src/jtag/drivers/am335xgpio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2022 by Steve Marple, stevemarple@googlemail.com        *
   5  *                                                                         *
   6  *   Based on bcm2835gpio.c and linuxgpiod.c                               *
   7  ***************************************************************************/
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include "config.h"
  11 #endif
  12
  13 #include <jtag/adapter.h>
  14 #include <jtag/interface.h>
  15 #include <transport/transport.h>
  16 #include "bitbang.h"
  17
  18 #include <sys/mman.h>
  19
  20 /* GPIO register base addresses. Values taken from "AM335x and AMIC110 Sitara
  21  * Processors Technical Reference Manual", Chapter 2 Memory Map.
  22  */
  23 #define AM335XGPIO_NUM_GPIO_PER_CHIP 32
  24 #define AM335XGPIO_NUM_GPIO_CHIPS 4
  25 #define AM335XGPIO_GPIO0_HW_ADDR 0x44E07000
  26 #define AM335XGPIO_GPIO1_HW_ADDR 0x4804C000
  27 #define AM335XGPIO_GPIO2_HW_ADDR 0x481AC000
  28 #define AM335XGPIO_GPIO3_HW_ADDR 0x481AE000
  29
  30 /* 32-bit offsets from GPIO chip base address. Values taken from "AM335x and
  31  * AMIC110 Sitara Processors Technical Reference Manual", Chapter 25
  32  * General-Purpose Input/Output.
  33  */
  34 #define AM335XGPIO_GPIO_OE_OFFSET (0x134 / 4)
  35 #define AM335XGPIO_GPIO_DATAIN_OFFSET (0x138 / 4)
  36 #define AM335XGPIO_GPIO_DATAOUT_OFFSET (0x13C / 4)  /* DATAOUT register uses 0 for output, 1 for input */
  37 #define AM335XGPIO_GPIO_CLEARDATAOUT_OFFSET (0x190 / 4)
  38 #define AM335XGPIO_GPIO_SETDATAOUT_OFFSET (0x194 / 4)
  39
  40 #define AM335XGPIO_READ_REG(chip_num, offset) \
  41         (*(am335xgpio_gpio_chip_mmap_addr[(chip_num)] + (offset)))
  42
  43 #define AM335XGPIO_WRITE_REG(chip_num, offset, value) \
  44         (*(am335xgpio_gpio_chip_mmap_addr[(chip_num)] + (offset)) = (value))
  45
  46 #define AM335XGPIO_SET_REG_BITS(chip_num, offset, bit_mask) \
  47         (*(am335xgpio_gpio_chip_mmap_addr[(chip_num)] + (offset)) |= (bit_mask))
  48
  49 #define AM335XGPIO_CLEAR_REG_BITS(chip_num, offset, bit_mask) \
  50         (*(am335xgpio_gpio_chip_mmap_addr[(chip_num)] + (offset)) &= ~(bit_mask))
  51
  52 #define AM335XGPIO_SET_INPUT(gpio_config) \
  53         AM335XGPIO_SET_REG_BITS((gpio_config)->chip_num, AM335XGPIO_GPIO_OE_OFFSET, BIT((gpio_config)->gpio_num))
  54 #define AM335XGPIO_SET_OUTPUT(gpio_config) \
  55         AM335XGPIO_CLEAR_REG_BITS((gpio_config)->chip_num, AM335XGPIO_GPIO_OE_OFFSET, BIT((gpio_config)->gpio_num))
  56 #define AM335XGPIO_SET_HIGH(gpio_config) \
  57         AM335XGPIO_WRITE_REG((gpio_config)->chip_num, AM335XGPIO_GPIO_SETDATAOUT_OFFSET, BIT((gpio_config)->gpio_num))
  58 #define AM335XGPIO_SET_LOW(gpio_config) \
  59         AM335XGPIO_WRITE_REG((gpio_config)->chip_num, AM335XGPIO_GPIO_CLEARDATAOUT_OFFSET, BIT((gpio_config)->gpio_num))
  60
  61 enum amx335gpio_initial_gpio_mode {
  62         AM335XGPIO_GPIO_MODE_INPUT,
  63         AM335XGPIO_GPIO_MODE_OUTPUT_LOW,
  64         AM335XGPIO_GPIO_MODE_OUTPUT_HIGH,
  65 };
  66
  67 static const uint32_t am335xgpio_gpio_chip_hw_addr[AM335XGPIO_NUM_GPIO_CHIPS] = {
  68         AM335XGPIO_GPIO0_HW_ADDR,
  69         AM335XGPIO_GPIO1_HW_ADDR,
  70         AM335XGPIO_GPIO2_HW_ADDR,
  71         AM335XGPIO_GPIO3_HW_ADDR,
  72 };
  73
  74 /* Memory-mapped address pointers */
  75 static volatile uint32_t *am335xgpio_gpio_chip_mmap_addr[AM335XGPIO_NUM_GPIO_CHIPS];
  76
  77 static int dev_mem_fd;
  78 static enum amx335gpio_initial_gpio_mode initial_gpio_mode[ADAPTER_GPIO_IDX_NUM];
  79
  80 /* Transition delay coefficients */
