drivers/usb/misc/usb251xb.c - kernel/msm-4.19 - Gitiles

 /*
  * Driver for Microchip USB251xB USB 2.0 Hi-Speed Hub Controller
  * Configuration via SMBus.
  *
  * Copyright (c) 2017 SKIDATA AG
  *
  * This work is based on the USB3503 driver by Dongjin Kim and
  * a not-accepted patch by Fabien Lahoudere, see:
  * https://patchwork.kernel.org/patch/9257715/
  *
  * 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/delay.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/nls.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/slab.h>

 /* Internal Register Set Addresses & Default Values acc. to DS00001692C */
 #define USB251XB_ADDR_VENDOR_ID_LSB	0x00
 #define USB251XB_ADDR_VENDOR_ID_MSB	0x01
 #define USB251XB_DEF_VENDOR_ID		0x0424

 #define USB251XB_ADDR_PRODUCT_ID_LSB	0x02
 #define USB251XB_ADDR_PRODUCT_ID_MSB	0x03
 #define USB251XB_DEF_PRODUCT_ID_12	0x2512 /* USB2512B/12Bi */
 #define USB251XB_DEF_PRODUCT_ID_13	0x2513 /* USB2513B/13Bi */
 #define USB251XB_DEF_PRODUCT_ID_14	0x2514 /* USB2514B/14Bi */

 #define USB251XB_ADDR_DEVICE_ID_LSB	0x04
 #define USB251XB_ADDR_DEVICE_ID_MSB	0x05
 #define USB251XB_DEF_DEVICE_ID		0x0BB3

 #define USB251XB_ADDR_CONFIG_DATA_1	0x06
 #define USB251XB_DEF_CONFIG_DATA_1	0x9B
 #define USB251XB_ADDR_CONFIG_DATA_2	0x07
 #define USB251XB_DEF_CONFIG_DATA_2	0x20
 #define USB251XB_ADDR_CONFIG_DATA_3	0x08
 #define USB251XB_DEF_CONFIG_DATA_3	0x02

 #define USB251XB_ADDR_NON_REMOVABLE_DEVICES	0x09
 #define USB251XB_DEF_NON_REMOVABLE_DEVICES	0x00

 #define USB251XB_ADDR_PORT_DISABLE_SELF	0x0A
 #define USB251XB_DEF_PORT_DISABLE_SELF	0x00
 #define USB251XB_ADDR_PORT_DISABLE_BUS	0x0B
 #define USB251XB_DEF_PORT_DISABLE_BUS	0x00

 #define USB251XB_ADDR_MAX_POWER_SELF	0x0C
 #define USB251XB_DEF_MAX_POWER_SELF	0x01
 #define USB251XB_ADDR_MAX_POWER_BUS	0x0D
 #define USB251XB_DEF_MAX_POWER_BUS	0x32

 #define USB251XB_ADDR_MAX_CURRENT_SELF	0x0E
 #define USB251XB_DEF_MAX_CURRENT_SELF	0x01
 #define USB251XB_ADDR_MAX_CURRENT_BUS	0x0F
 #define USB251XB_DEF_MAX_CURRENT_BUS	0x32

 #define USB251XB_ADDR_POWER_ON_TIME	0x10
 #define USB251XB_DEF_POWER_ON_TIME	0x32

 #define USB251XB_ADDR_LANGUAGE_ID_HIGH	0x11
 #define USB251XB_ADDR_LANGUAGE_ID_LOW	0x12
 #define USB251XB_DEF_LANGUAGE_ID	0x0000

 #define USB251XB_STRING_BUFSIZE			62
 #define USB251XB_ADDR_MANUFACTURER_STRING_LEN	0x13
 #define USB251XB_ADDR_MANUFACTURER_STRING	0x16
 #define USB251XB_DEF_MANUFACTURER_STRING	"Microchip"

 #define USB251XB_ADDR_PRODUCT_STRING_LEN	0x14
 #define USB251XB_ADDR_PRODUCT_STRING		0x54
 #define USB251XB_DEF_PRODUCT_STRING		"USB251xB/xBi"

 #define USB251XB_ADDR_SERIAL_STRING_LEN		0x15
 #define USB251XB_ADDR_SERIAL_STRING		0x92
 #define USB251XB_DEF_SERIAL_STRING		""

 #define USB251XB_ADDR_BATTERY_CHARGING_ENABLE	0xD0
 #define USB251XB_DEF_BATTERY_CHARGING_ENABLE	0x00

 #define USB251XB_ADDR_BOOST_UP	0xF6
 #define USB251XB_DEF_BOOST_UP	0x00
 #define USB251XB_ADDR_BOOST_X	0xF8
 #define USB251XB_DEF_BOOST_X	0x00

 #define USB251XB_ADDR_PORT_SWAP	0xFA
 #define USB251XB_DEF_PORT_SWAP	0x00

 #define USB251XB_ADDR_PORT_MAP_12	0xFB
 #define USB251XB_DEF_PORT_MAP_12	0x00
 #define USB251XB_ADDR_PORT_MAP_34	0xFC
 #define USB251XB_DEF_PORT_MAP_34	0x00 /* USB2513B/i & USB2514B/i only */

 #define USB251XB_ADDR_STATUS_COMMAND		0xFF
 #define USB251XB_STATUS_COMMAND_SMBUS_DOWN	0x04
 #define USB251XB_STATUS_COMMAND_RESET		0x02
 #define USB251XB_STATUS_COMMAND_ATTACH		0x01

 #define USB251XB_I2C_REG_SZ	0x100
 #define USB251XB_I2C_WRITE_SZ	0x10

 #define DRIVER_NAME	"usb251xb"
 #define DRIVER_DESC	"Microchip USB 2.0 Hi-Speed Hub Controller"
 #define DRIVER_VERSION	"1.0"

 struct usb251xb {
 	struct device *dev;
 	struct i2c_client *i2c;
 	u8 skip_config;
 	int gpio_reset;
 	u16 vendor_id;
 	u16 product_id;
 	u16 device_id;
 	u8  conf_data1;
 	u8  conf_data2;
 	u8  conf_data3;
 	u8  non_rem_dev;
 	u8  port_disable_sp;
 	u8  port_disable_bp;
 	u8  max_power_sp;
 	u8  max_power_bp;
 	u8  max_current_sp;
 	u8  max_current_bp;
 	u8  power_on_time;
 	u16 lang_id;
 	u8 manufacturer_len;
 	u8 product_len;
 	u8 serial_len;
 	char manufacturer[USB251XB_STRING_BUFSIZE];
 	char product[USB251XB_STRING_BUFSIZE];
 	char serial[USB251XB_STRING_BUFSIZE];
 	u8  bat_charge_en;
 	u8  boost_up;
 	u8  boost_x;
 	u8  port_swap;
 	u8  port_map12;
 	u8  port_map34;
 	u8  status;
 };

