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 < AM335XGPIO_NUM_GPIO_CHIPS
  90                 && gpio_config->gpio_num < AM335XGPIO_NUM_GPIO_PER_CHIP;
  91 }
  92
  93 static int get_gpio_value(const struct adapter_gpio_config *gpio_config)
  94 {
  95         unsigned int shift = gpio_config->gpio_num;
  96         uint32_t value = AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_DATAIN_OFFSET);
  97         value = (value >> shift) & 1;
  98         return value ^ (gpio_config->active_low ? 1 : 0);
  99 }
 100
 101 static void set_gpio_value(const struct adapter_gpio_config *gpio_config, int value)
 102 {
 103         value = value ^ (gpio_config->active_low ? 1 : 0);
 104         switch (gpio_config->drive) {
 105         case ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL:
 106                 if (value)
 107                         AM335XGPIO_SET_HIGH(gpio_config);
 108                 else
 109                         AM335XGPIO_SET_LOW(gpio_config);
 110                 /* For performance reasons assume the GPIO is already set as an output
 111                  * and therefore the call can be omitted here.
 112                  */
 113                 break;
 114         case ADAPTER_GPIO_DRIVE_MODE_OPEN_DRAIN:
 115                 if (value) {
 116                         AM335XGPIO_SET_INPUT(gpio_config);
 117                 } else {
 118                         AM335XGPIO_SET_LOW(gpio_config);
 119                         AM335XGPIO_SET_OUTPUT(gpio_config);
 120                 }
 121                 break;
 122         case ADAPTER_GPIO_DRIVE_MODE_OPEN_SOURCE:
 123                 if (value) {
 124                         AM335XGPIO_SET_HIGH(gpio_config);
 125                         AM335XGPIO_SET_OUTPUT(gpio_config);
 126                 } else {
 127                         AM335XGPIO_SET_INPUT(gpio_config);
 128                 }
 129                 break;
 130         }
 131 }
 132
 133 static enum amx335gpio_initial_gpio_mode get_gpio_mode(const struct adapter_gpio_config *gpio_config)
 134 {
 135         if (AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_OE_OFFSET) & BIT(gpio_config->gpio_num))
 136                 return AM335XGPIO_GPIO_MODE_INPUT;
 137
 138         /* Return output level too so that pin mode can be fully restored */
 139         if (AM335XGPIO_READ_REG(gpio_config->chip_num, AM335XGPIO_GPIO_DATAOUT_OFFSET) & BIT(gpio_config->gpio_num))
 140                 return AM335XGPIO_GPIO_MODE_OUTPUT_HIGH;
 141         return AM335XGPIO_GPIO_MODE_OUTPUT_LOW;
 142 }
 143
 144 static const char *get_gpio_mode_name(enum amx335gpio_initial_gpio_mode gpio_mode)
 145 {
 146         switch (gpio_mode) {
 147         case AM335XGPIO_GPIO_MODE_INPUT:
 148                 return "input";
 149         case AM335XGPIO_GPIO_MODE_OUTPUT_LOW:
 150                 return "output (low)";
 151         case AM335XGPIO_GPIO_MODE_OUTPUT_HIGH:
 152                 return "output (high)";
 153         }
 154         return "unknown";
 155 }
 156
 157 static void initialize_gpio(enum adapter_gpio_config_index idx)
 158 {
 159         if (!is_gpio_config_valid(&adapter_gpio_config[idx]))
 160                 return;
 161
 162         initial_gpio_mode[idx] = get_gpio_mode(&adapter_gpio_config[idx]);
 163         LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %s",
 164                         adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num,
 165                         get_gpio_mode_name(initial_gpio_mode[idx]));
 166
 167         if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) {
 168                 LOG_WARNING("am335xgpio does not support pull-up or pull-down settings (signal %s)",
 169                         adapter_gpio_get_name(idx));
 170         }
 171
 172         switch (adapter_gpio_config[idx].init_state) {
 173         case ADAPTER_GPIO_INIT_STATE_INACTIVE:
 174                 set_gpio_value(&adapter_gpio_config[idx], 0);
 175                 break;
 176         case ADAPTER_GPIO_INIT_STATE_ACTIVE:
 177                 set_gpio_value(&adapter_gpio_config[idx], 1);
 178                 break;
 179         case ADAPTER_GPIO_INIT_STATE_INPUT:
 180                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[idx]);
 181                 break;
 182         }
 183
 184         /* Direction for non push-pull is already set by set_gpio_value() */
 185         if (adapter_gpio_config[idx].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL
 186                 && adapter_gpio_config[idx].init_state != ADAPTER_GPIO_INIT_STATE_INPUT)
 187                 AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 188 }
 189
 190 static void restore_gpio(enum adapter_gpio_config_index idx)
 191 {
 192         if (is_gpio_config_valid(&adapter_gpio_config[idx])) {
