src/jtag/drivers/bcm2835gpio.c

   1 /***************************************************************************
   2  *   Copyright (C) 2013 by Paul Fertser, fercerpav@gmail.com               *
   3  *                                                                         *
   4  *   Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
   5  *   Based on at91rm9200.c (c) Anders Larsen                               *
   6  *   and RPi GPIO examples by Gert van Loo & Dom                           *
   7  *                                                                         *
   8  *   This program is free software; you can redistribute it and/or modify  *
   9  *   it under the terms of the GNU General Public License as published by  *
  10  *   the Free Software Foundation; either version 2 of the License, or     *
  11  *   (at your option) any later version.                                   *
  12  *                                                                         *
  13  *   This program is distributed in the hope that it will be useful,       *
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  16  *   GNU General Public License for more details.                          *
  17  *                                                                         *
  18  *   You should have received a copy of the GNU General Public License     *
  19  *   along with this program; if not, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  22  ***************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <jtag/interface.h>
  29 #include "bitbang.h"
  30
  31 #include <sys/mman.h>
  32
  33 uint32_t bcm2835_peri_base = 0x20000000;
  34 #define BCM2835_GPIO_BASE       (bcm2835_peri_base + 0x200000) /* GPIO controller */
  35
  36 #define BCM2835_PADS_GPIO_0_27          (bcm2835_peri_base + 0x100000)
  37 #define BCM2835_PADS_GPIO_0_27_OFFSET   (0x2c / 4)
  38
  39 /* GPIO setup macros */
  40 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  41 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  42 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  43                 INP_GPIO(g);                                            \
  44                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  45 #define OUT_GPIO(g) SET_MODE_GPIO(g, 1)
  46
  47 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  48 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  49 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  50
  51 static int dev_mem_fd;
  52 static volatile uint32_t *pio_base;
  53
  54 static int bcm2835gpio_read(void);
  55 static void bcm2835gpio_write(int tck, int tms, int tdi);
  56 static void bcm2835gpio_reset(int trst, int srst);
  57
  58 static int bcm2835_swdio_read(void);
  59 static void bcm2835_swdio_drive(bool is_output);
  60
  61 static int bcm2835gpio_init(void);
  62 static int bcm2835gpio_quit(void);
  63
  64 static struct bitbang_interface bcm2835gpio_bitbang = {
  65         .read = bcm2835gpio_read,
  66         .write = bcm2835gpio_write,
  67         .reset = bcm2835gpio_reset,
  68         .swdio_read = bcm2835_swdio_read,
  69         .swdio_drive = bcm2835_swdio_drive,
  70         .blink = NULL
  71 };
  72
  73 /* GPIO numbers for each signal. Negative values are invalid */
  74 static int tck_gpio = -1;
  75 static int tck_gpio_mode;
  76 static int tms_gpio = -1;
  77 static int tms_gpio_mode;
  78 static int tdi_gpio = -1;
  79 static int tdi_gpio_mode;
  80 static int tdo_gpio = -1;
  81 static int tdo_gpio_mode;
  82 static int trst_gpio = -1;
  83 static int trst_gpio_mode;
  84 static int srst_gpio = -1;
  85 static int srst_gpio_mode;
  86 static int swclk_gpio = -1;
  87 static int swclk_gpio_mode;
  88 static int swdio_gpio = -1;
  89 static int swdio_gpio_mode;
  90
  91 /* Transition delay coefficients */
  92 static int speed_coeff = 113714;
  93 static int speed_offset = 28;
  94 static unsigned int jtag_delay;
  95
  96 static int bcm2835gpio_read(void)
  97 {
  98         return !!(GPIO_LEV & 1<<tdo_gpio);
  99 }
 100
 101 static void bcm2835gpio_write(int tck, int tms, int tdi)
 102 {
 103         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
 104         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
 105
 106         GPIO_SET = set;
 107         GPIO_CLR = clear;
 108
 109         for (unsigned int i = 0; i < jtag_delay; i++)
 110                 asm volatile ("");
 111 }
 112
 113 static void bcm2835gpio_swd_write(int tck, int tms, int tdi)
 114 {
 115         uint32_t set = tck<<swclk_gpio | tdi<<swdio_gpio;
 116         uint32_t clear = !tck<<swclk_gpio | !tdi<<swdio_gpio;
 117
 118         GPIO_SET = set;
 119         GPIO_CLR = clear;
 120
 121         for (unsigned int i = 0; i < jtag_delay; i++)
 122                 asm volatile ("");
 123 }
 124
 125 /* (1) assert or (0) deassert reset lines */
 126 static void bcm2835gpio_reset(int trst, int srst)
 127 {
