// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Synopsys DesignWare I2C adapter driver.
 *
 * Based on the TI DAVINCI I2C adapter driver.
 *
 * Copyright (C) 2006 Texas Instruments.
 * Copyright (C) 2007 MontaVista Software Inc.
 * Copyright (C) 2009 Provigent Ltd.
 */
/*
 * Includes Intel Corporation's changes/modifications dated: 2018.
 * Changed/modified portions - Copyright (c) 2018, Intel Corporation.
 */
#include <linux/acpi.h>
#include <linux/clk-provider.h>
#include <linux/clk.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/units.h>
#include <acpi/actypes.h>

#include "i2c-designware-core.h"

static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
{
	return clk_get_rate(dev->clk) / KILO;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id dw_i2c_acpi_match[] = {
	{ "INT33C2", 0 },
	{ "INT33C3", 0 },
	{ "INT3432", 0 },
	{ "INT3433", 0 },
	{ "80860F41", ACCESS_NO_IRQ_SUSPEND },
	{ "808622C1", ACCESS_NO_IRQ_SUSPEND },
	{ "80862BC1", 0 },
	{ "AMD0010", ACCESS_INTR_MASK },
	{ "AMDI0010", ACCESS_INTR_MASK },
	{ "AMDI0510", 0 },
	{ "APMC0D0F", 0 },
	{ "HISI02A1", 0 },
	{ "HISI02A2", 0 },
	{ "HISI02A3", 0 },
	{ "HYGO0010", ACCESS_INTR_MASK },
	{ }
};
MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
#endif

struct dw_i2c_acpi_handler_data {
	struct acpi_connection_info info;
	struct platform_device *pdev;
};

static acpi_status
dw_i2c_acpi_space_handler(u32 function, acpi_physical_address address,
			u32 bits, u64 *value64,
			void *handler_context, void *region_context)
{
	struct dw_i2c_acpi_handler_data *data = handler_context;
	struct acpi_connection_info *info = &data->info;
	struct dw_i2c_dev *dev = platform_get_drvdata(data->pdev);
	struct acpi_resource_i2c_serialbus *sb;
	struct acpi_resource *ares;
	u8 target;
	int ret, length;
	u8 *value = (u8 *)value64;
	u8 *buffer;
	u32 accessor_type = function >> 16;
	u8 addr = (u8)address;
	struct i2c_msg msgs[2];


	acpi_buffer_to_resource(info->connection, info->length, &ares);
	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
		return AE_BAD_PARAMETER;

	sb = &ares->data.i2c_serial_bus;
	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
		return AE_BAD_PARAMETER;

	pr_debug("%s: Found I2C Resource type, addr %d\n",
				__func__, sb->slave_address);
	target = sb->slave_address;

	length = acpi_get_serial_access_length(accessor_type, info->access_length);
	pr_debug("%s: access opeation region, addr 0x%x operation %d len %d\n",
		__func__, addr, function, length);

	if (!value64)
		return AE_BAD_PARAMETER;

	function &= ACPI_IO_MASK; 
	if (function == ACPI_READ) {
		buffer = kzalloc(length, GFP_KERNEL);
	
		msgs[0].addr = target;
		msgs[0].flags = 0;
		msgs[0].len = 1;
		msgs[0].buf = &addr;
	
		msgs[1].addr = target;
		msgs[1].flags = I2C_M_RD;
		msgs[1].len = length;
		msgs[1].buf = buffer;
	
		ret = i2c_transfer(&dev->adapter, msgs, 2);
		if (ret < 0) {
			pr_info("%s: i2c read failed\n", __func__);	
			return AE_ERROR;		
		}
	
		memcpy(value + 2, buffer, length - 2);
		value[0] = value[1] = 0;
		kfree(buffer);
	} else if (function == ACPI_WRITE) {
//		buffer = kzalloc(length - 1, GFP_KERNEL);
//		
//		buffer[0] = addr;
//		memcpy(buffer + 1, value + 2, length - 2);
//		msgs[0].addr = target;
//		msgs[0].flags = 0;
//		msgs[0].len = length - 1;
//		msgs[0].buf = buffer;
//
//		ret = i2c_transfer(&dev->adapter, msgs, 2);
//		if (ret < 0) {
//			pr_info("%s: i2c read failed\n", __func__);	
//			return AE_ERROR;		
//		}
//		kfree(buffer);
//
	}

	return AE_OK;
}

static int dw_i2c_acpi_install_space_handler(struct platform_device *pdev)
{
	acpi_handle *handle = ACPI_HANDLE(&pdev->dev);
	struct dw_i2c_acpi_handler_data *data;
	acpi_status status;

	if (!handle)
		return -EFAULT;

	data = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_acpi_handler_data),
			    GFP_KERNEL);

	if(!data)
		return -ENOMEM;

	data->pdev = pdev;
	status = acpi_install_address_space_handler(handle,
				ACPI_ADR_SPACE_GSBUS,
				&dw_i2c_acpi_space_handler,
				NULL,
				data);
	if (ACPI_FAILURE(status))
		return -EFAULT;
	return 0;
}