 193                 switch (initial_gpio_mode[idx]) {
 194                 case AM335XGPIO_GPIO_MODE_INPUT:
 195                         AM335XGPIO_SET_INPUT(&adapter_gpio_config[idx]);
 196                         break;
 197                 case AM335XGPIO_GPIO_MODE_OUTPUT_LOW:
 198                         AM335XGPIO_SET_LOW(&adapter_gpio_config[idx]);
 199                         AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 200                         break;
 201                 case AM335XGPIO_GPIO_MODE_OUTPUT_HIGH:
 202                         AM335XGPIO_SET_HIGH(&adapter_gpio_config[idx]);
 203                         AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[idx]);
 204                         break;
 205                 }
 206         }
 207 }
 208
 209 static bb_value_t am335xgpio_read(void)
 210 {
 211         return get_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDO]) ? BB_HIGH : BB_LOW;
 212 }
 213
 214 static int am335xgpio_write(int tck, int tms, int tdi)
 215 {
 216         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDI], tdi);
 217         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TMS], tms);
 218         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TCK], tck); /* Write clock last */
 219
 220         for (unsigned int i = 0; i < jtag_delay; ++i)
 221                 asm volatile ("");
 222
 223         return ERROR_OK;
 224 }
 225
 226 static int am335xgpio_swd_write(int swclk, int swdio)
 227 {
 228         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO], swdio);
 229         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK], swclk); /* Write clock last */
 230
 231         for (unsigned int i = 0; i < jtag_delay; ++i)
 232                 asm volatile ("");
 233
 234         return ERROR_OK;
 235 }
 236
 237 /* (1) assert or (0) deassert reset lines */
 238 static int am335xgpio_reset(int trst, int srst)
 239 {
 240         /* As the "adapter reset_config" command keeps the srst and trst gpio drive
 241          * mode settings in sync we can use our standard set_gpio_value() function
 242          * that honours drive mode and active low.
 243          */
 244         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST]))
 245                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST], srst);
 246
 247         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST]))
 248                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST], trst);
 249
 250         LOG_DEBUG("trst %d gpio: %d %d, srst %d gpio: %d %d",
 251                 trst,
 252                 (int)adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].chip_num,
 253                 (int)adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].gpio_num,
 254                 srst,
 255                 (int)adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].chip_num,
 256                 (int)adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].gpio_num);
 257         return ERROR_OK;
 258 }
 259
 260 static void am335xgpio_swdio_drive(bool is_output)
 261 {
 262         if (is_output) {
 263                 if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR]))
 264                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 1);
 265                 AM335XGPIO_SET_OUTPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 266         } else {
 267                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 268                 if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR]))
 269                         set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 0);
 270         }
 271 }
 272
 273 static int am335xgpio_swdio_read(void)
 274 {
 275         return get_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 276 }
 277
 278 static int am335xgpio_blink(int on)
 279 {
 280         if (is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED]))
 281                 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED], on);
 282
 283         return ERROR_OK;
 284 }
 285
 286 static struct bitbang_interface am335xgpio_bitbang = {
 287         .read = am335xgpio_read,
 288         .write = am335xgpio_write,
 289         .swdio_read = am335xgpio_swdio_read,
 290         .swdio_drive = am335xgpio_swdio_drive,
 291         .swd_write = am335xgpio_swd_write,
 292         .blink = am335xgpio_blink
 293 };
 294
 295 static int am335xgpio_khz(int khz, int *jtag_speed)
 296 {
 297         if (!khz) {
 298                 LOG_DEBUG("RCLK not supported");
 299                 return ERROR_FAIL;
 300         }
 301         *jtag_speed = speed_coeff / khz - speed_offset;
 302         if (*jtag_speed < 0)
 303                 *jtag_speed = 0;
 304         return ERROR_OK;
 305 }
 306
 307 static int am335xgpio_speed_div(int speed, int *khz)
