// SPDX-License-Identifier: GPL-2.0
/*
 * Fintek F81232 USB to serial adaptor driver
 * Fintek F81532A/534A/535/536 USB to 2/4/8/12 serial adaptor driver
 *
 * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
 * Copyright (C) 2012 Linux Foundation
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial_reg.h>

#define F81232_ID               \
        { USB_DEVICE(0x1934, 0x0706) }  /* 1 port UART device */

#define F81534A_SERIES_ID       \
        { USB_DEVICE(0x2c42, 0x1602) }, /* In-Box 2 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1604) }, /* In-Box 4 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1605) }, /* In-Box 8 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1606) }, /* In-Box 12 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1608) }, /* Non-Flash type */ \
        { USB_DEVICE(0x2c42, 0x1632) }, /* 2 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1634) }, /* 4 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1635) }, /* 8 port UART device */ \
        { USB_DEVICE(0x2c42, 0x1636) }  /* 12 port UART device */

#define F81534A_CTRL_ID         \
        { USB_DEVICE(0x2c42, 0x16f8) }  /* Global control device */

static const struct usb_device_id f81232_id_table[] = {
        F81232_ID,
        { }                                     /* Terminating entry */
};

static const struct usb_device_id f81534a_id_table[] = {
        F81534A_SERIES_ID,
        { }                                     /* Terminating entry */
};

static const struct usb_device_id f81534a_ctrl_id_table[] = {
        F81534A_CTRL_ID,
        { }                                     /* Terminating entry */
};

static const struct usb_device_id combined_id_table[] = {
        F81232_ID,
        F81534A_SERIES_ID,
        F81534A_CTRL_ID,
        { }                                     /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, combined_id_table);

/* Maximum baudrate for F81232 */
#define F81232_MAX_BAUDRATE             1500000
#define F81232_DEF_BAUDRATE             9600

/* USB Control EP parameter */
#define F81232_REGISTER_REQUEST         0xa0
#define F81232_GET_REGISTER             0xc0
#define F81232_SET_REGISTER             0x40

#define SERIAL_BASE_ADDRESS             0x0120
#define RECEIVE_BUFFER_REGISTER         (0x00 + SERIAL_BASE_ADDRESS)
#define INTERRUPT_ENABLE_REGISTER       (0x01 + SERIAL_BASE_ADDRESS)
#define FIFO_CONTROL_REGISTER           (0x02 + SERIAL_BASE_ADDRESS)
#define LINE_CONTROL_REGISTER           (0x03 + SERIAL_BASE_ADDRESS)
#define MODEM_CONTROL_REGISTER          (0x04 + SERIAL_BASE_ADDRESS)
#define LINE_STATUS_REGISTER            (0x05 + SERIAL_BASE_ADDRESS)
#define MODEM_STATUS_REGISTER           (0x06 + SERIAL_BASE_ADDRESS)

/*
 * F81232 Clock registers (106h)
 *
 * Bit1-0:      Clock source selector
 *                      00: 1.846MHz.
 *                      01: 18.46MHz.
 *                      10: 24MHz.
 *                      11: 14.77MHz.
 */
#define F81232_CLK_REGISTER             0x106
#define F81232_CLK_1_846_MHZ            0
#define F81232_CLK_18_46_MHZ            BIT(0)
#define F81232_CLK_24_MHZ               BIT(1)
#define F81232_CLK_14_77_MHZ            (BIT(1) | BIT(0))
#define F81232_CLK_MASK                 GENMASK(1, 0)

#define F81534A_MODE_REG                0x107
#define F81534A_TRIGGER_MASK            GENMASK(3, 2)
#define F81534A_TRIGGER_MULTIPLE_4X     BIT(3)
#define F81534A_FIFO_128BYTE            (BIT(1) | BIT(0))

/* Serial port self GPIO control, 2bytes [control&output data][input data] */
#define F81534A_GPIO_REG                0x10e
#define F81534A_GPIO_MODE2_DIR          BIT(6) /* 1: input, 0: output */
#define F81534A_GPIO_MODE1_DIR          BIT(5)
#define F81534A_GPIO_MODE0_DIR          BIT(4)
#define F81534A_GPIO_MODE2_OUTPUT       BIT(2)
#define F81534A_GPIO_MODE1_OUTPUT       BIT(1)
#define F81534A_GPIO_MODE0_OUTPUT       BIT(0)

