linux/drivers/usb/serial/f81232.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Fintek F81232 USB to serial adaptor driver
   4 *
   5 * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
   6 * Copyright (C) 2012 Linux Foundation
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/errno.h>
  11#include <linux/slab.h>
  12#include <linux/tty.h>
  13#include <linux/tty_driver.h>
  14#include <linux/tty_flip.h>
  15#include <linux/serial.h>
  16#include <linux/module.h>
  17#include <linux/moduleparam.h>
  18#include <linux/mutex.h>
  19#include <linux/uaccess.h>
  20#include <linux/usb.h>
  21#include <linux/usb/serial.h>
  22#include <linux/serial_reg.h>
  23
  24static const struct usb_device_id id_table[] = {
  25        { USB_DEVICE(0x1934, 0x0706) },
  26        { }                                     /* Terminating entry */
  27};
  28MODULE_DEVICE_TABLE(usb, id_table);
  29
  30/* Maximum baudrate for F81232 */
  31#define F81232_MAX_BAUDRATE             115200
  32
  33/* USB Control EP parameter */
  34#define F81232_REGISTER_REQUEST         0xa0
  35#define F81232_GET_REGISTER             0xc0
  36#define F81232_SET_REGISTER             0x40
  37
  38#define SERIAL_BASE_ADDRESS             0x0120
  39#define RECEIVE_BUFFER_REGISTER         (0x00 + SERIAL_BASE_ADDRESS)
  40#define INTERRUPT_ENABLE_REGISTER       (0x01 + SERIAL_BASE_ADDRESS)
  41#define FIFO_CONTROL_REGISTER           (0x02 + SERIAL_BASE_ADDRESS)
  42#define LINE_CONTROL_REGISTER           (0x03 + SERIAL_BASE_ADDRESS)
  43#define MODEM_CONTROL_REGISTER          (0x04 + SERIAL_BASE_ADDRESS)
  44#define MODEM_STATUS_REGISTER           (0x06 + SERIAL_BASE_ADDRESS)
  45
  46struct f81232_private {
  47        struct mutex lock;
  48        u8 modem_control;
  49        u8 modem_status;
  50        struct work_struct interrupt_work;
  51        struct usb_serial_port *port;
  52};
  53
  54static int calc_baud_divisor(speed_t baudrate)
  55{
  56        return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
  57}
  58
  59static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
  60{
  61        int status;
  62        u8 *tmp;
  63        struct usb_device *dev = port->serial->dev;
  64
  65        tmp = kmalloc(sizeof(*val), GFP_KERNEL);
  66        if (!tmp)
  67                return -ENOMEM;
  68
  69        status = usb_control_msg(dev,
  70                                usb_rcvctrlpipe(dev, 0),
  71                                F81232_REGISTER_REQUEST,
  72                                F81232_GET_REGISTER,
  73                                reg,
  74                                0,
  75                                tmp,
  76                                sizeof(*val),
  77                                USB_CTRL_GET_TIMEOUT);
  78        if (status != sizeof(*val)) {
  79                dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
  80
  81                if (status < 0)
  82                        status = usb_translate_errors(status);
  83                else
  84                        status = -EIO;
  85        } else {
  86                status = 0;
  87                *val = *tmp;
  88        }
  89
  90        kfree(tmp);
  91        return status;
  92}
  93
  94static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
  95{
  96        int status;
  97        u8 *tmp;
  98        struct usb_device *dev = port->serial->dev;
  99
 100        tmp = kmalloc(sizeof(val), GFP_KERNEL);
 101        if (!tmp)
 102                return -ENOMEM;
 103
 104        *tmp = val;
 105
 106        status = usb_control_msg(dev,
 107                                usb_sndctrlpipe(dev, 0),
 108                                F81232_REGISTER_REQUEST,
 109                                F81232_SET_REGISTER,
 110                                reg,
 111                                0,
 112                                tmp,
 113                                sizeof(val),
 114                                USB_CTRL_SET_TIMEOUT);
 115        if (status != sizeof(val)) {
 116                dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
 117
 118                if (status < 0)
 119                        status = usb_translate_errors(status);
 120                else
 121                        status = -EIO;
 122        } else {
 123                status = 0;
 124        }
 125
 126        kfree(tmp);
 127        return status;
 128}
 129
 130static void f81232_read_msr(struct usb_serial_port *port)
 131{
 132        int status;
 133        u8 current_msr;
 134        struct tty_struct *tty;
 135        struct f81232_private *priv = usb_get_serial_port_data(port);
 136
 137        mutex_lock(&priv->lock);
 138        status = f81232_get_register(port, MODEM_STATUS_REGISTER,
 139                        &current_msr);
 140        if (status) {
 141                dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
 142                mutex_unlock(&priv->lock);
 143                return;
 144        }
 145
 146        if (!(current_msr & UART_MSR_ANY_DELTA)) {
 147                mutex_unlock(&priv->lock);
