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 bb_value_t bcm2835gpio_read(void)
  98 {
  99         return (GPIO_LEV & 1<<tdo_gpio) ? BB_HIGH : BB_LOW;
 100 }
 101
 102 static int bcm2835gpio_write(int tck, int tms, int tdi)
 103 {
 104         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
 105         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
 106
 107         GPIO_SET = set;
 108         GPIO_CLR = clear;
 109
 110         for (unsigned int i = 0; i < jtag_delay; i++)
 111                 asm volatile ("");
 112
 113         return ERROR_OK;
 114 }
 115
 116 static int bcm2835gpio_swd_write(int swclk, int swdio)
 117 {
 118         uint32_t set = swclk << swclk_gpio | swdio << swdio_gpio;
 119         uint32_t clear = !swclk << swclk_gpio | !swdio << swdio_gpio;
 120
 121         GPIO_SET = set;
 122         GPIO_CLR = clear;
 123
 124         for (unsigned int i = 0; i < jtag_delay; i++)
 125                 asm volatile ("");
 126
 127         return ERROR_OK;
 128 }
 129
 130 /* (1) assert or (0) deassert reset lines */
 131 static int bcm2835gpio_reset(int trst, int srst)
 132 {
 133         uint32_t set = 0;
 134         uint32_t clear = 0;
 135
 136         if (trst_gpio > 0) {
 137                 set |= !trst<<trst_gpio;
 138                 clear |= trst<<trst_gpio;
 139         }
 140
 141         if (srst_gpio > 0) {
 142                 set |= !srst<<srst_gpio;
 143                 clear |= srst<<srst_gpio;
 144         }
 145
 146         GPIO_SET = set;
 147         GPIO_CLR = clear;
 148
 149         return ERROR_OK;
 150 }
 151
 152 static void bcm2835_swdio_drive(bool is_output)
 153 {
 154         if (swdio_dir_gpio > 0) {
 155                 if (is_output) {
 156                         GPIO_SET = 1 << swdio_dir_gpio;
 157                         OUT_GPIO(swdio_gpio);
 158                 } else {
 159                         INP_GPIO(swdio_gpio);
 160                         GPIO_CLR = 1 << swdio_dir_gpio;
 161                 }
 162         } else {
 163                 if (is_output)
 164                         OUT_GPIO(swdio_gpio);
 165                 else
 166                         INP_GPIO(swdio_gpio);
 167         }
 168 }
 169
 170 static int bcm2835_swdio_read(void)
 171 {
 172         return !!(GPIO_LEV & 1 << swdio_gpio);
 173 }
 174
 175 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 176 {
 177         if (!khz) {
 178                 LOG_DEBUG("RCLK not supported");
 179                 return ERROR_FAIL;
 180         }
 181         *jtag_speed = speed_coeff/khz - speed_offset;
 182         if (*jtag_speed < 0)
 183                 *jtag_speed = 0;
 184         return ERROR_OK;
 185 }
 186
 187 static int bcm2835gpio_speed_div(int speed, int *khz)
 188 {
 189         *khz = speed_coeff/(speed + speed_offset);
 190         return ERROR_OK;
 191 }
 192
 193 static int bcm2835gpio_speed(int speed)
 194 {
 195         jtag_delay = speed;
 196         return ERROR_OK;
 197 }
 198
 199 static int is_gpio_valid(int gpio)
 200 {
 201         return gpio >= 0 && gpio <= 53;
 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_command_handlers[] = {
 342         {
 343                 .name = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 = "bcm2835gpio_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 char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 438
 439 static struct jtag_interface bcm2835gpio_interface = {
 440         .supported = DEBUG_CAP_TMS_SEQ,
 441         .execute_queue = bitbang_execute_queue,
 442 };
 443
 444 struct adapter_driver bcm2835gpio_adapter_driver = {
 445         .name = "bcm2835gpio",
 446         .transports = bcm2835_transports,
 447         .commands = bcm2835gpio_command_handlers,
 448
 449         .init = bcm2835gpio_init,
 450         .quit = bcm2835gpio_quit,
 451         .reset = bcm2835gpio_reset,
 452         .speed = bcm2835gpio_speed,
 453         .khz = bcm2835gpio_khz,
 454         .speed_div = bcm2835gpio_speed_div,
 455
 456         .jtag_ops = &bcm2835gpio_interface,
 457         .swd_ops = &bitbang_swd,
 458 };
 459
 460 static bool bcm2835gpio_jtag_mode_possible(void)
 461 {
 462         if (!is_gpio_valid(tck_gpio))
 463                 return 0;
 464         if (!is_gpio_valid(tms_gpio))
 465                 return 0;
 466         if (!is_gpio_valid(tdi_gpio))
 467                 return 0;
 468         if (!is_gpio_valid(tdo_gpio))
 469                 return 0;
 470         return 1;
 471 }
 472
 473 static bool bcm2835gpio_swd_mode_possible(void)
 474 {
 475         if (!is_gpio_valid(swclk_gpio))
 476                 return 0;
 477         if (!is_gpio_valid(swdio_gpio))
 478                 return 0;
 479         return 1;
 480 }
 481
 482 static int bcm2835gpio_init(void)
 483 {
 484         bitbang_interface = &bcm2835gpio_bitbang;
 485
 486         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 487