#define F81534A_CTRL_CMD_ENABLE_PORT    0x116

struct f81232_private {
        struct mutex lock;
        u8 modem_control;
        u8 modem_status;
        u8 shadow_lcr;
        speed_t baud_base;
        struct work_struct lsr_work;
        struct work_struct interrupt_work;
        struct usb_serial_port *port;
};

static u32 const baudrate_table[] = { 115200, 921600, 1152000, 1500000 };
static u8 const clock_table[] = { F81232_CLK_1_846_MHZ, F81232_CLK_14_77_MHZ,
                                F81232_CLK_18_46_MHZ, F81232_CLK_24_MHZ };

static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)
{
        return DIV_ROUND_CLOSEST(clockrate, baudrate);
}

static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
{
        int status;
        struct usb_device *dev = port->serial->dev;

        status = usb_control_msg_recv(dev,
                                      0,
                                      F81232_REGISTER_REQUEST,
                                      F81232_GET_REGISTER,
                                      reg,
                                      0,
                                      val,
                                      sizeof(*val),
                                      USB_CTRL_GET_TIMEOUT,
                                      GFP_KERNEL);
        if (status) {
                dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
                status = usb_translate_errors(status);
        }

        return status;
}

static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
{
        int status;
        struct usb_device *dev = port->serial->dev;

        status = usb_control_msg_send(dev,
                                      0,
                                      F81232_REGISTER_REQUEST,
                                      F81232_SET_REGISTER,
                                      reg,
                                      0,
                                      &val,
                                      sizeof(val),
                                      USB_CTRL_SET_TIMEOUT,
                                      GFP_KERNEL);
        if (status) {
                dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
                status = usb_translate_errors(status);
        }

        return status;
}

static int f81232_set_mask_register(struct usb_serial_port *port, u16 reg,
                                        u8 mask, u8 val)
{
        int status;
        u8 tmp;

        status = f81232_get_register(port, reg, &tmp);
        if (status)
                return status;

        tmp = (tmp & ~mask) | (val & mask);

        return f81232_set_register(port, reg, tmp);
}

static void f81232_read_msr(struct usb_serial_port *port)
{
        int status;
        u8 current_msr;
        struct tty_struct *tty;
        struct f81232_private *priv = usb_get_serial_port_data(port);

        mutex_lock(&priv->lock);
        status = f81232_get_register(port, MODEM_STATUS_REGISTER,
                        &current_msr);
        if (status) {
                dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
                mutex_unlock(&priv->lock);
                return;
        }

        if (!(current_msr & UART_MSR_ANY_DELTA)) {
                mutex_unlock(&priv->lock);
                return;
        }

        priv->modem_status = current_msr;

        if (current_msr & UART_MSR_DCTS)
                port->icount.cts++;
        if (current_msr & UART_MSR_DDSR)
                port->icount.dsr++;
        if (current_msr & UART_MSR_TERI)
                port->icount.rng++;
        if (current_msr & UART_MSR_DDCD) {
                port->icount.dcd++;
                tty = tty_port_tty_get(&port->port);
                if (tty) {
                        usb_serial_handle_dcd_change(port, tty,
                                        current_msr & UART_MSR_DCD);

                        tty_kref_put(tty);
                }
        }

        wake_up_interruptible(&port->port.delta_msr_wait);
        mutex_unlock(&priv->lock);
}

static int f81232_set_mctrl(struct usb_serial_port *port,
                                           unsigned int set, unsigned int clear)
{
        u8 val;
        int status;
        struct f81232_private *priv = usb_get_serial_port_data(port);

        if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
                return 0;       /* no change */

        /* 'set' takes precedence over 'clear' */
        clear &= ~set;

