src/jtag/drivers/imx_gpio.c

   1 /***************************************************************************
   2  *   Copyright (C) 2017 by Grzegorz Kostka, kostka.grzegorz@gmail.com      *
   3  *                                                                         *
   4  *   Based on bcm2835gpio.c                                                 *
   5  *                                                                         *
   6  *   This program is free software; you can redistribute it and/or modify  *
   7  *   it under the terms of the GNU General Public License as published by  *
   8  *   the Free Software Foundation; either version 2 of the License, or     *
   9  *   (at your option) any later version.                                   *
  10  *                                                                         *
  11  *   This program is distributed in the hope that it will be useful,       *
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  14  *   GNU General Public License for more details.                          *
  15  *                                                                         *
  16  *   You should have received a copy of the GNU General Public License     *
  17  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  18  ***************************************************************************/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <jtag/interface.h>
  25 #include "bitbang.h"
  26
  27 #include <sys/mman.h>
  28
  29 #define IMX_GPIO_BASE 0x0209c000
  30 #define IMX_GPIO_SIZE 0x00004000
  31 #define IMX_GPIO_REGS_COUNT 8
  32
  33 static uint32_t imx_gpio_peri_base = IMX_GPIO_BASE;
  34
  35 struct imx_gpio_regs {
  36         uint32_t dr;
  37         uint32_t gdir;
  38         uint32_t psr;
  39         uint32_t icr1;
  40         uint32_t icr2;
  41         uint32_t imr;
  42         uint32_t isr;
  43         uint32_t edge_sel;
  44 } __attribute__((aligned(IMX_GPIO_SIZE)));
  45
  46 static int dev_mem_fd;
  47 static volatile struct imx_gpio_regs *pio_base;
  48
  49 /* GPIO setup functions */
  50 static inline bool gpio_mode_get(int g)
  51 {
  52         return pio_base[g / 32].gdir >> (g & 0x1F) & 1;
  53 }
  54
  55 static inline void gpio_mode_input_set(int g)
  56 {
  57         pio_base[g / 32].gdir &=  ~(1u << (g & 0x1F));
  58 }
  59
  60 static inline void gpio_mode_output_set(int g)
  61 {
  62         pio_base[g / 32].gdir |=  (1u << (g & 0x1F));
  63 }
  64
  65 static inline void gpio_mode_set(int g, int m)
  66 {
  67         (m) ? gpio_mode_output_set(g) : gpio_mode_input_set(g);
  68 }
  69
  70 static inline void gpio_set(int g)
  71 {
  72         pio_base[g / 32].dr |=  (1u << (g & 0x1F));
  73 }
  74
  75 static inline void gpio_clear(int g)
  76 {
  77         pio_base[g / 32].dr &=  ~(1u << (g & 0x1F));
  78 }
  79
  80 static inline bool gpio_level(int g)
  81 {
  82         return pio_base[g / 32].dr >> (g & 0x1F) & 1;
  83 }
  84
  85 static bb_value_t imx_gpio_read(void);
  86 static int imx_gpio_write(int tck, int tms, int tdi);
  87
  88 static int imx_gpio_swdio_read(void);
  89 static void imx_gpio_swdio_drive(bool is_output);
  90
  91 static int imx_gpio_init(void);
  92 static int imx_gpio_quit(void);
  93
  94 static struct bitbang_interface imx_gpio_bitbang = {
  95         .read = imx_gpio_read,
  96         .write = imx_gpio_write,
  97         .swdio_read = imx_gpio_swdio_read,
  98         .swdio_drive = imx_gpio_swdio_drive,
  99         .blink = NULL
 100 };
 101
 102 /* GPIO numbers for each signal. Negative values are invalid */
 103 static int tck_gpio = -1;
 104 static int tck_gpio_mode;
 105 static int tms_gpio = -1;
 106 static int tms_gpio_mode;
 107 static int tdi_gpio = -1;
 108 static int tdi_gpio_mode;
 109 static int tdo_gpio = -1;
 110 static int tdo_gpio_mode;
 111 static int trst_gpio = -1;
 112 static int trst_gpio_mode;
 113 static int srst_gpio = -1;
 114 static int srst_gpio_mode;
 115 static int swclk_gpio = -1;
 116 static int swclk_gpio_mode;
 117 static int swdio_gpio = -1;
 118 static int swdio_gpio_mode;
 119
 120 /* Transition delay coefficients. Tuned for IMX6UL 528MHz. Adjusted
 121  * experimentally for:10kHz, 100Khz, 500KHz. Speeds above 800Khz are impossible
 122  * to reach via memory mapped method (at least for IMX6UL@528MHz).