 struct usb251xb_data {
 	u16 product_id;
 	char product_str[USB251XB_STRING_BUFSIZE / 2]; /* ASCII string */
 };

 static const struct usb251xb_data usb2512b_data = {
 	.product_id = 0x2512,
 	.product_str = "USB2512B",
 };

 static const struct usb251xb_data usb2512bi_data = {
 	.product_id = 0x2512,
 	.product_str = "USB2512Bi",
 };

 static const struct usb251xb_data usb2513b_data = {
 	.product_id = 0x2513,
 	.product_str = "USB2513B",
 };

 static const struct usb251xb_data usb2513bi_data = {
 	.product_id = 0x2513,
 	.product_str = "USB2513Bi",
 };

 static const struct usb251xb_data usb2514b_data = {
 	.product_id = 0x2514,
 	.product_str = "USB2514B",
 };

 static const struct usb251xb_data usb2514bi_data = {
 	.product_id = 0x2514,
 	.product_str = "USB2514Bi",
 };

 static void usb251xb_reset(struct usb251xb *hub, int state)
 {
 	if (!gpio_is_valid(hub->gpio_reset))
 		return;

 	gpio_set_value_cansleep(hub->gpio_reset, state);

 	/* wait for hub recovery/stabilization */
 	if (state)
 		usleep_range(500, 750);	/* >=500us at power on */
 	else
 		usleep_range(1, 10);	/* >=1us at power down */
 }

 static int usb251xb_connect(struct usb251xb *hub)
 {
 	struct device *dev = hub->dev;
 	int err, i;
 	char i2c_wb[USB251XB_I2C_REG_SZ];

 	memset(i2c_wb, 0, USB251XB_I2C_REG_SZ);

 	if (hub->skip_config) {
 		dev_info(dev, "Skip hub configuration, only attach.\n");
 		i2c_wb[0] = 0x01;
 		i2c_wb[1] = USB251XB_STATUS_COMMAND_ATTACH;

 		usb251xb_reset(hub, 1);

 		err = i2c_smbus_write_i2c_block_data(hub->i2c,
 				USB251XB_ADDR_STATUS_COMMAND, 2, i2c_wb);
 		if (err) {
 			dev_err(dev, "attaching hub failed: %d\n", err);
 			return err;
 		}
 		return 0;
 	}

 	i2c_wb[USB251XB_ADDR_VENDOR_ID_MSB]     = (hub->vendor_id >> 8) & 0xFF;
 	i2c_wb[USB251XB_ADDR_VENDOR_ID_LSB]     = hub->vendor_id & 0xFF;
 	i2c_wb[USB251XB_ADDR_PRODUCT_ID_MSB]    = (hub->product_id >> 8) & 0xFF;
 	i2c_wb[USB251XB_ADDR_PRODUCT_ID_LSB]    = hub->product_id & 0xFF;
 	i2c_wb[USB251XB_ADDR_DEVICE_ID_MSB]     = (hub->device_id >> 8) & 0xFF;
 	i2c_wb[USB251XB_ADDR_DEVICE_ID_LSB]     = hub->device_id & 0xFF;
 	i2c_wb[USB251XB_ADDR_CONFIG_DATA_1]     = hub->conf_data1;
 	i2c_wb[USB251XB_ADDR_CONFIG_DATA_2]     = hub->conf_data2;
 	i2c_wb[USB251XB_ADDR_CONFIG_DATA_3]     = hub->conf_data3;
 	i2c_wb[USB251XB_ADDR_NON_REMOVABLE_DEVICES] = hub->non_rem_dev;
 	i2c_wb[USB251XB_ADDR_PORT_DISABLE_SELF] = hub->port_disable_sp;
 	i2c_wb[USB251XB_ADDR_PORT_DISABLE_BUS]  = hub->port_disable_bp;
 	i2c_wb[USB251XB_ADDR_MAX_POWER_SELF]    = hub->max_power_sp;
 	i2c_wb[USB251XB_ADDR_MAX_POWER_BUS]     = hub->max_power_bp;
 	i2c_wb[USB251XB_ADDR_MAX_CURRENT_SELF]  = hub->max_current_sp;
 	i2c_wb[USB251XB_ADDR_MAX_CURRENT_BUS]   = hub->max_current_bp;
 	i2c_wb[USB251XB_ADDR_POWER_ON_TIME]     = hub->power_on_time;
 	i2c_wb[USB251XB_ADDR_LANGUAGE_ID_HIGH]  = (hub->lang_id >> 8) & 0xFF;
 	i2c_wb[USB251XB_ADDR_LANGUAGE_ID_LOW]   = hub->lang_id & 0xFF;
 	i2c_wb[USB251XB_ADDR_MANUFACTURER_STRING_LEN] = hub->manufacturer_len;
 	i2c_wb[USB251XB_ADDR_PRODUCT_STRING_LEN]      = hub->product_len;
 	i2c_wb[USB251XB_ADDR_SERIAL_STRING_LEN]       = hub->serial_len;
 	memcpy(&i2c_wb[USB251XB_ADDR_MANUFACTURER_STRING], hub->manufacturer,
 	       USB251XB_STRING_BUFSIZE);
 	memcpy(&i2c_wb[USB251XB_ADDR_SERIAL_STRING], hub->serial,
 	       USB251XB_STRING_BUFSIZE);
 	memcpy(&i2c_wb[USB251XB_ADDR_PRODUCT_STRING], hub->product,
 	       USB251XB_STRING_BUFSIZE);
 	i2c_wb[USB251XB_ADDR_BATTERY_CHARGING_ENABLE] = hub->bat_charge_en;
 	i2c_wb[USB251XB_ADDR_BOOST_UP]          = hub->boost_up;
 	i2c_wb[USB251XB_ADDR_BOOST_X]           = hub->boost_x;
 	i2c_wb[USB251XB_ADDR_PORT_SWAP]         = hub->port_swap;
 	i2c_wb[USB251XB_ADDR_PORT_MAP_12]       = hub->port_map12;
 	i2c_wb[USB251XB_ADDR_PORT_MAP_34]       = hub->port_map34;
 	i2c_wb[USB251XB_ADDR_STATUS_COMMAND] = USB251XB_STATUS_COMMAND_ATTACH;

 	usb251xb_reset(hub, 1);

