drivers/usb/misc/usb3503.c - arm/linux - Git at Google

 /*
  * Driver for SMSC USB3503 USB 2.0 hub controller driver
  *
  * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/clk.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/usb3503.h>
 #include <linux/regmap.h>

 #define USB3503_VIDL		0x00
 #define USB3503_VIDM		0x01
 #define USB3503_PIDL		0x02
 #define USB3503_PIDM		0x03
 #define USB3503_DIDL		0x04
 #define USB3503_DIDM		0x05

 #define USB3503_CFG1		0x06
 #define USB3503_SELF_BUS_PWR	(1 << 7)

 #define USB3503_CFG2		0x07
 #define USB3503_CFG3		0x08
 #define USB3503_NRD		0x09

 #define USB3503_PDS		0x0a

 #define USB3503_SP_ILOCK	0xe7
 #define USB3503_SPILOCK_CONNECT	(1 << 1)
 #define USB3503_SPILOCK_CONFIG	(1 << 0)

 #define USB3503_CFGP		0xee
 #define USB3503_CLKSUSP		(1 << 7)

 #define USB3503_RESET		0xff

 struct usb3503 {
 	enum usb3503_mode	mode;
 	struct regmap		*regmap;
 	struct device		*dev;
 	struct clk		*clk;
 	u8	port_off_mask;
 	int	gpio_intn;
 	int	gpio_reset;
 	int	gpio_connect;
 	bool	secondary_ref_clk;
 };

 static int usb3503_reset(struct usb3503 *hub, int state)
 {
 	if (!state && gpio_is_valid(hub->gpio_connect))
 		gpio_set_value_cansleep(hub->gpio_connect, 0);

 	if (gpio_is_valid(hub->gpio_reset))
 		gpio_set_value_cansleep(hub->gpio_reset, state);

 	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
 	if (state)
 		usleep_range(4000, 10000);

 	return 0;
 }

 static int usb3503_connect(struct usb3503 *hub)
 {
 	struct device *dev = hub->dev;
 	int err;

 	usb3503_reset(hub, 1);

 	if (hub->regmap) {
 		/* SP_ILOCK: set connect_n, config_n for config */
 		err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
 			   (USB3503_SPILOCK_CONNECT
 				 | USB3503_SPILOCK_CONFIG));
 		if (err < 0) {
 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
 			return err;
 		}

 		/* PDS : Set the ports which are disabled in self-powered mode. */
 		if (hub->port_off_mask) {
 			err = regmap_update_bits(hub->regmap, USB3503_PDS,
 					hub->port_off_mask,
 					hub->port_off_mask);
 			if (err < 0) {
 				dev_err(dev, "PDS failed (%d)\n", err);
 				return err;
 			}
 		}

 		/* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
 		err = regmap_update_bits(hub->regmap, USB3503_CFG1,
 					 USB3503_SELF_BUS_PWR,
 					 USB3503_SELF_BUS_PWR);
 		if (err < 0) {
 			dev_err(dev, "CFG1 failed (%d)\n", err);
 			return err;
 		}

 		/* SP_LOCK: clear connect_n, config_n for hub connect */
 		err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
 					 (USB3503_SPILOCK_CONNECT
 					  | USB3503_SPILOCK_CONFIG), 0);
 		if (err < 0) {
 			dev_err(dev, "SP_ILOCK failed (%d)\n", err);
 			return err;
 		}
 	}

 	if (gpio_is_valid(hub->gpio_connect))
 		gpio_set_value_cansleep(hub->gpio_connect, 1);

 	hub->mode = USB3503_MODE_HUB;
 	dev_info(dev, "switched to HUB mode\n");

 	return 0;
 }

 static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
 {
 	struct device *dev = hub->dev;
 	int err = 0;

 	switch (mode) {
 	case USB3503_MODE_HUB:
 		err = usb3503_connect(hub);
 		break;

 	case USB3503_MODE_STANDBY:
 		usb3503_reset(hub, 0);
 		dev_info(dev, "switched to STANDBY mode\n");
 		break;

 	default:
 		dev_err(dev, "unknown mode is requested\n");
 		err = -EINVAL;
 		break;
 	}

 	return err;
 }

 static const struct regmap_config usb3503_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,