 488         if (transport_is_jtag() && !bcm2835gpio_jtag_mode_possible()) {
 489                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
 490                 return ERROR_JTAG_INIT_FAILED;
 491         }
 492
 493         if (transport_is_swd() && !bcm2835gpio_swd_mode_possible()) {
 494                 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
 495                 return ERROR_JTAG_INIT_FAILED;
 496         }
 497
 498         dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
 499         if (dev_mem_fd < 0) {
 500                 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
 501                 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 502         }
 503         if (dev_mem_fd < 0) {
 504                 LOG_ERROR("open: %s", strerror(errno));
 505                 return ERROR_JTAG_INIT_FAILED;
 506         }
 507
 508         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 509                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 510
 511         if (pio_base == MAP_FAILED) {
 512                 LOG_ERROR("mmap: %s", strerror(errno));
 513                 close(dev_mem_fd);
 514                 return ERROR_JTAG_INIT_FAILED;
 515         }
 516
 517         static volatile uint32_t *pads_base;
 518         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 519                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 520
 521         if (pads_base == MAP_FAILED) {
 522                 LOG_ERROR("mmap: %s", strerror(errno));
 523                 close(dev_mem_fd);
 524                 return ERROR_JTAG_INIT_FAILED;
 525         }
 526
 527         /* set 4mA drive strength, slew rate limited, hysteresis on */
 528         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 529
 530         /*
 531          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 532          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 533          */
 534         if (transport_is_jtag()) {
 535                 tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 536                 tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 537                 tck_gpio_mode = MODE_GPIO(tck_gpio);
 538                 tms_gpio_mode = MODE_GPIO(tms_gpio);
 539
 540                 INP_GPIO(tdo_gpio);
 541
 542                 GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio;
 543                 GPIO_SET = 1<<tms_gpio;
 544
 545                 OUT_GPIO(tdi_gpio);
 546                 OUT_GPIO(tck_gpio);
 547                 OUT_GPIO(tms_gpio);
 548
 549                 if (trst_gpio != -1) {
 550                         trst_gpio_mode = MODE_GPIO(trst_gpio);
 551                         GPIO_SET = 1 << trst_gpio;
 552                         OUT_GPIO(trst_gpio);
 553                 }
 554         }
 555
 556         if (transport_is_swd()) {
 557                 swclk_gpio_mode = MODE_GPIO(swclk_gpio);
 558                 swdio_gpio_mode = MODE_GPIO(swdio_gpio);
 559
 560                 GPIO_CLR = 1<<swdio_gpio | 1<<swclk_gpio;
 561
 562                 OUT_GPIO(swclk_gpio);
 563                 OUT_GPIO(swdio_gpio);
 564         }
 565
 566         if (srst_gpio != -1) {
 567                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 568                 GPIO_SET = 1 << srst_gpio;
 569                 OUT_GPIO(srst_gpio);
 570         }
 571
 572         if (swdio_dir_gpio != -1) {
 573                 swdio_dir_gpio_mode = MODE_GPIO(swdio_dir_gpio);
 574                 GPIO_SET = 1 << swdio_dir_gpio;
 575                 OUT_GPIO(swdio_dir_gpio);
 576         }
 577
 578         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 579                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 580                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 581
 582         return ERROR_OK;
 583 }
 584
 585 static int bcm2835gpio_quit(void)
 586 {
 587         if (transport_is_jtag()) {
 588                 SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 589                 SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 590                 SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 591                 SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 592                 if (trst_gpio != -1)
 593                         SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 594         }
 595
 596         if (transport_is_swd()) {
 597                 SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
 598                 SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
 599         }
 600
 601         if (srst_gpio != -1)
 602                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 603
 604         if (swdio_dir_gpio != -1)
 605                 SET_MODE_GPIO(swdio_dir_gpio, swdio_dir_gpio_mode);
 606
 607         return ERROR_OK;
 608 }