 128         uint32_t set = 0;
 129         uint32_t clear = 0;
 130
 131         if (trst_gpio > 0) {
 132                 set |= !trst<<trst_gpio;
 133                 clear |= trst<<trst_gpio;
 134         }
 135
 136         if (srst_gpio > 0) {
 137                 set |= !srst<<srst_gpio;
 138                 clear |= srst<<srst_gpio;
 139         }
 140
 141         GPIO_SET = set;
 142         GPIO_CLR = clear;
 143 }
 144
 145 static void bcm2835_swdio_drive(bool is_output)
 146 {
 147         if (is_output)
 148                 OUT_GPIO(swdio_gpio);
 149         else
 150                 INP_GPIO(swdio_gpio);
 151 }
 152
 153 static int bcm2835_swdio_read(void)
 154 {
 155         return !!(GPIO_LEV & 1 << swdio_gpio);
 156 }
 157
 158 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 159 {
 160         if (!khz) {
 161                 LOG_DEBUG("RCLK not supported");
 162                 return ERROR_FAIL;
 163         }
 164         *jtag_speed = speed_coeff/khz - speed_offset;
 165         if (*jtag_speed < 0)
 166                 *jtag_speed = 0;
 167         return ERROR_OK;
 168 }
 169
 170 static int bcm2835gpio_speed_div(int speed, int *khz)
 171 {
 172         *khz = speed_coeff/(speed + speed_offset);
 173         return ERROR_OK;
 174 }
 175
 176 static int bcm2835gpio_speed(int speed)
 177 {
 178         jtag_delay = speed;
 179         return ERROR_OK;
 180 }
 181
 182 static int is_gpio_valid(int gpio)
 183 {
 184         return gpio >= 0 && gpio <= 53;
 185 }
 186
 187 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 188 {
 189         if (CMD_ARGC == 4) {
 190                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 191                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 192                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 193                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 194         } else if (CMD_ARGC != 0) {
 195                 return ERROR_COMMAND_SYNTAX_ERROR;
 196         }
 197
 198         command_print(CMD_CTX,
 199                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 200                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 201
 202         return ERROR_OK;
 203 }
 204
 205 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 206 {
 207         if (CMD_ARGC == 1)
 208                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 209
 210         command_print(CMD_CTX, "BCM2835 GPIO config: tck = %d", tck_gpio);
 211         return ERROR_OK;
 212 }
 213
 214 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 215 {
 216         if (CMD_ARGC == 1)
 217                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 218
 219         command_print(CMD_CTX, "BCM2835 GPIO config: tms = %d", tms_gpio);
 220         return ERROR_OK;
 221 }
 222
 223 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 224 {
 225         if (CMD_ARGC == 1)
 226                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 227
 228         command_print(CMD_CTX, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 229         return ERROR_OK;
 230 }
 231
 232 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 233 {
 234         if (CMD_ARGC == 1)
 235                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 236
 237         command_print(CMD_CTX, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 238         return ERROR_OK;
 239 }
 240
 241 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 242 {
 243         if (CMD_ARGC == 1)
 244                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 245
 246         command_print(CMD_CTX, "BCM2835 GPIO config: srst = %d", srst_gpio);
 247         return ERROR_OK;
 248 }
 249
 250 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 251 {
 252         if (CMD_ARGC == 1)
 253                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 254
 255         command_print(CMD_CTX, "BCM2835 GPIO config: trst = %d", trst_gpio);
 256         return ERROR_OK;
 257 }
 258
 259 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionums)
 260 {
 261         if (CMD_ARGC == 2) {
 262                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 263                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 264         } else if (CMD_ARGC != 0) {
 265                 return ERROR_COMMAND_SYNTAX_ERROR;
 266         }
 267
 268         command_print(CMD_CTX,
 269                         "BCM2835 GPIO nums: swclk = %d, swdio = %d",
 270                         swclk_gpio, swdio_gpio);
 271
 272         return ERROR_OK;
 273 }
 274
 275 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swclk)
 276 {
 277         if (CMD_ARGC == 1)
 278                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 279
 280         command_print(CMD_CTX, "BCM2835 num: swclk = %d", swclk_gpio);
 281         return ERROR_OK;
 282 }
 283