 	.max_register = USB3503_RESET,
 };

 static int usb3503_probe(struct usb3503 *hub)
 {
 	struct device *dev = hub->dev;
 	struct usb3503_platform_data *pdata = dev_get_platdata(dev);
 	struct device_node *np = dev->of_node;
 	int err;
 	u32 mode = USB3503_MODE_HUB;
 	const u32 *property;
 	int len;

 	if (pdata) {
 		hub->port_off_mask	= pdata->port_off_mask;
 		hub->gpio_intn		= pdata->gpio_intn;
 		hub->gpio_connect	= pdata->gpio_connect;
 		hub->gpio_reset		= pdata->gpio_reset;
 		hub->mode		= pdata->initial_mode;
 	} else if (np) {
 		struct clk *clk;
 		u32 rate = 0;
 		hub->port_off_mask = 0;

 		if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
 			switch (rate) {
 			case 38400000:
 			case 26000000:
 			case 19200000:
 			case 12000000:
 				hub->secondary_ref_clk = 0;
 				break;
 			case 24000000:
 			case 27000000:
 			case 25000000:
 			case 50000000:
 				hub->secondary_ref_clk = 1;
 				break;
 			default:
 				dev_err(dev,
 					"unsupported reference clock rate (%d)\n",
 					(int) rate);
 				return -EINVAL;
 			}
 		}

 		clk = devm_clk_get(dev, "refclk");
 		if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
 			dev_err(dev, "unable to request refclk (%ld)\n",
 					PTR_ERR(clk));
 			return PTR_ERR(clk);
 		}

 		if (!IS_ERR(clk)) {
 			hub->clk = clk;

 			if (rate != 0) {
 				err = clk_set_rate(hub->clk, rate);
 				if (err) {
 					dev_err(dev,
 						"unable to set reference clock rate to %d\n",
 						(int) rate);
 					return err;
 				}
 			}

 			err = clk_prepare_enable(hub->clk);
 			if (err) {
 				dev_err(dev,
 					"unable to enable reference clock\n");
 				return err;
 			}
 		}

 		property = of_get_property(np, "disabled-ports", &len);
 		if (property && (len / sizeof(u32)) > 0) {
 			int i;
 			for (i = 0; i < len / sizeof(u32); i++) {
 				u32 port = be32_to_cpu(property[i]);
 				if ((1 <= port) && (port <= 3))
 					hub->port_off_mask |= (1 << port);
 			}
 		}

 		hub->gpio_intn	= of_get_named_gpio(np, "intn-gpios", 0);
 		if (hub->gpio_intn == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
 		if (hub->gpio_connect == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
 		if (hub->gpio_reset == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
 		of_property_read_u32(np, "initial-mode", &mode);
 		hub->mode = mode;
 	}

 	if (hub->port_off_mask && !hub->regmap)
 		dev_err(dev, "Ports disabled with no control interface\n");

 	if (gpio_is_valid(hub->gpio_intn)) {
 		int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
 						   GPIOF_OUT_INIT_HIGH;
 		err = devm_gpio_request_one(dev, hub->gpio_intn, val,
 					    "usb3503 intn");
 		if (err) {
 			dev_err(dev,
 				"unable to request GPIO %d as interrupt pin (%d)\n",
 				hub->gpio_intn, err);
 			return err;
 		}
 	}

 	if (gpio_is_valid(hub->gpio_connect)) {
 		err = devm_gpio_request_one(dev, hub->gpio_connect,
 				GPIOF_OUT_INIT_LOW, "usb3503 connect");
 		if (err) {
 			dev_err(dev,
 				"unable to request GPIO %d as connect pin (%d)\n",
 				hub->gpio_connect, err);
 			return err;
 		}
 	}

 	if (gpio_is_valid(hub->gpio_reset)) {
 		err = devm_gpio_request_one(dev, hub->gpio_reset,
 				GPIOF_OUT_INIT_LOW, "usb3503 reset");
 		if (err) {
 			dev_err(dev,
 				"unable to request GPIO %d as reset pin (%d)\n",
 				hub->gpio_reset, err);
 			return err;
 		}
 	}

 	usb3503_switch_mode(hub, hub->mode);

 	dev_info(dev, "%s: probed in %s mode\n", __func__,
 			(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");

 	return 0;
 }

 static int usb3503_i2c_probe(struct i2c_client *i2c,
 			     const struct i2c_device_id *id)
 {
 	struct usb3503 *hub;
 	int err;

