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, see <http://www.gnu.org/licenses/>. *
  20  ***************************************************************************/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <jtag/interface.h>
  27 #include "bitbang.h"
  28
  29 #include <sys/mman.h>
  30
  31 uint32_t bcm2835_peri_base = 0x20000000;
  32 #define BCM2835_GPIO_BASE       (bcm2835_peri_base + 0x200000) /* GPIO controller */
  33
  34 #define BCM2835_PADS_GPIO_0_27          (bcm2835_peri_base + 0x100000)
  35 #define BCM2835_PADS_GPIO_0_27_OFFSET   (0x2c / 4)
  36
  37 /* GPIO setup macros */
  38 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  39 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  40 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  41                 INP_GPIO(g);                                            \
  42                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  43 #define OUT_GPIO(g) SET_MODE_GPIO(g, 1)
  44
  45 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  46 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  47 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  48
  49 static int dev_mem_fd;
  50 static volatile uint32_t *pio_base;
  51
  52 static bb_value_t bcm2835gpio_read(void);
  53 static int bcm2835gpio_write(int tck, int tms, int tdi);
  54 static int bcm2835gpio_reset(int trst, int srst);
  55
  56 static int bcm2835_swdio_read(void);
  57 static void bcm2835_swdio_drive(bool is_output);
  58
  59 static int bcm2835gpio_init(void);
  60 static int bcm2835gpio_quit(void);
  61
  62 static struct bitbang_interface bcm2835gpio_bitbang = {
  63         .read = bcm2835gpio_read,
  64         .write = bcm2835gpio_write,
  65         .reset = bcm2835gpio_reset,
  66         .swdio_read = bcm2835_swdio_read,
  67         .swdio_drive = bcm2835_swdio_drive,
  68         .blink = NULL
  69 };
  70
  71 /* GPIO numbers for each signal. Negative values are invalid */
  72 static int tck_gpio = -1;
  73 static int tck_gpio_mode;
  74 static int tms_gpio = -1;
  75 static int tms_gpio_mode;
  76 static int tdi_gpio = -1;
  77 static int tdi_gpio_mode;
  78 static int tdo_gpio = -1;
  79 static int tdo_gpio_mode;
  80 static int trst_gpio = -1;
  81 static int trst_gpio_mode;
  82 static int srst_gpio = -1;
  83 static int srst_gpio_mode;
  84 static int swclk_gpio = -1;
  85 static int swclk_gpio_mode;
  86 static int swdio_gpio = -1;
  87 static int swdio_gpio_mode;
  88
  89 /* Transition delay coefficients */
  90 static int speed_coeff = 113714;
  91 static int speed_offset = 28;
  92 static unsigned int jtag_delay;
  93
  94 static bb_value_t bcm2835gpio_read(void)
  95 {
  96         return (GPIO_LEV & 1<<tdo_gpio) ? BB_HIGH : BB_LOW;
  97 }
  98
  99 static int bcm2835gpio_write(int tck, int tms, int tdi)
 100 {
 101         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
 102         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
 103
 104         GPIO_SET = set;
 105         GPIO_CLR = clear;
 106
 107         for (unsigned int i = 0; i < jtag_delay; i++)
 108                 asm volatile ("");
 109
 110         return ERROR_OK;
 111 }
 112
 113 static int 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         return ERROR_OK;
 125 }
 126
 127 /* (1) assert or (0) deassert reset lines */
 128 static int bcm2835gpio_reset(int trst, int srst)
 129 {
 130         uint32_t set = 0;
 131         uint32_t clear = 0;
 132
 133         if (trst_gpio > 0) {
 134                 set |= !trst<<trst_gpio;
 135                 clear |= trst<<trst_gpio;
 136         }
 137
 138         if (srst_gpio > 0) {
 139                 set |= !srst<<srst_gpio;
 140                 clear |= srst<<srst_gpio;
 141         }
 142
 143         GPIO_SET = set;
 144         GPIO_CLR = clear;
 145
 146         return ERROR_OK;
 147 }
 148
 149 static void bcm2835_swdio_drive(bool is_output)
 150 {
 151         if (is_output)
 152                 OUT_GPIO(swdio_gpio);
 153         else
 154                 INP_GPIO(swdio_gpio);
 155 }
 156
 157 static int bcm2835_swdio_read(void)
 158 {
 159         return !!(GPIO_LEV & 1 << swdio_gpio);
 160 }
 161
 162 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 163 {
 164         if (!khz) {
 165                 LOG_DEBUG("RCLK not supported");
 166                 return ERROR_FAIL;
 167         }
 168         *jtag_speed = speed_coeff/khz - speed_offset;
 169         if (*jtag_speed < 0)
 170                 *jtag_speed = 0;
 171         return ERROR_OK;
 172 }
 173
 174 static int bcm2835gpio_speed_div(int speed, int *khz)
 175 {
 176         *khz = speed_coeff/(speed + speed_offset);
 177         return ERROR_OK;
 178 }
 179
 180 static int bcm2835gpio_speed(int speed)
 181 {
 182         jtag_delay = speed;
