_i2c_adapter(struct i2c_adapter *adap)
{
        return !strcmp(adap->name, AMDISP_I2C_ADAP_NAME);
}

static void instantiate_isp_i2c_client(struct amdisp_platform *isp4_platform,
                                       struct i2c_adapter *adap)
{
        struct i2c_board_info *info = &isp4_platform->board_info;
        struct i2c_client *i2c_dev;

        guard(mutex)(&isp4_platform->lock);

        if (isp4_platform->i2c_dev)
                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;
        }
        isp4_platform->i2c_dev = i2c_dev;
}

static int isp_i2c_bus_notify(struct notifier_block *nb,
                              unsigned long action, void *data)
{
        struct amdisp_platform *isp4_platform =
                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(isp4_platform, adap);
                break;
        case BUS_NOTIFY_REMOVED_DEVICE:
                client = i2c_verify_client(dev);
                if (!client)
                        break;

                scoped_guard(mutex, &isp4_platform->lock) {
                        if (isp4_platform->i2c_dev == client) {
                                dev_dbg(&client->adapter->dev, "amdisp i2c_client removed\n");
                                isp4_platform->i2c_dev = NULL;
                        }
                }
                break;
        default:
                break;
        }

        return NOTIFY_DONE;
}

static struct amdisp_platform *prepare_amdisp_platform(struct device *dev,
                                                       const struct amdisp_platform_info *src)
{
        struct amdisp_platform *isp4_platform;
        int ret;

        isp4_platform = devm_kzalloc(dev, sizeof(*isp4_platform), GFP_KERNEL);
        if (!isp4_platform)
                return ERR_PTR(-ENOMEM);

        ret = devm_mutex_init(dev, &isp4_platform->lock);
        if (ret)
                return ERR_PTR(ret);

        isp4_platform->board_info.dev_name = src->board_info.dev_name;
        strscpy(isp4_platform->board_info.type, src->board_info.type);
        isp4_platform->board_info.addr = src->board_info.addr;
        isp4_platform->pinfo = src;

        ret = software_node_register_node_group(src->swnodes);
        if (ret)
                return ERR_PTR(ret);

        /* initialize ov05c10_camera_node */
        isp4_platform->board_info.swnode = src->swnodes[6];

        return isp4_platform;
}

static int try_to_instantiate_i2c_client(struct device *dev, void *data)
{
        struct i2c_adapter *adap = i2c_verify_adapter(dev);
        struct amdisp_platform *isp4_platform = data;

        if (!isp4_platform || !adap)
                return 0;
        if (!adap->owner)
                return 0;

        if (is_isp_i2c_adapter(adap))
                instantiate_isp_i2c_client(isp4_platform, adap);

        return 0;
}

static int amd_isp_probe(struct platform_device *pdev)
{
        const struct amdisp_platform_info *pinfo;
        struct amdisp_platform *isp4_platform;
        struct acpi_device *adev;
        int ret;

        pinfo = device_get_match_data(&pdev->dev);
        if (!pinfo)
                return dev_err_probe(&pdev->dev, -EINVAL,
                                     "failed to get valid ACPI data\n");

        isp4_platform = prepare_amdisp_platform(&pdev->dev, pinfo);
        if (IS_ERR(isp4_platform))
                return dev_err_probe(&pdev->dev, PTR_ERR(isp4_platform),
                                     "failed to prepare AMD ISP platform fwnode\n");

        isp4_platform->i2c_nb.notifier_call = isp_i2c_bus_notify;
        ret = bus_register_notifier(&i2c_bus_type, &isp4_platform->i2c_nb);
        if (ret)
                goto error_unregister_sw_node;

        adev = ACPI_COMPANION(&pdev->dev);
        /* initialize root amd_camera_node */
        adev->driver_data = (void *)pinfo->swnodes[0];

        /* check if adapter is already registered and create i2c client instance */
        i2c_for_each_dev(isp4_platform, try_to_instantiate_i2c_client);

        platform_set_drvdata(pdev, isp4_platform);
        return 0;

error_unregister_sw_node:
        software_node_unregister_node_group(isp4_platform->pinfo->swnodes);
        return ret;
}

static void amd_isp_remove(struct platform_device *pdev)
{
        struct amdisp_platform *isp4_platform = platform_get_drvdata(pdev);

        bus_unregister_notifier(&i2c_bus_type, &isp4_platform->i2c_nb);
        i2c_unregister_device(isp4_platform->i2c_dev);
        software_node_unregister_node_group(isp4_platform->pinfo->swnodes);
}

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@amd.com>");
MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@amd.com>");
MODULE_DESCRIPTION("AMD ISP4 Platform Driver");
MODULE_LICENSE("GPL");