  81 static int speed_coeff = 600000;
  82 static int speed_offset = 575;
  83 static unsigned int jtag_delay;
  84
  85 static const struct adapter_gpio_config *adapter_gpio_config;
  86
  87 static bool is_gpio_config_valid(const struct adapter_gpio_config *gpio_config)
  88 {
  89         return gpio_config->chip_num >= 0
  90                 && gpio_config->chip_num < AM335XGPIO_NUM_GPIO_CHIPS
  91                 && gpio_config->gpio_num >= 0
  92                 && gpio_config->gpio_num < AM335XGPIO_NUM_GPIO_PER_CHIP;
  93 }
  94
  95 static int get_gpio_value(const struct adapter_gpio_config *gpio_config)
  96 {
  97         unsigned int shift = gpio_config->gpio_num;
  98         uint32_t value = AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_DATAIN_OFFSET);
  99         value = (value >> shift) & 1;
 100         return value ^ (gpio_config->active_low ? 1 : 0);
 101 }
 102
 103 static void set_gpio_value(const struct adapter_gpio_config *gpio_config, int value)
 104 {
 105         value = value ^ (gpio_config->active_low ? 1 : 0);
 106         switch (gpio_config->drive) {
 107         case ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL:
 108                 if (value)
 109                         AM335XGPIO_SET_HIGH(gpio_config);
 110                 else
 111                         AM335XGPIO_SET_LOW(gpio_config);
 112                 /* For performance reasons assume the GPIO is already set as an output
 113                  * and therefore the call can be omitted here.
 114                  */
 115                 break;
 116         case ADAPTER_GPIO_DRIVE_MODE_OPEN_DRAIN:
 117                 if (value) {
 118                         AM335XGPIO_SET_INPUT(gpio_config);
 119                 } else {
 120                         AM335XGPIO_SET_LOW(gpio_config);
 121                         AM335XGPIO_SET_OUTPUT(gpio_config);
 122                 }
 123                 break;
 124         case ADAPTER_GPIO_DRIVE_MODE_OPEN_SOURCE:
 125                 if (value) {
 126                         AM335XGPIO_SET_HIGH(gpio_config);
 127                         AM335XGPIO_SET_OUTPUT(gpio_config);
 128                 } else {
 129                         AM335XGPIO_SET_INPUT(gpio_config);
 130                 }
 131                 break;
 132         }
 133 }
 134
 135 static enum amx335gpio_initial_gpio_mode get_gpio_mode(const struct adapter_gpio_config *gpio_config)
 136 {
 137         if (AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_OE_OFFSET) & BIT(gpio_config->gpio_num))
 138                 return AM335XGPIO_GPIO_MODE_INPUT;
 139
 140         /* Return output level too so that pin mode can be fully restored */
 141         if (AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_DATAOUT_OFFSET) & BIT(gpio_config->gpio_num))
 142                 return AM335XGPIO_GPIO_MODE_OUTPUT_HIGH;
 143         return AM335XGPIO_GPIO_MODE_OUTPUT_LOW;
 144 }
 145
 146 static const char *get_gpio_mode_name(enum amx335gpio_initial_gpio_mode gpio_mode)
 147 {
 148         switch (gpio_mode) {
 149         case AM335XGPIO_GPIO_MODE_INPUT:
 150                 return "input";
 151         case AM335XGPIO_GPIO_MODE_OUTPUT_LOW:
 152                 return "output (low)";
 153         case AM335XGPIO_GPIO_MODE_OUTPUT_HIGH:
 154                 return "output (high)";
 155         }
 156         return "unknown";
 157 }
 158
 159 static void initialize_gpio(enum adapter_gpio_config_index idx)
 160 {
 161         if (!is_gpio_config_valid(&adapter_gpio_config[idx]))
 162                 return;
 163
 164         initial_gpio_mode[idx] = get_gpio_mode(&adapter_gpio_config[idx]);
