// SPDX-License-Identifier: GPL-2.0+
/*
 * 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/
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/nls.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.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_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_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_57  0xF7
#define USB251XB_DEF_BOOST_57   0x00
#define USB251XB_ADDR_BOOST_14  0xF8
#define USB251XB_DEF_BOOST_14   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 /* USB251{3B/i,4B/i,7/i} only */
#define USB251XB_ADDR_PORT_MAP_56       0xFD
#define USB251XB_DEF_PORT_MAP_56        0x00 /* USB2517/i only */
#define USB251XB_ADDR_PORT_MAP_7        0xFE
#define USB251XB_DEF_PORT_MAP_7         0x00 /* USB2517/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"

struct usb251xb {
        struct device *dev;
        struct i2c_client *i2c;
        struct regulator *vdd;
        u8 skip_config;
        struct gpio_desc *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_57;
        u8  boost_14;
        u8  port_swap;
        u8  port_map12;
        u8  port_map34;
        u8  port_map56;
        u8  port_map7;
        u8  status;
};

struct usb251xb_data {
        u16 product_id;
        u8 port_cnt;
        bool led_support;
        bool bat_support;
        char product_str[USB251XB_STRING_BUFSIZE / 2]; /* ASCII string */
};

static const struct usb251xb_data usb2422_data = {
        .product_id = 0x2422,
        .port_cnt = 2,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2422",
};

static const struct usb251xb_data usb2512b_data = {
        .product_id = 0x2512,
        .port_cnt = 2,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2512B",
};

static const struct usb251xb_data usb2512bi_data = {
        .product_id = 0x2512,
        .port_cnt = 2,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2512Bi",
};

static const struct usb251xb_data usb2513b_data = {
        .product_id = 0x2513,
        .port_cnt = 3,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2513B",
};

static const struct usb251xb_data usb2513bi_data = {
        .product_id = 0x2513,
        .port_cnt = 3,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2513Bi",
};

static const struct usb251xb_data usb2514b_data = {
        .product_id = 0x2514,
        .port_cnt = 4,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2514B",
};

static const struct usb251xb_data usb2514bi_data = {
        .product_id = 0x2514,
        .port_cnt = 4,
        .led_support = false,
        .bat_support = true,
        .product_str = "USB2514Bi",
};

static const struct usb251xb_data usb2517_data = {
        .product_id = 0x2517,
        .port_cnt = 7,
        .led_support = true,
        .bat_support = false,
        .product_str = "USB2517",
};

static const struct usb251xb_data usb2517i_data = {
        .product_id = 0x2517,
        .port_cnt = 7,
        .led_support = true,
        .bat_support = false,
        .product_str = "USB2517i",
};

#ifdef CONFIG_GPIOLIB
static int usb251xb_check_dev_children(struct device *dev, void *child)
{
        if (dev->type == &i2c_adapter_type) {
                return device_for_each_child(dev, child,
                                             usb251xb_check_dev_children);
        }

        return (dev == child);
}

static int usb251x_check_gpio_chip(struct usb251xb *hub)
{
        struct gpio_chip *gc = gpiod_to_chip(hub->gpio_reset);
        struct i2c_adapter *adap;
        int ret;

        if (!hub->i2c)
                return 0;

        if (!hub->gpio_reset)
                return 0;

        if (!gc)
                return -EINVAL;

        adap = hub->i2c->adapter;
        ret = usb251xb_check_dev_children(&adap->dev, gc->parent);
        if (ret) {
                dev_err(hub->dev, "Reset GPIO chip is at the same i2c-bus\n");
                return -EINVAL;
        }

        return 0;
}
#else
static int usb251x_check_gpio_chip(struct usb251xb *hub)
{
        return 0;
}
#endif

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

        if (hub->i2c)
                i2c_lock_bus(hub->i2c->adapter, I2C_LOCK_SEGMENT);

        gpiod_set_value_cansleep(hub->gpio_reset, 1);
        usleep_range(1, 10);    /* >=1us RESET_N asserted */
        gpiod_set_value_cansleep(hub->gpio_reset, 0);