 148                return;
 149        }
 150
 151        priv->modem_status = current_msr;
 152
 153        if (current_msr & UART_MSR_DCTS)
 154                port->icount.cts++;
 155        if (current_msr & UART_MSR_DDSR)
 156                port->icount.dsr++;
 157        if (current_msr & UART_MSR_TERI)
 158                port->icount.rng++;
 159        if (current_msr & UART_MSR_DDCD) {
 160                port->icount.dcd++;
 161                tty = tty_port_tty_get(&port->port);
 162                if (tty) {
 163                        usb_serial_handle_dcd_change(port, tty,
 164                                        current_msr & UART_MSR_DCD);
 165
 166                        tty_kref_put(tty);
 167                }
 168        }
 169
 170        wake_up_interruptible(&port->port.delta_msr_wait);
 171        mutex_unlock(&priv->lock);
 172}
 173
 174static int f81232_set_mctrl(struct usb_serial_port *port,
 175                                           unsigned int set, unsigned int clear)
 176{
 177        u8 val;
 178        int status;
 179        struct f81232_private *priv = usb_get_serial_port_data(port);
 180
 181        if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
 182                return 0;       /* no change */
 183
 184        /* 'set' takes precedence over 'clear' */
 185        clear &= ~set;
 186
 187        /* force enable interrupt with OUT2 */
 188        mutex_lock(&priv->lock);
 189        val = UART_MCR_OUT2 | priv->modem_control;
 190
 191        if (clear & TIOCM_DTR)
 192                val &= ~UART_MCR_DTR;
 193
 194        if (clear & TIOCM_RTS)
 195                val &= ~UART_MCR_RTS;
 196
 197        if (set & TIOCM_DTR)
 198                val |= UART_MCR_DTR;
 199
 200        if (set & TIOCM_RTS)
 201                val |= UART_MCR_RTS;
 202
 203        dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
 204                        val, priv->modem_control);
 205
 206        status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
 207        if (status) {
 208                dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
 209                mutex_unlock(&priv->lock);
 210                return status;
 211        }
 212
 213        priv->modem_control = val;
 214        mutex_unlock(&priv->lock);
 215
 216        return 0;
 217}
 218
 219static void f81232_update_line_status(struct usb_serial_port *port,
 220                                      unsigned char *data,
 221                                      size_t actual_length)
 222{
 223        struct f81232_private *priv = usb_get_serial_port_data(port);
 224
 225        if (!actual_length)
 226                return;
 227
 228        switch (data[0] & 0x07) {
 229        case 0x00: /* msr change */
 230                dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
 231                schedule_work(&priv->interrupt_work);
 232                break;
 233        case 0x02: /* tx-empty */
 234                break;
 235        case 0x04: /* rx data available */
 236                break;
 237        case 0x06: /* lsr change */
 238                /* we can forget it. the LSR will read from bulk-in */
 239                dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
 240                break;
 241        }
 242}
 243
 244static void f81232_read_int_callback(struct urb *urb)
 245{
 246        struct usb_serial_port *port =  urb->context;
 247        unsigned char *data = urb->transfer_buffer;
 248        unsigned int actual_length = urb->actual_length;
 249        int status = urb->status;
 250        int retval;
 251
 252        switch (status) {
 253        case 0:
 254                /* success */
 255                break;
 256        case -ECONNRESET:
 257        case -ENOENT:
 258        case -ESHUTDOWN:
 259                /* this urb is terminated, clean up */
 260                dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 261                        __func__, status);
 262                return;
 263        default:
 264                dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 265                        __func__, status);
 266                goto exit;
 267        }
 268
 269        usb_serial_debug_data(&port->dev, __func__,
 270                              urb->actual_length, urb->transfer_buffer);
 271
 272        f81232_update_line_status(port, data, actual_length);
 273
 274exit:
 275        retval = usb_submit_urb(urb, GFP_ATOMIC);
 276        if (retval)
 277                dev_err(&urb->dev->dev,
 278                        "%s - usb_submit_urb failed with result %d\n",
 279                        __func__, retval);
 280}
 281
 282static void f81232_process_read_urb(struct urb *urb)
 283{
 284        struct usb_serial_port *port = urb->context;
 285        unsigned char *data = urb->transfer_buffer;
 286        char tty_flag;
 287        unsigned int i;
 288        u8 lsr;
 289
 290        /*
 291         * When opening the port we get a 1-byte packet with the current LSR,
 292         * which we discard.
