drivers/i2c/busses/i2c-designware-platdrv.c - kernel/msm-4.19 - Gitiles

 /*
  * Synopsys DesignWare I2C adapter driver (master only).
  *
  * Based on the TI DAVINCI I2C adapter driver.
  *
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
  *
  * ----------------------------------------------------------------------------
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  * ----------------------------------------------------------------------------
  *
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/dmi.h>
 #include <linux/i2c.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/err.h>
 #include <linux/interrupt.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/io.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/platform_data/i2c-designware.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)/1000;
 }

 #ifdef CONFIG_ACPI
 /*
  * The HCNT/LCNT information coming from ACPI should be the most accurate
  * for given platform. However, some systems get it wrong. On such systems
  * we get better results by calculating those based on the input clock.
  */
 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
 	{
 		.ident = "Dell Inspiron 7348",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
 		},
 	},
 	{ }
 };

 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 			       u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 {
 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 	union acpi_object *obj;

 	if (dmi_check_system(dw_i2c_no_acpi_params))
 		return;

 	if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
 		return;

 	obj = (union acpi_object *)buf.pointer;
 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
 		const union acpi_object *objs = obj->package.elements;

 		*hcnt = (u16)objs[0].integer.value;
 		*lcnt = (u16)objs[1].integer.value;
 		*sda_hold = (u32)objs[2].integer.value;
 	}

 	kfree(buf.pointer);
 }

 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 {
 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 	u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
 	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 	const struct acpi_device_id *id;
 	struct acpi_device *adev;
 	const char *uid;

 	dev->adapter.nr = -1;
 	dev->tx_fifo_depth = 32;
 	dev->rx_fifo_depth = 32;

 	/*
 	 * Try to get SDA hold time and *CNT values from an ACPI method for
 	 * selected speed modes.
 	 */
 	dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
 	dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
 	dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
 	dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);

 	switch (dev->clk_freq) {
 	case 100000:
 		dev->sda_hold_time = ss_ht;
 		break;
 	case 1000000:
 		dev->sda_hold_time = fp_ht;
 		break;
 	case 3400000:
 		dev->sda_hold_time = hs_ht;
 		break;
 	case 400000:
 	default:
 		dev->sda_hold_time = fs_ht;
 		break;
 	}

 	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 	if (id && id->driver_data)
 		dev->flags |= (u32)id->driver_data;

 	if (acpi_bus_get_device(handle, &adev))
 		return -ENODEV;

 	/*
 	 * Cherrytrail I2C7 gets used for the PMIC which gets accessed
 	 * through ACPI opregions during late suspend / early resume
 	 * disable pm for it.
 	 */
 	uid = adev->pnp.unique_id;
 	if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
 		dev->pm_disabled = true;

 	return 0;
 }

 static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ "INT33C2", 0 },
 	{ "INT33C3", 0 },
 	{ "INT3432", 0 },
 	{ "INT3433", 0 },
 	{ "80860F41", 0 },
 	{ "808622C1", MODEL_CHERRYTRAIL },
 	{ "AMD0010", ACCESS_INTR_MASK },
 	{ "AMDI0010", ACCESS_INTR_MASK },
 	{ "AMDI0510", 0 },
 	{ "APMC0D0F", 0 },
 	{ "HISI02A1", 0 },
 	{ "HISI02A2", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 #else
 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 {
 	return -ENODEV;
 }
 #endif

 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 {
 	if (IS_ERR(i_dev->clk))
 		return PTR_ERR(i_dev->clk);

 	if (prepare)
 		return clk_prepare_enable(i_dev->clk);

 	clk_disable_unprepare(i_dev->clk);
 	return 0;
 }

 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 {
 	u32 param, tx_fifo_depth, rx_fifo_depth;

 	/*
 	 * Try to detect the FIFO depth if not set by interface driver,
 	 * the depth could be from 2 to 256 from HW spec.
 	 */
 	param = i2c_dw_read_comp_param(dev);
 	tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 	rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 	if (!dev->tx_fifo_depth) {
 		dev->tx_fifo_depth = tx_fifo_depth;
 		dev->rx_fifo_depth = rx_fifo_depth;
 		dev->adapter.nr = id;
 	} else if (tx_fifo_depth >= 2) {
 		dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
 				tx_fifo_depth);
 		dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 				rx_fifo_depth);
 	}
 }

 static int dw_i2c_plat_probe(struct platform_device *pdev)
 {
 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct dw_i2c_dev *dev;
 	struct i2c_adapter *adap;
 	struct resource *mem;
 	int irq, r;
 	u32 acpi_speed, ht = 0;

