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
  55 static int bcm2835_swdio_read(void);
  56 static void bcm2835_swdio_drive(bool is_output);
  57
  58 static int bcm2835gpio_init(void);
  59 static int bcm2835gpio_quit(void);
  60
  61 static struct bitbang_interface bcm2835gpio_bitbang = {
  62         .read = bcm2835gpio_read,
  63         .write = bcm2835gpio_write,
  64         .swdio_read = bcm2835_swdio_read,
  65         .swdio_drive = bcm2835_swdio_drive,
  66         .blink = NULL
  67 };
  68
  69 /* GPIO numbers for each signal. Negative values are invalid */
  70 static int tck_gpio = -1;
  71 static int tck_gpio_mode;
  72 static int tms_gpio = -1;
  73 static int tms_gpio_mode;
  74 static int tdi_gpio = -1;
  75 static int tdi_gpio_mode;
  76 static int tdo_gpio = -1;
  77 static int tdo_gpio_mode;
  78 static int trst_gpio = -1;
  79 static int trst_gpio_mode;
  80 static int srst_gpio = -1;
  81 static int srst_gpio_mode;
  82 static int swclk_gpio = -1;
  83 static int swclk_gpio_mode;
  84 static int swdio_gpio = -1;
  85 static int swdio_gpio_mode;
  86
  87 /* Transition delay coefficients */
  88 static int speed_coeff = 113714;
  89 static int speed_offset = 28;
  90 static unsigned int jtag_delay;
  91
  92 static bb_value_t bcm2835gpio_read(void)
  93 {
  94         return (GPIO_LEV & 1<<tdo_gpio) ? BB_HIGH : BB_LOW;
  95 }
  96
  97 static int bcm2835gpio_write(int tck, int tms, int tdi)
  98 {
  99         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
 100         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
 101
 102         GPIO_SET = set;
 103         GPIO_CLR = clear;
 104
 105         for (unsigned int i = 0; i < jtag_delay; i++)
 106                 asm volatile ("");
 107
 108         return ERROR_OK;
 109 }
 110
 111 static int bcm2835gpio_swd_write(int tck, int tms, int tdi)
 112 {
 113         uint32_t set = tck<<swclk_gpio | tdi<<swdio_gpio;
 114         uint32_t clear = !tck<<swclk_gpio | !tdi<<swdio_gpio;
 115
 116         GPIO_SET = set;
 117         GPIO_CLR = clear;
 118
 119         for (unsigned int i = 0; i < jtag_delay; i++)
 120                 asm volatile ("");
 121
 122         return ERROR_OK;
 123 }
 124
 125 /* (1) assert or (0) deassert reset lines */
 126 static int 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         return ERROR_OK;
 145 }
 146
 147 static void bcm2835_swdio_drive(bool is_output)
 148 {
 149         if (is_output)
 150                 OUT_GPIO(swdio_gpio);
 151         else
 152                 INP_GPIO(swdio_gpio);
 153 }
 154
 155 static int bcm2835_swdio_read(void)
 156 {
 157         return !!(GPIO_LEV & 1 << swdio_gpio);
 158 }
 159
 160 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 161 {
 162         if (!khz) {
 163                 LOG_DEBUG("RCLK not supported");
 164                 return ERROR_FAIL;
 165         }
 166         *jtag_speed = speed_coeff/khz - speed_offset;
 167         if (*jtag_speed < 0)
 168                 *jtag_speed = 0;
 169         return ERROR_OK;
 170 }
 171
 172 static int bcm2835gpio_speed_div(int speed, int *khz)
 173 {
 174         *khz = speed_coeff/(speed + speed_offset);
 175         return ERROR_OK;
 176 }
 177
 178 static int bcm2835gpio_speed(int speed)
 179 {
 180         jtag_delay = speed;
 181         return ERROR_OK;
 182 }
 183
 184 static int is_gpio_valid(int gpio)
 185 {
 186         return gpio >= 0 && gpio <= 53;
 187 }
 188
 189 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 190 {
 191         if (CMD_ARGC == 4) {
 192                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 193                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 194                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 195                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 196         } else if (CMD_ARGC != 0) {
 197                 return ERROR_COMMAND_SYNTAX_ERROR;
 198         }
 199
 200         command_print(CMD,
 201                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 202                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 203
 204         return ERROR_OK;
 205 }
 206
 207 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 208 {
 209         if (CMD_ARGC == 1)
 210                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 211
 212         command_print(CMD, "BCM2835 GPIO config: tck = %d", tck_gpio);
 213         return ERROR_OK;
 214 }
 215
 216 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 217 {
 218         if (CMD_ARGC == 1)
 219                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 220
 221         command_print(CMD, "BCM2835 GPIO config: tms = %d", tms_gpio);
 222         return ERROR_OK;
 223 }
 224
 225 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 226 {
 227         if (CMD_ARGC == 1)
 228                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 229
 230         command_print(CMD, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 231         return ERROR_OK;
 232 }
 233
 234 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 235 {
 236         if (CMD_ARGC == 1)
 237                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 238
 239         command_print(CMD, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 240         return ERROR_OK;
 241 }
 242
 243 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 244 {
 245         if (CMD_ARGC == 1)
 246                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 247
 248         command_print(CMD, "BCM2835 GPIO config: srst = %d", srst_gpio);
 249         return ERROR_OK;
 250 }
 251
 252 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 253 {
 254         if (CMD_ARGC == 1)