 293         */
 294        if ((urb->actual_length < 2) || (urb->actual_length % 2))
 295                return;
 296
 297        /* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
 298
 299        for (i = 0; i < urb->actual_length; i += 2) {
 300                tty_flag = TTY_NORMAL;
 301                lsr = data[i];
 302
 303                if (lsr & UART_LSR_BRK_ERROR_BITS) {
 304                        if (lsr & UART_LSR_BI) {
 305                                tty_flag = TTY_BREAK;
 306                                port->icount.brk++;
 307                                usb_serial_handle_break(port);
 308                        } else if (lsr & UART_LSR_PE) {
 309                                tty_flag = TTY_PARITY;
 310                                port->icount.parity++;
 311                        } else if (lsr & UART_LSR_FE) {
 312                                tty_flag = TTY_FRAME;
 313                                port->icount.frame++;
 314                        }
 315
 316                        if (lsr & UART_LSR_OE) {
 317                                port->icount.overrun++;
 318                                tty_insert_flip_char(&port->port, 0,
 319                                                TTY_OVERRUN);
 320                        }
 321                }
 322
 323                if (port->port.console && port->sysrq) {
 324                        if (usb_serial_handle_sysrq_char(port, data[i + 1]))
 325                                continue;
 326                }
 327
 328                tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
 329        }
 330
 331        tty_flip_buffer_push(&port->port);
 332}
 333
 334static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 335{
 336        /* FIXME - Stubbed out for now */
 337
 338        /*
 339         * break_state = -1 to turn on break, and 0 to turn off break
 340         * see drivers/char/tty_io.c to see it used.
 341         * last_set_data_urb_value NEVER has the break bit set in it.
 342         */
 343}
 344
 345static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
 346{
 347        u8 lcr;
 348        int divisor;
 349        int status = 0;
 350
 351        divisor = calc_baud_divisor(baudrate);
 352
 353        status = f81232_get_register(port, LINE_CONTROL_REGISTER,
 354                         &lcr); /* get LCR */
 355        if (status) {
 356                dev_err(&port->dev, "%s failed to get LCR: %d\n",
 357                        __func__, status);
 358                return;
 359        }
 360
 361        status = f81232_set_register(port, LINE_CONTROL_REGISTER,
 362                         lcr | UART_LCR_DLAB); /* Enable DLAB */
 363        if (status) {
 364                dev_err(&port->dev, "%s failed to set DLAB: %d\n",
 365                        __func__, status);
 366                return;
 367        }
 368
 369        status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
 370                         divisor & 0x00ff); /* low */
 371        if (status) {
 372                dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
 373                        __func__, status);
 374                goto reapply_lcr;
 375        }
 376
 377        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
 378                         (divisor & 0xff00) >> 8); /* high */
 379        if (status) {
 380                dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
 381                        __func__, status);
 382        }
 383
 384reapply_lcr:
 385        status = f81232_set_register(port, LINE_CONTROL_REGISTER,
 386                        lcr & ~UART_LCR_DLAB);
 387        if (status) {
 388                dev_err(&port->dev, "%s failed to set DLAB: %d\n",
 389                        __func__, status);
 390        }
 391}
 392
 393static int f81232_port_enable(struct usb_serial_port *port)
 394{
 395        u8 val;
 396        int status;
 397
 398        /* fifo on, trigger8, clear TX/RX*/
 399        val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
 400                        UART_FCR_CLEAR_XMIT;
 401
 402        status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
 403        if (status) {
 404                dev_err(&port->dev, "%s failed to set FCR: %d\n",
 405                        __func__, status);
 406                return status;
 407        }
 408
 409        /* MSR Interrupt only, LSR will read from Bulk-in odd byte */
 410        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
 411                        UART_IER_MSI);
