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 <transport/transport.h>
  28 #include "bitbang.h"
  29
  30 #include <sys/mman.h>
  31
  32 uint32_t bcm2835_peri_base = 0x20000000;
  33 #define BCM2835_GPIO_BASE       (bcm2835_peri_base + 0x200000) /* GPIO controller */
  34
  35 #define BCM2835_PADS_GPIO_0_27          (bcm2835_peri_base + 0x100000)
  36 #define BCM2835_PADS_GPIO_0_27_OFFSET   (0x2c / 4)
  37
  38 /* GPIO setup macros */
  39 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  40 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  41 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  42                 INP_GPIO(g);                                            \
  43                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  44 #define OUT_GPIO(g) SET_MODE_GPIO(g, 1)
  45
  46 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  47 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  48 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  49
  50 static int dev_mem_fd;
  51 static volatile uint32_t *pio_base;
  52
  53 static bb_value_t bcm2835gpio_read(void);
  54 static int bcm2835gpio_write(int tck, int tms, int tdi);
  55
  56 static int bcm2835_swdio_read(void);
  57 static void bcm2835_swdio_drive(bool is_output);
  58 static int bcm2835gpio_swd_write(int swclk, int swdio);
  59
  60 static int bcm2835gpio_init(void);
  61 static int bcm2835gpio_quit(void);
  62
  63 static struct bitbang_interface bcm2835gpio_bitbang = {
  64         .read = bcm2835gpio_read,
  65         .write = bcm2835gpio_write,
  66         .swdio_read = bcm2835_swdio_read,
  67         .swdio_drive = bcm2835_swdio_drive,
  68         .swd_write = bcm2835gpio_swd_write,
  69         .blink = NULL
  70 };
  71
  72 /* GPIO numbers for each signal. Negative values are invalid */
  73 static int tck_gpio = -1;
  74 static int tck_gpio_mode;
  75 static int tms_gpio = -1;
  76 static int tms_gpio_mode;
  77 static int tdi_gpio = -1;
  78 static int tdi_gpio_mode;
  79 static int tdo_gpio = -1;
  80 static int tdo_gpio_mode;
  81 static int trst_gpio = -1;
  82 static int trst_gpio_mode;
  83 static int srst_gpio = -1;
  84 static int srst_gpio_mode;
  85 static int swclk_gpio = -1;
  86 static int swclk_gpio_mode;
  87 static int swdio_gpio = -1;
  88 static int swdio_gpio_mode;
  89 static int swdio_dir_gpio = -1;
  90 static int swdio_dir_gpio_mode;
  91
  92 /* Transition delay coefficients */
  93 static int speed_coeff = 113714;
  94 static int speed_offset = 28;
  95 static unsigned int jtag_delay;
  96
  97 static int is_gpio_valid(int gpio)
  98 {
  99         return gpio >= 0 && gpio <= 31;
 100 }
 101
 102 static bb_value_t bcm2835gpio_read(void)
 103 {
 104         return (GPIO_LEV & 1<<tdo_gpio) ? BB_HIGH : BB_LOW;
 105 }
 106
 107 static int bcm2835gpio_write(int tck, int tms, int tdi)
 108 {
 109         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
 110         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
 111
 112         GPIO_SET = set;
 113         GPIO_CLR = clear;
 114
 115         for (unsigned int i = 0; i < jtag_delay; i++)
 116                 asm volatile ("");
 117
 118         return ERROR_OK;
 119 }
 120
 121 static int bcm2835gpio_swd_write(int swclk, int swdio)
 122 {
 123         uint32_t set = swclk << swclk_gpio | swdio << swdio_gpio;
 124         uint32_t clear = !swclk << swclk_gpio | !swdio << swdio_gpio;
 125
 126         GPIO_SET = set;
 127         GPIO_CLR = clear;
 128
 129         for (unsigned int i = 0; i < jtag_delay; i++)
 130                 asm volatile ("");
 131
 132         return ERROR_OK;
 133 }
 134
 135 /* (1) assert or (0) deassert reset lines */
 136 static int bcm2835gpio_reset(int trst, int srst)
 137 {
 138         uint32_t set = 0;
 139         uint32_t clear = 0;
 140
 141         if (is_gpio_valid(trst_gpio)) {
 142                 set |= !trst<<trst_gpio;
 143                 clear |= trst<<trst_gpio;
 144         }
 145
 146         if (is_gpio_valid(srst_gpio)) {
 147                 set |= !srst<<srst_gpio;
 148                 clear |= srst<<srst_gpio;
 149         }
 150
 151         GPIO_SET = set;
 152         GPIO_CLR = clear;
 153
 154         return ERROR_OK;
 155 }
 156
 157 static void bcm2835_swdio_drive(bool is_output)
