src/jtag/drivers/bcm2835gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2013 by Paul Fertser, fercerpav@gmail.com               *
   5  *                                                                         *
   6  *   Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
   7  *   Based on at91rm9200.c (c) Anders Larsen                               *
   8  *   and RPi GPIO examples by Gert van Loo & Dom                           *
   9  ***************************************************************************/
  10
  11 #ifdef HAVE_CONFIG_H
  12 #include "config.h"
  13 #endif
  14
  15 #include <jtag/adapter.h>
  16 #include <jtag/interface.h>
  17 #include <transport/transport.h>
  18 #include "bitbang.h"
  19
  20 #include <sys/mman.h>
  21
  22 uint32_t bcm2835_peri_base = 0x20000000;
  23 #define BCM2835_GPIO_BASE       (bcm2835_peri_base + 0x200000) /* GPIO controller */
  24
  25 #define BCM2835_PADS_GPIO_0_27          (bcm2835_peri_base + 0x100000)
  26 #define BCM2835_PADS_GPIO_0_27_OFFSET   (0x2c / 4)
  27
  28 /* See "GPIO Function Select Registers (GPFSELn)" in "Broadcom BCM2835 ARM Peripherals" datasheet. */
  29 #define BCM2835_GPIO_MODE_INPUT 0
  30 #define BCM2835_GPIO_MODE_OUTPUT 1
  31
  32 /* GPIO setup macros */
  33 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  34 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  35 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  36                 INP_GPIO(g);                                            \
  37                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  38 #define OUT_GPIO(g) SET_MODE_GPIO(g, BCM2835_GPIO_MODE_OUTPUT)
  39
  40 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  41 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  42 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  43
  44 static int dev_mem_fd;
  45 static volatile uint32_t *pio_base = MAP_FAILED;
  46 static volatile uint32_t *pads_base = MAP_FAILED;
  47
  48 /* Transition delay coefficients */
  49 static int speed_coeff = 113714;
  50 static int speed_offset = 28;
  51 static unsigned int jtag_delay;
  52
  53 static const struct adapter_gpio_config *adapter_gpio_config;
  54 static struct initial_gpio_state {
  55         unsigned int mode;
  56         unsigned int output_level;
  57 } initial_gpio_state[ADAPTER_GPIO_IDX_NUM];
  58 static uint32_t initial_drive_strength_etc;
  59
  60 static bool is_gpio_config_valid(enum adapter_gpio_config_index idx)
  61 {
  62         /* Only chip 0 is supported, accept unset value (-1) too */
  63         return adapter_gpio_config[idx].chip_num >= -1
  64                 && adapter_gpio_config[idx].chip_num <= 0
  65                 && adapter_gpio_config[idx].gpio_num >= 0
  66                 && adapter_gpio_config[idx].gpio_num <= 31;
  67 }
  68
  69 static void set_gpio_value(const struct adapter_gpio_config *gpio_config, int value)
  70 {
  71         value = value ^ (gpio_config->active_low ? 1 : 0);
  72         switch (gpio_config->drive) {
  73         case ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL:
  74                 if (value)
  75                         GPIO_SET = 1 << gpio_config->gpio_num;
  76                 else
  77                         GPIO_CLR = 1 << gpio_config->gpio_num;
  78                 /* For performance reasons assume the GPIO is already set as an output
  79                  * and therefore the call can be omitted here.