 284 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swdio)
 285 {
 286         if (CMD_ARGC == 1)
 287                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 288
 289         command_print(CMD_CTX, "BCM2835 num: swdio = %d", swdio_gpio);
 290         return ERROR_OK;
 291 }
 292
 293 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 294 {
 295         if (CMD_ARGC == 2) {
 296                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 297                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 298         }
 299         return ERROR_OK;
 300 }
 301
 302 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
 303 {
 304         if (CMD_ARGC == 1)
 305                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
 306         return ERROR_OK;
 307 }
 308
 309 static const struct command_registration bcm2835gpio_command_handlers[] = {
 310         {
 311                 .name = "bcm2835gpio_jtag_nums",
 312                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 313                 .mode = COMMAND_CONFIG,
 314                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 315                 .usage = "(tck tms tdi tdo)* ",
 316         },
 317         {
 318                 .name = "bcm2835gpio_tck_num",
 319                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 320                 .mode = COMMAND_CONFIG,
 321                 .help = "gpio number for tck.",
 322         },
 323         {
 324                 .name = "bcm2835gpio_tms_num",
 325                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 326                 .mode = COMMAND_CONFIG,
 327                 .help = "gpio number for tms.",
 328         },
 329         {
 330                 .name = "bcm2835gpio_tdo_num",
 331                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 332                 .mode = COMMAND_CONFIG,
 333                 .help = "gpio number for tdo.",
 334         },
 335         {
 336                 .name = "bcm2835gpio_tdi_num",
 337                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 338                 .mode = COMMAND_CONFIG,
 339                 .help = "gpio number for tdi.",
 340         },
 341         {
 342                 .name = "bcm2835gpio_swd_nums",
 343                 .handler = &bcm2835gpio_handle_swd_gpionums,
 344                 .mode = COMMAND_CONFIG,
 345                 .help = "gpio numbers for swclk, swdio. (in that order)",
 346                 .usage = "(swclk swdio)* ",
 347         },
 348         {
 349                 .name = "bcm2835gpio_swclk_num",
 350                 .handler = &bcm2835gpio_handle_swd_gpionum_swclk,
 351                 .mode = COMMAND_CONFIG,
 352                 .help = "gpio number for swclk.",
 353         },
 354         {
 355                 .name = "bcm2835gpio_swdio_num",
 356                 .handler = &bcm2835gpio_handle_swd_gpionum_swdio,
 357                 .mode = COMMAND_CONFIG,
 358                 .help = "gpio number for swdio.",
 359         },
 360         {
 361                 .name = "bcm2835gpio_srst_num",
 362                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 363                 .mode = COMMAND_CONFIG,
 364                 .help = "gpio number for srst.",
 365         },
 366         {
 367                 .name = "bcm2835gpio_trst_num",
 368                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 369                 .mode = COMMAND_CONFIG,
 370                 .help = "gpio number for trst.",
 371         },
 372         {
 373                 .name = "bcm2835gpio_speed_coeffs",
 374                 .handler = &bcm2835gpio_handle_speed_coeffs,
 375                 .mode = COMMAND_CONFIG,
 376                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 377         },
 378         {
 379                 .name = "bcm2835gpio_peripheral_base",
 380                 .handler = &bcm2835gpio_handle_peripheral_base,
 381                 .mode = COMMAND_CONFIG,
 382                 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
 383         },
 384
 385         COMMAND_REGISTRATION_DONE
 386 };
 387
 388 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 389
 390 struct jtag_interface bcm2835gpio_interface = {
 391         .name = "bcm2835gpio",
 392         .supported = DEBUG_CAP_TMS_SEQ,
 393         .execute_queue = bitbang_execute_queue,
 394         .transports = bcm2835_transports,
 395         .swd = &bitbang_swd,
 396         .speed = bcm2835gpio_speed,
 397         .khz = bcm2835gpio_khz,
 398         .speed_div = bcm2835gpio_speed_div,
 399         .commands = bcm2835gpio_command_handlers,
 400         .init = bcm2835gpio_init,
 401         .quit = bcm2835gpio_quit,
 402 };
 403
 404 static bool bcm2835gpio_jtag_mode_possible(void)
 405 {
 406         if (!is_gpio_valid(tck_gpio))
 407                 return 0;
 408         if (!is_gpio_valid(tms_gpio))