 	/* write registers */
 	for (i = 0; i < (USB251XB_I2C_REG_SZ / USB251XB_I2C_WRITE_SZ); i++) {
 		int offset = i * USB251XB_I2C_WRITE_SZ;
 		char wbuf[USB251XB_I2C_WRITE_SZ + 1];

 		/* The first data byte transferred tells the hub how many data
 		 * bytes will follow (byte count).
 		 */
 		wbuf[0] = USB251XB_I2C_WRITE_SZ;
 		memcpy(&wbuf[1], &i2c_wb[offset], USB251XB_I2C_WRITE_SZ);

 		dev_dbg(dev, "writing %d byte block %d to 0x%02X\n",
 			USB251XB_I2C_WRITE_SZ, i, offset);

 		err = i2c_smbus_write_i2c_block_data(hub->i2c, offset,
 						     USB251XB_I2C_WRITE_SZ + 1,
 						     wbuf);
 		if (err)
 			goto out_err;
 	}

 	dev_info(dev, "Hub configuration was successful.\n");
 	return 0;

 out_err:
 	dev_err(dev, "configuring block %d failed: %d\n", i, err);
 	return err;
 }

 #ifdef CONFIG_OF
 static int usb251xb_get_ofdata(struct usb251xb *hub,
 			       struct usb251xb_data *data)
 {
 	struct device *dev = hub->dev;
 	struct device_node *np = dev->of_node;
 	int len, err, i;
 	u32 *property_u32 = NULL;
 	const u32 *cproperty_u32;
 	const char *cproperty_char;
 	char str[USB251XB_STRING_BUFSIZE / 2];

 	if (!np) {
 		dev_err(dev, "failed to get ofdata\n");
 		return -ENODEV;
 	}

 	if (of_get_property(np, "skip-config", NULL))
 		hub->skip_config = 1;
 	else
 		hub->skip_config = 0;

 	hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
 	if (hub->gpio_reset == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
 	if (gpio_is_valid(hub->gpio_reset)) {
 		err = devm_gpio_request_one(dev, hub->gpio_reset,
 					    GPIOF_OUT_INIT_LOW,
 					    "usb251xb reset");
 		if (err) {
 			dev_err(dev,
 				"unable to request GPIO %d as reset pin (%d)\n",
 				hub->gpio_reset, err);
 			return err;
 		}
 	}

 	if (of_property_read_u16_array(np, "vendor-id", &hub->vendor_id, 1))
 		hub->vendor_id = USB251XB_DEF_VENDOR_ID;

 	if (of_property_read_u16_array(np, "product-id",
 				       &hub->product_id, 1))
 		hub->product_id = data->product_id;

 	if (of_property_read_u16_array(np, "device-id", &hub->device_id, 1))
 		hub->device_id = USB251XB_DEF_DEVICE_ID;

 	hub->conf_data1 = USB251XB_DEF_CONFIG_DATA_1;
 	if (of_get_property(np, "self-powered", NULL)) {
 		hub->conf_data1 |= BIT(7);

 		/* Configure Over-Current sens when self-powered */
 		hub->conf_data1 &= ~BIT(2);
 		if (of_get_property(np, "ganged-sensing", NULL))
 			hub->conf_data1 &= ~BIT(1);
 		else if (of_get_property(np, "individual-sensing", NULL))
 			hub->conf_data1 |= BIT(1);
 	} else if (of_get_property(np, "bus-powered", NULL)) {
 		hub->conf_data1 &= ~BIT(7);

 		/* Disable Over-Current sense when bus-powered */
 		hub->conf_data1 |= BIT(2);
 	}

 	if (of_get_property(np, "disable-hi-speed", NULL))
 		hub->conf_data1 |= BIT(5);

 	if (of_get_property(np, "multi-tt", NULL))
 		hub->conf_data1 |= BIT(4);
 	else if (of_get_property(np, "single-tt", NULL))
 		hub->conf_data1 &= ~BIT(4);

 	if (of_get_property(np, "disable-eop", NULL))
 		hub->conf_data1 |= BIT(3);

 	if (of_get_property(np, "individual-port-switching", NULL))
 		hub->conf_data1 |= BIT(0);
 	else if (of_get_property(np, "ganged-port-switching", NULL))
 		hub->conf_data1 &= ~BIT(0);

 	hub->conf_data2 = USB251XB_DEF_CONFIG_DATA_2;
 	if (of_get_property(np, "dynamic-power-switching", NULL))
 		hub->conf_data2 |= BIT(7);

 	if (of_get_property(np, "oc-delay-100us", NULL)) {
 		hub->conf_data2 &= ~BIT(5);
 		hub->conf_data2 &= ~BIT(4);
 	} else if (of_get_property(np, "oc-delay-4ms", NULL)) {
 		hub->conf_data2 &= ~BIT(5);
 		hub->conf_data2 |= BIT(4);
 	} else if (of_get_property(np, "oc-delay-8ms", NULL)) {
 		hub->conf_data2 |= BIT(5);
 		hub->conf_data2 &= ~BIT(4);
 	} else if (of_get_property(np, "oc-delay-16ms", NULL)) {
 		hub->conf_data2 |= BIT(5);
 		hub->conf_data2 |= BIT(4);
 	}

 	if (of_get_property(np, "compound-device", NULL))
 		hub->conf_data2 |= BIT(3);

 	hub->conf_data3 = USB251XB_DEF_CONFIG_DATA_3;
 	if (of_get_property(np, "port-mapping-mode", NULL))
 		hub->conf_data3 |= BIT(3);

 	if (of_get_property(np, "string-support", NULL))
 		hub->conf_data3 |= BIT(0);

 	hub->non_rem_dev = USB251XB_DEF_NON_REMOVABLE_DEVICES;
 	cproperty_u32 = of_get_property(np, "non-removable-ports", &len);
 	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
 		for (i = 0; i < len / sizeof(u32); i++) {
 			u32 port = be32_to_cpu(cproperty_u32[i]);

 			if ((port >= 1) && (port <= 4))
 				hub->non_rem_dev |= BIT(port);
 		}
 	}

 	hub->port_disable_sp = USB251XB_DEF_PORT_DISABLE_SELF;
 	cproperty_u32 = of_get_property(np, "sp-disabled-ports", &len);
 	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
 		for (i = 0; i < len / sizeof(u32); i++) {
 			u32 port = be32_to_cpu(cproperty_u32[i]);

 			if ((port >= 1) && (port <= 4))
 				hub->port_disable_sp |= BIT(port);
 		}
 	}

 	hub->port_disable_bp = USB251XB_DEF_PORT_DISABLE_BUS;
 	cproperty_u32 = of_get_property(np, "bp-disabled-ports", &len);
 	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
 		for (i = 0; i < len / sizeof(u32); i++) {
 			u32 port = be32_to_cpu(cproperty_u32[i]);