 	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
 	if (!hub)
 		return -ENOMEM;

 	i2c_set_clientdata(i2c, hub);
 	hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
 	if (IS_ERR(hub->regmap)) {
 		err = PTR_ERR(hub->regmap);
 		dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
 		return err;
 	}
 	hub->dev = &i2c->dev;

 	return usb3503_probe(hub);
 }

 static int usb3503_i2c_remove(struct i2c_client *i2c)
 {
 	struct usb3503 *hub;

 	hub = i2c_get_clientdata(i2c);
 	if (hub->clk)
 		clk_disable_unprepare(hub->clk);

 	return 0;
 }

 static int usb3503_platform_probe(struct platform_device *pdev)
 {
 	struct usb3503 *hub;

 	hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
 	if (!hub)
 		return -ENOMEM;
 	hub->dev = &pdev->dev;
 	platform_set_drvdata(pdev, hub);

 	return usb3503_probe(hub);
 }

 static int usb3503_platform_remove(struct platform_device *pdev)
 {
 	struct usb3503 *hub;

 	hub = platform_get_drvdata(pdev);
 	if (hub->clk)
 		clk_disable_unprepare(hub->clk);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int usb3503_i2c_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct usb3503 *hub = i2c_get_clientdata(client);

 	usb3503_switch_mode(hub, USB3503_MODE_STANDBY);

 	if (hub->clk)
 		clk_disable_unprepare(hub->clk);

 	return 0;
 }

 static int usb3503_i2c_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct usb3503 *hub = i2c_get_clientdata(client);

 	if (hub->clk)
 		clk_prepare_enable(hub->clk);

 	usb3503_switch_mode(hub, hub->mode);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
 		usb3503_i2c_resume);

 static const struct i2c_device_id usb3503_id[] = {
 	{ USB3503_I2C_NAME, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, usb3503_id);

 #ifdef CONFIG_OF
 static const struct of_device_id usb3503_of_match[] = {
 	{ .compatible = "smsc,usb3503", },
 	{ .compatible = "smsc,usb3503a", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, usb3503_of_match);
 #endif

 static struct i2c_driver usb3503_i2c_driver = {
 	.driver = {
 		.name = USB3503_I2C_NAME,
 		.pm = &usb3503_i2c_pm_ops,
 		.of_match_table = of_match_ptr(usb3503_of_match),
 	},
 	.probe		= usb3503_i2c_probe,
 	.remove		= usb3503_i2c_remove,
 	.id_table	= usb3503_id,
 };

 static struct platform_driver usb3503_platform_driver = {
 	.driver = {
 		.name = USB3503_I2C_NAME,
 		.of_match_table = of_match_ptr(usb3503_of_match),
 	},
 	.probe		= usb3503_platform_probe,
 	.remove		= usb3503_platform_remove,
 };

 static int __init usb3503_init(void)
 {
 	int err;

 	err = i2c_add_driver(&usb3503_i2c_driver);
 	if (err != 0)
 		pr_err("usb3503: Failed to register I2C driver: %d\n", err);

 	err = platform_driver_register(&usb3503_platform_driver);
 	if (err != 0)
 		pr_err("usb3503: Failed to register platform driver: %d\n",
 		       err);

 	return 0;
 }
 module_init(usb3503_init);

 static void __exit usb3503_exit(void)
 {
 	platform_driver_unregister(&usb3503_platform_driver);
 	i2c_del_driver(&usb3503_i2c_driver);
 }
 module_exit(usb3503_exit);

 MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
 MODULE_DESCRIPTION("USB3503 USB HUB driver");
 MODULE_LICENSE("GPL");
	/*
	* Driver for SMSC USB3503 USB 2.0 hub controller driver
	*
	* Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/clk.h>
	#include <linux/i2c.h>
	#include <linux/gpio.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/of_gpio.h>
	#include <linux/platform_device.h>
	#include <linux/platform_data/usb3503.h>
	#include <linux/regmap.h>