 412        if (status) {
 413                dev_err(&port->dev, "%s failed to set IER: %d\n",
 414                        __func__, status);
 415                return status;
 416        }
 417
 418        return 0;
 419}
 420
 421static int f81232_port_disable(struct usb_serial_port *port)
 422{
 423        int status;
 424
 425        status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
 426        if (status) {
 427                dev_err(&port->dev, "%s failed to set IER: %d\n",
 428                        __func__, status);
 429                return status;
 430        }
 431
 432        return 0;
 433}
 434
 435static void f81232_set_termios(struct tty_struct *tty,
 436                struct usb_serial_port *port, struct ktermios *old_termios)
 437{
 438        u8 new_lcr = 0;
 439        int status = 0;
 440        speed_t baudrate;
 441
 442        /* Don't change anything if nothing has changed */
 443        if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 444                return;
 445
 446        if (C_BAUD(tty) == B0)
 447                f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
 448        else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
 449                f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
 450
 451        baudrate = tty_get_baud_rate(tty);
 452        if (baudrate > 0) {
 453                if (baudrate > F81232_MAX_BAUDRATE) {
 454                        baudrate = F81232_MAX_BAUDRATE;
 455                        tty_encode_baud_rate(tty, baudrate, baudrate);
 456                }
 457                f81232_set_baudrate(port, baudrate);
 458        }
 459
 460        if (C_PARENB(tty)) {
 461                new_lcr |= UART_LCR_PARITY;
 462
 463                if (!C_PARODD(tty))
 464                        new_lcr |= UART_LCR_EPAR;
 465
 466                if (C_CMSPAR(tty))
 467                        new_lcr |= UART_LCR_SPAR;
 468        }
 469
 470        if (C_CSTOPB(tty))
 471                new_lcr |= UART_LCR_STOP;
 472
 473        switch (C_CSIZE(tty)) {
 474        case CS5:
 475                new_lcr |= UART_LCR_WLEN5;
 476                break;
 477        case CS6:
 478                new_lcr |= UART_LCR_WLEN6;
 479                break;
 480        case CS7:
 481                new_lcr |= UART_LCR_WLEN7;
 482                break;
 483        default:
 484        case CS8:
 485                new_lcr |= UART_LCR_WLEN8;
 486                break;
 487        }
 488
 489        status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
 490        if (status) {
 491                dev_err(&port->dev, "%s failed to set LCR: %d\n",
 492                        __func__, status);
 493        }
 494}
 495
 496static int f81232_tiocmget(struct tty_struct *tty)
 497{
 498        int r;
 499        struct usb_serial_port *port = tty->driver_data;
 500        struct f81232_private *port_priv = usb_get_serial_port_data(port);
 501        u8 mcr, msr;
 502
 503        /* force get current MSR changed state */
 504        f81232_read_msr(port);
 505
 506        mutex_lock(&port_priv->lock);
 507        mcr = port_priv->modem_control;
 508        msr = port_priv->modem_status;
 509        mutex_unlock(&port_priv->lock);
 510
 511        r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
 512                (mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
 513                (msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
 514                (msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
 515                (msr & UART_MSR_RI ? TIOCM_RI : 0) |
 516                (msr & UART_MSR_DSR ? TIOCM_DSR : 0);
 517
 518        return r;
 519}
 520
 521static int f81232_tiocmset(struct tty_struct *tty,
 522                        unsigned int set, unsigned int clear)
 523{
 524        struct usb_serial_port *port = tty->driver_data;
 525
 526        return f81232_set_mctrl(port, set, clear);
 527}
 528
 529static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 530{
 531        int result;
 532
 533        result = f81232_port_enable(port);
 534        if (result)
 535                return result;
 536
 537        /* Setup termios */
 538        if (tty)
 539                f81232_set_termios(tty, port, NULL);
 540
 541        result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 542        if (result) {
 543                dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 544                        " error %d\n", __func__, result);
 545                return result;