        /* wait for hub recovery/stabilization */
        usleep_range(500, 750); /* >=500us after RESET_N deasserted */

        if (hub->i2c)
                i2c_unlock_bus(hub->i2c->adapter, I2C_LOCK_SEGMENT);
}

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

        if (!hub->i2c) {
                usb251xb_reset(hub);
                dev_info(dev, "hub is put in default configuration.\n");
                return 0;
        }

        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);

                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_57]          = hub->boost_57;
        i2c_wb[USB251XB_ADDR_BOOST_14]          = hub->boost_14;
        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_PORT_MAP_56]       = hub->port_map56;
        i2c_wb[USB251XB_ADDR_PORT_MAP_7]        = hub->port_map7;
        i2c_wb[USB251XB_ADDR_STATUS_COMMAND] = USB251XB_STATUS_COMMAND_ATTACH;

        usb251xb_reset(hub);

        /* 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;
}

static void usb251xb_get_ports_field(struct usb251xb *hub,
                                    const char *prop_name, u8 port_cnt,
                                    bool ds_only, u8 *fld)
{
        struct device *dev = hub->dev;
        u32 port;

        of_property_for_each_u32(dev->of_node, prop_name, port) {
                if ((port >= ds_only ? 1 : 0) && (port <= port_cnt))
                        *fld |= BIT(port);
                else
                        dev_warn(dev, "port %u doesn't exist\n", port);
        }
}

static int usb251xb_get_ofdata(struct usb251xb *hub,
                               const struct usb251xb_data *data)
{
        struct device *dev = hub->dev;
        struct device_node *np = dev->of_node;
        int len;
        u32 property_u32 = 0;
        const char *cproperty_char;
        char str[USB251XB_STRING_BUFSIZE / 2];

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

        hub->skip_config = of_property_read_bool(np, "skip-config");

        hub->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(hub->gpio_reset))
                return dev_err_probe(dev, PTR_ERR(hub->gpio_reset),
                                     "unable to request GPIO reset pin\n");

        if (of_property_read_u16(np, "vendor-id", &hub->vendor_id))
                hub->vendor_id = USB251XB_DEF_VENDOR_ID;

        if (of_property_read_u16(np, "product-id", &hub->product_id))
                hub->product_id = data->product_id;

        if (of_property_read_u16(np, "device-id", &hub->device_id))
                hub->device_id = USB251XB_DEF_DEVICE_ID;

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

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

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

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

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

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

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

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

        if (!of_property_read_u32(np, "oc-delay-us", &property_u32)) {
                if (property_u32 == 100) {
                        /* 100 us*/
                        hub->conf_data2 &= ~BIT(5);
                        hub->conf_data2 &= ~BIT(4);
                } else if (property_u32 == 4000) {
                        /* 4 ms */
                        hub->conf_data2 &= ~BIT(5);
                        hub->conf_data2 |= BIT(4);
                } else if (property_u32 == 16000) {
                        /* 16 ms */
                        hub->conf_data2 |= BIT(5);
                        hub->conf_data2 |= BIT(4);
                } else {
                        /* 8 ms (DEFAULT) */
                        hub->conf_data2 |= BIT(5);
                        hub->conf_data2 &= ~BIT(4);
                }
        }

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

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

        if (data->led_support && of_get_property(np, "led-usb-mode", NULL))
                hub->conf_data3 &= ~BIT(1);