 308 {
 309         *khz = speed_coeff / (speed + speed_offset);
 310         return ERROR_OK;
 311 }
 312
 313 static int am335xgpio_speed(int speed)
 314 {
 315         jtag_delay = speed;
 316         return ERROR_OK;
 317 }
 318
 319 COMMAND_HANDLER(am335xgpio_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, "AM335x GPIO config: speed_coeffs = %d, speed_offset = %d",
 327                                   speed_coeff, speed_offset);
 328         return ERROR_OK;
 329 }
 330
 331 static const struct command_registration am335xgpio_subcommand_handlers[] = {
 332         {
 333                 .name = "speed_coeffs",
 334                 .handler = am335xgpio_handle_speed_coeffs,
 335                 .mode = COMMAND_CONFIG,
 336                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 337                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 338         },
 339         COMMAND_REGISTRATION_DONE
 340 };
 341
 342 static const struct command_registration am335xgpio_command_handlers[] = {
 343         {
 344                 .name = "am335xgpio",
 345                 .mode = COMMAND_ANY,
 346                 .help = "perform am335xgpio management",
 347                 .chain = am335xgpio_subcommand_handlers,
 348                 .usage = "",
 349         },
 350         COMMAND_REGISTRATION_DONE
 351 };
 352
 353 static const char * const am335xgpio_transports[] = { "jtag", "swd", NULL };
 354
 355 static struct jtag_interface am335xgpio_interface = {
 356         .supported = DEBUG_CAP_TMS_SEQ,
 357         .execute_queue = bitbang_execute_queue,
 358 };
 359
 360 static bool am335xgpio_jtag_mode_possible(void)
 361 {
 362         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TCK]))
 363                 return false;
 364         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TMS]))
 365                 return false;
 366         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDI]))
 367                 return false;
 368         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_TDO]))
 369                 return false;
 370         return true;
 371 }
 372
 373 static bool am335xgpio_swd_mode_possible(void)
 374 {
 375         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK]))
 376                 return false;
 377         if (!is_gpio_config_valid(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]))
 378                 return false;
 379         return true;
 380 }
 381
 382 static void am335xgpio_munmap(void)
 383 {
 384         for (unsigned int i = 0; i < AM335XGPIO_NUM_GPIO_CHIPS && am335xgpio_gpio_chip_mmap_addr[i] != MAP_FAILED; ++i)
 385                 if (munmap((void *)am335xgpio_gpio_chip_mmap_addr[i], sysconf(_SC_PAGE_SIZE)) < 0)
 386                         LOG_ERROR("Cannot unmap GPIO memory for chip %d: %s", i, strerror(errno));
 387 }
 388
 389 static int am335xgpio_init(void)
 390 {
 391         LOG_INFO("AM335x GPIO JTAG/SWD bitbang driver");
 392
 393         bitbang_interface = &am335xgpio_bitbang;
 394         adapter_gpio_config = adapter_gpio_get_config();
 395
 396         if (transport_is_jtag() && !am335xgpio_jtag_mode_possible()) {
 397                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
 398                 return ERROR_JTAG_INIT_FAILED;
 399         }
 400
 401         if (transport_is_swd() && !am335xgpio_swd_mode_possible()) {
 402                 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
 403                 return ERROR_JTAG_INIT_FAILED;
 404         }
 405
 406         dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
 407         if (dev_mem_fd < 0) {
 408                 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
 409                 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 410         }
 411         if (dev_mem_fd < 0) {
 412                 LOG_ERROR("open: %s", strerror(errno));
 413                 return ERROR_JTAG_INIT_FAILED;
 414         }
 415
 416         for (unsigned int i = 0; i < AM335XGPIO_NUM_GPIO_CHIPS; ++i) {
 417                 am335xgpio_gpio_chip_mmap_addr[i] = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 418                                 MAP_SHARED, dev_mem_fd, am335xgpio_gpio_chip_hw_addr[i]);
 419
 420                 if (am335xgpio_gpio_chip_mmap_addr[i] == MAP_FAILED) {
 421                         LOG_ERROR("mmap: %s", strerror(errno));
 422                         am335xgpio_munmap();
 423                         close(dev_mem_fd);
 424                         return ERROR_JTAG_INIT_FAILED;
 425                 }
 426         }
 427         close(dev_mem_fd);
 428
 429         /* Configure JTAG/SWD signals. Default directions and initial states are handled
 430          * by adapter.c and "adapter gpio" command.