 			if ((port >= 1) && (port <= 4))
 				hub->port_disable_bp |= BIT(port);
 		}
 	}

 	hub->max_power_sp = USB251XB_DEF_MAX_POWER_SELF;
 	if (!of_property_read_u32(np, "max-sp-power", property_u32))
 		hub->max_power_sp = min_t(u8, be32_to_cpu(*property_u32) / 2,
 					  250);

 	hub->max_power_bp = USB251XB_DEF_MAX_POWER_BUS;
 	if (!of_property_read_u32(np, "max-bp-power", property_u32))
 		hub->max_power_bp = min_t(u8, be32_to_cpu(*property_u32) / 2,
 					  250);

 	hub->max_current_sp = USB251XB_DEF_MAX_CURRENT_SELF;
 	if (!of_property_read_u32(np, "max-sp-current", property_u32))
 		hub->max_current_sp = min_t(u8, be32_to_cpu(*property_u32) / 2,
 					    250);

 	hub->max_current_bp = USB251XB_DEF_MAX_CURRENT_BUS;
 	if (!of_property_read_u32(np, "max-bp-current", property_u32))
 		hub->max_current_bp = min_t(u8, be32_to_cpu(*property_u32) / 2,
 					    250);

 	hub->power_on_time = USB251XB_DEF_POWER_ON_TIME;
 	if (!of_property_read_u32(np, "power-on-time", property_u32))
 		hub->power_on_time = min_t(u8, be32_to_cpu(*property_u32) / 2,
 					   255);

 	if (of_property_read_u16_array(np, "language-id", &hub->lang_id, 1))
 		hub->lang_id = USB251XB_DEF_LANGUAGE_ID;

 	cproperty_char = of_get_property(np, "manufacturer", NULL);
 	strlcpy(str, cproperty_char ? : USB251XB_DEF_MANUFACTURER_STRING,
 		sizeof(str));
 	hub->manufacturer_len = strlen(str) & 0xFF;
 	memset(hub->manufacturer, 0, USB251XB_STRING_BUFSIZE);
 	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
 	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
 			      (wchar_t *)hub->manufacturer,
 			      USB251XB_STRING_BUFSIZE);

 	cproperty_char = of_get_property(np, "product", NULL);
 	strlcpy(str, cproperty_char ? : data->product_str, sizeof(str));
 	hub->product_len = strlen(str) & 0xFF;
 	memset(hub->product, 0, USB251XB_STRING_BUFSIZE);
 	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
 	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
 			      (wchar_t *)hub->product,
 			      USB251XB_STRING_BUFSIZE);

 	cproperty_char = of_get_property(np, "serial", NULL);
 	strlcpy(str, cproperty_char ? : USB251XB_DEF_SERIAL_STRING,
 		sizeof(str));
 	hub->serial_len = strlen(str) & 0xFF;
 	memset(hub->serial, 0, USB251XB_STRING_BUFSIZE);
 	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
 	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
 			      (wchar_t *)hub->serial,
 			      USB251XB_STRING_BUFSIZE);

 	/* The following parameters are currently not exposed to devicetree, but
 	 * may be as soon as needed.
 	 */
 	hub->bat_charge_en = USB251XB_DEF_BATTERY_CHARGING_ENABLE;
 	hub->boost_up = USB251XB_DEF_BOOST_UP;
 	hub->boost_x = USB251XB_DEF_BOOST_X;
 	hub->port_swap = USB251XB_DEF_PORT_SWAP;
 	hub->port_map12 = USB251XB_DEF_PORT_MAP_12;
 	hub->port_map34 = USB251XB_DEF_PORT_MAP_34;

 	return 0;
 }

 static const struct of_device_id usb251xb_of_match[] = {
 	{
 		.compatible = "microchip,usb2512b",
 		.data = &usb2512b_data,
 	}, {
 		.compatible = "microchip,usb2512bi",
 		.data = &usb2512bi_data,
 	}, {
 		.compatible = "microchip,usb2513b",
 		.data = &usb2513b_data,
 	}, {
 		.compatible = "microchip,usb2513bi",
 		.data = &usb2513bi_data,
 	}, {
 		.compatible = "microchip,usb2514b",
 		.data = &usb2514b_data,
 	}, {
 		.compatible = "microchip,usb2514bi",
 		.data = &usb2514bi_data,
 	}, {
 		/* sentinel */
 	}
 };
 MODULE_DEVICE_TABLE(of, usb251xb_of_match);
 #else /* CONFIG_OF */
 static int usb251xb_get_ofdata(struct usb251xb *hub,
 			       struct usb251xb_data *data)
 {
 	return 0;
 }
 #endif /* CONFIG_OF */

 static int usb251xb_probe(struct usb251xb *hub)
 {
 	struct device *dev = hub->dev;
 	struct device_node *np = dev->of_node;
 	const struct of_device_id *of_id = of_match_device(usb251xb_of_match,
 							   dev);
 	int err;

 	if (np) {
 		err = usb251xb_get_ofdata(hub,
 					  (struct usb251xb_data *)of_id->data);
 		if (err) {
 			dev_err(dev, "failed to get ofdata: %d\n", err);
 			return err;
 		}
 	}

 	err = usb251xb_connect(hub);
 	if (err) {
 		dev_err(dev, "Failed to connect hub (%d)\n", err);
 		return err;
 	}

 	dev_info(dev, "Hub probed successfully\n");

 	return 0;
 }

 static int usb251xb_i2c_probe(struct i2c_client *i2c,
 			      const struct i2c_device_id *id)
 {
 	struct usb251xb *hub;

 	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb251xb), GFP_KERNEL);
 	if (!hub)
 		return -ENOMEM;

 	i2c_set_clientdata(i2c, hub);
 	hub->dev = &i2c->dev;
 	hub->i2c = i2c;

 	return usb251xb_probe(hub);
 }

 static const struct i2c_device_id usb251xb_id[] = {
 	{ "usb2512b", 0 },
 	{ "usb2512bi", 0 },
 	{ "usb2513b", 0 },
 	{ "usb2513bi", 0 },
 	{ "usb2514b", 0 },
 	{ "usb2514bi", 0 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(i2c, usb251xb_id);

 static struct i2c_driver usb251xb_i2c_driver = {
 	.driver = {
 		.name = DRIVER_NAME,
 		.of_match_table = of_match_ptr(usb251xb_of_match),
 	},
 	.probe    = usb251xb_i2c_probe,
 	.id_table = usb251xb_id,
 };

 module_i2c_driver(usb251xb_i2c_driver);