 123  * Measured mmap raw GPIO toggling speed on IMX6UL@528MHz: 1.3MHz.
 124  */
 125 static int speed_coeff = 50000;
 126 static int speed_offset = 100;
 127 static unsigned int jtag_delay;
 128
 129 static bb_value_t imx_gpio_read(void)
 130 {
 131         return gpio_level(tdo_gpio) ? BB_HIGH : BB_LOW;
 132 }
 133
 134 static int imx_gpio_write(int tck, int tms, int tdi)
 135 {
 136         tms ? gpio_set(tms_gpio) : gpio_clear(tms_gpio);
 137         tdi ? gpio_set(tdi_gpio) : gpio_clear(tdi_gpio);
 138         tck ? gpio_set(tck_gpio) : gpio_clear(tck_gpio);
 139
 140         for (unsigned int i = 0; i < jtag_delay; i++)
 141                 asm volatile ("");
 142
 143         return ERROR_OK;
 144 }
 145
 146 static int imx_gpio_swd_write(int tck, int tms, int tdi)
 147 {
 148         tdi ? gpio_set(swdio_gpio) : gpio_clear(swdio_gpio);
 149         tck ? gpio_set(swclk_gpio) : gpio_clear(swclk_gpio);
 150
 151         for (unsigned int i = 0; i < jtag_delay; i++)
 152                 asm volatile ("");
 153
 154         return ERROR_OK;
 155 }
 156
 157 /* (1) assert or (0) deassert reset lines */
 158 static int imx_gpio_reset(int trst, int srst)
 159 {
 160         if (trst_gpio != -1)
 161                 trst ? gpio_clear(trst_gpio) : gpio_set(trst_gpio);
 162
 163         if (srst_gpio != -1)
 164                 srst ? gpio_clear(srst_gpio) : gpio_set(srst_gpio);
 165
 166         return ERROR_OK;
 167 }
 168
 169 static void imx_gpio_swdio_drive(bool is_output)
 170 {
 171         if (is_output)
 172                 gpio_mode_output_set(swdio_gpio);
 173         else
 174                 gpio_mode_input_set(swdio_gpio);
 175 }
 176
 177 static int imx_gpio_swdio_read(void)
 178 {
 179         return gpio_level(swdio_gpio);
 180 }
 181
 182 static int imx_gpio_khz(int khz, int *jtag_speed)
 183 {
 184         if (!khz) {
 185                 LOG_DEBUG("RCLK not supported");
 186                 return ERROR_FAIL;
 187         }
 188         *jtag_speed = speed_coeff/khz - speed_offset;
 189         if (*jtag_speed < 0)
 190                 *jtag_speed = 0;
 191         return ERROR_OK;
 192 }
 193
 194 static int imx_gpio_speed_div(int speed, int *khz)
 195 {
 196         *khz = speed_coeff/(speed + speed_offset);
 197         return ERROR_OK;
 198 }
 199
 200 static int imx_gpio_speed(int speed)
 201 {
 202         jtag_delay = speed;
 203         return ERROR_OK;
 204 }
 205
 206 static int is_gpio_valid(int gpio)
 207 {
 208         return gpio >= 0 && gpio < 32 * IMX_GPIO_REGS_COUNT;
 209 }
 210
 211 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionums)
 212 {
 213         if (CMD_ARGC == 4) {
 214                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 215                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 216                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 217                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 218         } else if (CMD_ARGC != 0) {
 219                 return ERROR_COMMAND_SYNTAX_ERROR;
 220         }
 221
 222         command_print(CMD,
 223                         "imx_gpio GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 224                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 225
 226         return ERROR_OK;
 227 }
 228
 229 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tck)
 230 {
 231         if (CMD_ARGC == 1)
 232                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 233
 234         command_print(CMD, "imx_gpio GPIO config: tck = %d", tck_gpio);
 235         return ERROR_OK;
 236 }
 237
 238 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tms)
 239 {
 240         if (CMD_ARGC == 1)
 241                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 242
 243         command_print(CMD, "imx_gpio GPIO config: tms = %d", tms_gpio);
 244         return ERROR_OK;
 245 }
 246
 247 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tdo)
 248 {
 249         if (CMD_ARGC == 1)
 250                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 251
 252         command_print(CMD, "imx_gpio GPIO config: tdo = %d", tdo_gpio);
 253         return ERROR_OK;
 254 }
 255
 256 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tdi)
 257 {
 258         if (CMD_ARGC == 1)
 259                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 260
 261         command_print(CMD, "imx_gpio GPIO config: tdi = %d", tdi_gpio);
 262         return ERROR_OK;