 431          */
 432         if (transport_is_jtag()) {
 433                 initialize_gpio(ADAPTER_GPIO_IDX_TDO);
 434                 initialize_gpio(ADAPTER_GPIO_IDX_TDI);
 435                 initialize_gpio(ADAPTER_GPIO_IDX_TMS);
 436                 initialize_gpio(ADAPTER_GPIO_IDX_TCK);
 437                 initialize_gpio(ADAPTER_GPIO_IDX_TRST);
 438         }
 439
 440         if (transport_is_swd()) {
 441                 /* swdio and its buffer should be initialized in the order that prevents
 442                  * two outputs from being connected together. This will occur if the
 443                  * swdio GPIO of the AM335x is configured as an output while its
 444                  * external buffer is configured to send the swdio signal from the
 445                  * target to the AM335x.
 446                  */
 447                 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].init_state == ADAPTER_GPIO_INIT_STATE_INPUT) {
 448                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 449                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 450                 } else {
 451                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 452                         initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
 453                 }
 454
 455                 initialize_gpio(ADAPTER_GPIO_IDX_SWCLK);
 456         }
 457
 458         initialize_gpio(ADAPTER_GPIO_IDX_SRST);
 459         initialize_gpio(ADAPTER_GPIO_IDX_LED);
 460
 461         return ERROR_OK;
 462 }
 463
 464 static int am335xgpio_quit(void)
 465 {
 466         if (transport_is_jtag()) {
 467                 restore_gpio(ADAPTER_GPIO_IDX_TDO);
 468                 restore_gpio(ADAPTER_GPIO_IDX_TDI);
 469                 restore_gpio(ADAPTER_GPIO_IDX_TMS);
 470                 restore_gpio(ADAPTER_GPIO_IDX_TCK);
 471                 restore_gpio(ADAPTER_GPIO_IDX_TRST);
 472         }
 473
 474         if (transport_is_swd()) {
 475                 /* Restore swdio/swdio_dir to their initial modes, even if that means
 476                  * connecting two outputs. Begin by making swdio an input so that the
 477                  * current and final states of swdio and swdio_dir do not have to be
 478                  * considered to calculate the safe restoration order.
 479                  */
 480                 AM335XGPIO_SET_INPUT(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO]);
 481                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
 482                 restore_gpio(ADAPTER_GPIO_IDX_SWDIO);
 483
 484                 restore_gpio(ADAPTER_GPIO_IDX_SWCLK);
 485         }
 486
 487         restore_gpio(ADAPTER_GPIO_IDX_SRST);
 488         restore_gpio(ADAPTER_GPIO_IDX_LED);
 489
 490         am335xgpio_munmap();
 491
 492         return ERROR_OK;
 493 }
 494
 495 struct adapter_driver am335xgpio_adapter_driver = {
 496         .name = "am335xgpio",
 497         .transports = am335xgpio_transports,
 498         .commands = am335xgpio_command_handlers,
 499
 500         .init = am335xgpio_init,
 501         .quit = am335xgpio_quit,
 502         .reset = am335xgpio_reset,
 503         .speed = am335xgpio_speed,
 504         .khz = am335xgpio_khz,
 505         .speed_div = am335xgpio_speed_div,
 506
 507         .jtag_ops = &am335xgpio_interface,
 508         .swd_ops = &bitbang_swd,
 509 };