 158 {
 159         if (is_gpio_valid(swdio_dir_gpio)) {
 160                 if (is_output) {
 161                         GPIO_SET = 1 << swdio_dir_gpio;
 162                         OUT_GPIO(swdio_gpio);
 163                 } else {
 164                         INP_GPIO(swdio_gpio);
 165                         GPIO_CLR = 1 << swdio_dir_gpio;
 166                 }
 167         } else {
 168                 if (is_output)
 169                         OUT_GPIO(swdio_gpio);
 170                 else
 171                         INP_GPIO(swdio_gpio);
 172         }
 173 }
 174
 175 static int bcm2835_swdio_read(void)
 176 {
 177         return !!(GPIO_LEV & 1 << swdio_gpio);
 178 }
 179
 180 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 181 {
 182         if (!khz) {
 183                 LOG_DEBUG("RCLK not supported");
 184                 return ERROR_FAIL;
 185         }
 186         *jtag_speed = speed_coeff/khz - speed_offset;
 187         if (*jtag_speed < 0)
 188                 *jtag_speed = 0;
 189         return ERROR_OK;
 190 }
 191
 192 static int bcm2835gpio_speed_div(int speed, int *khz)
 193 {
 194         *khz = speed_coeff/(speed + speed_offset);
 195         return ERROR_OK;
 196 }
 197
 198 static int bcm2835gpio_speed(int speed)
 199 {
 200         jtag_delay = speed;
 201         return ERROR_OK;
 202 }
 203
 204 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 205 {
 206         if (CMD_ARGC == 4) {
 207                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 208                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 209                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 210                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 211         } else if (CMD_ARGC != 0) {
 212                 return ERROR_COMMAND_SYNTAX_ERROR;
 213         }
 214
 215         command_print(CMD,
 216                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 217                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 218
 219         return ERROR_OK;
 220 }
 221
 222 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 223 {
 224         if (CMD_ARGC == 1)
 225                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 226
 227         command_print(CMD, "BCM2835 GPIO config: tck = %d", tck_gpio);
 228         return ERROR_OK;
 229 }
 230
 231 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 232 {
 233         if (CMD_ARGC == 1)
 234                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 235
 236         command_print(CMD, "BCM2835 GPIO config: tms = %d", tms_gpio);
 237         return ERROR_OK;
 238 }
 239
 240 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 241 {
 242         if (CMD_ARGC == 1)
 243                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 244
 245         command_print(CMD, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 246         return ERROR_OK;
 247 }
 248
 249 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 250 {
 251         if (CMD_ARGC == 1)
 252                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 253
 254         command_print(CMD, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 255         return ERROR_OK;
 256 }
 257
 258 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 259 {
 260         if (CMD_ARGC == 1)
 261                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 262
 263         command_print(CMD, "BCM2835 GPIO config: srst = %d", srst_gpio);
 264         return ERROR_OK;
 265 }
 266
 267 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 268 {
 269         if (CMD_ARGC == 1)
 270                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 271
 272         command_print(CMD, "BCM2835 GPIO config: trst = %d", trst_gpio);
 273         return ERROR_OK;
 274 }
 275
 276 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionums)
 277 {
 278         if (CMD_ARGC == 2) {
 279                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 280                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 281         } else if (CMD_ARGC != 0) {
 282                 return ERROR_COMMAND_SYNTAX_ERROR;
 283         }
 284
 285         command_print(CMD,
 286                         "BCM2835 GPIO nums: swclk = %d, swdio = %d",
