linux/drivers/usb/serial/upd78f0730.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Renesas Electronics uPD78F0730 USB to serial converter driver
   4 *
   5 * Copyright (C) 2014,2016 Maksim Salau <maksim.salau@gmail.com>
   6 *
   7 * Protocol of the adaptor is described in the application note U19660EJ1V0AN00
   8 * μPD78F0730 8-bit Single-Chip Microcontroller
   9 * USB-to-Serial Conversion Software
  10 * <https://www.renesas.com/en-eu/doc/DocumentServer/026/U19660EJ1V0AN00.pdf>
  11 *
  12 * The adaptor functionality is limited to the following:
  13 * - data bits: 7 or 8
  14 * - stop bits: 1 or 2
  15 * - parity: even, odd or none
  16 * - flow control: none
  17 * - baud rates: 0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
  18 * - signals: DTR, RTS and BREAK
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/tty.h>
  24#include <linux/usb.h>
  25#include <linux/usb/serial.h>
  26
  27#define DRIVER_DESC "Renesas uPD78F0730 USB to serial converter driver"
  28
  29#define DRIVER_AUTHOR "Maksim Salau <maksim.salau@gmail.com>"
  30
  31static const struct usb_device_id id_table[] = {
  32        { USB_DEVICE(0x0409, 0x0063) }, /* V850ESJX3-STICK */
  33        { USB_DEVICE(0x045B, 0x0212) }, /* YRPBRL78G13, YRPBRL78G14 */
  34        { USB_DEVICE(0x064B, 0x7825) }, /* Analog Devices EVAL-ADXL362Z-DB */
  35        {}
  36};
  37
  38MODULE_DEVICE_TABLE(usb, id_table);
  39
  40/*
  41 * Each adaptor is associated with a private structure, that holds the current
  42 * state of control signals (DTR, RTS and BREAK).
  43 */
  44struct upd78f0730_port_private {
  45        struct mutex    lock;           /* mutex to protect line_signals */
  46        u8              line_signals;
  47};
  48
  49/* Op-codes of control commands */
  50#define UPD78F0730_CMD_LINE_CONTROL     0x00
  51#define UPD78F0730_CMD_SET_DTR_RTS      0x01
  52#define UPD78F0730_CMD_SET_XON_XOFF_CHR 0x02
  53#define UPD78F0730_CMD_OPEN_CLOSE       0x03
  54#define UPD78F0730_CMD_SET_ERR_CHR      0x04
  55
  56/* Data sizes in UPD78F0730_CMD_LINE_CONTROL command */
  57#define UPD78F0730_DATA_SIZE_7_BITS     0x00
  58#define UPD78F0730_DATA_SIZE_8_BITS     0x01
  59#define UPD78F0730_DATA_SIZE_MASK       0x01
  60
  61/* Stop-bit modes in UPD78F0730_CMD_LINE_CONTROL command */
  62#define UPD78F0730_STOP_BIT_1_BIT       0x00
  63#define UPD78F0730_STOP_BIT_2_BIT       0x02
  64#define UPD78F0730_STOP_BIT_MASK        0x02
  65
  66/* Parity modes in UPD78F0730_CMD_LINE_CONTROL command */
  67#define UPD78F0730_PARITY_NONE  0x00
  68#define UPD78F0730_PARITY_EVEN  0x04
  69#define UPD78F0730_PARITY_ODD   0x08
  70#define UPD78F0730_PARITY_MASK  0x0C
  71
  72/* Flow control modes in UPD78F0730_CMD_LINE_CONTROL command */
  73#define UPD78F0730_FLOW_CONTROL_NONE    0x00
  74#define UPD78F0730_FLOW_CONTROL_HW      0x10
  75#define UPD78F0730_FLOW_CONTROL_SW      0x20
  76#define UPD78F0730_FLOW_CONTROL_MASK    0x30
  77
  78/* Control signal bits in UPD78F0730_CMD_SET_DTR_RTS command */
  79#define UPD78F0730_RTS          0x01
  80#define UPD78F0730_DTR          0x02
  81#define UPD78F0730_BREAK        0x04
  82
  83/* Port modes in UPD78F0730_CMD_OPEN_CLOSE command */
  84#define UPD78F0730_PORT_CLOSE   0x00
  85#define UPD78F0730_PORT_OPEN    0x01
  86
  87/* Error character substitution modes in UPD78F0730_CMD_SET_ERR_CHR command */
  88#define UPD78F0730_ERR_CHR_DISABLED     0x00
  89#define UPD78F0730_ERR_CHR_ENABLED      0x01
  90
  91/*
  92 * Declaration of command structures
  93 */
  94
  95/* UPD78F0730_CMD_LINE_CONTROL command */
  96struct upd78f0730_line_control {
  97        u8      opcode;
  98        __le32  baud_rate;
  99        u8      params;
 100} __packed;
 101
 102/* UPD78F0730_CMD_SET_DTR_RTS command */
 103struct upd78f0730_set_dtr_rts {
 104        u8 opcode;
 105        u8 params;
 106};
 107
 108/* UPD78F0730_CMD_SET_XON_OFF_CHR command */