 255                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 256
 257         command_print(CMD, "BCM2835 GPIO config: trst = %d", trst_gpio);
 258         return ERROR_OK;
 259 }
 260
 261 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionums)
 262 {
 263         if (CMD_ARGC == 2) {
 264                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 265                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 266         } else if (CMD_ARGC != 0) {
 267                 return ERROR_COMMAND_SYNTAX_ERROR;
 268         }
 269
 270         command_print(CMD,
 271                         "BCM2835 GPIO nums: swclk = %d, swdio = %d",
 272                         swclk_gpio, swdio_gpio);
 273
 274         return ERROR_OK;
 275 }
 276
 277 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swclk)
 278 {
 279         if (CMD_ARGC == 1)
 280                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 281
 282         command_print(CMD, "BCM2835 num: swclk = %d", swclk_gpio);
 283         return ERROR_OK;
 284 }
 285
 286 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swdio)
 287 {
 288         if (CMD_ARGC == 1)
 289                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 290
 291         command_print(CMD, "BCM2835 num: swdio = %d", swdio_gpio);
 292         return ERROR_OK;
 293 }
 294
 295 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 296 {
 297         if (CMD_ARGC == 2) {
 298                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 299                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 300         }
 301
 302         command_print(CMD, "BCM2835 GPIO: speed_coeffs = %d, speed_offset = %d",
 303                                   speed_coeff, speed_offset);
 304         return ERROR_OK;
 305 }
 306
 307 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
 308 {
 309         if (CMD_ARGC == 1)
 310                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
 311
 312         command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
 313                                   bcm2835_peri_base);
 314         return ERROR_OK;
 315 }
 316
 317 static const struct command_registration bcm2835gpio_command_handlers[] = {
 318         {
 319                 .name = "bcm2835gpio_jtag_nums",
 320                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 321                 .mode = COMMAND_CONFIG,
 322                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 323                 .usage = "[tck tms tdi tdo]",
 324         },
 325         {
 326                 .name = "bcm2835gpio_tck_num",
 327                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 328                 .mode = COMMAND_CONFIG,
 329                 .help = "gpio number for tck.",
 330                 .usage = "[tck]",
 331         },
 332         {
 333                 .name = "bcm2835gpio_tms_num",
 334                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 335                 .mode = COMMAND_CONFIG,
 336                 .help = "gpio number for tms.",
 337                 .usage = "[tms]",
 338         },
 339         {
 340                 .name = "bcm2835gpio_tdo_num",
 341                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 342                 .mode = COMMAND_CONFIG,
 343                 .help = "gpio number for tdo.",
 344                 .usage = "[tdo]",
 345         },
 346         {
 347                 .name = "bcm2835gpio_tdi_num",
 348                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 349                 .mode = COMMAND_CONFIG,
 350                 .help = "gpio number for tdi.",
 351                 .usage = "[tdi]",
 352         },
 353         {
 354                 .name = "bcm2835gpio_swd_nums",
 355                 .handler = &bcm2835gpio_handle_swd_gpionums,
 356                 .mode = COMMAND_CONFIG,
 357                 .help = "gpio numbers for swclk, swdio. (in that order)",
 358                 .usage = "[swclk swdio]",
 359         },
 360         {
 361                 .name = "bcm2835gpio_swclk_num",
 362                 .handler = &bcm2835gpio_handle_swd_gpionum_swclk,
 363                 .mode = COMMAND_CONFIG,
 364                 .help = "gpio number for swclk.",
 365                 .usage = "[swclk]",
 366         },
 367         {
 368                 .name = "bcm2835gpio_swdio_num",
 369                 .handler = &bcm2835gpio_handle_swd_gpionum_swdio,
 370                 .mode = COMMAND_CONFIG,
 371                 .help = "gpio number for swdio.",
 372                 .usage = "[swdio]",
 373         },
 374         {
 375                 .name = "bcm2835gpio_srst_num",
 376                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 377                 .mode = COMMAND_CONFIG,
 378                 .help = "gpio number for srst.",
 379                 .usage = "[srst]",
 380         },
 381         {
 382                 .name = "bcm2835gpio_trst_num",
 383                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 384                 .mode = COMMAND_CONFIG,
 385                 .help = "gpio number for trst.",
 386                 .usage = "[trst]",
 387         },
 388         {
 389                 .name = "bcm2835gpio_speed_coeffs",
 390                 .handler = &bcm2835gpio_handle_speed_coeffs,
 391                 .mode = COMMAND_CONFIG,
 392                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 393                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 394         },
 395         {
 396                 .name = "bcm2835gpio_peripheral_base",
 397                 .handler = &bcm2835gpio_handle_peripheral_base,