 287                         swclk_gpio, swdio_gpio);
 288
 289         return ERROR_OK;
 290 }
 291
 292 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swclk)
 293 {
 294         if (CMD_ARGC == 1)
 295                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 296
 297         command_print(CMD, "BCM2835 num: swclk = %d", swclk_gpio);
 298         return ERROR_OK;
 299 }
 300
 301 COMMAND_HANDLER(bcm2835gpio_handle_swd_gpionum_swdio)
 302 {
 303         if (CMD_ARGC == 1)
 304                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 305
 306         command_print(CMD, "BCM2835 num: swdio = %d", swdio_gpio);
 307         return ERROR_OK;
 308 }
 309
 310 COMMAND_HANDLER(bcm2835gpio_handle_swd_dir_gpionum_swdio)
 311 {
 312         if (CMD_ARGC == 1)
 313                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_dir_gpio);
 314
 315         command_print(CMD, "BCM2835 num: swdio_dir = %d", swdio_dir_gpio);
 316         return ERROR_OK;
 317 }
 318
 319 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 320 {
 321         if (CMD_ARGC == 2) {
 322                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 323                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 324         }
 325
 326         command_print(CMD, "BCM2835 GPIO: speed_coeffs = %d, speed_offset = %d",
 327                                   speed_coeff, speed_offset);
 328         return ERROR_OK;
 329 }
 330
 331 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
 332 {
 333         if (CMD_ARGC == 1)
 334                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
 335
 336         command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
 337                                   bcm2835_peri_base);
 338         return ERROR_OK;
 339 }
 340
 341 static const struct command_registration bcm2835gpio_subcommand_handlers[] = {
 342         {
 343                 .name = "jtag_nums",
 344                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 345                 .mode = COMMAND_CONFIG,
 346                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 347                 .usage = "[tck tms tdi tdo]",
 348         },
 349         {
 350                 .name = "tck_num",
 351                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 352                 .mode = COMMAND_CONFIG,
 353                 .help = "gpio number for tck.",
 354                 .usage = "[tck]",
 355         },
 356         {
 357                 .name = "tms_num",
 358                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 359                 .mode = COMMAND_CONFIG,
 360                 .help = "gpio number for tms.",
 361                 .usage = "[tms]",
 362         },
 363         {
 364                 .name = "tdo_num",
 365                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 366                 .mode = COMMAND_CONFIG,
 367                 .help = "gpio number for tdo.",
 368                 .usage = "[tdo]",
 369         },
 370         {
 371                 .name = "tdi_num",
 372                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 373                 .mode = COMMAND_CONFIG,
 374                 .help = "gpio number for tdi.",
 375                 .usage = "[tdi]",
 376         },
 377         {
 378                 .name = "swd_nums",
 379                 .handler = &bcm2835gpio_handle_swd_gpionums,
 380                 .mode = COMMAND_CONFIG,
 381                 .help = "gpio numbers for swclk, swdio. (in that order)",
 382                 .usage = "[swclk swdio]",
 383         },
 384         {
 385                 .name = "swclk_num",
 386                 .handler = &bcm2835gpio_handle_swd_gpionum_swclk,
 387                 .mode = COMMAND_CONFIG,
 388                 .help = "gpio number for swclk.",
 389                 .usage = "[swclk]",
 390         },
 391         {
 392                 .name = "swdio_num",
 393                 .handler = &bcm2835gpio_handle_swd_gpionum_swdio,
 394                 .mode = COMMAND_CONFIG,
 395                 .help = "gpio number for swdio.",
 396                 .usage = "[swdio]",
 397         },
 398         {
 399                 .name = "swdio_dir_num",