 109struct upd78f0730_set_xon_xoff_chr {
 110        u8 opcode;
 111        u8 xon;
 112        u8 xoff;
 113};
 114
 115/* UPD78F0730_CMD_OPEN_CLOSE command */
 116struct upd78f0730_open_close {
 117        u8 opcode;
 118        u8 state;
 119};
 120
 121/* UPD78F0730_CMD_SET_ERR_CHR command */
 122struct upd78f0730_set_err_chr {
 123        u8 opcode;
 124        u8 state;
 125        u8 err_char;
 126};
 127
 128static int upd78f0730_send_ctl(struct usb_serial_port *port,
 129                        const void *data, int size)
 130{
 131        struct usb_device *usbdev = port->serial->dev;
 132        void *buf;
 133        int res;
 134
 135        if (size <= 0 || !data)
 136                return -EINVAL;
 137
 138        buf = kmemdup(data, size, GFP_KERNEL);
 139        if (!buf)
 140                return -ENOMEM;
 141
 142        res = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x00,
 143                        USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
 144                        0x0000, 0x0000, buf, size, USB_CTRL_SET_TIMEOUT);
 145
 146        kfree(buf);
 147
 148        if (res != size) {
 149                struct device *dev = &port->dev;
 150
 151                dev_err(dev, "failed to send control request %02x: %d\n",
 152                        *(u8 *)data, res);
 153                /* The maximum expected length of a transfer is 6 bytes */
 154                if (res >= 0)
 155                        res = -EIO;
 156
 157                return res;
 158        }
 159
 160        return 0;
 161}
 162
 163static int upd78f0730_port_probe(struct usb_serial_port *port)
 164{
 165        struct upd78f0730_port_private *private;
 166
 167        private = kzalloc(sizeof(*private), GFP_KERNEL);
 168        if (!private)
 169                return -ENOMEM;
 170
 171        mutex_init(&private->lock);
 172        usb_set_serial_port_data(port, private);
 173
 174        return 0;
 175}
 176
 177static int upd78f0730_port_remove(struct usb_serial_port *port)
 178{
 179        struct upd78f0730_port_private *private;
 180
 181        private = usb_get_serial_port_data(port);
 182        mutex_destroy(&private->lock);
 183        kfree(private);
 184
 185        return 0;
 186}
 187
 188static int upd78f0730_tiocmget(struct tty_struct *tty)
 189{
 190        struct device *dev = tty->dev;
 191        struct upd78f0730_port_private *private;
 192        struct usb_serial_port *port = tty->driver_data;
 193        int signals;
 194        int res;
 195
 196        private = usb_get_serial_port_data(port);
 197
 198        mutex_lock(&private->lock);
 199        signals = private->line_signals;
 200        mutex_unlock(&private->lock);
 201
 202        res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |
 203                ((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);
 204
 205        dev_dbg(dev, "%s - res = %x\n", __func__, res);
 206
 207        return res;
 208}
 209
 210static int upd78f0730_tiocmset(struct tty_struct *tty,
 211                        unsigned int set, unsigned int clear)
 212{
 213        struct device *dev = tty->dev;
 214        struct usb_serial_port *port = tty->driver_data;
 215        struct upd78f0730_port_private *private;
 216        struct upd78f0730_set_dtr_rts request;
 217        int res;
 218
 219        private = usb_get_serial_port_data(port);
 220
 221        mutex_lock(&private->lock);
 222        if (set & TIOCM_DTR) {
 223                private->line_signals |= UPD78F0730_DTR;
 224                dev_dbg(dev, "%s - set DTR\n", __func__);
 225        }
 226        if (set & TIOCM_RTS) {
 227                private->line_signals |= UPD78F0730_RTS;
 228                dev_dbg(dev, "%s - set RTS\n", __func__);
 229        }
 230        if (clear & TIOCM_DTR) {
 231                private->line_signals &= ~UPD78F0730_DTR;