  80                  */
  81                 break;
  82         case ADAPTER_GPIO_DRIVE_MODE_OPEN_DRAIN:
  83                 if (value) {
  84                         INP_GPIO(gpio_config->gpio_num);
  85                 } else {
  86                         GPIO_CLR = 1 << gpio_config->gpio_num;
  87                         OUT_GPIO(gpio_config->gpio_num);
  88                 }
  89                 break;
  90         case ADAPTER_GPIO_DRIVE_MODE_OPEN_SOURCE:
  91                 if (value) {
  92                         GPIO_SET = 1 << gpio_config->gpio_num;
  93                         OUT_GPIO(gpio_config->gpio_num);
  94                 } else {
  95                         INP_GPIO(gpio_config->gpio_num);
  96                 }
  97                 break;
  98         }
  99 }
 100
 101 static void restore_gpio(enum adapter_gpio_config_index idx)
 102 {
 103         if (is_gpio_config_valid(idx)) {
 104                 SET_MODE_GPIO(adapter_gpio_config[idx].gpio_num, initial_gpio_state[idx].mode);
 105                 if (initial_gpio_state[idx].mode == BCM2835_GPIO_MODE_OUTPUT) {
 106                         if (initial_gpio_state[idx].output_level)
 107                                 GPIO_SET = 1 << adapter_gpio_config[idx].gpio_num;
 108                         else
 109                                 GPIO_CLR = 1 << adapter_gpio_config[idx].gpio_num;
 110                 }
 111         }
 112 }
 113
 114 static void initialize_gpio(enum adapter_gpio_config_index idx)
 115 {
 116         if (!is_gpio_config_valid(idx))
 117                 return;
 118
 119         initial_gpio_state[idx].mode = MODE_GPIO(adapter_gpio_config[idx].gpio_num);
 120         unsigned int shift = adapter_gpio_config[idx].gpio_num;
 121         initial_gpio_state[idx].output_level = (GPIO_LEV >> shift) & 1;
 122         LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %d",
 123                         adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num,
 124                         initial_gpio_state[idx].mode);
 125
 126         if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) {
 127                 LOG_WARNING("BCM2835 GPIO does not support pull-up or pull-down settings (signal %s)",
 128                         adapter_gpio_get_name(idx));
 129         }
 130
 131         switch (adapter_gpio_config[idx].init_state) {
 132         case ADAPTER_GPIO_INIT_STATE_INACTIVE:
 133                 set_gpio_value(&adapter_gpio_config[idx], 0);
 134                 break;
 135         case ADAPTER_GPIO_INIT_STATE_ACTIVE:
 136                 set_gpio_value(&adapter_gpio_config[idx], 1);
 137                 break;
 138         case ADAPTER_GPIO_INIT_STATE_INPUT:
 139                 INP_GPIO(adapter_gpio_config[idx].gpio_num);
 140                 break;
 141         }
 142
 143         /* Direction for non push-pull is already set by set_gpio_value() */
 144         if (adapter_gpio_config[idx].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL)
 145                 OUT_GPIO(adapter_gpio_config[idx].gpio_num);
 146 }
 147
 148 static bb_value_t bcm2835gpio_read(void)
 149 {
 150         unsigned int shift = adapter_gpio_config[ADAPTER_GPIO_IDX_TDO].gpio_num;
 151         uint32_t value = (GPIO_LEV >> shift) & 1;
 152         return value ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_TDO].active_low ? BB_HIGH : BB_LOW);
 153
 154 }
 155
 156 static int bcm2835gpio_write(int tck, int tms, int tdi)
 157 {
 158         uint32_t set = tck << adapter_gpio_config[ADAPTER_GPIO_IDX_TCK].gpio_num |
 159                         tms << adapter_gpio_config[ADAPTER_GPIO_IDX_TMS].gpio_num |
 160                         tdi << adapter_gpio_config[ADAPTER_GPIO_IDX_TDI].gpio_num;
 161         uint32_t clear = !tck << adapter_gpio_config[ADAPTER_GPIO_IDX_TCK].gpio_num |
 162                         !tms << adapter_gpio_config[ADAPTER_GPIO_IDX_TMS].gpio_num |
 163                         !tdi << adapter_gpio_config[ADAPTER_GPIO_IDX_TDI].gpio_num;
 164
 165         GPIO_SET = set;
 166         GPIO_CLR = clear;
 167
 168         for (unsigned int i = 0; i < jtag_delay; i++)
 169                 asm volatile ("");
 170
 171         return ERROR_OK;
 172 }
 173
 174 /* Requires push-pull drive mode for swclk and swdio */
 175 static int bcm2835gpio_swd_write_fast(int swclk, int swdio)
 176 {
 177         swclk = swclk ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].active_low ? 1 : 0);
 178         swdio = swdio ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].active_low ? 1 : 0);
 179
 180         uint32_t set = swclk << adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].gpio_num |
 181                                         swdio << adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