 400                 .handler = &bcm2835gpio_handle_swd_dir_gpionum_swdio,
 401                 .mode = COMMAND_CONFIG,
 402                 .help = "gpio number for swdio direction control pin (set=output mode, clear=input mode)",
 403                 .usage = "[swdio_dir]",
 404         },
 405         {
 406                 .name = "srst_num",
 407                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 408                 .mode = COMMAND_CONFIG,
 409                 .help = "gpio number for srst.",
 410                 .usage = "[srst]",
 411         },
 412         {
 413                 .name = "trst_num",
 414                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 415                 .mode = COMMAND_CONFIG,
 416                 .help = "gpio number for trst.",
 417                 .usage = "[trst]",
 418         },
 419         {
 420                 .name = "speed_coeffs",
 421                 .handler = &bcm2835gpio_handle_speed_coeffs,
 422                 .mode = COMMAND_CONFIG,
 423                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 424                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 425         },
 426         {
 427                 .name = "peripheral_base",
 428                 .handler = &bcm2835gpio_handle_peripheral_base,
 429                 .mode = COMMAND_CONFIG,
 430                 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
 431                 .usage = "[base]",
 432         },
 433
 434         COMMAND_REGISTRATION_DONE
 435 };
 436
 437 static const struct command_registration bcm2835gpio_command_handlers[] = {
 438         {
 439                 .name = "bcm2835gpio",
 440                 .mode = COMMAND_ANY,
 441                 .help = "perform bcm2835gpio management",
 442                 .chain = bcm2835gpio_subcommand_handlers,
 443                 .usage = "",
 444         },
 445         COMMAND_REGISTRATION_DONE
 446 };
 447
 448 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 449
 450 static struct jtag_interface bcm2835gpio_interface = {
 451         .supported = DEBUG_CAP_TMS_SEQ,
 452         .execute_queue = bitbang_execute_queue,
 453 };
 454
 455 struct adapter_driver bcm2835gpio_adapter_driver = {
 456         .name = "bcm2835gpio",
 457         .transports = bcm2835_transports,
 458         .commands = bcm2835gpio_command_handlers,
 459
 460         .init = bcm2835gpio_init,
 461         .quit = bcm2835gpio_quit,
 462         .reset = bcm2835gpio_reset,
 463         .speed = bcm2835gpio_speed,
 464         .khz = bcm2835gpio_khz,
 465         .speed_div = bcm2835gpio_speed_div,
 466
 467         .jtag_ops = &bcm2835gpio_interface,
 468         .swd_ops = &bitbang_swd,
 469 };
 470
 471 static bool bcm2835gpio_jtag_mode_possible(void)
 472 {
 473         if (!is_gpio_valid(tck_gpio))
 474                 return 0;
 475         if (!is_gpio_valid(tms_gpio))
 476                 return 0;
 477         if (!is_gpio_valid(tdi_gpio))
 478                 return 0;
 479         if (!is_gpio_valid(tdo_gpio))
 480                 return 0;
 481         return 1;
 482 }
 483
 484 static bool bcm2835gpio_swd_mode_possible(void)
 485 {
 486         if (!is_gpio_valid(swclk_gpio))
 487                 return 0;
 488         if (!is_gpio_valid(swdio_gpio))
 489                 return 0;
 490         return 1;
 491 }
 492
 493 static int bcm2835gpio_init(void)
 494 {
 495         bitbang_interface = &bcm2835gpio_bitbang;
 496
 497         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 498
 499         if (transport_is_jtag() && !bcm2835gpio_jtag_mode_possible()) {
 500                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
 501                 return ERROR_JTAG_INIT_FAILED;
 502         }
 503
 504         if (transport_is_swd() && !bcm2835gpio_swd_mode_possible()) {
 505                 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
 506                 return ERROR_JTAG_INIT_FAILED;
 507         }
 508
 509         dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
 510         if (dev_mem_fd < 0) {
 511                 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
 512                 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 513         }
 514         if (dev_mem_fd < 0) {