 183         return ERROR_OK;
 184 }
 185
 186 static int is_gpio_valid(int gpio)
 187 {
 188         return gpio >= 0 && gpio <= 53;
 189 }
 190
 191 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 192 {
 193         if (CMD_ARGC == 4) {
 194                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 195                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 196                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 197                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 198         } else if (CMD_ARGC != 0) {
 199                 return ERROR_COMMAND_SYNTAX_ERROR;
 200         }
 201
 202         command_print(CMD_CTX,
 203                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 204                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 205
 206         return ERROR_OK;
 207 }
 208
 209 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 210 {
 211         if (CMD_ARGC == 1)
 212                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 213
 214         command_print(CMD_CTX, "BCM2835 GPIO config: tck = %d", tck_gpio);
 215         return ERROR_OK;
 216 }
 217
 218 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 219 {
 220         if (CMD_ARGC == 1)
 221                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 222
 223         command_print(CMD_CTX, "BCM2835 GPIO config: tms = %d", tms_gpio);
 224         return ERROR_OK;
 225 }
 226
 227 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 228 {
 229         if (CMD_ARGC == 1)
 230                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 231
 232         command_print(CMD_CTX, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 233         return ERROR_OK;
 234 }
 235
 236 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 237 {
 238         if (CMD_ARGC == 1)
 239                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 240
 241         command_print(CMD_CTX, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 242         return ERROR_OK;
 243 }
 244
 245 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 246 {
 247         if (CMD_ARGC == 1)
 248                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 249
 250         command_print(CMD_CTX, "BCM2835 GPIO config: srst = %d", srst_gpio);
 251         return ERROR_OK;
 252 }
 253
 254 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 255 {
 256         if (CMD_ARGC == 1)
 257                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 258
 259         command_print(CMD_CTX, "BCM2835 GPIO config: trst = %d", trst_gpio);
 260         return ERROR_OK;
 261 }
 262
 263 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionums)
 264 {
 265         if (CMD_ARGC == 2) {
 266                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 267                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 268         } else if (CMD_ARGC != 0) {
 269                 return ERROR_COMMAND_SYNTAX_ERROR;
 270         }
 271
 272         command_print(CMD_CTX,
 273                         "BCM2835 GPIO nums: swclk = %d, swdio = %d",
 274                         swclk_gpio, swdio_gpio);
 275
 276         return ERROR_OK;
 277 }
 278
 279 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swclk)
 280 {
 281         if (CMD_ARGC == 1)
 282                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 283
 284         command_print(CMD_CTX, "BCM2835 num: swclk = %d", swclk_gpio);
 285         return ERROR_OK;
 286 }
 287
 288 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swdio)
 289 {
 290         if (CMD_ARGC == 1)
 291                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 292
 293         command_print(CMD_CTX, "BCM2835 num: swdio = %d", swdio_gpio);
 294         return ERROR_OK;
 295 }
 296
 297 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 298 {
 299         if (CMD_ARGC == 2) {
 300                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 301                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 302         }
 303         return ERROR_OK;
 304 }
 305
 306 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
 307 {
 308         if (CMD_ARGC == 1)
 309                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
 310         return ERROR_OK;
 311 }
 312
 313 static const struct command_registration bcm2835gpio_command_handlers[] = {
 314         {
 315                 .name = "bcm2835gpio_jtag_nums",
 316                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 317                 .mode = COMMAND_CONFIG,
 318                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 319                 .usage = "(tck tms tdi tdo)* ",
 320         },
 321         {
 322                 .name = "bcm2835gpio_tck_num",