 MODULE_AUTHOR("Richard Leitner <richard.leitner@skidata.com>");
 MODULE_DESCRIPTION("USB251xB/xBi USB 2.0 Hub Controller Driver");
 MODULE_LICENSE("GPL");
	/*
	* Driver for Microchip USB251xB USB 2.0 Hi-Speed Hub Controller
	* Configuration via SMBus.
	*
	* Copyright (c) 2017 SKIDATA AG
	*
	* This work is based on the USB3503 driver by Dongjin Kim and
	* a not-accepted patch by Fabien Lahoudere, see:
	* https://patchwork.kernel.org/patch/9257715/
	*
	* 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/delay.h>
	#include <linux/gpio.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/nls.h>
	#include <linux/of_device.h>
	#include <linux/of_gpio.h>
	#include <linux/slab.h>

	/* Internal Register Set Addresses & Default Values acc. to DS00001692C */
	#define USB251XB_ADDR_VENDOR_ID_LSB 0x00
	#define USB251XB_ADDR_VENDOR_ID_MSB 0x01
	#define USB251XB_DEF_VENDOR_ID 0x0424

	#define USB251XB_ADDR_PRODUCT_ID_LSB 0x02
	#define USB251XB_ADDR_PRODUCT_ID_MSB 0x03
	#define USB251XB_DEF_PRODUCT_ID_12 0x2512 /* USB2512B/12Bi */
	#define USB251XB_DEF_PRODUCT_ID_13 0x2513 /* USB2513B/13Bi */
	#define USB251XB_DEF_PRODUCT_ID_14 0x2514 /* USB2514B/14Bi */

	#define USB251XB_ADDR_DEVICE_ID_LSB 0x04
	#define USB251XB_ADDR_DEVICE_ID_MSB 0x05
	#define USB251XB_DEF_DEVICE_ID 0x0BB3

	#define USB251XB_ADDR_CONFIG_DATA_1 0x06
	#define USB251XB_DEF_CONFIG_DATA_1 0x9B
	#define USB251XB_ADDR_CONFIG_DATA_2 0x07
	#define USB251XB_DEF_CONFIG_DATA_2 0x20
	#define USB251XB_ADDR_CONFIG_DATA_3 0x08
	#define USB251XB_DEF_CONFIG_DATA_3 0x02

	#define USB251XB_ADDR_NON_REMOVABLE_DEVICES 0x09
	#define USB251XB_DEF_NON_REMOVABLE_DEVICES 0x00

	#define USB251XB_ADDR_PORT_DISABLE_SELF 0x0A
	#define USB251XB_DEF_PORT_DISABLE_SELF 0x00
	#define USB251XB_ADDR_PORT_DISABLE_BUS 0x0B
	#define USB251XB_DEF_PORT_DISABLE_BUS 0x00

	#define USB251XB_ADDR_MAX_POWER_SELF 0x0C
	#define USB251XB_DEF_MAX_POWER_SELF 0x01
	#define USB251XB_ADDR_MAX_POWER_BUS 0x0D
	#define USB251XB_DEF_MAX_POWER_BUS 0x32

	#define USB251XB_ADDR_MAX_CURRENT_SELF 0x0E
	#define USB251XB_DEF_MAX_CURRENT_SELF 0x01
	#define USB251XB_ADDR_MAX_CURRENT_BUS 0x0F
	#define USB251XB_DEF_MAX_CURRENT_BUS 0x32

	#define USB251XB_ADDR_POWER_ON_TIME 0x10
	#define USB251XB_DEF_POWER_ON_TIME 0x32

	#define USB251XB_ADDR_LANGUAGE_ID_HIGH 0x11
	#define USB251XB_ADDR_LANGUAGE_ID_LOW 0x12
	#define USB251XB_DEF_LANGUAGE_ID 0x0000

	#define USB251XB_STRING_BUFSIZE 62
	#define USB251XB_ADDR_MANUFACTURER_STRING_LEN 0x13
	#define USB251XB_ADDR_MANUFACTURER_STRING 0x16
	#define USB251XB_DEF_MANUFACTURER_STRING "Microchip"

	#define USB251XB_ADDR_PRODUCT_STRING_LEN 0x14
	#define USB251XB_ADDR_PRODUCT_STRING 0x54
	#define USB251XB_DEF_PRODUCT_STRING "USB251xB/xBi"

	#define USB251XB_ADDR_SERIAL_STRING_LEN 0x15
	#define USB251XB_ADDR_SERIAL_STRING 0x92
	#define USB251XB_DEF_SERIAL_STRING ""

	#define USB251XB_ADDR_BATTERY_CHARGING_ENABLE 0xD0
	#define USB251XB_DEF_BATTERY_CHARGING_ENABLE 0x00

	#define USB251XB_ADDR_BOOST_UP 0xF6
	#define USB251XB_DEF_BOOST_UP 0x00
	#define USB251XB_ADDR_BOOST_X 0xF8
	#define USB251XB_DEF_BOOST_X 0x00

	#define USB251XB_ADDR_PORT_SWAP 0xFA
	#define USB251XB_DEF_PORT_SWAP 0x00

	#define USB251XB_ADDR_PORT_MAP_12 0xFB
	#define USB251XB_DEF_PORT_MAP_12 0x00
	#define USB251XB_ADDR_PORT_MAP_34 0xFC
	#define USB251XB_DEF_PORT_MAP_34 0x00 /* USB2513B/i & USB2514B/i only */

	#define USB251XB_ADDR_STATUS_COMMAND 0xFF
	#define USB251XB_STATUS_COMMAND_SMBUS_DOWN 0x04
	#define USB251XB_STATUS_COMMAND_RESET 0x02
	#define USB251XB_STATUS_COMMAND_ATTACH 0x01