 	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;

 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dev->base = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(dev->base))
 		return PTR_ERR(dev->base);

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

 	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(dev->rst)) {
 		if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 	} else {
 		reset_control_deassert(dev->rst);
 	}

 	if (pdata) {
 		dev->clk_freq = pdata->i2c_scl_freq;
 	} else {
 		device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
 					 &ht);
 		device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
 					 &dev->sda_falling_time);
 		device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
 					 &dev->scl_falling_time);
 		device_property_read_u32(&pdev->dev, "clock-frequency",
 					 &dev->clk_freq);
 	}

 	acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 	/*
 	 * Find bus speed from the "clock-frequency" device property, ACPI
 	 * or by using fast mode if neither is set.
 	 */
 	if (acpi_speed && dev->clk_freq)
 		dev->clk_freq = min(dev->clk_freq, acpi_speed);
 	else if (acpi_speed || dev->clk_freq)
 		dev->clk_freq = max(dev->clk_freq, acpi_speed);
 	else
 		dev->clk_freq = 400000;

 	if (has_acpi_companion(&pdev->dev))
 		dw_i2c_acpi_configure(pdev);

 	/*
 	 * Only standard mode at 100kHz, fast mode at 400kHz,
 	 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 	 */
 	if (dev->clk_freq != 100000 && dev->clk_freq != 400000
 	    && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 		dev_err(&pdev->dev,
 			"Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
 		r = -EINVAL;
 		goto exit_reset;
 	}

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

 	dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;

 	dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
 			  DW_IC_CON_RESTART_EN;

 	switch (dev->clk_freq) {
 	case 100000:
 		dev->master_cfg |= DW_IC_CON_SPEED_STD;
 		break;
 	case 3400000:
 		dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
 		break;
 	default:
 		dev->master_cfg |= DW_IC_CON_SPEED_FAST;
 	}

 	dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (!i2c_dw_plat_prepare_clk(dev, true)) {
 		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;

 		if (!dev->sda_hold_time && ht)
 			dev->sda_hold_time = div_u64(
 				(u64)dev->get_clk_rate_khz(dev) * ht + 500000,
 				1000000);
 	}

 	dw_i2c_set_fifo_size(dev, pdev->id);

 	adap = &dev->adapter;
 	adap->owner = THIS_MODULE;
 	adap->class = I2C_CLASS_DEPRECATED;
 	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 	adap->dev.of_node = pdev->dev.of_node;

 	if (dev->pm_disabled) {
 		pm_runtime_forbid(&pdev->dev);
 	} else {
 		pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 		pm_runtime_use_autosuspend(&pdev->dev);
 		pm_runtime_set_active(&pdev->dev);
 		pm_runtime_enable(&pdev->dev);
 	}

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

 	return r;

 exit_probe:
 	if (!dev->pm_disabled)
 		pm_runtime_disable(&pdev->dev);
 exit_reset:
 	if (!IS_ERR_OR_NULL(dev->rst))
 		reset_control_assert(dev->rst);
 	return r;
 }

 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);

 	i2c_dw_disable(dev);

 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	if (!dev->pm_disabled)
 		pm_runtime_disable(&pdev->dev);
 	if (!IS_ERR_OR_NULL(dev->rst))
 		reset_control_assert(dev->rst);

 	i2c_dw_remove_lock_support(dev);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id dw_i2c_of_match[] = {
 	{ .compatible = "snps,designware-i2c", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 #endif

 #ifdef CONFIG_PM_SLEEP
 static int dw_i2c_plat_prepare(struct device *dev)
 {
 	return pm_runtime_suspended(dev);
 }

 static void dw_i2c_plat_complete(struct device *dev)
 {
 	if (dev->power.direct_complete)
 		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 platform_device *pdev = to_platform_device(dev);
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

 	i2c_dw_disable(i_dev);
 	i2c_dw_plat_prepare_clk(i_dev, false);

 	return 0;
 }

 static int dw_i2c_plat_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

 	i2c_dw_plat_prepare_clk(i_dev, true);
 	i2c_dw_init(i_dev);

 	return 0;
 }

 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 	.prepare = dw_i2c_plat_prepare,
 	.complete = dw_i2c_plat_complete,
 	SET_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);
 }
 subsys_initcall(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");
	/*
	* Synopsys DesignWare I2C adapter driver (master only).
	*
	* Based on the TI DAVINCI I2C adapter driver.
	*
	* Copyright (C) 2006 Texas Instruments.
	* Copyright (C) 2007 MontaVista Software Inc.
	* Copyright (C) 2009 Provigent Ltd.
	*
	* ----------------------------------------------------------------------------
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	* ----------------------------------------------------------------------------
	*
	*/
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/dmi.h>
	#include <linux/i2c.h>
	#include <linux/clk.h>
	#include <linux/clk-provider.h>
	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/err.h>
	#include <linux/interrupt.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/io.h>
	#include <linux/reset.h>
	#include <linux/slab.h>
	#include <linux/acpi.h>
	#include <linux/platform_data/i2c-designware.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)/1000;
	}