        /* force enable interrupt with OUT2 */
        mutex_lock(&priv->lock);
        val = UART_MCR_OUT2 | priv->modem_control;

        if (clear & TIOCM_DTR)
                val &= ~UART_MCR_DTR;

        if (clear & TIOCM_RTS)
                val &= ~UART_MCR_RTS;

        if (set & TIOCM_DTR)
                val |= UART_MCR_DTR;

        if (set & TIOCM_RTS)
                val |= UART_MCR_RTS;

        dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
                        val, priv->modem_control);

        status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
        if (status) {
                dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
                mutex_unlock(&priv->lock);
                return status;
        }

        priv->modem_control = val;
        mutex_unlock(&priv->lock);

        return 0;
}

static void f81232_update_line_status(struct usb_serial_port *port,
                                      unsigned char *data,
                                      size_t actual_length)
{
        struct f81232_private *priv = usb_get_serial_port_data(port);

        if (!actual_length)
                return;

        switch (data[0] & 0x07) {
        case 0x00: /* msr change */
                dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
                schedule_work(&priv->interrupt_work);
                break;
        case 0x02: /* tx-empty */
                break;
        case 0x04: /* rx data available */
                break;
        case 0x06: /* lsr change */
                /* we can forget it. the LSR will read from bulk-in */
                dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
                break;
        }
}

static void f81232_read_int_callback(struct urb *urb)
{
        struct usb_serial_port *port =  urb->context;
        unsigned char *data = urb->transfer_buffer;
        unsigned int actual_length = urb->actual_length;
        int status = urb->status;
        int retval;

        switch (status) {
        case 0:
                /* success */
                break;
        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
                /* this urb is terminated, clean up */
                dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
                        __func__, status);
                return;
        default:
                dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
                        __func__, status);
                goto exit;
        }

        usb_serial_debug_data(&port->dev, __func__,
                              urb->actual_length, urb->transfer_buffer);

        f81232_update_line_status(port, data, actual_length);

exit:
        retval = usb_submit_urb(urb, GFP_ATOMIC);
        if (retval)
                dev_err(&urb->dev->dev,
                        "%s - usb_submit_urb failed with result %d\n",
                        __func__, retval);
}

static char f81232_handle_lsr(struct usb_serial_port *port, u8 lsr)
{
        struct f81232_private *priv = usb_get_serial_port_data(port);
        char tty_flag = TTY_NORMAL;

        if (!(lsr & UART_LSR_BRK_ERROR_BITS))
                return tty_flag;

        if (lsr & UART_LSR_BI) {
                tty_flag = TTY_BREAK;
                port->icount.brk++;
                usb_serial_handle_break(port);
        } else if (lsr & UART_LSR_PE) {
                tty_flag = TTY_PARITY;
                port->icount.parity++;
        } else if (lsr & UART_LSR_FE) {
                tty_flag = TTY_FRAME;
                port->icount.frame++;
        }

        if (lsr & UART_LSR_OE) {
                port->icount.overrun++;
                schedule_work(&priv->lsr_work);
                tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
        }

        return tty_flag;
}

static void f81232_process_read_urb(struct urb *urb)
{
        struct usb_serial_port *port = urb->context;
        unsigned char *data = urb->transfer_buffer;
        char tty_flag;
        unsigned int i;
        u8 lsr;

        /*
         * When opening the port we get a 1-byte packet with the current LSR,
         * which we discard.
         */
        if ((urb->actual_length < 2) || (urb->actual_length % 2))
                return;

        /* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */

        for (i = 0; i < urb->actual_length; i += 2) {
                lsr = data[i];
                tty_flag = f81232_handle_lsr(port, lsr);

                if (port->sysrq) {
                        if (usb_serial_handle_sysrq_char(port, data[i + 1]))
                                continue;
                }

                tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
        }

        tty_flip_buffer_push(&port->port);
}

static void f81534a_process_read_urb(struct urb *urb)
{
        struct usb_serial_port *port = urb->context;
        unsigned char *data = urb->transfer_buffer;
        char tty_flag;
        unsigned int i;
        u8 lsr;
        u8 len;

        if (urb->actual_length < 3) {
                dev_err(&port->dev, "short message received: %d\n",
                                urb->actual_length);
                return;
        }

        len = data[0];
        if (len != urb->actual_length) {
                dev_err(&port->dev, "malformed message received: %d (%d)\n",
                                urb->actual_length, len);
                return;
        }