 398                 .mode = COMMAND_CONFIG,
 399                 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
 400                 .usage = "[base]",
 401         },
 402
 403         COMMAND_REGISTRATION_DONE
 404 };
 405
 406 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 407
 408 struct jtag_interface bcm2835gpio_interface = {
 409         .name = "bcm2835gpio",
 410         .supported = DEBUG_CAP_TMS_SEQ,
 411         .execute_queue = bitbang_execute_queue,
 412         .transports = bcm2835_transports,
 413         .swd = &bitbang_swd,
 414         .speed = bcm2835gpio_speed,
 415         .khz = bcm2835gpio_khz,
 416         .speed_div = bcm2835gpio_speed_div,
 417         .commands = bcm2835gpio_command_handlers,
 418         .init = bcm2835gpio_init,
 419         .quit = bcm2835gpio_quit,
 420         .reset = bcm2835gpio_reset,
 421 };
 422
 423 static bool bcm2835gpio_jtag_mode_possible(void)
 424 {
 425         if (!is_gpio_valid(tck_gpio))
 426                 return 0;
 427         if (!is_gpio_valid(tms_gpio))
 428                 return 0;
 429         if (!is_gpio_valid(tdi_gpio))
 430                 return 0;
 431         if (!is_gpio_valid(tdo_gpio))
 432                 return 0;
 433         return 1;
 434 }
 435
 436 static bool bcm2835gpio_swd_mode_possible(void)
 437 {
 438         if (!is_gpio_valid(swclk_gpio))
 439                 return 0;
 440         if (!is_gpio_valid(swdio_gpio))
 441                 return 0;
 442         return 1;
 443 }
 444
 445 static int bcm2835gpio_init(void)
 446 {
 447         bitbang_interface = &bcm2835gpio_bitbang;
 448
 449         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 450
 451         if (bcm2835gpio_jtag_mode_possible()) {
 452                 if (bcm2835gpio_swd_mode_possible())
 453                         LOG_INFO("JTAG and SWD modes enabled");
 454                 else
 455                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 456         } else if (bcm2835gpio_swd_mode_possible()) {
 457                 LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
 458         } else {
 459                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
 460                 return ERROR_JTAG_INIT_FAILED;
 461         }
 462
 463         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 464         if (dev_mem_fd < 0) {
 465                 perror("open");
 466                 return ERROR_JTAG_INIT_FAILED;
 467         }
 468
 469         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 470                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 471
 472         if (pio_base == MAP_FAILED) {
 473                 perror("mmap");
 474                 close(dev_mem_fd);
 475                 return ERROR_JTAG_INIT_FAILED;
 476         }
 477
 478         static volatile uint32_t *pads_base;
 479         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 480                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 481
 482         if (pads_base == MAP_FAILED) {
 483                 perror("mmap");
 484                 close(dev_mem_fd);
 485                 return ERROR_JTAG_INIT_FAILED;
 486         }
 487
 488         /* set 4mA drive strength, slew rate limited, hysteresis on */
 489         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 490
 491         tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 492         tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 493         tck_gpio_mode = MODE_GPIO(tck_gpio);
 494         tms_gpio_mode = MODE_GPIO(tms_gpio);
 495         swclk_gpio_mode = MODE_GPIO(swclk_gpio);
 496         swdio_gpio_mode = MODE_GPIO(swdio_gpio);
 497         /*
 498          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 499          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 500          */
 501         INP_GPIO(tdo_gpio);
 502
 503         GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio | 1<<swdio_gpio | 1<<swclk_gpio;
 504         GPIO_SET = 1<<tms_gpio;
 505
 506         OUT_GPIO(tdi_gpio);
 507         OUT_GPIO(tck_gpio);
 508         OUT_GPIO(tms_gpio);
 509         OUT_GPIO(swclk_gpio);
 510         OUT_GPIO(swdio_gpio);
 511         if (trst_gpio != -1) {
 512                 trst_gpio_mode = MODE_GPIO(trst_gpio);
 513                 GPIO_SET = 1 << trst_gpio;
 514                 OUT_GPIO(trst_gpio);
 515         }
 516         if (srst_gpio != -1) {
 517                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 518                 GPIO_SET = 1 << srst_gpio;
 519                 OUT_GPIO(srst_gpio);
 520         }
 521
 522         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 523                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 524                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 525
 526         if (swd_mode) {
 527                 bcm2835gpio_bitbang.write = bcm2835gpio_swd_write;
 528                 bitbang_switch_to_swd();
 529         }
 530
 531         return ERROR_OK;
 532 }
 533
 534 static int bcm2835gpio_quit(void)
 535 {
 536         SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 537         SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 538         SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 539         SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 540         SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
 541         SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
 542         if (trst_gpio != -1)
 543                 SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 544         if (srst_gpio != -1)
 545                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 546
 547         return ERROR_OK;
 548 }