 232                dev_dbg(dev, "%s - clear DTR\n", __func__);
 233        }
 234        if (clear & TIOCM_RTS) {
 235                private->line_signals &= ~UPD78F0730_RTS;
 236                dev_dbg(dev, "%s - clear RTS\n", __func__);
 237        }
 238        request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
 239        request.params = private->line_signals;
 240
 241        res = upd78f0730_send_ctl(port, &request, sizeof(request));
 242        mutex_unlock(&private->lock);
 243
 244        return res;
 245}
 246
 247static void upd78f0730_break_ctl(struct tty_struct *tty, int break_state)
 248{
 249        struct device *dev = tty->dev;
 250        struct upd78f0730_port_private *private;
 251        struct usb_serial_port *port = tty->driver_data;
 252        struct upd78f0730_set_dtr_rts request;
 253
 254        private = usb_get_serial_port_data(port);
 255
 256        mutex_lock(&private->lock);
 257        if (break_state) {
 258                private->line_signals |= UPD78F0730_BREAK;
 259                dev_dbg(dev, "%s - set BREAK\n", __func__);
 260        } else {
 261                private->line_signals &= ~UPD78F0730_BREAK;
 262                dev_dbg(dev, "%s - clear BREAK\n", __func__);
 263        }
 264        request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
 265        request.params = private->line_signals;
 266
 267        upd78f0730_send_ctl(port, &request, sizeof(request));
 268        mutex_unlock(&private->lock);
 269}
 270
 271static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)
 272{
 273        struct tty_struct *tty = port->port.tty;
 274        unsigned int set = 0;
 275        unsigned int clear = 0;
 276
 277        if (on)
 278                set = TIOCM_DTR | TIOCM_RTS;
 279        else
 280                clear = TIOCM_DTR | TIOCM_RTS;
 281
 282        upd78f0730_tiocmset(tty, set, clear);
 283}
 284
 285static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
 286{
 287        const speed_t baud_rate = tty_get_baud_rate(tty);
 288        static const speed_t supported[] = {
 289                0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
 290        };
 291        int i;
 292
 293        for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {
 294                if (baud_rate == supported[i])
 295                        return baud_rate;
 296        }
 297
 298        /* If the baud rate is not supported, switch to the default one */
 299        tty_encode_baud_rate(tty, 9600, 9600);
 300
 301        return tty_get_baud_rate(tty);
 302}
 303
 304static void upd78f0730_set_termios(struct tty_struct *tty,
 305                                struct usb_serial_port *port,
 306                                struct ktermios *old_termios)
 307{
 308        struct device *dev = &port->dev;
 309        struct upd78f0730_line_control request;
 310        speed_t baud_rate;
 311
 312        if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 313                return;
 314
 315        if (C_BAUD(tty) == B0)
 316                upd78f0730_dtr_rts(port, 0);
 317        else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
 318                upd78f0730_dtr_rts(port, 1);
 319
 320        baud_rate = upd78f0730_get_baud_rate(tty);
 321        request.opcode = UPD78F0730_CMD_LINE_CONTROL;
 322        request.baud_rate = cpu_to_le32(baud_rate);
 323        request.params = 0;
 324        dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);
 325
 326        switch (C_CSIZE(tty)) {
 327        case CS7:
 328                request.params |= UPD78F0730_DATA_SIZE_7_BITS;
 329                dev_dbg(dev, "%s - 7 data bits\n", __func__);
 330                break;
 331        default:
 332                tty->termios.c_cflag &= ~CSIZE;
 333                tty->termios.c_cflag |= CS8;
 334                dev_warn(dev, "data size is not supported, using 8 bits\n");