        /* bulk-in data: [LEN][Data.....][LSR] */
        lsr = data[len - 1];
        tty_flag = f81232_handle_lsr(port, lsr);

        if (port->sysrq) {
                for (i = 1; i < len - 1; ++i) {
                        if (!usb_serial_handle_sysrq_char(port, data[i])) {
                                tty_insert_flip_char(&port->port, data[i],
                                                tty_flag);
                        }
                }
        } else {
                tty_insert_flip_string_fixed_flag(&port->port, &data[1],
                                                        tty_flag, len - 2);
        }

        tty_flip_buffer_push(&port->port);
}

static int f81232_break_ctl(struct tty_struct *tty, int break_state)
{
        struct usb_serial_port *port = tty->driver_data;
        struct f81232_private *priv = usb_get_serial_port_data(port);
        int status;

        mutex_lock(&priv->lock);

        if (break_state)
                priv->shadow_lcr |= UART_LCR_SBC;
        else
                priv->shadow_lcr &= ~UART_LCR_SBC;

        status = f81232_set_register(port, LINE_CONTROL_REGISTER,
                                        priv->shadow_lcr);
        if (status)
                dev_err(&port->dev, "set break failed: %d\n", status);

        mutex_unlock(&priv->lock);

        return status;
}

static int f81232_find_clk(speed_t baudrate)
{
        int idx;

        for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {
                if (baudrate <= baudrate_table[idx] &&
                                baudrate_table[idx] % baudrate == 0)
                        return idx;
        }

        return -EINVAL;
}

static void f81232_set_baudrate(struct tty_struct *tty,
                                struct usb_serial_port *port, speed_t baudrate,
                                speed_t old_baudrate)
{
        struct f81232_private *priv = usb_get_serial_port_data(port);
        u8 lcr;
        int divisor;
        int status = 0;
        int i;
        int idx;
        speed_t baud_list[] = { baudrate, old_baudrate, F81232_DEF_BAUDRATE };

        for (i = 0; i < ARRAY_SIZE(baud_list); ++i) {
                baudrate = baud_list[i];
                if (baudrate == 0) {
                        tty_encode_baud_rate(tty, 0, 0);
                        return;
                }

                idx = f81232_find_clk(baudrate);
                if (idx >= 0) {
                        tty_encode_baud_rate(tty, baudrate, baudrate);
                        break;
                }
        }

        if (idx < 0)
                return;

        priv->baud_base = baudrate_table[idx];
        divisor = calc_baud_divisor(baudrate, priv->baud_base);

        status = f81232_set_mask_register(port, F81232_CLK_REGISTER,
                        F81232_CLK_MASK, clock_table[idx]);
        if (status) {
                dev_err(&port->dev, "%s failed to set CLK_REG: %d\n",
                        __func__, status);
                return;
        }

        status = f81232_get_register(port, LINE_CONTROL_REGISTER,
                         &lcr); /* get LCR */
        if (status) {
                dev_err(&port->dev, "%s failed to get LCR: %d\n",
                        __func__, status);
                return;
        }

        status = f81232_set_register(port, LINE_CONTROL_REGISTER,
                         lcr | UART_LCR_DLAB); /* Enable DLAB */
        if (status) {
                dev_err(&port->dev, "%s failed to set DLAB: %d\n",
                        __func__, status);
                return;
        }

        status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
                         divisor & 0x00ff); /* low */
        if (status) {
                dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
                        __func__, status);
                goto reapply_lcr;
        }

        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
                         (divisor & 0xff00) >> 8); /* high */
        if (status) {
                dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
                        __func__, status);
        }

reapply_lcr:
        status = f81232_set_register(port, LINE_CONTROL_REGISTER,
                        lcr & ~UART_LCR_DLAB);
        if (status) {
                dev_err(&port->dev, "%s failed to set DLAB: %d\n",
                        __func__, status);
        }
}

static int f81232_port_enable(struct usb_serial_port *port)
{
        u8 val;
        int status;

        /* fifo on, trigger8, clear TX/RX*/
        val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
                        UART_FCR_CLEAR_XMIT;

        status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
        if (status) {
                dev_err(&port->dev, "%s failed to set FCR: %d\n",
                        __func__, status);
                return status;
        }

        /* MSR Interrupt only, LSR will read from Bulk-in odd byte */
        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
                        UART_IER_MSI);
        if (status) {
                dev_err(&port->dev, "%s failed to set IER: %d\n",
                        __func__, status);
                return status;
        }

        return 0;
}

static int f81232_port_disable(struct usb_serial_port *port)
{
        int status;

        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
        if (status) {
                dev_err(&port->dev, "%s failed to set IER: %d\n",
                        __func__, status);
                return status;
        }

        return 0;
}

static void f81232_set_termios(struct tty_struct *tty,
                               struct usb_serial_port *port,
                               const struct ktermios *old_termios)
{
        struct f81232_private *priv = usb_get_serial_port_data(port);
        u8 new_lcr = 0;
        int status = 0;
        speed_t baudrate;
        speed_t old_baud;