	#define USB3503_VIDL 0x00
	#define USB3503_VIDM 0x01
	#define USB3503_PIDL 0x02
	#define USB3503_PIDM 0x03
	#define USB3503_DIDL 0x04
	#define USB3503_DIDM 0x05

	#define USB3503_CFG1 0x06
	#define USB3503_SELF_BUS_PWR (1 << 7)

	#define USB3503_CFG2 0x07
	#define USB3503_CFG3 0x08
	#define USB3503_NRD 0x09

	#define USB3503_PDS 0x0a

	#define USB3503_SP_ILOCK 0xe7
	#define USB3503_SPILOCK_CONNECT (1 << 1)
	#define USB3503_SPILOCK_CONFIG (1 << 0)

	#define USB3503_CFGP 0xee
	#define USB3503_CLKSUSP (1 << 7)

	#define USB3503_RESET 0xff

	struct usb3503 {
	enum usb3503_mode mode;
	struct regmap *regmap;
	struct device *dev;
	struct clk *clk;
	u8 port_off_mask;
	int gpio_intn;
	int gpio_reset;
	int gpio_connect;
	bool secondary_ref_clk;
	};

	static int usb3503_reset(struct usb3503 *hub, int state)
	{
	if (!state && gpio_is_valid(hub->gpio_connect))
	gpio_set_value_cansleep(hub->gpio_connect, 0);

	if (gpio_is_valid(hub->gpio_reset))
	gpio_set_value_cansleep(hub->gpio_reset, state);

	/* Wait T_HUBINIT == 4ms for hub logic to stabilize */
	if (state)
	usleep_range(4000, 10000);

	return 0;
	}

	static int usb3503_connect(struct usb3503 *hub)
	{
	struct device *dev = hub->dev;
	int err;

	usb3503_reset(hub, 1);

	if (hub->regmap) {
	/* SP_ILOCK: set connect_n, config_n for config */
	err = regmap_write(hub->regmap, USB3503_SP_ILOCK,
	(USB3503_SPILOCK_CONNECT
	\| USB3503_SPILOCK_CONFIG));
	if (err < 0) {
	dev_err(dev, "SP_ILOCK failed (%d)\n", err);
	return err;
	}

	/* PDS : Set the ports which are disabled in self-powered mode. */
	if (hub->port_off_mask) {
	err = regmap_update_bits(hub->regmap, USB3503_PDS,
	hub->port_off_mask,
	hub->port_off_mask);
	if (err < 0) {
	dev_err(dev, "PDS failed (%d)\n", err);
	return err;
	}
	}

	/* CFG1 : Set SELF_BUS_PWR, this enables self-powered operation. */
	err = regmap_update_bits(hub->regmap, USB3503_CFG1,
	USB3503_SELF_BUS_PWR,
	USB3503_SELF_BUS_PWR);
	if (err < 0) {
	dev_err(dev, "CFG1 failed (%d)\n", err);
	return err;
	}

	/* SP_LOCK: clear connect_n, config_n for hub connect */
	err = regmap_update_bits(hub->regmap, USB3503_SP_ILOCK,
	(USB3503_SPILOCK_CONNECT
	\| USB3503_SPILOCK_CONFIG), 0);
	if (err < 0) {
	dev_err(dev, "SP_ILOCK failed (%d)\n", err);
	return err;
	}
	}

	if (gpio_is_valid(hub->gpio_connect))
	gpio_set_value_cansleep(hub->gpio_connect, 1);

	hub->mode = USB3503_MODE_HUB;
	dev_info(dev, "switched to HUB mode\n");

	return 0;
	}

	static int usb3503_switch_mode(struct usb3503 *hub, enum usb3503_mode mode)
	{
	struct device *dev = hub->dev;
	int err = 0;

	switch (mode) {
	case USB3503_MODE_HUB:
	err = usb3503_connect(hub);
	break;

	case USB3503_MODE_STANDBY:
	usb3503_reset(hub, 0);
	dev_info(dev, "switched to STANDBY mode\n");
	break;

	default:
	dev_err(dev, "unknown mode is requested\n");
	err = -EINVAL;
	break;
	}