	#ifdef CONFIG_ACPI
	/*
	* The HCNT/LCNT information coming from ACPI should be the most accurate
	* for given platform. However, some systems get it wrong. On such systems
	* we get better results by calculating those based on the input clock.
	*/
	static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
	{
	.ident = "Dell Inspiron 7348",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
	DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
	},
	},
	{ }
	};

	static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
	u16 hcnt, u16 lcnt, u32 *sda_hold)
	{
	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
	union acpi_object *obj;

	if (dmi_check_system(dw_i2c_no_acpi_params))
	return;

	if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
	return;

	obj = (union acpi_object *)buf.pointer;
	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
	const union acpi_object *objs = obj->package.elements;

	*hcnt = (u16)objs[0].integer.value;
	*lcnt = (u16)objs[1].integer.value;
	*sda_hold = (u32)objs[2].integer.value;
	}

	kfree(buf.pointer);
	}

	static int dw_i2c_acpi_configure(struct platform_device *pdev)
	{
	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
	u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
	const struct acpi_device_id *id;
	struct acpi_device *adev;
	const char *uid;

	dev->adapter.nr = -1;
	dev->tx_fifo_depth = 32;
	dev->rx_fifo_depth = 32;

	/*
	* Try to get SDA hold time and *CNT values from an ACPI method for
	* selected speed modes.
	*/
	dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
	dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
	dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
	dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);

	switch (dev->clk_freq) {
	case 100000:
	dev->sda_hold_time = ss_ht;
	break;
	case 1000000:
	dev->sda_hold_time = fp_ht;
	break;
	case 3400000:
	dev->sda_hold_time = hs_ht;
	break;
	case 400000:
	default:
	dev->sda_hold_time = fs_ht;
	break;
	}

	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
	if (id && id->driver_data)
	dev->flags \|= (u32)id->driver_data;

	if (acpi_bus_get_device(handle, &adev))
	return -ENODEV;

	/*
	* Cherrytrail I2C7 gets used for the PMIC which gets accessed
	* through ACPI opregions during late suspend / early resume
	* disable pm for it.
	*/
	uid = adev->pnp.unique_id;
	if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
	dev->pm_disabled = true;

	return 0;
	}

	static const struct acpi_device_id dw_i2c_acpi_match[] = {
	{ "INT33C2", 0 },
	{ "INT33C3", 0 },
	{ "INT3432", 0 },
	{ "INT3433", 0 },
	{ "80860F41", 0 },
	{ "808622C1", MODEL_CHERRYTRAIL },
	{ "AMD0010", ACCESS_INTR_MASK },
	{ "AMDI0010", ACCESS_INTR_MASK },
	{ "AMDI0510", 0 },
	{ "APMC0D0F", 0 },
	{ "HISI02A1", 0 },
	{ "HISI02A2", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
	#else
	static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
	{
	return -ENODEV;
	}
	#endif

	static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
	{
	if (IS_ERR(i_dev->clk))
	return PTR_ERR(i_dev->clk);

	if (prepare)
	return clk_prepare_enable(i_dev->clk);

	clk_disable_unprepare(i_dev->clk);
	return 0;
	}

	static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
	{
	u32 param, tx_fifo_depth, rx_fifo_depth;

	/*
	* Try to detect the FIFO depth if not set by interface driver,
	* the depth could be from 2 to 256 from HW spec.
	*/
	param = i2c_dw_read_comp_param(dev);
	tx_fifo_depth = ((param >> 16) & 0xff) + 1;
	rx_fifo_depth = ((param >> 8) & 0xff) + 1;
	if (!dev->tx_fifo_depth) {
	dev->tx_fifo_depth = tx_fifo_depth;
	dev->rx_fifo_depth = rx_fifo_depth;
	dev->adapter.nr = id;
	} else if (tx_fifo_depth >= 2) {
	dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
	tx_fifo_depth);
	dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
	rx_fifo_depth);
	}
	}

	static int dw_i2c_plat_probe(struct platform_device *pdev)
	{
	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct dw_i2c_dev *dev;
	struct i2c_adapter *adap;
	struct resource *mem;
	int irq, r;
	u32 acpi_speed, ht = 0;