        /* Don't change anything if nothing has changed */
        if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
                return;

        if (C_BAUD(tty) == B0)
                f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
        else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
                f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);

        baudrate = tty_get_baud_rate(tty);
        if (baudrate > 0) {
                if (old_termios)
                        old_baud = tty_termios_baud_rate(old_termios);
                else
                        old_baud = F81232_DEF_BAUDRATE;

                f81232_set_baudrate(tty, port, baudrate, old_baud);
        }

        if (C_PARENB(tty)) {
                new_lcr |= UART_LCR_PARITY;

                if (!C_PARODD(tty))
                        new_lcr |= UART_LCR_EPAR;

                if (C_CMSPAR(tty))
                        new_lcr |= UART_LCR_SPAR;
        }

        if (C_CSTOPB(tty))
                new_lcr |= UART_LCR_STOP;

        new_lcr |= UART_LCR_WLEN(tty_get_char_size(tty->termios.c_cflag));

        mutex_lock(&priv->lock);

        new_lcr |= (priv->shadow_lcr & UART_LCR_SBC);
        status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
        if (status) {
                dev_err(&port->dev, "%s failed to set LCR: %d\n",
                        __func__, status);
        }

        priv->shadow_lcr = new_lcr;

        mutex_unlock(&priv->lock);
}

static int f81232_tiocmget(struct tty_struct *tty)
{
        int r;
        struct usb_serial_port *port = tty->driver_data;
        struct f81232_private *port_priv = usb_get_serial_port_data(port);
        u8 mcr, msr;

        /* force get current MSR changed state */
        f81232_read_msr(port);

        mutex_lock(&port_priv->lock);
        mcr = port_priv->modem_control;
        msr = port_priv->modem_status;
        mutex_unlock(&port_priv->lock);

        r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
                (mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
                (msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
                (msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
                (msr & UART_MSR_RI ? TIOCM_RI : 0) |
                (msr & UART_MSR_DSR ? TIOCM_DSR : 0);

        return r;
}

static int f81232_tiocmset(struct tty_struct *tty,
                        unsigned int set, unsigned int clear)
{
        struct usb_serial_port *port = tty->driver_data;

        return f81232_set_mctrl(port, set, clear);
}

static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
{
        int result;

        result = f81232_port_enable(port);
        if (result)
                return result;

        /* Setup termios */
        if (tty)
                f81232_set_termios(tty, port, NULL);

        result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
        if (result) {
                dev_err(&port->dev, "%s - failed submitting interrupt urb,"
                        " error %d\n", __func__, result);
                return result;
        }

        result = usb_serial_generic_open(tty, port);
        if (result) {
                usb_kill_urb(port->interrupt_in_urb);
                return result;
        }

        return 0;
}

static int f81534a_open(struct tty_struct *tty, struct usb_serial_port *port)
{
        int status;
        u8 mask;
        u8 val;

        val = F81534A_TRIGGER_MULTIPLE_4X | F81534A_FIFO_128BYTE;
        mask = F81534A_TRIGGER_MASK | F81534A_FIFO_128BYTE;

        status = f81232_set_mask_register(port, F81534A_MODE_REG, mask, val);
        if (status) {
                dev_err(&port->dev, "failed to set MODE_REG: %d\n", status);
                return status;
        }

        return f81232_open(tty, port);
}

static void f81232_close(struct usb_serial_port *port)
{
        struct f81232_private *port_priv = usb_get_serial_port_data(port);

        f81232_port_disable(port);
        usb_serial_generic_close(port);
        usb_kill_urb(port->interrupt_in_urb);
        flush_work(&port_priv->interrupt_work);
        flush_work(&port_priv->lsr_work);
}

static void f81232_dtr_rts(struct usb_serial_port *port, int on)
{
        if (on)
                f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
        else
                f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
}

static bool f81232_tx_empty(struct usb_serial_port *port)
{
        int status;
        u8 tmp;

        status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp);
        if (!status) {
                if ((tmp & UART_LSR_TEMT) != UART_LSR_TEMT)
                        return false;
        }

        return true;
}

static int f81232_carrier_raised(struct usb_serial_port *port)
{
        u8 msr;
        struct f81232_private *priv = usb_get_serial_port_data(port);