	#define USB251XB_I2C_REG_SZ 0x100
	#define USB251XB_I2C_WRITE_SZ 0x10

	#define DRIVER_NAME "usb251xb"
	#define DRIVER_DESC "Microchip USB 2.0 Hi-Speed Hub Controller"
	#define DRIVER_VERSION "1.0"

	struct usb251xb {
	struct device *dev;
	struct i2c_client *i2c;
	u8 skip_config;
	int gpio_reset;
	u16 vendor_id;
	u16 product_id;
	u16 device_id;
	u8 conf_data1;
	u8 conf_data2;
	u8 conf_data3;
	u8 non_rem_dev;
	u8 port_disable_sp;
	u8 port_disable_bp;
	u8 max_power_sp;
	u8 max_power_bp;
	u8 max_current_sp;
	u8 max_current_bp;
	u8 power_on_time;
	u16 lang_id;
	u8 manufacturer_len;
	u8 product_len;
	u8 serial_len;
	char manufacturer[USB251XB_STRING_BUFSIZE];
	char product[USB251XB_STRING_BUFSIZE];
	char serial[USB251XB_STRING_BUFSIZE];
	u8 bat_charge_en;
	u8 boost_up;
	u8 boost_x;
	u8 port_swap;
	u8 port_map12;
	u8 port_map34;
	u8 status;
	};

	struct usb251xb_data {
	u16 product_id;
	char product_str[USB251XB_STRING_BUFSIZE / 2]; /* ASCII string */
	};

	static const struct usb251xb_data usb2512b_data = {
	.product_id = 0x2512,
	.product_str = "USB2512B",
	};

	static const struct usb251xb_data usb2512bi_data = {
	.product_id = 0x2512,
	.product_str = "USB2512Bi",
	};

	static const struct usb251xb_data usb2513b_data = {
	.product_id = 0x2513,
	.product_str = "USB2513B",
	};

	static const struct usb251xb_data usb2513bi_data = {
	.product_id = 0x2513,
	.product_str = "USB2513Bi",
	};

	static const struct usb251xb_data usb2514b_data = {
	.product_id = 0x2514,
	.product_str = "USB2514B",
	};

	static const struct usb251xb_data usb2514bi_data = {
	.product_id = 0x2514,
	.product_str = "USB2514Bi",
	};

	static void usb251xb_reset(struct usb251xb *hub, int state)
	{
	if (!gpio_is_valid(hub->gpio_reset))
	return;

	gpio_set_value_cansleep(hub->gpio_reset, state);

	/* wait for hub recovery/stabilization */
	if (state)
	usleep_range(500, 750); /* >=500us at power on */
	else
	usleep_range(1, 10); /* >=1us at power down */
	}

	static int usb251xb_connect(struct usb251xb *hub)
	{
	struct device *dev = hub->dev;
	int err, i;
	char i2c_wb[USB251XB_I2C_REG_SZ];

	memset(i2c_wb, 0, USB251XB_I2C_REG_SZ);

	if (hub->skip_config) {
	dev_info(dev, "Skip hub configuration, only attach.\n");
	i2c_wb[0] = 0x01;
	i2c_wb[1] = USB251XB_STATUS_COMMAND_ATTACH;

	usb251xb_reset(hub, 1);

	err = i2c_smbus_write_i2c_block_data(hub->i2c,
	USB251XB_ADDR_STATUS_COMMAND, 2, i2c_wb);
	if (err) {
	dev_err(dev, "attaching hub failed: %d\n", err);
	return err;
	}
	return 0;
	}

	i2c_wb[USB251XB_ADDR_VENDOR_ID_MSB] = (hub->vendor_id >> 8) & 0xFF;
	i2c_wb[USB251XB_ADDR_VENDOR_ID_LSB] = hub->vendor_id & 0xFF;
	i2c_wb[USB251XB_ADDR_PRODUCT_ID_MSB] = (hub->product_id >> 8) & 0xFF;
	i2c_wb[USB251XB_ADDR_PRODUCT_ID_LSB] = hub->product_id & 0xFF;
	i2c_wb[USB251XB_ADDR_DEVICE_ID_MSB] = (hub->device_id >> 8) & 0xFF;
	i2c_wb[USB251XB_ADDR_DEVICE_ID_LSB] = hub->device_id & 0xFF;
	i2c_wb[USB251XB_ADDR_CONFIG_DATA_1] = hub->conf_data1;
	i2c_wb[USB251XB_ADDR_CONFIG_DATA_2] = hub->conf_data2;
	i2c_wb[USB251XB_ADDR_CONFIG_DATA_3] = hub->conf_data3;
	i2c_wb[USB251XB_ADDR_NON_REMOVABLE_DEVICES] = hub->non_rem_dev;
	i2c_wb[USB251XB_ADDR_PORT_DISABLE_SELF] = hub->port_disable_sp;
	i2c_wb[USB251XB_ADDR_PORT_DISABLE_BUS] = hub->port_disable_bp;
	i2c_wb[USB251XB_ADDR_MAX_POWER_SELF] = hub->max_power_sp;
	i2c_wb[USB251XB_ADDR_MAX_POWER_BUS] = hub->max_power_bp;
	i2c_wb[USB251XB_ADDR_MAX_CURRENT_SELF] = hub->max_current_sp;
	i2c_wb[USB251XB_ADDR_MAX_CURRENT_BUS] = hub->max_current_bp;
	i2c_wb[USB251XB_ADDR_POWER_ON_TIME] = hub->power_on_time;
	i2c_wb[USB251XB_ADDR_LANGUAGE_ID_HIGH] = (hub->lang_id >> 8) & 0xFF;
	i2c_wb[USB251XB_ADDR_LANGUAGE_ID_LOW] = hub->lang_id & 0xFF;
	i2c_wb[USB251XB_ADDR_MANUFACTURER_STRING_LEN] = hub->manufacturer_len;
	i2c_wb[USB251XB_ADDR_PRODUCT_STRING_LEN] = hub->product_len;
	i2c_wb[USB251XB_ADDR_SERIAL_STRING_LEN] = hub->serial_len;
	memcpy(&i2c_wb[USB251XB_ADDR_MANUFACTURER_STRING], hub->manufacturer,
	USB251XB_STRING_BUFSIZE);
	memcpy(&i2c_wb[USB251XB_ADDR_SERIAL_STRING], hub->serial,
	USB251XB_STRING_BUFSIZE);
	memcpy(&i2c_wb[USB251XB_ADDR_PRODUCT_STRING], hub->product,
	USB251XB_STRING_BUFSIZE);
	i2c_wb[USB251XB_ADDR_BATTERY_CHARGING_ENABLE] = hub->bat_charge_en;
	i2c_wb[USB251XB_ADDR_BOOST_UP] = hub->boost_up;
	i2c_wb[USB251XB_ADDR_BOOST_X] = hub->boost_x;
	i2c_wb[USB251XB_ADDR_PORT_SWAP] = hub->port_swap;
	i2c_wb[USB251XB_ADDR_PORT_MAP_12] = hub->port_map12;
	i2c_wb[USB251XB_ADDR_PORT_MAP_34] = hub->port_map34;
	i2c_wb[USB251XB_ADDR_STATUS_COMMAND] = USB251XB_STATUS_COMMAND_ATTACH;

	usb251xb_reset(hub, 1);

	/* write registers */
	for (i = 0; i < (USB251XB_I2C_REG_SZ / USB251XB_I2C_WRITE_SZ); i++) {
	int offset = i * USB251XB_I2C_WRITE_SZ;
	char wbuf[USB251XB_I2C_WRITE_SZ + 1];