 515                 LOG_ERROR("open: %s", strerror(errno));
 516                 return ERROR_JTAG_INIT_FAILED;
 517         }
 518
 519         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 520                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 521
 522         if (pio_base == MAP_FAILED) {
 523                 LOG_ERROR("mmap: %s", strerror(errno));
 524                 close(dev_mem_fd);
 525                 return ERROR_JTAG_INIT_FAILED;
 526         }
 527
 528         static volatile uint32_t *pads_base;
 529         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 530                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 531
 532         if (pads_base == MAP_FAILED) {
 533                 LOG_ERROR("mmap: %s", strerror(errno));
 534                 close(dev_mem_fd);
 535                 return ERROR_JTAG_INIT_FAILED;
 536         }
 537
 538         /* set 4mA drive strength, slew rate limited, hysteresis on */
 539         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 540
 541         /*
 542          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 543          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 544          */
 545         if (transport_is_jtag()) {
 546                 tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 547                 tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 548                 tck_gpio_mode = MODE_GPIO(tck_gpio);
 549                 tms_gpio_mode = MODE_GPIO(tms_gpio);
 550
 551                 INP_GPIO(tdo_gpio);
 552
 553                 GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio;
 554                 GPIO_SET = 1<<tms_gpio;
 555
 556                 OUT_GPIO(tdi_gpio);
 557                 OUT_GPIO(tck_gpio);
 558                 OUT_GPIO(tms_gpio);
 559
 560                 if (is_gpio_valid(trst_gpio)) {
 561                         trst_gpio_mode = MODE_GPIO(trst_gpio);
 562                         GPIO_SET = 1 << trst_gpio;
 563                         OUT_GPIO(trst_gpio);
 564                 }
 565         }
 566
 567         if (transport_is_swd()) {
 568                 /* Make buffer an output before the GPIO connected to it */
 569                 if (is_gpio_valid(swdio_dir_gpio)) {
 570                         swdio_dir_gpio_mode = MODE_GPIO(swdio_dir_gpio);
 571                         GPIO_SET = 1 << swdio_dir_gpio;
 572                         OUT_GPIO(swdio_dir_gpio);
 573                 }
 574
 575                 swclk_gpio_mode = MODE_GPIO(swclk_gpio);
 576                 swdio_gpio_mode = MODE_GPIO(swdio_gpio);
 577
 578                 GPIO_CLR = 1<<swdio_gpio | 1<<swclk_gpio;
 579
 580                 OUT_GPIO(swclk_gpio);
 581                 OUT_GPIO(swdio_gpio);
 582         }
 583
 584         if (is_gpio_valid(srst_gpio)) {
 585                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 586                 GPIO_SET = 1 << srst_gpio;
 587                 OUT_GPIO(srst_gpio);
 588         }
 589
 590         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 591                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 592                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 593
 594         return ERROR_OK;
 595 }
 596
 597 static int bcm2835gpio_quit(void)
 598 {
 599         if (transport_is_jtag()) {
 600                 SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 601                 SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 602                 SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 603                 SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 604                 if (is_gpio_valid(trst_gpio))
 605                         SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 606         }
 607
 608         if (transport_is_swd()) {
 609                 SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
 610                 SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
 611         }
 612
 613         if (is_gpio_valid(srst_gpio))
 614                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 615
 616         if (is_gpio_valid(swdio_dir_gpio))
 617                 SET_MODE_GPIO(swdio_dir_gpio, swdio_dir_gpio_mode);
 618
 619         return ERROR_OK;
 620 }