	return err;
	}

	static const struct regmap_config usb3503_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = USB3503_RESET,
	};

	static int usb3503_probe(struct usb3503 *hub)
	{
	struct device *dev = hub->dev;
	struct usb3503_platform_data *pdata = dev_get_platdata(dev);
	struct device_node *np = dev->of_node;
	int err;
	u32 mode = USB3503_MODE_HUB;
	const u32 *property;
	int len;

	if (pdata) {
	hub->port_off_mask = pdata->port_off_mask;
	hub->gpio_intn = pdata->gpio_intn;
	hub->gpio_connect = pdata->gpio_connect;
	hub->gpio_reset = pdata->gpio_reset;
	hub->mode = pdata->initial_mode;
	} else if (np) {
	struct clk *clk;
	u32 rate = 0;
	hub->port_off_mask = 0;

	if (!of_property_read_u32(np, "refclk-frequency", &rate)) {
	switch (rate) {
	case 38400000:
	case 26000000:
	case 19200000:
	case 12000000:
	hub->secondary_ref_clk = 0;
	break;
	case 24000000:
	case 27000000:
	case 25000000:
	case 50000000:
	hub->secondary_ref_clk = 1;
	break;
	default:
	dev_err(dev,
	"unsupported reference clock rate (%d)\n",
	(int) rate);
	return -EINVAL;
	}
	}

	clk = devm_clk_get(dev, "refclk");
	if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) {
	dev_err(dev, "unable to request refclk (%ld)\n",
	PTR_ERR(clk));
	return PTR_ERR(clk);
	}

	if (!IS_ERR(clk)) {
	hub->clk = clk;

	if (rate != 0) {
	err = clk_set_rate(hub->clk, rate);
	if (err) {
	dev_err(dev,
	"unable to set reference clock rate to %d\n",
	(int) rate);
	return err;
	}
	}

	err = clk_prepare_enable(hub->clk);
	if (err) {
	dev_err(dev,
	"unable to enable reference clock\n");
	return err;
	}
	}

	property = of_get_property(np, "disabled-ports", &len);
	if (property && (len / sizeof(u32)) > 0) {
	int i;
	for (i = 0; i < len / sizeof(u32); i++) {
	u32 port = be32_to_cpu(property[i]);
	if ((1 <= port) && (port <= 3))
	hub->port_off_mask \|= (1 << port);
	}
	}

	hub->gpio_intn = of_get_named_gpio(np, "intn-gpios", 0);
	if (hub->gpio_intn == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	hub->gpio_connect = of_get_named_gpio(np, "connect-gpios", 0);
	if (hub->gpio_connect == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
	if (hub->gpio_reset == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	of_property_read_u32(np, "initial-mode", &mode);
	hub->mode = mode;
	}

	if (hub->port_off_mask && !hub->regmap)
	dev_err(dev, "Ports disabled with no control interface\n");

	if (gpio_is_valid(hub->gpio_intn)) {
	int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW :
	GPIOF_OUT_INIT_HIGH;
	err = devm_gpio_request_one(dev, hub->gpio_intn, val,
	"usb3503 intn");
	if (err) {
	dev_err(dev,
	"unable to request GPIO %d as interrupt pin (%d)\n",
	hub->gpio_intn, err);
	return err;
	}
	}

	if (gpio_is_valid(hub->gpio_connect)) {
	err = devm_gpio_request_one(dev, hub->gpio_connect,
	GPIOF_OUT_INIT_LOW, "usb3503 connect");
	if (err) {
	dev_err(dev,
	"unable to request GPIO %d as connect pin (%d)\n",
	hub->gpio_connect, err);
	return err;
	}
	}

	if (gpio_is_valid(hub->gpio_reset)) {
	err = devm_gpio_request_one(dev, hub->gpio_reset,
	GPIOF_OUT_INIT_LOW, "usb3503 reset");
	if (err) {
	dev_err(dev,
	"unable to request GPIO %d as reset pin (%d)\n",
	hub->gpio_reset, err);
	return err;
	}
	}

	usb3503_switch_mode(hub, hub->mode);

	dev_info(dev, "%s: probed in %s mode\n", __func__,
	(hub->mode == USB3503_MODE_HUB) ? "hub" : "standby");

	return 0;
	}

	static int usb3503_i2c_probe(struct i2c_client *i2c,
	const struct i2c_device_id *id)
	{
	struct usb3503 *hub;
	int err;