#ifdef CONFIG_OF
#define BT1_I2C_CTL			0x100
#define BT1_I2C_CTL_ADDR_MASK		GENMASK(7, 0)
#define BT1_I2C_CTL_WR			BIT(8)
#define BT1_I2C_CTL_GO			BIT(31)
#define BT1_I2C_DI			0x104
#define BT1_I2C_DO			0x108



static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
{
	struct dw_i2c_dev *dev = context;
	int ret;

	/*
	 * Note these methods shouldn't ever fail because the system controller
	 * registers are memory mapped. We check the return value just in case.
	 */
	ret = regmap_write(dev->sysmap, BT1_I2C_CTL,
			   BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
	if (ret)
		return ret;

	return regmap_read(dev->sysmap, BT1_I2C_DO, val);
}

static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
{
	struct dw_i2c_dev *dev = context;
	int ret;

	ret = regmap_write(dev->sysmap, BT1_I2C_DI, val);
	if (ret)
		return ret;

	return regmap_write(dev->sysmap, BT1_I2C_CTL,
		BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
}

static struct regmap_config bt1_i2c_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.fast_io = true,
	.reg_read = bt1_i2c_read,
	.reg_write = bt1_i2c_write,
	.max_register = DW_IC_COMP_TYPE,
};

static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
{
	dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent);
	if (IS_ERR(dev->sysmap))
		return PTR_ERR(dev->sysmap);

	dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg);
	return PTR_ERR_OR_ZERO(dev->map);
}

#define MSCC_ICPU_CFG_TWI_DELAY		0x0
#define MSCC_ICPU_CFG_TWI_DELAY_ENABLE	BIT(0)
#define MSCC_ICPU_CFG_TWI_SPIKE_FILTER	0x4

static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
{
	writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
	       dev->ext + MSCC_ICPU_CFG_TWI_DELAY);

	return 0;
}

static int dw_i2c_of_configure(struct platform_device *pdev)
{
	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);

	switch (dev->flags & MODEL_MASK) {
	case MODEL_MSCC_OCELOT:
		dev->ext = devm_platform_ioremap_resource(pdev, 1);
		if (!IS_ERR(dev->ext))
			dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
		break;
	default:
		break;
	}

	return 0;
}

static const struct of_device_id dw_i2c_of_match[] = {
	{ .compatible = "snps,designware-i2c", },
	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
	{ .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
	{},
};
MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
#else
static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
{
	return -ENODEV;
}

static inline int dw_i2c_of_configure(struct platform_device *pdev)
{
	return -ENODEV;
}
#endif

static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
{
	pm_runtime_disable(dev->dev);

	if (dev->shared_with_punit)
		pm_runtime_put_noidle(dev->dev);
}

static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
{
	struct platform_device *pdev = to_platform_device(dev->dev);
	int ret;

	switch (dev->flags & MODEL_MASK) {
	case MODEL_BAIKAL_BT1:
		ret = bt1_i2c_request_regs(dev);
		break;
	default:
		dev->base = devm_platform_ioremap_resource(pdev, 0);
		ret = PTR_ERR_OR_ZERO(dev->base);
		break;
	}

	return ret;
}

static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
	{
		.ident = "Qtechnology QT5222",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Qtechnology"),
			DMI_MATCH(DMI_PRODUCT_NAME, "QT5222"),
		},
	},
	{ } /* terminate list */
};

static int dw_i2c_plat_probe(struct platform_device *pdev)
{
	struct i2c_adapter *adap;
	struct dw_i2c_dev *dev;
	struct i2c_timings *t;
	int irq, ret;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	dev->flags = (uintptr_t)device_get_match_data(&pdev->dev);
	dev->dev = &pdev->dev;
	dev->irq = irq;
	platform_set_drvdata(pdev, dev);

	ret = dw_i2c_plat_request_regs(dev);
	if (ret)
		return ret;

	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
	if (IS_ERR(dev->rst))
		return PTR_ERR(dev->rst);

	reset_control_deassert(dev->rst);

	t = &dev->timings;
	i2c_parse_fw_timings(&pdev->dev, t, false);

	i2c_dw_adjust_bus_speed(dev);

	if (pdev->dev.of_node)
		dw_i2c_of_configure(pdev);

	if (has_acpi_companion(&pdev->dev))
		i2c_dw_acpi_configure(&pdev->dev);

	ret = i2c_dw_validate_speed(dev);
	if (ret)
		goto exit_reset;

	ret = i2c_dw_probe_lock_support(dev);
	if (ret)
		goto exit_reset;

	i2c_dw_configure(dev);