	/* The first data byte transferred tells the hub how many data
	* bytes will follow (byte count).
	*/
	wbuf[0] = USB251XB_I2C_WRITE_SZ;
	memcpy(&wbuf[1], &i2c_wb[offset], USB251XB_I2C_WRITE_SZ);

	dev_dbg(dev, "writing %d byte block %d to 0x%02X\n",
	USB251XB_I2C_WRITE_SZ, i, offset);

	err = i2c_smbus_write_i2c_block_data(hub->i2c, offset,
	USB251XB_I2C_WRITE_SZ + 1,
	wbuf);
	if (err)
	goto out_err;
	}

	dev_info(dev, "Hub configuration was successful.\n");
	return 0;

	out_err:
	dev_err(dev, "configuring block %d failed: %d\n", i, err);
	return err;
	}

	#ifdef CONFIG_OF
	static int usb251xb_get_ofdata(struct usb251xb *hub,
	struct usb251xb_data *data)
	{
	struct device *dev = hub->dev;
	struct device_node *np = dev->of_node;
	int len, err, i;
	u32 *property_u32 = NULL;
	const u32 *cproperty_u32;
	const char *cproperty_char;
	char str[USB251XB_STRING_BUFSIZE / 2];

	if (!np) {
	dev_err(dev, "failed to get ofdata\n");
	return -ENODEV;
	}

	if (of_get_property(np, "skip-config", NULL))
	hub->skip_config = 1;
	else
	hub->skip_config = 0;

	hub->gpio_reset = of_get_named_gpio(np, "reset-gpios", 0);
	if (hub->gpio_reset == -EPROBE_DEFER)
	return -EPROBE_DEFER;
	if (gpio_is_valid(hub->gpio_reset)) {
	err = devm_gpio_request_one(dev, hub->gpio_reset,
	GPIOF_OUT_INIT_LOW,
	"usb251xb reset");
	if (err) {
	dev_err(dev,
	"unable to request GPIO %d as reset pin (%d)\n",
	hub->gpio_reset, err);
	return err;
	}
	}

	if (of_property_read_u16_array(np, "vendor-id", &hub->vendor_id, 1))
	hub->vendor_id = USB251XB_DEF_VENDOR_ID;

	if (of_property_read_u16_array(np, "product-id",
	&hub->product_id, 1))
	hub->product_id = data->product_id;

	if (of_property_read_u16_array(np, "device-id", &hub->device_id, 1))
	hub->device_id = USB251XB_DEF_DEVICE_ID;

	hub->conf_data1 = USB251XB_DEF_CONFIG_DATA_1;
	if (of_get_property(np, "self-powered", NULL)) {
	hub->conf_data1 \|= BIT(7);

	/* Configure Over-Current sens when self-powered */
	hub->conf_data1 &= ~BIT(2);
	if (of_get_property(np, "ganged-sensing", NULL))
	hub->conf_data1 &= ~BIT(1);
	else if (of_get_property(np, "individual-sensing", NULL))
	hub->conf_data1 \|= BIT(1);
	} else if (of_get_property(np, "bus-powered", NULL)) {
	hub->conf_data1 &= ~BIT(7);

	/* Disable Over-Current sense when bus-powered */
	hub->conf_data1 \|= BIT(2);
	}

	if (of_get_property(np, "disable-hi-speed", NULL))
	hub->conf_data1 \|= BIT(5);

	if (of_get_property(np, "multi-tt", NULL))
	hub->conf_data1 \|= BIT(4);
	else if (of_get_property(np, "single-tt", NULL))
	hub->conf_data1 &= ~BIT(4);

	if (of_get_property(np, "disable-eop", NULL))
	hub->conf_data1 \|= BIT(3);

	if (of_get_property(np, "individual-port-switching", NULL))
	hub->conf_data1 \|= BIT(0);
	else if (of_get_property(np, "ganged-port-switching", NULL))
	hub->conf_data1 &= ~BIT(0);

	hub->conf_data2 = USB251XB_DEF_CONFIG_DATA_2;
	if (of_get_property(np, "dynamic-power-switching", NULL))
	hub->conf_data2 \|= BIT(7);

	if (of_get_property(np, "oc-delay-100us", NULL)) {
	hub->conf_data2 &= ~BIT(5);
	hub->conf_data2 &= ~BIT(4);
	} else if (of_get_property(np, "oc-delay-4ms", NULL)) {
	hub->conf_data2 &= ~BIT(5);
	hub->conf_data2 \|= BIT(4);
	} else if (of_get_property(np, "oc-delay-8ms", NULL)) {
	hub->conf_data2 \|= BIT(5);
	hub->conf_data2 &= ~BIT(4);
	} else if (of_get_property(np, "oc-delay-16ms", NULL)) {
	hub->conf_data2 \|= BIT(5);
	hub->conf_data2 \|= BIT(4);
	}

	if (of_get_property(np, "compound-device", NULL))
	hub->conf_data2 \|= BIT(3);

	hub->conf_data3 = USB251XB_DEF_CONFIG_DATA_3;
	if (of_get_property(np, "port-mapping-mode", NULL))
	hub->conf_data3 \|= BIT(3);

	if (of_get_property(np, "string-support", NULL))
	hub->conf_data3 \|= BIT(0);

	hub->non_rem_dev = USB251XB_DEF_NON_REMOVABLE_DEVICES;
	cproperty_u32 = of_get_property(np, "non-removable-ports", &len);
	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
	for (i = 0; i < len / sizeof(u32); i++) {
	u32 port = be32_to_cpu(cproperty_u32[i]);

	if ((port >= 1) && (port <= 4))
	hub->non_rem_dev \|= BIT(port);
	}
	}

	hub->port_disable_sp = USB251XB_DEF_PORT_DISABLE_SELF;
	cproperty_u32 = of_get_property(np, "sp-disabled-ports", &len);
	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
	for (i = 0; i < len / sizeof(u32); i++) {
	u32 port = be32_to_cpu(cproperty_u32[i]);

	if ((port >= 1) && (port <= 4))
	hub->port_disable_sp \|= BIT(port);
	}
	}

	hub->port_disable_bp = USB251XB_DEF_PORT_DISABLE_BUS;
	cproperty_u32 = of_get_property(np, "bp-disabled-ports", &len);
	if (cproperty_u32 && (len / sizeof(u32)) > 0) {
	for (i = 0; i < len / sizeof(u32); i++) {
	u32 port = be32_to_cpu(cproperty_u32[i]);