	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb3503), GFP_KERNEL);
	if (!hub)
	return -ENOMEM;

	i2c_set_clientdata(i2c, hub);
	hub->regmap = devm_regmap_init_i2c(i2c, &usb3503_regmap_config);
	if (IS_ERR(hub->regmap)) {
	err = PTR_ERR(hub->regmap);
	dev_err(&i2c->dev, "Failed to initialise regmap: %d\n", err);
	return err;
	}
	hub->dev = &i2c->dev;

	return usb3503_probe(hub);
	}

	static int usb3503_i2c_remove(struct i2c_client *i2c)
	{
	struct usb3503 *hub;

	hub = i2c_get_clientdata(i2c);
	if (hub->clk)
	clk_disable_unprepare(hub->clk);

	return 0;
	}

	static int usb3503_platform_probe(struct platform_device *pdev)
	{
	struct usb3503 *hub;

	hub = devm_kzalloc(&pdev->dev, sizeof(struct usb3503), GFP_KERNEL);
	if (!hub)
	return -ENOMEM;
	hub->dev = &pdev->dev;
	platform_set_drvdata(pdev, hub);

	return usb3503_probe(hub);
	}

	static int usb3503_platform_remove(struct platform_device *pdev)
	{
	struct usb3503 *hub;

	hub = platform_get_drvdata(pdev);
	if (hub->clk)
	clk_disable_unprepare(hub->clk);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int usb3503_i2c_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct usb3503 *hub = i2c_get_clientdata(client);

	usb3503_switch_mode(hub, USB3503_MODE_STANDBY);

	if (hub->clk)
	clk_disable_unprepare(hub->clk);

	return 0;
	}

	static int usb3503_i2c_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct usb3503 *hub = i2c_get_clientdata(client);

	if (hub->clk)
	clk_prepare_enable(hub->clk);

	usb3503_switch_mode(hub, hub->mode);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(usb3503_i2c_pm_ops, usb3503_i2c_suspend,
	usb3503_i2c_resume);

	static const struct i2c_device_id usb3503_id[] = {
	{ USB3503_I2C_NAME, 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, usb3503_id);

	#ifdef CONFIG_OF
	static const struct of_device_id usb3503_of_match[] = {
	{ .compatible = "smsc,usb3503", },
	{ .compatible = "smsc,usb3503a", },
	{},
	};
	MODULE_DEVICE_TABLE(of, usb3503_of_match);
	#endif

	static struct i2c_driver usb3503_i2c_driver = {
	.driver = {
	.name = USB3503_I2C_NAME,
	.pm = &usb3503_i2c_pm_ops,
	.of_match_table = of_match_ptr(usb3503_of_match),
	},
	.probe = usb3503_i2c_probe,
	.remove = usb3503_i2c_remove,
	.id_table = usb3503_id,
	};

	static struct platform_driver usb3503_platform_driver = {
	.driver = {
	.name = USB3503_I2C_NAME,
	.of_match_table = of_match_ptr(usb3503_of_match),
	},
	.probe = usb3503_platform_probe,
	.remove = usb3503_platform_remove,
	};

	static int __init usb3503_init(void)
	{
	int err;

	err = i2c_add_driver(&usb3503_i2c_driver);
	if (err != 0)
	pr_err("usb3503: Failed to register I2C driver: %d\n", err);

	err = platform_driver_register(&usb3503_platform_driver);
	if (err != 0)
	pr_err("usb3503: Failed to register platform driver: %d\n",
	err);

	return 0;
	}
	module_init(usb3503_init);

	static void __exit usb3503_exit(void)
	{
	platform_driver_unregister(&usb3503_platform_driver);
	i2c_del_driver(&usb3503_i2c_driver);
	}
	module_exit(usb3503_exit);

	MODULE_AUTHOR("Dongjin Kim <tobetter@gmail.com>");
	MODULE_DESCRIPTION("USB3503 USB HUB driver");
	MODULE_LICENSE("GPL");