	/* Optional interface clock */
	dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
	if (IS_ERR(dev->pclk)) {
		ret = PTR_ERR(dev->pclk);
		goto exit_reset;
	}

	dev->clk = devm_clk_get_optional(&pdev->dev, "baudclk");
	if (IS_ERR(dev->clk)) {
		ret = PTR_ERR(dev->clk);
		goto exit_reset;
	}

	ret = i2c_dw_prepare_clk(dev, true);
	if (ret)
		goto exit_reset;

	if (dev->clk) {
		u64 clk_khz;

		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
		clk_khz = dev->get_clk_rate_khz(dev);

		if (!dev->sda_hold_time && t->sda_hold_ns)
			dev->sda_hold_time =
				DIV_S64_ROUND_CLOSEST(clk_khz * t->sda_hold_ns, MICRO);
	}

	adap = &dev->adapter;
	adap->owner = THIS_MODULE;
	adap->class = dmi_check_system(dw_i2c_hwmon_class_dmi) ?
					I2C_CLASS_HWMON : I2C_CLASS_DEPRECATED;
	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
	adap->dev.of_node = pdev->dev.of_node;
	adap->nr = -1;

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

	/* The code below assumes runtime PM to be disabled. */
	WARN_ON(pm_runtime_enabled(&pdev->dev));

	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);

	if (dev->shared_with_punit)
		pm_runtime_get_noresume(&pdev->dev);

	pm_runtime_enable(&pdev->dev);

	ret = i2c_dw_probe(dev);
	if (ret)
		goto exit_probe;

	return ret;

exit_probe:
	dw_i2c_plat_pm_cleanup(dev);
exit_reset:
	reset_control_assert(dev->rst);

	dw_i2c_acpi_install_space_handler(pdev);

	return ret;
}

static int dw_i2c_plat_remove(struct platform_device *pdev)
{
	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);

	pm_runtime_get_sync(&pdev->dev);

	i2c_del_adapter(&dev->adapter);

	dev->disable(dev);

	pm_runtime_dont_use_autosuspend(&pdev->dev);
	pm_runtime_put_sync(&pdev->dev);
	dw_i2c_plat_pm_cleanup(dev);

	reset_control_assert(dev->rst);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int 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 void dw_i2c_plat_complete(struct device *dev)
{
	/*
	 * The device can only be in runtime suspend at this point if it has not
	 * been resumed throughout the ending system suspend/resume cycle, so if
	 * the platform firmware might mess up with it, request the runtime PM
	 * framework to resume it.
	 */
	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
		pm_request_resume(dev);
}
#else
#define dw_i2c_plat_prepare	NULL
#define dw_i2c_plat_complete	NULL
#endif

#ifdef CONFIG_PM
static int dw_i2c_plat_suspend(struct device *dev)
{
	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);

	i_dev->suspended = true;

	if (i_dev->shared_with_punit)
		return 0;

	i_dev->disable(i_dev);
	i2c_dw_prepare_clk(i_dev, false);

	return 0;
}

static int dw_i2c_plat_resume(struct device *dev)
{
	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);

	if (!i_dev->shared_with_punit)
		i2c_dw_prepare_clk(i_dev, true);

	i_dev->init(i_dev);
	i_dev->suspended = false;

	return 0;
}

static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
	.prepare = dw_i2c_plat_prepare,
	.complete = dw_i2c_plat_complete,
	SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
	SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
};

#define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
#else
#define DW_I2C_DEV_PMOPS NULL
#endif

/* Work with hotplug and coldplug */
MODULE_ALIAS("platform:i2c_designware");

static struct platform_driver dw_i2c_driver = {
	.probe = dw_i2c_plat_probe,
	.remove = dw_i2c_plat_remove,
	.driver		= {
		.name	= "i2c_designware",
		.of_match_table = of_match_ptr(dw_i2c_of_match),
		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
		.pm	= DW_I2C_DEV_PMOPS,
	},
};

static int __init dw_i2c_init_driver(void)
{
	return platform_driver_register(&dw_i2c_driver);
}
fs_initcall_sync(dw_i2c_init_driver);

static void __exit dw_i2c_exit_driver(void)
{
	platform_driver_unregister(&dw_i2c_driver);
}
module_exit(dw_i2c_exit_driver);

MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
MODULE_LICENSE("GPL");