 182         uint32_t clear = !swclk << adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].gpio_num |
 183                                         !swdio << adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
 184
 185         GPIO_SET = set;
 186         GPIO_CLR = clear;
 187
 188         for (unsigned int i = 0; i < jtag_delay; i++)
 189                 asm volatile ("");
 190
 191         return ERROR_OK;
 192 }
 193
 194 /* Generic mode that works for open-drain/open-source drive modes, but slower */
 195 static int bcm2835gpio_swd_write_generic(int swclk, int swdio)
 196 {
 197         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO], swdio);
 198         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK], swclk); /* Write clock last */
 199
 200         for (unsigned int i = 0; i < jtag_delay; ++i)
 201                 asm volatile ("");
 202
 203         return ERROR_OK;
 204 }
 205
 206 /* (1) assert or (0) deassert reset lines */
 207 static int bcm2835gpio_reset(int trst, int srst)
 208 {
 209         /* As the "adapter reset_config" command keeps the srst and trst gpio drive
 210          * mode settings in sync we can use our standard set_gpio_value() function
 211          * that honours drive mode and active low.
 212          */
 213         if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SRST))
 214                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST], srst);
 215
 216         if (is_gpio_config_valid(ADAPTER_GPIO_IDX_TRST))
 217                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST], trst);
 218
 219         LOG_DEBUG("BCM2835 GPIO: bcm2835gpio_reset(%d, %d), trst_gpio: %d %d, srst_gpio: %d %d",
 220                 trst, srst,
 221                 adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].gpio_num,
 222                 adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].gpio_num);
 223         return ERROR_OK;
 224 }
 225
 226 static void bcm2835_swdio_drive(bool is_output)
 227 {
 228         if (is_output) {
 229                 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO_DIR))
 230                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 1);
 231                 OUT_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
 232         } else {
 233                 INP_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
 234                 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO_DIR))
 235                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 0);
 236         }
 237 }
 238
 239 static int bcm2835_swdio_read(void)
 240 {
 241         unsigned int shift = adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
 242         uint32_t value = (GPIO_LEV >> shift) & 1;
 243         return value ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].active_low ? 1 : 0);
 244 }
 245
 246 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 247 {
 248         if (!khz) {
 249                 LOG_DEBUG("BCM2835 GPIO: RCLK not supported");
 250                 return ERROR_FAIL;
 251         }
 252         *jtag_speed = speed_coeff/khz - speed_offset;
 253         if (*jtag_speed < 0)
 254                 *jtag_speed = 0;
 255         return ERROR_OK;
 256 }
 257
 258 static int bcm2835gpio_speed_div(int speed, int *khz)
 259 {
 260         *khz = speed_coeff/(speed + speed_offset);
 261         return ERROR_OK;
 262 }
 263
 264 static int bcm2835gpio_speed(int speed)
 265 {
 266         jtag_delay = speed;
 267         return ERROR_OK;
 268 }
 269
 270 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 271 {
 272         if (CMD_ARGC == 2) {
 273                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 274                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 275         }
 276
 277         command_print(CMD, "BCM2835 GPIO: speed_coeffs = %d, speed_offset = %d",
 278                                   speed_coeff, speed_offset);
 279         return ERROR_OK;
 280 }
 281
 282 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
 283 {
 284         if (CMD_ARGC == 1)
 285                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
 286
 287         command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
 288                                   bcm2835_peri_base);
 289         return ERROR_OK;
 290 }
 291
 292 static const struct command_registration bcm2835gpio_subcommand_handlers[] = {
 293         {
 294                 .name = "speed_coeffs",
 295                 .handler = &bcm2835gpio_handle_speed_coeffs,
 296                 .mode = COMMAND_CONFIG,
 297                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 298                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 299         },
 300         {
 301                 .name = "peripheral_base",
 302                 .handler = &bcm2835gpio_handle_peripheral_base,