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

        hub->non_rem_dev = USB251XB_DEF_NON_REMOVABLE_DEVICES;
        usb251xb_get_ports_field(hub, "non-removable-ports", data->port_cnt,
                                 true, &hub->non_rem_dev);

        hub->port_disable_sp = USB251XB_DEF_PORT_DISABLE_SELF;
        usb251xb_get_ports_field(hub, "sp-disabled-ports", data->port_cnt,
                                 true, &hub->port_disable_sp);

        hub->port_disable_bp = USB251XB_DEF_PORT_DISABLE_BUS;
        usb251xb_get_ports_field(hub, "bp-disabled-ports", data->port_cnt,
                                 true, &hub->port_disable_bp);

        hub->max_power_sp = USB251XB_DEF_MAX_POWER_SELF;
        if (!of_property_read_u32(np, "sp-max-total-current-microamp",
            &property_u32))
                hub->max_power_sp = min_t(u8, property_u32 / 2000, 50);

        hub->max_power_bp = USB251XB_DEF_MAX_POWER_BUS;
        if (!of_property_read_u32(np, "bp-max-total-current-microamp",
            &property_u32))
                hub->max_power_bp = min_t(u8, property_u32 / 2000, 255);

        hub->max_current_sp = USB251XB_DEF_MAX_CURRENT_SELF;
        if (!of_property_read_u32(np, "sp-max-removable-current-microamp",
            &property_u32))
                hub->max_current_sp = min_t(u8, property_u32 / 2000, 50);

        hub->max_current_bp = USB251XB_DEF_MAX_CURRENT_BUS;
        if (!of_property_read_u32(np, "bp-max-removable-current-microamp",
            &property_u32))
                hub->max_current_bp = min_t(u8, property_u32 / 2000, 255);

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

        if (of_property_read_u16(np, "language-id", &hub->lang_id))
                hub->lang_id = USB251XB_DEF_LANGUAGE_ID;

        if (of_property_read_u8(np, "boost-up", &hub->boost_up))
                hub->boost_up = USB251XB_DEF_BOOST_UP;

        cproperty_char = of_get_property(np, "manufacturer", NULL);
        strscpy(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);
        strscpy(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);
        strscpy(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 datasheet documents the register as 'Port Swap' but in real the
         * register controls the USB DP/DM signal swapping for each port.
         */
        hub->port_swap = USB251XB_DEF_PORT_SWAP;
        usb251xb_get_ports_field(hub, "swap-dx-lanes", data->port_cnt,
                                 false, &hub->port_swap);

        /* 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_57 = USB251XB_DEF_BOOST_57;
        hub->boost_14 = USB251XB_DEF_BOOST_14;
        hub->port_map12 = USB251XB_DEF_PORT_MAP_12;
        hub->port_map34 = USB251XB_DEF_PORT_MAP_34;
        hub->port_map56 = USB251XB_DEF_PORT_MAP_56;
        hub->port_map7  = USB251XB_DEF_PORT_MAP_7;

        return 0;
}

static const struct of_device_id usb251xb_of_match[] = {
        {
                .compatible = "microchip,usb2422",
                .data = &usb2422_data,
        }, {
                .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,
        }, {
                .compatible = "microchip,usb2517",
                .data = &usb2517_data,
        }, {
                .compatible = "microchip,usb2517i",
                .data = &usb2517i_data,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(of, usb251xb_of_match);

static void usb251xb_regulator_disable_action(void *data)
{
        struct usb251xb *hub = data;

        regulator_disable(hub->vdd);
}

static int usb251xb_probe(struct usb251xb *hub)
{
        struct device *dev = hub->dev;
        struct device_node *np = dev->of_node;
        const struct usb251xb_data *usb_data = of_device_get_match_data(dev);
        int err;

        if (np && usb_data) {
                err = usb251xb_get_ofdata(hub, usb_data);
                if (err)
                        return dev_err_probe(dev, err, "failed to get ofdata\n");
        }

