drivers/usb/serial/upd78f0730.c

   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
  31 static 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
  38 MODULE_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  */
  44 struct 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 */
  96 struct upd78f0730_line_control {
  97         u8      opcode;
  98         __le32  baud_rate;
  99         u8      params;
 100 } __packed;
 101
 102 /* UPD78F0730_CMD_SET_DTR_RTS command */
 103 struct upd78f0730_set_dtr_rts {
 104         u8 opcode;
 105         u8 params;
 106 };
 107
 108 /* UPD78F0730_CMD_SET_XON_OFF_CHR command */
 109 struct upd78f0730_set_xon_xoff_chr {
 110         u8 opcode;
 111         u8 xon;
 112         u8 xoff;
 113 };
 114
 115 /* UPD78F0730_CMD_OPEN_CLOSE command */
 116 struct upd78f0730_open_close {
 117         u8 opcode;
 118         u8 state;
 119 };
 120
 121 /* UPD78F0730_CMD_SET_ERR_CHR command */
 122 struct upd78f0730_set_err_chr {
 123         u8 opcode;
 124         u8 state;
 125         u8 err_char;
 126 };
 127
 128 static 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 < 0) {
 149                 struct device *dev = &port->dev;
 150
 151                 dev_err(dev, "failed to send control request %02x: %d\n",
 152                         *(u8 *)data, res);
 153
 154                 return res;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int upd78f0730_port_probe(struct usb_serial_port *port)
 161 {
 162         struct upd78f0730_port_private *private;
 163
 164         private = kzalloc(sizeof(*private), GFP_KERNEL);
 165         if (!private)
 166                 return -ENOMEM;
 167
 168         mutex_init(&private->lock);
 169         usb_set_serial_port_data(port, private);
 170
 171         return 0;
 172 }
 173
 174 static void upd78f0730_port_remove(struct usb_serial_port *port)
 175 {
 176         struct upd78f0730_port_private *private;
 177
 178         private = usb_get_serial_port_data(port);
 179         mutex_destroy(&private->lock);
 180         kfree(private);
 181 }
 182
 183 static int upd78f0730_tiocmget(struct tty_struct *tty)
 184 {
 185         struct upd78f0730_port_private *private;
 186         struct usb_serial_port *port = tty->driver_data;
 187         int signals;
 188         int res;
 189
 190         private = usb_get_serial_port_data(port);
 191
 192         mutex_lock(&private->lock);
 193         signals = private->line_signals;
 194         mutex_unlock(&private->lock);
 195
 196         res = ((signals & UPD78F0730_DTR) ? TIOCM_DTR : 0) |
 197                 ((signals & UPD78F0730_RTS) ? TIOCM_RTS : 0);
 198
 199         dev_dbg(&port->dev, "%s - res = %x\n", __func__, res);
 200
 201         return res;
 202 }
 203
 204 static int upd78f0730_tiocmset(struct tty_struct *tty,
 205                         unsigned int set, unsigned int clear)
 206 {
 207         struct usb_serial_port *port = tty->driver_data;
 208         struct upd78f0730_port_private *private;
 209         struct upd78f0730_set_dtr_rts request;
 210         struct device *dev = &port->dev;
 211         int res;
 212
 213         private = usb_get_serial_port_data(port);
 214
 215         mutex_lock(&private->lock);
 216         if (set & TIOCM_DTR) {
 217                 private->line_signals |= UPD78F0730_DTR;
 218                 dev_dbg(dev, "%s - set DTR\n", __func__);
 219         }
 220         if (set & TIOCM_RTS) {
 221                 private->line_signals |= UPD78F0730_RTS;
 222                 dev_dbg(dev, "%s - set RTS\n", __func__);
 223         }
 224         if (clear & TIOCM_DTR) {
 225                 private->line_signals &= ~UPD78F0730_DTR;
 226                 dev_dbg(dev, "%s - clear DTR\n", __func__);
 227         }
 228         if (clear & TIOCM_RTS) {
 229                 private->line_signals &= ~UPD78F0730_RTS;
 230                 dev_dbg(dev, "%s - clear RTS\n", __func__);