 303                 .mode = COMMAND_CONFIG,
 304                 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
 305                 .usage = "[base]",
 306         },
 307
 308         COMMAND_REGISTRATION_DONE
 309 };
 310
 311 static const struct command_registration bcm2835gpio_command_handlers[] = {
 312         {
 313                 .name = "bcm2835gpio",
 314                 .mode = COMMAND_ANY,
 315                 .help = "perform bcm2835gpio management",
 316                 .chain = bcm2835gpio_subcommand_handlers,
 317                 .usage = "",
 318         },
 319         COMMAND_REGISTRATION_DONE
 320 };
 321
 322 static bool bcm2835gpio_jtag_mode_possible(void)
 323 {
 324         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TCK))
 325                 return false;
 326         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TMS))
 327                 return false;
 328         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TDI))
 329                 return false;
 330         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TDO))
 331                 return false;
 332         return true;
 333 }
 334
 335 static bool bcm2835gpio_swd_mode_possible(void)
 336 {
 337         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_SWCLK))
 338                 return false;
 339         if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO))
 340                 return false;
 341         return true;
 342 }
 343
 344 static void bcm2835gpio_munmap(void)
 345 {
 346         if (pio_base != MAP_FAILED) {
 347                 munmap((void *)pio_base, sysconf(_SC_PAGE_SIZE));
 348                 pio_base = MAP_FAILED;
 349         }
 350
 351         if (pads_base != MAP_FAILED) {
 352                 munmap((void *)pads_base, sysconf(_SC_PAGE_SIZE));
 353                 pads_base = MAP_FAILED;
 354         }
 355 }
 356
 357 static int bcm2835gpio_blink(int on)
 358 {
 359         if (is_gpio_config_valid(ADAPTER_GPIO_IDX_LED))
 360                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED], on);
 361
 362         return ERROR_OK;
 363 }
 364
 365 static struct bitbang_interface bcm2835gpio_bitbang = {
 366         .read = bcm2835gpio_read,
 367         .write = bcm2835gpio_write,
 368         .swdio_read = bcm2835_swdio_read,
 369         .swdio_drive = bcm2835_swdio_drive,
 370         .swd_write = bcm2835gpio_swd_write_generic,
 371         .blink = bcm2835gpio_blink,
 372 };
 373
 374 static int bcm2835gpio_init(void)
 375 {
 376         LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
 377
 378         bitbang_interface = &bcm2835gpio_bitbang;
 379         adapter_gpio_config = adapter_gpio_get_config();
 380
 381         if (transport_is_jtag() && !bcm2835gpio_jtag_mode_possible()) {
 382                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
 383                 return ERROR_JTAG_INIT_FAILED;
 384         }
 385
 386         if (transport_is_swd() && !bcm2835gpio_swd_mode_possible()) {
 387                 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
 388                 return ERROR_JTAG_INIT_FAILED;
 389         }
 390
 391         dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
 392         if (dev_mem_fd < 0) {
 393                 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
 394                 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 395         }
 396         if (dev_mem_fd < 0) {
 397                 LOG_ERROR("open: %s", strerror(errno));
 398                 return ERROR_JTAG_INIT_FAILED;
 399         }
 400
 401         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 402                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 403
 404         if (pio_base == MAP_FAILED) {
 405                 LOG_ERROR("mmap: %s", strerror(errno));
 406                 close(dev_mem_fd);
 407                 return ERROR_JTAG_INIT_FAILED;
 408         }
 409
 410         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 411                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 412
 413         if (pads_base == MAP_FAILED) {
 414                 LOG_ERROR("mmap: %s", strerror(errno));
 415                 bcm2835gpio_munmap();
 416                 close(dev_mem_fd);
 417                 return ERROR_JTAG_INIT_FAILED;
 418         }
 419
 420         close(dev_mem_fd);
 421
 422         /* set 4mA drive strength, slew rate limited, hysteresis on */
 423         initial_drive_strength_etc = pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] & 0x1f;
 424         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
 425
 426         /* Configure JTAG/SWD signals. Default directions and initial states are handled
 427          * by adapter.c and "adapter gpio" command.