 165         LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %s",
 166                         adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num,
 167                         get_gpio_mode_name(initial_gpio_mode[idx]));
 168
 169         if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) {
 170                 LOG_WARNING("am335xgpio does not support pull-up or pull-down settings (signal %s)",
 171                         adapter_gpio_get_name(idx));
 172         }
 173
 174         switch (adapter_gpio_config[idx].init_state) {
 175         case ADAPTER_GPIO_INIT_STATE_INACTIVE:
 176                 set_gpio_value(&adapter_gpio_config[idx], 0);
 177                 break;
 178         case ADAPTER_GPIO_INIT_STATE_ACTIVE:
 179                 set_gpio_value(&adapter_gpio_config[idx], 1);
 180                 break;
 181         case ADAPTER_GPIO_INIT_STATE_INPUT:
 182                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[idx]);
 183                 break;
 184         }
 185
 186         /* Direction for non push-pull is already set by set_gpio_value() */
 187         if (adapter_gpio_config[idx].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL
 188                 && adapter_gpio_config[idx].init_state != ADAPTER_GPIO_INIT_STATE_INPUT)
 189                 AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 190 }
 191
 192 static void restore_gpio(enum adapter_gpio_config_index idx)
 193 {
 194         if (is_gpio_config_valid(&adapter_gpio_config[idx])) {
 195                 switch (initial_gpio_mode[idx]) {
 196                 case AM335XGPIO_GPIO_MODE_INPUT:
 197                         AM335XGPIO_SET_INPUT(&adapter_gpio_config[idx]);
 198                         break;
 199                 case AM335XGPIO_GPIO_MODE_OUTPUT_LOW:
 200                         AM335XGPIO_SET_LOW(&adapter_gpio_config[idx]);
 201                         AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 202                         break;
 203                 case AM335XGPIO_GPIO_MODE_OUTPUT_HIGH:
 204                         AM335XGPIO_SET_HIGH(&adapter_gpio_config[idx]);
 205                         AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 206                         break;
 207                 }
 208         }
 209 }
 210
 211 static bb_value_t am335xgpio_read(void)
 212 {
 213         return get_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDO]) ? BB_HIGH : BB_LOW;
 214 }
 215
 216 static int am335xgpio_write(int tck, int tms, int tdi)
 217 {
 218         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDI], tdi);
 219         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TMS], tms);
 220         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TCK], tck); /* Write clock last */
 221
 222         for (unsigned int i = 0; i < jtag_delay; ++i)
 223                 asm volatile ("");
 224
 225         return ERROR_OK;
 226 }
 227
 228 static int am335xgpio_swd_write(int swclk, int swdio)
 229 {
 230         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO], swdio);
 231         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK], swclk); /* Write clock last */
 232
 233         for (unsigned int i = 0; i < jtag_delay; ++i)
 234                 asm volatile ("");
 235
 236         return ERROR_OK;
 237 }
 238
 239 /* (1) assert or (0) deassert reset lines */
 240 static int am335xgpio_reset(int trst, int srst)
 241 {
 242         /* As the "adapter reset_config" command keeps the srst and trst gpio drive
 243          * mode settings in sync we can use our standard set_gpio_value() function
 244          * that honours drive mode and active low.