 335                fallthrough;
 336        case CS8:
 337                request.params |= UPD78F0730_DATA_SIZE_8_BITS;
 338                dev_dbg(dev, "%s - 8 data bits\n", __func__);
 339                break;
 340        }
 341
 342        if (C_PARENB(tty)) {
 343                if (C_PARODD(tty)) {
 344                        request.params |= UPD78F0730_PARITY_ODD;
 345                        dev_dbg(dev, "%s - odd parity\n", __func__);
 346                } else {
 347                        request.params |= UPD78F0730_PARITY_EVEN;
 348                        dev_dbg(dev, "%s - even parity\n", __func__);
 349                }
 350
 351                if (C_CMSPAR(tty)) {
 352                        tty->termios.c_cflag &= ~CMSPAR;
 353                        dev_warn(dev, "MARK/SPACE parity is not supported\n");
 354                }
 355        } else {
 356                request.params |= UPD78F0730_PARITY_NONE;
 357                dev_dbg(dev, "%s - no parity\n", __func__);
 358        }
 359
 360        if (C_CSTOPB(tty)) {
 361                request.params |= UPD78F0730_STOP_BIT_2_BIT;
 362                dev_dbg(dev, "%s - 2 stop bits\n", __func__);
 363        } else {
 364                request.params |= UPD78F0730_STOP_BIT_1_BIT;
 365                dev_dbg(dev, "%s - 1 stop bit\n", __func__);
 366        }
 367
 368        if (C_CRTSCTS(tty)) {
 369                tty->termios.c_cflag &= ~CRTSCTS;
 370                dev_warn(dev, "RTSCTS flow control is not supported\n");
 371        }
 372        if (I_IXOFF(tty) || I_IXON(tty)) {
 373                tty->termios.c_iflag &= ~(IXOFF | IXON);
 374                dev_warn(dev, "XON/XOFF flow control is not supported\n");
 375        }
 376        request.params |= UPD78F0730_FLOW_CONTROL_NONE;
 377        dev_dbg(dev, "%s - no flow control\n", __func__);
 378
 379        upd78f0730_send_ctl(port, &request, sizeof(request));
 380}
 381
 382static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)
 383{
 384        static const struct upd78f0730_open_close request = {
 385                .opcode = UPD78F0730_CMD_OPEN_CLOSE,
 386                .state = UPD78F0730_PORT_OPEN
 387        };
 388        int res;
 389
 390        res = upd78f0730_send_ctl(port, &request, sizeof(request));
 391        if (res)
 392                return res;
 393
 394        if (tty)
 395                upd78f0730_set_termios(tty, port, NULL);
 396
 397        return usb_serial_generic_open(tty, port);
 398}
 399
 400static void upd78f0730_close(struct usb_serial_port *port)
 401{
 402        static const struct upd78f0730_open_close request = {
 403                .opcode = UPD78F0730_CMD_OPEN_CLOSE,
 404                .state = UPD78F0730_PORT_CLOSE
 405        };
 406
 407        usb_serial_generic_close(port);
 408        upd78f0730_send_ctl(port, &request, sizeof(request));
 409}
 410
 411static struct usb_serial_driver upd78f0730_device = {
 412        .driver  = {
 413                .owner  = THIS_MODULE,
 414                .name   = "upd78f0730",
 415        },
 416        .id_table       = id_table,
 417        .num_ports      = 1,
 418        .port_probe     = upd78f0730_port_probe,
 419        .port_remove    = upd78f0730_port_remove,
 420        .open           = upd78f0730_open,
 421        .close          = upd78f0730_close,
 422        .set_termios    = upd78f0730_set_termios,
 423        .tiocmget       = upd78f0730_tiocmget,
 424        .tiocmset       = upd78f0730_tiocmset,
 425        .dtr_rts        = upd78f0730_dtr_rts,
 426        .break_ctl      = upd78f0730_break_ctl,
 427};
 428
 429static struct usb_serial_driver * const serial_drivers[] = {
 430        &upd78f0730_device,
 431        NULL
 432};
 433
 434module_usb_serial_driver(serial_drivers, id_table);
 435
 436MODULE_DESCRIPTION(DRIVER_DESC);
 437MODULE_AUTHOR(DRIVER_AUTHOR);
 438MODULE_LICENSE("GPL v2");
 439