	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;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dev->base = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(dev->base))
	return PTR_ERR(dev->base);

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

	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
	if (IS_ERR(dev->rst)) {
	if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	} else {
	reset_control_deassert(dev->rst);
	}

	if (pdata) {
	dev->clk_freq = pdata->i2c_scl_freq;
	} else {
	device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
	&ht);
	device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
	&dev->sda_falling_time);
	device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
	&dev->scl_falling_time);
	device_property_read_u32(&pdev->dev, "clock-frequency",
	&dev->clk_freq);
	}

	acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
	/*
	* Find bus speed from the "clock-frequency" device property, ACPI
	* or by using fast mode if neither is set.
	*/
	if (acpi_speed && dev->clk_freq)
	dev->clk_freq = min(dev->clk_freq, acpi_speed);
	else if (acpi_speed \|\| dev->clk_freq)
	dev->clk_freq = max(dev->clk_freq, acpi_speed);
	else
	dev->clk_freq = 400000;

	if (has_acpi_companion(&pdev->dev))
	dw_i2c_acpi_configure(pdev);

	/*
	* Only standard mode at 100kHz, fast mode at 400kHz,
	* fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
	*/
	if (dev->clk_freq != 100000 && dev->clk_freq != 400000
	&& dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
	dev_err(&pdev->dev,
	"Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
	r = -EINVAL;
	goto exit_reset;
	}

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

	dev->functionality = I2C_FUNC_10BIT_ADDR \| DW_IC_DEFAULT_FUNCTIONALITY;

	dev->master_cfg = DW_IC_CON_MASTER \| DW_IC_CON_SLAVE_DISABLE \|
	DW_IC_CON_RESTART_EN;

	switch (dev->clk_freq) {
	case 100000:
	dev->master_cfg \|= DW_IC_CON_SPEED_STD;
	break;
	case 3400000:
	dev->master_cfg \|= DW_IC_CON_SPEED_HIGH;
	break;
	default:
	dev->master_cfg \|= DW_IC_CON_SPEED_FAST;
	}

	dev->clk = devm_clk_get(&pdev->dev, NULL);
	if (!i2c_dw_plat_prepare_clk(dev, true)) {
	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;

	if (!dev->sda_hold_time && ht)
	dev->sda_hold_time = div_u64(
	(u64)dev->get_clk_rate_khz(dev) * ht + 500000,
	1000000);
	}

	dw_i2c_set_fifo_size(dev, pdev->id);

	adap = &dev->adapter;
	adap->owner = THIS_MODULE;
	adap->class = I2C_CLASS_DEPRECATED;
	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
	adap->dev.of_node = pdev->dev.of_node;

	if (dev->pm_disabled) {
	pm_runtime_forbid(&pdev->dev);
	} else {
	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);
	}

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

	return r;

	exit_probe:
	if (!dev->pm_disabled)
	pm_runtime_disable(&pdev->dev);
	exit_reset:
	if (!IS_ERR_OR_NULL(dev->rst))
	reset_control_assert(dev->rst);
	return r;
	}

	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);

	i2c_dw_disable(dev);

	pm_runtime_dont_use_autosuspend(&pdev->dev);
	pm_runtime_put_sync(&pdev->dev);
	if (!dev->pm_disabled)
	pm_runtime_disable(&pdev->dev);
	if (!IS_ERR_OR_NULL(dev->rst))
	reset_control_assert(dev->rst);

	i2c_dw_remove_lock_support(dev);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id dw_i2c_of_match[] = {
	{ .compatible = "snps,designware-i2c", },
	{},
	};
	MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
	#endif

	#ifdef CONFIG_PM_SLEEP
	static int dw_i2c_plat_prepare(struct device *dev)
	{
	return pm_runtime_suspended(dev);
	}

	static void dw_i2c_plat_complete(struct device *dev)
	{
	if (dev->power.direct_complete)
	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 platform_device *pdev = to_platform_device(dev);
	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

	i2c_dw_disable(i_dev);
	i2c_dw_plat_prepare_clk(i_dev, false);

	return 0;
	}

	static int dw_i2c_plat_resume(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);

	i2c_dw_plat_prepare_clk(i_dev, true);
	i2c_dw_init(i_dev);

	return 0;
	}

	static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
	.prepare = dw_i2c_plat_prepare,
	.complete = dw_i2c_plat_complete,
	SET_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);
	}
	subsys_initcall(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");