 231         }
 232         request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
 233         request.params = private->line_signals;
 234
 235         res = upd78f0730_send_ctl(port, &request, sizeof(request));
 236         mutex_unlock(&private->lock);
 237
 238         return res;
 239 }
 240
 241 static int upd78f0730_break_ctl(struct tty_struct *tty, int break_state)
 242 {
 243         struct upd78f0730_port_private *private;
 244         struct usb_serial_port *port = tty->driver_data;
 245         struct upd78f0730_set_dtr_rts request;
 246         struct device *dev = &port->dev;
 247         int res;
 248
 249         private = usb_get_serial_port_data(port);
 250
 251         mutex_lock(&private->lock);
 252         if (break_state) {
 253                 private->line_signals |= UPD78F0730_BREAK;
 254                 dev_dbg(dev, "%s - set BREAK\n", __func__);
 255         } else {
 256                 private->line_signals &= ~UPD78F0730_BREAK;
 257                 dev_dbg(dev, "%s - clear BREAK\n", __func__);
 258         }
 259         request.opcode = UPD78F0730_CMD_SET_DTR_RTS;
 260         request.params = private->line_signals;
 261
 262         res = upd78f0730_send_ctl(port, &request, sizeof(request));
 263         mutex_unlock(&private->lock);
 264
 265         return res;
 266 }
 267
 268 static void upd78f0730_dtr_rts(struct usb_serial_port *port, int on)
 269 {
 270         struct tty_struct *tty = port->port.tty;
 271         unsigned int set = 0;
 272         unsigned int clear = 0;
 273
 274         if (on)
 275                 set = TIOCM_DTR | TIOCM_RTS;
 276         else
 277                 clear = TIOCM_DTR | TIOCM_RTS;
 278
 279         upd78f0730_tiocmset(tty, set, clear);
 280 }
 281
 282 static speed_t upd78f0730_get_baud_rate(struct tty_struct *tty)
 283 {
 284         const speed_t baud_rate = tty_get_baud_rate(tty);
 285         static const speed_t supported[] = {
 286                 0, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 153600
 287         };
 288         int i;
 289
 290         for (i = ARRAY_SIZE(supported) - 1; i >= 0; i--) {
 291                 if (baud_rate == supported[i])
 292                         return baud_rate;
 293         }
 294
 295         /* If the baud rate is not supported, switch to the default one */
 296         tty_encode_baud_rate(tty, 9600, 9600);
 297
 298         return tty_get_baud_rate(tty);
 299 }
 300
 301 static void upd78f0730_set_termios(struct tty_struct *tty,
 302                                    struct usb_serial_port *port,
 303                                    const struct ktermios *old_termios)
 304 {
 305         struct device *dev = &port->dev;
 306         struct upd78f0730_line_control request;
 307         speed_t baud_rate;
 308
 309         if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 310                 return;
 311
 312         if (C_BAUD(tty) == B0)
 313                 upd78f0730_dtr_rts(port, 0);
 314         else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
 315                 upd78f0730_dtr_rts(port, 1);
 316
 317         baud_rate = upd78f0730_get_baud_rate(tty);
 318         request.opcode = UPD78F0730_CMD_LINE_CONTROL;
 319         request.baud_rate = cpu_to_le32(baud_rate);
 320         request.params = 0;
 321         dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud_rate);
 322
 323         switch (C_CSIZE(tty)) {
 324         case CS7:
 325                 request.params |= UPD78F0730_DATA_SIZE_7_BITS;
 326                 dev_dbg(dev, "%s - 7 data bits\n", __func__);
 327                 break;
 328         default:
 329                 tty->termios.c_cflag &= ~CSIZE;
 330                 tty->termios.c_cflag |= CS8;
 331                 dev_warn(dev, "data size is not supported, using 8 bits\n");
 332                 fallthrough;
 333         case CS8:
 334                 request.params |= UPD78F0730_DATA_SIZE_8_BITS;
 335                 dev_dbg(dev, "%s - 8 data bits\n", __func__);
 336                 break;
 337         }
 338
 339         if (C_PARENB(tty)) {
 340                 if (C_PARODD(tty)) {
 341                         request.params |= UPD78F0730_PARITY_ODD;
 342                         dev_dbg(dev, "%s - odd parity\n", __func__);
 343                 } else {
 344                         request.params |= UPD78F0730_PARITY_EVEN;
 345                         dev_dbg(dev, "%s - even parity\n", __func__);
 346                 }
 347
 348                 if (C_CMSPAR(tty)) {
 349                         tty->termios.c_cflag &= ~CMSPAR;
 350                         dev_warn(dev, "MARK/SPACE parity is not supported\n");
 351                 }
 352         } else {
 353                 request.params |= UPD78F0730_PARITY_NONE;
 354                 dev_dbg(dev, "%s - no parity\n", __func__);
 355         }
 356
 357         if (C_CSTOPB(tty)) {
 358                 request.params |= UPD78F0730_STOP_BIT_2_BIT;
 359                 dev_dbg(dev, "%s - 2 stop bits\n", __func__);
 360         } else {
 361                 request.params |= UPD78F0730_STOP_BIT_1_BIT;
 362                 dev_dbg(dev, "%s - 1 stop bit\n", __func__);
 363         }
 364
 365         if (C_CRTSCTS(tty)) {
 366                 tty->termios.c_cflag &= ~CRTSCTS;
 367                 dev_warn(dev, "RTSCTS flow control is not supported\n");
 368         }
 369         if (I_IXOFF(tty) || I_IXON(tty)) {
 370                 tty->termios.c_iflag &= ~(IXOFF | IXON);
 371                 dev_warn(dev, "XON/XOFF flow control is not supported\n");
 372         }
 373         request.params |= UPD78F0730_FLOW_CONTROL_NONE;
 374         dev_dbg(dev, "%s - no flow control\n", __func__);
 375
 376         upd78f0730_send_ctl(port, &request, sizeof(request));
 377 }
 378
 379 static int upd78f0730_open(struct tty_struct *tty, struct usb_serial_port *port)
 380 {
 381         static const struct upd78f0730_open_close request = {
 382                 .opcode = UPD78F0730_CMD_OPEN_CLOSE,
 383                 .state = UPD78F0730_PORT_OPEN
 384         };
 385         int res;
 386
 387         res = upd78f0730_send_ctl(port, &request, sizeof(request));
 388         if (res)
 389                 return res;
 390
 391         if (tty)
 392                 upd78f0730_set_termios(tty, port, NULL);
 393
 394         return usb_serial_generic_open(tty, port);
 395 }
 396
 397 static void upd78f0730_close(struct usb_serial_port *port)
 398 {
 399         static const struct upd78f0730_open_close request = {
 400                 .opcode = UPD78F0730_CMD_OPEN_CLOSE,
 401                 .state = UPD78F0730_PORT_CLOSE
 402         };
 403
 404         usb_serial_generic_close(port);
 405         upd78f0730_send_ctl(port, &request, sizeof(request));
 406 }
 407
 408 static struct usb_serial_driver upd78f0730_device = {
 409         .driver  = {
 410                 .name   = "upd78f0730",
 411         },
 412         .id_table       = id_table,
 413         .num_ports      = 1,
 414         .port_probe     = upd78f0730_port_probe,
 415         .port_remove    = upd78f0730_port_remove,
 416         .open           = upd78f0730_open,
 417         .close          = upd78f0730_close,
 418         .set_termios    = upd78f0730_set_termios,
 419         .tiocmget       = upd78f0730_tiocmget,
 420         .tiocmset       = upd78f0730_tiocmset,
 421         .dtr_rts        = upd78f0730_dtr_rts,
 422         .break_ctl      = upd78f0730_break_ctl,
 423 };
 424
 425 static struct usb_serial_driver * const serial_drivers[] = {
 426         &upd78f0730_device,
 427         NULL
 428 };
 429
 430 module_usb_serial_driver(serial_drivers, id_table);
 431
 432 MODULE_DESCRIPTION(DRIVER_DESC);
 433 MODULE_AUTHOR(DRIVER_AUTHOR);
 434 MODULE_LICENSE("GPL v2");