 245          */
 246         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST]))
 247                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST], srst);
 248
 249         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST]))
 250                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST], trst);
 251
 252         LOG_DEBUG("am335xgpio_reset(%d, %d), trst_gpio: %d %d, srst_gpio: %d %d",
 253                 trst, srst,
 254                 adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].gpio_num,
 255                 adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].gpio_num);
 256         return ERROR_OK;
 257 }
 258
 259 static void am335xgpio_swdio_drive(bool is_output)
 260 {
 261         if (is_output) {
 262                 if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR]))
 263                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 1);
 264                 AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 265         } else {
 266                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 267                 if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR]))
 268                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 0);
 269         }
 270 }
 271
 272 static int am335xgpio_swdio_read(void)
 273 {
 274         return get_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 275 }
 276
 277 static int am335xgpio_blink(int on)
 278 {
 279         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED]))
 280                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED], on);
 281
 282         return ERROR_OK;
 283 }
 284
 285 static struct bitbang_interface am335xgpio_bitbang = {
 286         .read = am335xgpio_read,
 287         .write = am335xgpio_write,
 288         .swdio_read = am335xgpio_swdio_read,
 289         .swdio_drive = am335xgpio_swdio_drive,
 290         .swd_write = am335xgpio_swd_write,
 291         .blink = am335xgpio_blink
 292 };
 293
 294 static int am335xgpio_khz(int khz, int *jtag_speed)
 295 {
 296         if (!khz) {
 297                 LOG_DEBUG("RCLK not supported");
 298                 return ERROR_FAIL;
 299         }
 300         *jtag_speed = speed_coeff / khz - speed_offset;
 301         if (*jtag_speed < 0)
 302                 *jtag_speed = 0;
 303         return ERROR_OK;
 304 }
 305
 306 static int am335xgpio_speed_div(int speed, int *khz)
 307 {
 308         *khz = speed_coeff / (speed + speed_offset);
 309         return ERROR_OK;
 310 }
 311
 312 static int am335xgpio_speed(int speed)
 313 {
 314         jtag_delay = speed;
 315         return ERROR_OK;
 316 }
 317
 318 COMMAND_HANDLER(am335xgpio_handle_speed_coeffs)
 319 {
 320         if (CMD_ARGC == 2) {
 321                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 322                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 323         }
 324
 325         command_print(CMD, "AM335x GPIO config: speed_coeffs = %d, speed_offset = %d",
 326                                   speed_coeff, speed_offset);
 327         return ERROR_OK;
 328 }
 329
 330 static const struct command_registration am335xgpio_subcommand_handlers[] = {
 331         {
 332                 .name = "speed_coeffs",
 333                 .handler = am335xgpio_handle_speed_coeffs,
 334                 .mode = COMMAND_CONFIG,
 335                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 336                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 337         },
 338         COMMAND_REGISTRATION_DONE
 339 };
 340
 341 static const struct command_registration am335xgpio_command_handlers[] = {
 342         {
 343                 .name = "am335xgpio",
 344                 .mode = COMMAND_ANY,
 345                 .help = "perform am335xgpio management",
 346                 .chain = am335xgpio_subcommand_handlers,
 347                 .usage = "",
 348         },
 349         COMMAND_REGISTRATION_DONE
 350 };
 351
 352 static const char * const am335xgpio_transports[] = { "jtag", "swd", NULL };
 353
 354 static struct jtag_interface am335xgpio_interface = {
 355         .supported = DEBUG_CAP_TMS_SEQ,
 356         .execute_queue = bitbang_execute_queue,
 357 };
 358
 359 static bool am335xgpio_jtag_mode_possible(void)
 360 {
 361         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TCK]))
 362                 return false;
 363         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TMS]))
 364                 return false;
 365         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDI]))
 366                 return false;
 367         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDO]))
 368                 return false;
 369         return true;
 370 }
 371
 372 static bool am335xgpio_swd_mode_possible(void)
 373 {
 374         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK]))
 375                 return false;
 376         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]))
 377                 return false;
 378         return true;
 379 }
 380
 381 static void am335xgpio_munmap(void)
 382 {
 383         for (unsigned int i = 0; i < AM335XGPIO_NUM_GPIO_CHIPS && am335xgpio_gpio_chip_mmap_addr[i] != MAP_FAILED; ++i)
 384                 if (munmap((void *)am335xgpio_gpio_chip_mmap_addr[i], sysconf(_SC_PAGE_SIZE)) < 0)
 385                         LOG_ERROR("Cannot unmap GPIO memory for chip %d: %s", i, strerror(errno));
 386 }
 387
 388 static int am335xgpio_init(void)
 389 {
 390         LOG_INFO("AM335x GPIO JTAG/SWD bitbang driver");
 391
 392         bitbang_interface = &am335xgpio_bitbang;
 393         adapter_gpio_config = adapter_gpio_get_config();
 394
 395         if (transport_is_jtag() && !am335xgpio_jtag_mode_possible()) {
 396                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
 397                 return ERROR_JTAG_INIT_FAILED;
 398         }
 399
 400         if (transport_is_swd() && !am335xgpio_swd_mode_possible()) {
 401                 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
 402                 return ERROR_JTAG_INIT_FAILED;
 403         }
 404
 405         dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
 406         if (dev_mem_fd < 0) {
 407                 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
 408                 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 409         }
 410         if (dev_mem_fd < 0) {
 411                 LOG_ERROR("open: %s", strerror(errno));
 412                 return ERROR_JTAG_INIT_FAILED;
 413         }
 414
 415         for (unsigned int i = 0; i < AM335XGPIO_NUM_GPIO_CHIPS; ++i) {
 416                 am335xgpio_gpio_chip_mmap_addr[i] = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 417                                 MAP_SHARED, dev_mem_fd, am335xgpio_gpio_chip_hw_addr[i]);
 418
 419                 if (am335xgpio_gpio_chip_mmap_addr[i] == MAP_FAILED) {
 420                         LOG_ERROR("mmap: %s", strerror(errno));
 421                         am335xgpio_munmap();
 422                         close(dev_mem_fd);
 423                         return ERROR_JTAG_INIT_FAILED;
 424                 }
 425         }
 426         close(dev_mem_fd);
 427
 428         /* Configure JTAG/SWD signals. Default directions and initial states are handled
 429          * by adapter.c and "adapter gpio" command.