        mutex_lock(&priv->lock);
        msr = priv->modem_status;
        mutex_unlock(&priv->lock);

        if (msr & UART_MSR_DCD)
                return 1;
        return 0;
}

static void f81232_get_serial(struct tty_struct *tty, struct serial_struct *ss)
{
        struct usb_serial_port *port = tty->driver_data;
        struct f81232_private *priv = usb_get_serial_port_data(port);

        ss->baud_base = priv->baud_base;
}

static void  f81232_interrupt_work(struct work_struct *work)
{
        struct f81232_private *priv =
                container_of(work, struct f81232_private, interrupt_work);

        f81232_read_msr(priv->port);
}

static void f81232_lsr_worker(struct work_struct *work)
{
        struct f81232_private *priv;
        struct usb_serial_port *port;
        int status;
        u8 tmp;

        priv = container_of(work, struct f81232_private, lsr_work);
        port = priv->port;

        status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp);
        if (status)
                dev_warn(&port->dev, "read LSR failed: %d\n", status);
}

static int f81534a_ctrl_set_register(struct usb_interface *intf, u16 reg,
                                        u16 size, void *val)
{
        return usb_control_msg_send(interface_to_usbdev(intf),
                                                0,
                                                F81232_REGISTER_REQUEST,
                                                F81232_SET_REGISTER,
                                                reg,
                                                0,
                                                val,
                                                size,
                                                USB_CTRL_SET_TIMEOUT,
                                                GFP_KERNEL);
}

static int f81534a_ctrl_get_register(struct usb_interface *intf, u16 reg,
                                        u16 size, void *val)
{
        return usb_control_msg_recv(interface_to_usbdev(intf),
                                                0,
                                                F81232_REGISTER_REQUEST,
                                                F81232_GET_REGISTER,
                                                reg,
                                                0,
                                                val,
                                                size,
                                                USB_CTRL_GET_TIMEOUT,
                                                GFP_KERNEL);
}

static int f81534a_ctrl_enable_all_ports(struct usb_interface *intf, bool en)
{
        unsigned char enable[2] = {0};
        int status;

        /*
         * Enable all available serial ports, define as following:
         * bit 15       : Reset behavior (when HUB got soft reset)
         *                      0: maintain all serial port enabled state.
         *                      1: disable all serial port.
         * bit 0~11     : Serial port enable bit.
         */
        if (en) {
                /*
                 * The Fintek F81532A/534A/535/536 family relies on the
                 * F81534A_CTRL_CMD_ENABLE_PORT (116h) register during
                 * initialization to both determine serial port status and
                 * control port creation.
                 *
                 * If the driver experiences fast load/unload cycles, the
                 * device state may becomes unstable, resulting in the
                 * incomplete generation of serial ports.
                 *
                 * Performing a dummy read operation on the register prior
                 * to the initial write command resolves the issue.
                 *
                 * This clears the device's stale internal state. Subsequent
                 * write operations will correctly generate all serial ports.
                 */
                status = f81534a_ctrl_get_register(intf,
                                                F81534A_CTRL_CMD_ENABLE_PORT,
                                                sizeof(enable),
                                                enable);
                if (status)
                        return status;

                enable[0] = 0xff;
                enable[1] = 0x8f;
        }

        status = f81534a_ctrl_set_register(intf, F81534A_CTRL_CMD_ENABLE_PORT,
                        sizeof(enable), enable);
        if (status)
                dev_err(&intf->dev, "failed to enable ports: %d\n", status);

        return status;
}

static int f81534a_ctrl_probe(struct usb_interface *intf,
                                const struct usb_device_id *id)
{
        return f81534a_ctrl_enable_all_ports(intf, true);
}

static void f81534a_ctrl_disconnect(struct usb_interface *intf)
{
        f81534a_ctrl_enable_all_ports(intf, false);
}

static int f81534a_ctrl_resume(struct usb_interface *intf)
{
        return f81534a_ctrl_enable_all_ports(intf, true);
}

static int f81232_port_probe(struct usb_serial_port *port)
{
        struct f81232_private *priv;

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

        mutex_init(&priv->lock);
        INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
        INIT_WORK(&priv->lsr_work, f81232_lsr_worker);

        usb_set_serial_port_data(port, priv);

        priv->port = port;

        return 0;
}

static int f81534a_port_probe(struct usb_serial_port *port)
{
        int status;