 409                 return 0;
 410         if (!is_gpio_valid(tdi_gpio))
 411                 return 0;
 412         if (!is_gpio_valid(tdo_gpio))
 413                 return 0;
 414         return 1;
 415 }
 416
 417 static bool bcm2835gpio_swd_mode_possible(void)
 418 {
 419         if (!is_gpio_valid(swclk_gpio))
 420                 return 0;
 421         if (!is_gpio_valid(swdio_gpio))
 422                 return 0;
 423         return 1;
 424 }
 425
 426 static int bcm2835gpio_init(void)
 427 {
 428         bitbang_interface = &bcm2835gpio_bitbang;
 429
 430         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 431
 432         if (bcm2835gpio_jtag_mode_possible()) {
 433                 if (bcm2835gpio_swd_mode_possible())
 434                         LOG_INFO("JTAG and SWD modes enabled");
 435                 else
 436                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 437                 if (!is_gpio_valid(trst_gpio) && !is_gpio_valid(srst_gpio)) {
 438                         LOG_ERROR("Require at least one of trst or srst gpios to be specified");
 439                         return ERROR_JTAG_INIT_FAILED;
 440                 }
 441         } else if (bcm2835gpio_swd_mode_possible()) {
 442                 LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
 443         } else {
 444                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
 445                 return ERROR_JTAG_INIT_FAILED;
 446         }
 447
 448         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 449         if (dev_mem_fd < 0) {
 450                 perror("open");
 451                 return ERROR_JTAG_INIT_FAILED;
 452         }
 453
 454         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 455                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 456
 457         if (pio_base == MAP_FAILED) {
 458                 perror("mmap");
 459                 close(dev_mem_fd);
 460                 return ERROR_JTAG_INIT_FAILED;
 461         }
 462
 463         static volatile uint32_t *pads_base;
 464         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 465                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 466
 467         if (pads_base == MAP_FAILED) {
 468                 perror("mmap");
 469                 close(dev_mem_fd);
 470                 return ERROR_JTAG_INIT_FAILED;
 471         }
 472
 473         /* set 16mA drive strength */
 474         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000018 + 7;
 475
 476         tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 477         tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 478         tck_gpio_mode = MODE_GPIO(tck_gpio);
 479         tms_gpio_mode = MODE_GPIO(tms_gpio);
 480         swclk_gpio_mode = MODE_GPIO(swclk_gpio);
 481         swdio_gpio_mode = MODE_GPIO(swdio_gpio);
 482         /*
 483          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 484          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 485          */
 486         INP_GPIO(tdo_gpio);
 487
 488         GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio | 1<<swdio_gpio | 1<<swclk_gpio;
 489         GPIO_SET = 1<<tms_gpio;
 490
 491         OUT_GPIO(tdi_gpio);
 492         OUT_GPIO(tck_gpio);
 493         OUT_GPIO(tms_gpio);
 494         OUT_GPIO(swclk_gpio);
 495         OUT_GPIO(swdio_gpio);
 496         if (trst_gpio != -1) {
 497                 trst_gpio_mode = MODE_GPIO(trst_gpio);
 498                 GPIO_SET = 1 << trst_gpio;
 499                 OUT_GPIO(trst_gpio);
 500         }
 501         if (srst_gpio != -1) {
 502                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 503                 GPIO_SET = 1 << srst_gpio;
 504                 OUT_GPIO(srst_gpio);
 505         }
 506
 507         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 508                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 509                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 510
 511         if (swd_mode) {
 512                 bcm2835gpio_bitbang.write = bcm2835gpio_swd_write;
 513                 bitbang_switch_to_swd();
 514         }
 515
 516         return ERROR_OK;
 517 }
 518
 519 static int bcm2835gpio_quit(void)
 520 {
 521         SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 522         SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 523         SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 524         SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 525         SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
 526         SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
 527         if (trst_gpio != -1)
 528                 SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 529         if (srst_gpio != -1)
 530                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 531
 532         return ERROR_OK;
 533 }