        /*
         * usb251x SMBus-slave SCL lane is muxed with CFG_SEL0 pin. So if anyone
         * tries to work with the bus at the moment the hub reset is released,
         * it may cause an invalid config being latched by usb251x. Particularly
         * one of the config modes makes the hub loading a default registers
         * value without SMBus-slave interface activation. If the hub
         * accidentally gets this mode, this will cause the driver SMBus-
         * functions failure. Normally we could just lock the SMBus-segment the
         * hub i2c-interface resides for the device-specific reset timing. But
         * the GPIO controller, which is used to handle the hub reset, might be
         * placed at the same i2c-bus segment. In this case an error should be
         * returned since we can't safely use the GPIO controller to clear the
         * reset state (it may affect the hub configuration) and we can't lock
         * the i2c-bus segment (it will cause a deadlock).
         */
        err = usb251x_check_gpio_chip(hub);
        if (err)
                return err;

        hub->vdd = devm_regulator_get(dev, "vdd");
        if (IS_ERR(hub->vdd))
                return PTR_ERR(hub->vdd);

        err = regulator_enable(hub->vdd);
        if (err)
                return err;

        err = devm_add_action_or_reset(dev,
                                       usb251xb_regulator_disable_action, hub);
        if (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)
{
        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 int usb251xb_suspend(struct usb251xb *hub)
{
        return regulator_disable(hub->vdd);
}

static int usb251xb_resume(struct usb251xb *hub)
{
        int err;

        err = regulator_enable(hub->vdd);
        if (err)
                return err;

        return usb251xb_connect(hub);
}

static int usb251xb_i2c_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct usb251xb *hub = i2c_get_clientdata(client);

        return usb251xb_suspend(hub);
}

static int usb251xb_i2c_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct usb251xb *hub = i2c_get_clientdata(client);

        return usb251xb_resume(hub);
}

static DEFINE_SIMPLE_DEV_PM_OPS(usb251xb_i2c_pm_ops, usb251xb_i2c_suspend, usb251xb_i2c_resume);

static const struct i2c_device_id usb251xb_id[] = {
        { "usb2422" },
        { "usb2512b" },
        { "usb2512bi" },
        { "usb2513b" },
        { "usb2513bi" },
        { "usb2514b" },
        { "usb2514bi" },
        { "usb2517" },
        { "usb2517i" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, usb251xb_id);

static struct i2c_driver usb251xb_i2c_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = usb251xb_of_match,
                .pm = pm_sleep_ptr(&usb251xb_i2c_pm_ops),
        },
        .probe = usb251xb_i2c_probe,
        .id_table = usb251xb_id,
};

static int usb251xb_plat_probe(struct platform_device *pdev)
{
        struct usb251xb *hub;

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

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

        return usb251xb_probe(hub);
}

static int usb251xb_plat_suspend(struct device *dev)
{
        return usb251xb_suspend(dev_get_drvdata(dev));
}

static int usb251xb_plat_resume(struct device *dev)
{
        return usb251xb_resume(dev_get_drvdata(dev));
}

static DEFINE_SIMPLE_DEV_PM_OPS(usb251xb_plat_pm_ops, usb251xb_plat_suspend, usb251xb_plat_resume);

static struct platform_driver usb251xb_plat_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = usb251xb_of_match,
                .pm = pm_sleep_ptr(&usb251xb_plat_pm_ops),
        },
        .probe          = usb251xb_plat_probe,
};

static int __init usb251xb_init(void)
{
        int err;

        err = i2c_add_driver(&usb251xb_i2c_driver);
        if (err)
                return err;

        err = platform_driver_register(&usb251xb_plat_driver);
        if (err) {
                i2c_del_driver(&usb251xb_i2c_driver);
                return err;
        }

        return 0;
}
module_init(usb251xb_init);

static void __exit usb251xb_exit(void)
{
        platform_driver_unregister(&usb251xb_plat_driver);
        i2c_del_driver(&usb251xb_i2c_driver);
}
module_exit(usb251xb_exit);

MODULE_AUTHOR("Richard Leitner <richard.leitner@skidata.com>");
MODULE_DESCRIPTION("USB251x/xBi USB 2.0 Hub Controller Driver");
MODULE_LICENSE("GPL");