        /* tri-state with pull-high, default RS232 Mode */
        status = f81232_set_register(port, F81534A_GPIO_REG,
                                        F81534A_GPIO_MODE2_DIR);
        if (status)
                return status;

        return f81232_port_probe(port);
}

static int f81232_suspend(struct usb_serial *serial, pm_message_t message)
{
        struct usb_serial_port *port = serial->port[0];
        struct f81232_private *port_priv = usb_get_serial_port_data(port);
        int i;

        for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
                usb_kill_urb(port->read_urbs[i]);

        usb_kill_urb(port->interrupt_in_urb);

        if (port_priv) {
                flush_work(&port_priv->interrupt_work);
                flush_work(&port_priv->lsr_work);
        }

        return 0;
}

static int f81232_resume(struct usb_serial *serial)
{
        struct usb_serial_port *port = serial->port[0];
        int result;

        if (tty_port_initialized(&port->port)) {
                result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
                if (result) {
                        dev_err(&port->dev, "submit interrupt urb failed: %d\n",
                                        result);
                        return result;
                }
        }

        return usb_serial_generic_resume(serial);
}

static struct usb_serial_driver f81232_device = {
        .driver = {
                .name =         "f81232",
        },
        .id_table =             f81232_id_table,
        .num_ports =            1,
        .bulk_in_size =         256,
        .bulk_out_size =        256,
        .open =                 f81232_open,
        .close =                f81232_close,
        .dtr_rts =              f81232_dtr_rts,
        .carrier_raised =       f81232_carrier_raised,
        .get_serial =           f81232_get_serial,
        .break_ctl =            f81232_break_ctl,
        .set_termios =          f81232_set_termios,
        .tiocmget =             f81232_tiocmget,
        .tiocmset =             f81232_tiocmset,
        .tiocmiwait =           usb_serial_generic_tiocmiwait,
        .tx_empty =             f81232_tx_empty,
        .process_read_urb =     f81232_process_read_urb,
        .read_int_callback =    f81232_read_int_callback,
        .port_probe =           f81232_port_probe,
        .suspend =              f81232_suspend,
        .resume =               f81232_resume,
};

static struct usb_serial_driver f81534a_device = {
        .driver = {
                .name =         "f81534a",
        },
        .id_table =             f81534a_id_table,
        .num_ports =            1,
        .open =                 f81534a_open,
        .close =                f81232_close,
        .dtr_rts =              f81232_dtr_rts,
        .carrier_raised =       f81232_carrier_raised,
        .get_serial =           f81232_get_serial,
        .break_ctl =            f81232_break_ctl,
        .set_termios =          f81232_set_termios,
        .tiocmget =             f81232_tiocmget,
        .tiocmset =             f81232_tiocmset,
        .tiocmiwait =           usb_serial_generic_tiocmiwait,
        .tx_empty =             f81232_tx_empty,
        .process_read_urb =     f81534a_process_read_urb,
        .read_int_callback =    f81232_read_int_callback,
        .port_probe =           f81534a_port_probe,
        .suspend =              f81232_suspend,
        .resume =               f81232_resume,
};

static struct usb_serial_driver * const serial_drivers[] = {
        &f81232_device,
        &f81534a_device,
        NULL,
};

static struct usb_driver f81534a_ctrl_driver = {
        .name =         "f81534a_ctrl",
        .id_table =     f81534a_ctrl_id_table,
        .probe =        f81534a_ctrl_probe,
        .disconnect =   f81534a_ctrl_disconnect,
        .resume =       f81534a_ctrl_resume,
};

static int __init f81232_init(void)
{
        int status;

        status = usb_register_driver(&f81534a_ctrl_driver, THIS_MODULE,
                        KBUILD_MODNAME);
        if (status)
                return status;

        status = usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME,
                        combined_id_table);
        if (status) {
                usb_deregister(&f81534a_ctrl_driver);
                return status;
        }

        return 0;
}

static void __exit f81232_exit(void)
{
        usb_serial_deregister_drivers(serial_drivers);
        usb_deregister(&f81534a_ctrl_driver);
}

module_init(f81232_init);
module_exit(f81232_exit);

MODULE_DESCRIPTION("Fintek F81232/532A/534A/535/536 USB to serial driver");
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
MODULE_LICENSE("GPL v2");