 323                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 324                 .mode = COMMAND_CONFIG,
 325                 .help = "gpio number for tck.",
 326         },
 327         {
 328                 .name = "bcm2835gpio_tms_num",
 329                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 330                 .mode = COMMAND_CONFIG,
 331                 .help = "gpio number for tms.",
 332         },
 333         {
 334                 .name = "bcm2835gpio_tdo_num",
 335                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 336                 .mode = COMMAND_CONFIG,
 337                 .help = "gpio number for tdo.",
 338         },
 339         {
 340                 .name = "bcm2835gpio_tdi_num",
 341                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 342                 .mode = COMMAND_CONFIG,
 343                 .help = "gpio number for tdi.",
 344         },
 345         {
 346                 .name = "bcm2835gpio_swd_nums",
 347                 .handler = &bcm2835gpio_handle_swd_gpionums,
 348                 .mode = COMMAND_CONFIG,
 349                 .help = "gpio numbers for swclk, swdio. (in that order)",
 350                 .usage = "(swclk swdio)* ",
 351         },
 352         {
 353                 .name = "bcm2835gpio_swclk_num",
 354                 .handler = &bcm2835gpio_handle_swd_gpionum_swclk,
 355                 .mode = COMMAND_CONFIG,
 356                 .help = "gpio number for swclk.",
 357         },
 358         {
 359                 .name = "bcm2835gpio_swdio_num",
 360                 .handler = &bcm2835gpio_handle_swd_gpionum_swdio,
 361                 .mode = COMMAND_CONFIG,
 362                 .help = "gpio number for swdio.",
 363         },
 364         {
 365                 .name = "bcm2835gpio_srst_num",
 366                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 367                 .mode = COMMAND_CONFIG,
 368                 .help = "gpio number for srst.",
 369         },
 370         {
 371                 .name = "bcm2835gpio_trst_num",
 372                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 373                 .mode = COMMAND_CONFIG,
 374                 .help = "gpio number for trst.",
 375         },
 376         {
 377                 .name = "bcm2835gpio_speed_coeffs",
 378                 .handler = &bcm2835gpio_handle_speed_coeffs,
 379                 .mode = COMMAND_CONFIG,
 380                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 381         },
 382         {
 383                 .name = "bcm2835gpio_peripheral_base",
 384                 .handler = &bcm2835gpio_handle_peripheral_base,
 385                 .mode = COMMAND_CONFIG,
 386                 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
 387         },
 388
 389         COMMAND_REGISTRATION_DONE
 390 };
 391
 392 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 393
 394 struct jtag_interface bcm2835gpio_interface = {
 395         .name = "bcm2835gpio",
 396         .supported = DEBUG_CAP_TMS_SEQ,
 397         .execute_queue = bitbang_execute_queue,
 398         .transports = bcm2835_transports,
 399         .swd = &bitbang_swd,
 400         .speed = bcm2835gpio_speed,
 401         .khz = bcm2835gpio_khz,
 402         .speed_div = bcm2835gpio_speed_div,
 403         .commands = bcm2835gpio_command_handlers,
 404         .init = bcm2835gpio_init,
 405         .quit = bcm2835gpio_quit,
 406 };
 407
 408 static bool bcm2835gpio_jtag_mode_possible(void)
 409 {
 410         if (!is_gpio_valid(tck_gpio))
 411                 return 0;
 412         if (!is_gpio_valid(tms_gpio))
 413                 return 0;
 414         if (!is_gpio_valid(tdi_gpio))
 415                 return 0;
 416         if (!is_gpio_valid(tdo_gpio))
 417                 return 0;
 418         return 1;
 419 }
 420
 421 static bool bcm2835gpio_swd_mode_possible(void)
 422 {
 423         if (!is_gpio_valid(swclk_gpio))
 424                 return 0;
 425         if (!is_gpio_valid(swdio_gpio))
 426                 return 0;
 427         return 1;
 428 }
 429
 430 static int bcm2835gpio_init(void)
 431 {
 432         bitbang_interface = &bcm2835gpio_bitbang;
 433
 434         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 435
 436         if (bcm2835gpio_jtag_mode_possible()) {
 437                 if (bcm2835gpio_swd_mode_possible())
 438                         LOG_INFO("JTAG and SWD modes enabled");
 439                 else
 440                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 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 4mA drive strength, slew rate limited, hysteresis on */
 474         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 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 }