 546        }
 547
 548        result = usb_serial_generic_open(tty, port);
 549        if (result) {
 550                usb_kill_urb(port->interrupt_in_urb);
 551                return result;
 552        }
 553
 554        return 0;
 555}
 556
 557static void f81232_close(struct usb_serial_port *port)
 558{
 559        f81232_port_disable(port);
 560        usb_serial_generic_close(port);
 561        usb_kill_urb(port->interrupt_in_urb);
 562}
 563
 564static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 565{
 566        if (on)
 567                f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
 568        else
 569                f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
 570}
 571
 572static int f81232_carrier_raised(struct usb_serial_port *port)
 573{
 574        u8 msr;
 575        struct f81232_private *priv = usb_get_serial_port_data(port);
 576
 577        mutex_lock(&priv->lock);
 578        msr = priv->modem_status;
 579        mutex_unlock(&priv->lock);
 580
 581        if (msr & UART_MSR_DCD)
 582                return 1;
 583        return 0;
 584}
 585
 586static int f81232_get_serial_info(struct usb_serial_port *port,
 587                unsigned long arg)
 588{
 589        struct serial_struct ser;
 590
 591        memset(&ser, 0, sizeof(ser));
 592
 593        ser.type = PORT_16550A;
 594        ser.line = port->minor;
 595        ser.port = port->port_number;
 596        ser.baud_base = F81232_MAX_BAUDRATE;
 597
 598        if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
 599                return -EFAULT;
 600
 601        return 0;
 602}
 603
 604static int f81232_ioctl(struct tty_struct *tty,
 605                        unsigned int cmd, unsigned long arg)
 606{
 607        struct usb_serial_port *port = tty->driver_data;
 608
 609        switch (cmd) {
 610        case TIOCGSERIAL:
 611                return f81232_get_serial_info(port, arg);
 612        default:
 613                break;
 614        }
 615        return -ENOIOCTLCMD;
 616}
 617
 618static void  f81232_interrupt_work(struct work_struct *work)
 619{
 620        struct f81232_private *priv =
 621                container_of(work, struct f81232_private, interrupt_work);
 622
 623        f81232_read_msr(priv->port);
 624}
 625
 626static int f81232_port_probe(struct usb_serial_port *port)
 627{
 628        struct f81232_private *priv;
 629
 630        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 631        if (!priv)
 632                return -ENOMEM;
 633
 634        mutex_init(&priv->lock);
 635        INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
 636
 637        usb_set_serial_port_data(port, priv);
 638
 639        port->port.drain_delay = 256;
 640        priv->port = port;
 641
 642        return 0;
 643}
 644
 645static int f81232_port_remove(struct usb_serial_port *port)
 646{
 647        struct f81232_private *priv;
 648
 649        priv = usb_get_serial_port_data(port);
 650        kfree(priv);
 651
 652        return 0;
 653}
 654
 655static struct usb_serial_driver f81232_device = {
 656        .driver = {
 657                .owner =        THIS_MODULE,
 658                .name =         "f81232",
 659        },
 660        .id_table =             id_table,
 661        .num_ports =            1,
 662        .bulk_in_size =         256,
 663        .bulk_out_size =        256,
 664        .open =                 f81232_open,
 665        .close =                f81232_close,
 666        .dtr_rts =              f81232_dtr_rts,
 667        .carrier_raised =       f81232_carrier_raised,
 668        .ioctl =                f81232_ioctl,
 669        .break_ctl =            f81232_break_ctl,
 670        .set_termios =          f81232_set_termios,
 671        .tiocmget =             f81232_tiocmget,
 672        .tiocmset =             f81232_tiocmset,
 673        .tiocmiwait =           usb_serial_generic_tiocmiwait,
 674        .process_read_urb =     f81232_process_read_urb,
 675        .read_int_callback =    f81232_read_int_callback,
 676        .port_probe =           f81232_port_probe,
 677        .port_remove =          f81232_port_remove,
 678};
 679
 680static struct usb_serial_driver * const serial_drivers[] = {
 681        &f81232_device,
 682        NULL,
 683};
 684
 685module_usb_serial_driver(serial_drivers, id_table);
 686
 687MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 688MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
 689MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
 690MODULE_LICENSE("GPL v2");
 691