// SPDX-License-Identifier: GPL-2.0+
/*
 * Based on Synopsys DesignWare I2C adapter driver.
 *
 * Copyright (C) 2025 Advanced Micro Devices, Inc.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/soc/amd/isp4_misc.h>

#include "i2c-designware-core.h"

#define DRV_NAME                "amd_isp_i2c_designware"
#define AMD_ISP_I2C_INPUT_CLK   100 /* Mhz */

static void amd_isp_dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *i2c_dev)
{
        pm_runtime_disable(i2c_dev->dev);
}

static inline u32 amd_isp_dw_i2c_get_clk_rate(struct dw_i2c_dev *i2c_dev)
{
        return AMD_ISP_I2C_INPUT_CLK * 1000;
}

static int amd_isp_dw_i2c_plat_probe(struct platform_device *pdev)
{
        struct dw_i2c_dev *isp_i2c_dev;
        struct i2c_adapter *adap;
        int ret;

        isp_i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c_dev), GFP_KERNEL);
        if (!isp_i2c_dev)
                return -ENOMEM;
        isp_i2c_dev->dev = &pdev->dev;

        pdev->dev.init_name = DRV_NAME;

        /*
         * Use the polling mode to send/receive the data, because
         * no IRQ connection from ISP I2C
         */
        isp_i2c_dev->flags |= ACCESS_POLLING;
        platform_set_drvdata(pdev, isp_i2c_dev);

        isp_i2c_dev->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(isp_i2c_dev->base))
                return dev_err_probe(&pdev->dev, PTR_ERR(isp_i2c_dev->base),
                                     "failed to get IOMEM resource\n");

        isp_i2c_dev->get_clk_rate_khz = amd_isp_dw_i2c_get_clk_rate;
        ret = i2c_dw_fw_parse_and_configure(isp_i2c_dev);
        if (ret)
                return dev_err_probe(&pdev->dev, ret,
                                     "failed to parse i2c dw fwnode and configure\n");

        i2c_dw_configure(isp_i2c_dev);

        adap = &isp_i2c_dev->adapter;
        adap->owner = THIS_MODULE;
        scnprintf(adap->name, sizeof(adap->name), AMDISP_I2C_ADAP_NAME);
        ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
        adap->dev.of_node = pdev->dev.of_node;
        /* use dynamically allocated adapter id */
        adap->nr = -1;

        if (isp_i2c_dev->flags & ACCESS_NO_IRQ_SUSPEND)
                dev_pm_set_driver_flags(&pdev->dev,
                                        DPM_FLAG_SMART_PREPARE);
        else
                dev_pm_set_driver_flags(&pdev->dev,
                                        DPM_FLAG_SMART_PREPARE |
                                        DPM_FLAG_SMART_SUSPEND);

        device_enable_async_suspend(&pdev->dev);

        dev_pm_genpd_resume(&pdev->dev);
        ret = i2c_dw_probe(isp_i2c_dev);
        if (ret) {
                dev_err_probe(&pdev->dev, ret, "i2c_dw_probe failed\n");
                goto error_release_rpm;
        }
        dev_pm_genpd_suspend(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
        pm_runtime_enable(&pdev->dev);

        return 0;

error_release_rpm:
        amd_isp_dw_i2c_plat_pm_cleanup(isp_i2c_dev);
        return ret;
}

static void amd_isp_dw_i2c_plat_remove(struct platform_device *pdev)
{
        struct dw_i2c_dev *isp_i2c_dev = platform_get_drvdata(pdev);

        pm_runtime_get_sync(&pdev->dev);

        i2c_del_adapter(&isp_i2c_dev->adapter);

        i2c_dw_disable(isp_i2c_dev);

        pm_runtime_put_sync(&pdev->dev);
        amd_isp_dw_i2c_plat_pm_cleanup(isp_i2c_dev);
}

static int amd_isp_dw_i2c_plat_prepare(struct device *dev)
{
        /*
         * If the ACPI companion device object is present for this device, it
         * may be accessed during suspend and resume of other devices via I2C
         * operation regions, so tell the PM core and middle layers to avoid
         * skipping system suspend/resume callbacks for it in that case.
         */
        return !has_acpi_companion(dev);
}

static int amd_isp_dw_i2c_plat_runtime_suspend(struct device *dev)
{
        struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);

        i2c_dw_disable(i_dev);
        i2c_dw_prepare_clk(i_dev, false);

        return 0;
}

static int amd_isp_dw_i2c_plat_suspend(struct device *dev)
{
        struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
        int ret;

        if (!i_dev)
                return -ENODEV;

        ret = amd_isp_dw_i2c_plat_runtime_suspend(dev);
        if (!ret)
                i2c_mark_adapter_suspended(&i_dev->adapter);

        return ret;
}

static int amd_isp_dw_i2c_plat_runtime_resume(struct device *dev)
{
        struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);

        if (!i_dev)
                return -ENODEV;

        i2c_dw_prepare_clk(i_dev, true);
        i2c_dw_init(i_dev);

        return 0;
}

static int amd_isp_dw_i2c_plat_resume(struct device *dev)
{
        struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);

        amd_isp_dw_i2c_plat_runtime_resume(dev);
        i2c_mark_adapter_resumed(&i_dev->adapter);

        return 0;
}

static const struct dev_pm_ops amd_isp_dw_i2c_dev_pm_ops = {
        .prepare = pm_sleep_ptr(amd_isp_dw_i2c_plat_prepare),
        LATE_SYSTEM_SLEEP_PM_OPS(amd_isp_dw_i2c_plat_suspend, amd_isp_dw_i2c_plat_resume)
        RUNTIME_PM_OPS(amd_isp_dw_i2c_plat_runtime_suspend, amd_isp_dw_i2c_plat_runtime_resume, NULL)
};

/* Work with hotplug and coldplug */
MODULE_ALIAS("platform:amd_isp_i2c_designware");

static struct platform_driver amd_isp_dw_i2c_driver = {
        .probe = amd_isp_dw_i2c_plat_probe,
        .remove = amd_isp_dw_i2c_plat_remove,
        .driver         = {
                .name   = DRV_NAME,
                .pm     = pm_ptr(&amd_isp_dw_i2c_dev_pm_ops),
        },
};
module_platform_driver(amd_isp_dw_i2c_driver);

MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter in AMD ISP");
MODULE_IMPORT_NS("I2C_DW");
MODULE_IMPORT_NS("I2C_DW_COMMON");
MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vengutta@amd.com>");
MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@amd.com>");
MODULE_AUTHOR("Bin Du <bin.du@amd.com>");
MODULE_LICENSE("GPL");