 428          */
 429         if (transport_is_jtag()) {
 430                 initialize_gpio(ADAPTER_GPIO_IDX_TDO);
 431                 initialize_gpio(ADAPTER_GPIO_IDX_TDI);
 432                 initialize_gpio(ADAPTER_GPIO_IDX_TMS);
 433                 initialize_gpio(ADAPTER_GPIO_IDX_TCK);
 434                 initialize_gpio(ADAPTER_GPIO_IDX_TRST);
 435         }
 436
 437         if (transport_is_swd()) {
 438                 /* swdio and its buffer should be initialized in the order that prevents
 439                  * two outputs from being connected together. This will occur if the
 440                  * swdio GPIO of the AM335x is configured as an output while its
 441                  * external buffer is configured to send the swdio signal from the
 442                  * target to the AM335x.
 443                  */
 444                 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].init_state == ADAPTER_GPIO_INIT_STATE_INPUT) {
 445                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 446                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 447                 } else {
 448                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 449                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 450                 }
 451
 452                 initialize_gpio(ADAPTER_GPIO_IDX_SWCLK);
 453
 454                 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL &&
 455                                 adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL) {
 456                         LOG_DEBUG("BCM2835 GPIO using fast mode for SWD write");
 457                         bcm2835gpio_bitbang.swd_write = bcm2835gpio_swd_write_fast;
 458                 } else {
 459                         LOG_DEBUG("BCM2835 GPIO using generic mode for SWD write");
 460                         bcm2835gpio_bitbang.swd_write = bcm2835gpio_swd_write_generic;
 461                 }
 462         }
 463
 464         initialize_gpio(ADAPTER_GPIO_IDX_SRST);
 465         initialize_gpio(ADAPTER_GPIO_IDX_LED);
 466
 467         return ERROR_OK;
 468 }
 469
 470 static int bcm2835gpio_quit(void)
 471 {
 472         if (transport_is_jtag()) {
 473                 restore_gpio(ADAPTER_GPIO_IDX_TDO);
 474                 restore_gpio(ADAPTER_GPIO_IDX_TDI);
 475                 restore_gpio(ADAPTER_GPIO_IDX_TCK);
 476                 restore_gpio(ADAPTER_GPIO_IDX_TMS);
 477                 restore_gpio(ADAPTER_GPIO_IDX_TRST);
 478         }
 479
 480         if (transport_is_swd()) {
 481                 /* Restore swdio/swdio_dir to their initial modes, even if that means
 482                  * connecting two outputs. Begin by making swdio an input so that the
 483                  * current and final states of swdio and swdio_dir do not have to be
 484                  * considered to calculate the safe restoration order.
 485                  */
 486                 INP_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
 487                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 488                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO);
 489                 restore_gpio(ADAPTER_GPIO_IDX_SWCLK);
 490         }
 491
 492         restore_gpio(ADAPTER_GPIO_IDX_SRST);
 493         restore_gpio(ADAPTER_GPIO_IDX_LED);
 494
 495         /* Restore drive strength. MSB is password ("5A") */
 496         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 | initial_drive_strength_etc;
 497         bcm2835gpio_munmap();
 498
 499         return ERROR_OK;
 500 }
 501
 502
 503 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
 504
 505 static struct jtag_interface bcm2835gpio_interface = {
 506         .supported = DEBUG_CAP_TMS_SEQ,
 507         .execute_queue = bitbang_execute_queue,
 508 };
 509 struct adapter_driver bcm2835gpio_adapter_driver = {
 510         .name = "bcm2835gpio",
 511         .transports = bcm2835_transports,
 512         .commands = bcm2835gpio_command_handlers,
 513
 514         .init = bcm2835gpio_init,
 515         .quit = bcm2835gpio_quit,
 516         .reset = bcm2835gpio_reset,
 517         .speed = bcm2835gpio_speed,
 518         .khz = bcm2835gpio_khz,
 519         .speed_div = bcm2835gpio_speed_div,
 520
 521         .jtag_ops = &bcm2835gpio_interface,
 522         .swd_ops = &bitbang_swd,
 523 };