	if ((port >= 1) && (port <= 4))
	hub->port_disable_bp \|= BIT(port);
	}
	}

	hub->max_power_sp = USB251XB_DEF_MAX_POWER_SELF;
	if (!of_property_read_u32(np, "max-sp-power", property_u32))
	hub->max_power_sp = min_t(u8, be32_to_cpu(*property_u32) / 2,
	250);

	hub->max_power_bp = USB251XB_DEF_MAX_POWER_BUS;
	if (!of_property_read_u32(np, "max-bp-power", property_u32))
	hub->max_power_bp = min_t(u8, be32_to_cpu(*property_u32) / 2,
	250);

	hub->max_current_sp = USB251XB_DEF_MAX_CURRENT_SELF;
	if (!of_property_read_u32(np, "max-sp-current", property_u32))
	hub->max_current_sp = min_t(u8, be32_to_cpu(*property_u32) / 2,
	250);

	hub->max_current_bp = USB251XB_DEF_MAX_CURRENT_BUS;
	if (!of_property_read_u32(np, "max-bp-current", property_u32))
	hub->max_current_bp = min_t(u8, be32_to_cpu(*property_u32) / 2,
	250);

	hub->power_on_time = USB251XB_DEF_POWER_ON_TIME;
	if (!of_property_read_u32(np, "power-on-time", property_u32))
	hub->power_on_time = min_t(u8, be32_to_cpu(*property_u32) / 2,
	255);

	if (of_property_read_u16_array(np, "language-id", &hub->lang_id, 1))
	hub->lang_id = USB251XB_DEF_LANGUAGE_ID;

	cproperty_char = of_get_property(np, "manufacturer", NULL);
	strlcpy(str, cproperty_char ? : USB251XB_DEF_MANUFACTURER_STRING,
	sizeof(str));
	hub->manufacturer_len = strlen(str) & 0xFF;
	memset(hub->manufacturer, 0, USB251XB_STRING_BUFSIZE);
	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
	(wchar_t *)hub->manufacturer,
	USB251XB_STRING_BUFSIZE);

	cproperty_char = of_get_property(np, "product", NULL);
	strlcpy(str, cproperty_char ? : data->product_str, sizeof(str));
	hub->product_len = strlen(str) & 0xFF;
	memset(hub->product, 0, USB251XB_STRING_BUFSIZE);
	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
	(wchar_t *)hub->product,
	USB251XB_STRING_BUFSIZE);

	cproperty_char = of_get_property(np, "serial", NULL);
	strlcpy(str, cproperty_char ? : USB251XB_DEF_SERIAL_STRING,
	sizeof(str));
	hub->serial_len = strlen(str) & 0xFF;
	memset(hub->serial, 0, USB251XB_STRING_BUFSIZE);
	len = min_t(size_t, USB251XB_STRING_BUFSIZE / 2, strlen(str));
	len = utf8s_to_utf16s(str, len, UTF16_LITTLE_ENDIAN,
	(wchar_t *)hub->serial,
	USB251XB_STRING_BUFSIZE);

	/* The following parameters are currently not exposed to devicetree, but
	* may be as soon as needed.
	*/
	hub->bat_charge_en = USB251XB_DEF_BATTERY_CHARGING_ENABLE;
	hub->boost_up = USB251XB_DEF_BOOST_UP;
	hub->boost_x = USB251XB_DEF_BOOST_X;
	hub->port_swap = USB251XB_DEF_PORT_SWAP;
	hub->port_map12 = USB251XB_DEF_PORT_MAP_12;
	hub->port_map34 = USB251XB_DEF_PORT_MAP_34;

	return 0;
	}

	static const struct of_device_id usb251xb_of_match[] = {
	{
	.compatible = "microchip,usb2512b",
	.data = &usb2512b_data,
	}, {
	.compatible = "microchip,usb2512bi",
	.data = &usb2512bi_data,
	}, {
	.compatible = "microchip,usb2513b",
	.data = &usb2513b_data,
	}, {
	.compatible = "microchip,usb2513bi",
	.data = &usb2513bi_data,
	}, {
	.compatible = "microchip,usb2514b",
	.data = &usb2514b_data,
	}, {
	.compatible = "microchip,usb2514bi",
	.data = &usb2514bi_data,
	}, {
	/* sentinel */
	}
	};
	MODULE_DEVICE_TABLE(of, usb251xb_of_match);
	#else /* CONFIG_OF */
	static int usb251xb_get_ofdata(struct usb251xb *hub,
	struct usb251xb_data *data)
	{
	return 0;
	}
	#endif /* CONFIG_OF */

	static int usb251xb_probe(struct usb251xb *hub)
	{
	struct device *dev = hub->dev;
	struct device_node *np = dev->of_node;
	const struct of_device_id *of_id = of_match_device(usb251xb_of_match,
	dev);
	int err;

	if (np) {
	err = usb251xb_get_ofdata(hub,
	(struct usb251xb_data *)of_id->data);
	if (err) {
	dev_err(dev, "failed to get ofdata: %d\n", err);
	return err;
	}
	}

	err = usb251xb_connect(hub);
	if (err) {
	dev_err(dev, "Failed to connect hub (%d)\n", err);
	return err;
	}

	dev_info(dev, "Hub probed successfully\n");

	return 0;
	}

	static int usb251xb_i2c_probe(struct i2c_client *i2c,
	const struct i2c_device_id *id)
	{
	struct usb251xb *hub;

	hub = devm_kzalloc(&i2c->dev, sizeof(struct usb251xb), GFP_KERNEL);
	if (!hub)
	return -ENOMEM;

	i2c_set_clientdata(i2c, hub);
	hub->dev = &i2c->dev;
	hub->i2c = i2c;

	return usb251xb_probe(hub);
	}

	static const struct i2c_device_id usb251xb_id[] = {
	{ "usb2512b", 0 },
	{ "usb2512bi", 0 },
	{ "usb2513b", 0 },
	{ "usb2513bi", 0 },
	{ "usb2514b", 0 },
	{ "usb2514bi", 0 },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(i2c, usb251xb_id);

	static struct i2c_driver usb251xb_i2c_driver = {
	.driver = {
	.name = DRIVER_NAME,
	.of_match_table = of_match_ptr(usb251xb_of_match),
	},
	.probe = usb251xb_i2c_probe,
	.id_table = usb251xb_id,
	};

	module_i2c_driver(usb251xb_i2c_driver);

	MODULE_AUTHOR("Richard Leitner <richard.leitner@skidata.com>");
	MODULE_DESCRIPTION("USB251xB/xBi USB 2.0 Hub Controller Driver");
	MODULE_LICENSE("GPL");