 430          */
 431         if (transport_is_jtag()) {
 432                 initialize_gpio(ADAPTER_GPIO_IDX_TDO);
 433                 initialize_gpio(ADAPTER_GPIO_IDX_TDI);
 434                 initialize_gpio(ADAPTER_GPIO_IDX_TMS);
 435                 initialize_gpio(ADAPTER_GPIO_IDX_TCK);
 436                 initialize_gpio(ADAPTER_GPIO_IDX_TRST);
 437         }
 438
 439         if (transport_is_swd()) {
 440                 /* swdio and its buffer should be initialized in the order that prevents
 441                  * two outputs from being connected together. This will occur if the
 442                  * swdio GPIO of the AM335x is configured as an output while its
 443                  * external buffer is configured to send the swdio signal from the
 444                  * target to the AM335x.
 445                  */
 446                 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].init_state == ADAPTER_GPIO_INIT_STATE_INPUT) {
 447                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 448                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 449                 } else {
 450                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 451                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 452                 }
 453
 454                 initialize_gpio(ADAPTER_GPIO_IDX_SWCLK);
 455         }
 456
 457         initialize_gpio(ADAPTER_GPIO_IDX_SRST);
 458         initialize_gpio(ADAPTER_GPIO_IDX_LED);
 459
 460         return ERROR_OK;
 461 }
 462
 463 static int am335xgpio_quit(void)
 464 {
 465         if (transport_is_jtag()) {
 466                 restore_gpio(ADAPTER_GPIO_IDX_TDO);
 467                 restore_gpio(ADAPTER_GPIO_IDX_TDI);
 468                 restore_gpio(ADAPTER_GPIO_IDX_TMS);
 469                 restore_gpio(ADAPTER_GPIO_IDX_TCK);
 470                 restore_gpio(ADAPTER_GPIO_IDX_TRST);
 471         }
 472
 473         if (transport_is_swd()) {
 474                 /* Restore swdio/swdio_dir to their initial modes, even if that means
 475                  * connecting two outputs. Begin by making swdio an input so that the
 476                  * current and final states of swdio and swdio_dir do not have to be
 477                  * considered to calculate the safe restoration order.
 478                  */
 479                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 480                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 481                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO);
 482
 483                 restore_gpio(ADAPTER_GPIO_IDX_SWCLK);
 484         }
 485
 486         restore_gpio(ADAPTER_GPIO_IDX_SRST);
 487         restore_gpio(ADAPTER_GPIO_IDX_LED);
 488
 489         am335xgpio_munmap();
 490
 491         return ERROR_OK;
 492 }
 493
 494 struct adapter_driver am335xgpio_adapter_driver = {
 495         .name = "am335xgpio",
 496         .transports = am335xgpio_transports,
 497         .commands = am335xgpio_command_handlers,
 498
 499         .init = am335xgpio_init,
 500         .quit = am335xgpio_quit,
 501         .reset = am335xgpio_reset,
 502         .speed = am335xgpio_speed,
 503         .khz = am335xgpio_khz,
 504         .speed_div = am335xgpio_speed_div,
 505
 506         .jtag_ops = &am335xgpio_interface,
 507         .swd_ops = &bitbang_swd,
 508 };