 263 }
 264
 265 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_srst)
 266 {
 267         if (CMD_ARGC == 1)
 268                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 269
 270         command_print(CMD, "imx_gpio GPIO config: srst = %d", srst_gpio);
 271         return ERROR_OK;
 272 }
 273
 274 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_trst)
 275 {
 276         if (CMD_ARGC == 1)
 277                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 278
 279         command_print(CMD, "imx_gpio GPIO config: trst = %d", trst_gpio);
 280         return ERROR_OK;
 281 }
 282
 283 COMMAND_HANDLER(imx_gpio_handle_swd_gpionums)
 284 {
 285         if (CMD_ARGC == 2) {
 286                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 287                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 288         } else if (CMD_ARGC != 0) {
 289                 return ERROR_COMMAND_SYNTAX_ERROR;
 290         }
 291
 292         command_print(CMD,
 293                         "imx_gpio GPIO nums: swclk = %d, swdio = %d",
 294                         swclk_gpio, swdio_gpio);
 295
 296         return ERROR_OK;
 297 }
 298
 299 COMMAND_HANDLER(imx_gpio_handle_swd_gpionum_swclk)
 300 {
 301         if (CMD_ARGC == 1)
 302                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 303
 304         command_print(CMD, "imx_gpio num: swclk = %d", swclk_gpio);
 305         return ERROR_OK;
 306 }
 307
 308 COMMAND_HANDLER(imx_gpio_handle_swd_gpionum_swdio)
 309 {
 310         if (CMD_ARGC == 1)
 311                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 312
 313         command_print(CMD, "imx_gpio num: swdio = %d", swdio_gpio);
 314         return ERROR_OK;
 315 }
 316
 317 COMMAND_HANDLER(imx_gpio_handle_speed_coeffs)
 318 {
 319         if (CMD_ARGC == 2) {
 320                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 321                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 322         }
 323
 324         command_print(CMD, "imx_gpio: speed_coeffs = %d, speed_offset = %d",
 325                                   speed_coeff, speed_offset);
 326         return ERROR_OK;
 327 }
 328
 329 COMMAND_HANDLER(imx_gpio_handle_peripheral_base)
 330 {
 331         if (CMD_ARGC == 1)
 332                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], imx_gpio_peri_base);
 333
 334         command_print(CMD, "imx_gpio: peripheral_base = 0x%08x",
 335                                   imx_gpio_peri_base);
 336         return ERROR_OK;
 337 }
 338
 339 static const struct command_registration imx_gpio_command_handlers[] = {
 340         {
 341                 .name = "imx_gpio_jtag_nums",
 342                 .handler = &imx_gpio_handle_jtag_gpionums,
 343                 .mode = COMMAND_CONFIG,
 344                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 345                 .usage = "[tck tms tdi tdo]",
 346         },
 347         {
 348                 .name = "imx_gpio_tck_num",
 349                 .handler = &imx_gpio_handle_jtag_gpionum_tck,
 350                 .mode = COMMAND_CONFIG,
 351                 .help = "gpio number for tck.",
 352                 .usage = "[tck]",
 353         },
 354         {
 355                 .name = "imx_gpio_tms_num",
 356                 .handler = &imx_gpio_handle_jtag_gpionum_tms,
 357                 .mode = COMMAND_CONFIG,
 358                 .help = "gpio number for tms.",
 359                 .usage = "[tms]",
 360         },
 361         {
 362                 .name = "imx_gpio_tdo_num",
 363                 .handler = &imx_gpio_handle_jtag_gpionum_tdo,
 364                 .mode = COMMAND_CONFIG,
 365                 .help = "gpio number for tdo.",
 366                 .usage = "[tdo]",
 367         },
 368         {
 369                 .name = "imx_gpio_tdi_num",
 370                 .handler = &imx_gpio_handle_jtag_gpionum_tdi,
 371                 .mode = COMMAND_CONFIG,
 372                 .help = "gpio number for tdi.",
 373                 .usage = "[tdi]",
 374         },
 375         {
 376                 .name = "imx_gpio_swd_nums",
 377                 .handler = &imx_gpio_handle_swd_gpionums,
 378                 .mode = COMMAND_CONFIG,
 379                 .help = "gpio numbers for swclk, swdio. (in that order)",
 380                 .usage = "[swclk swdio]",
 381         },
 382         {
 383                 .name = "imx_gpio_swclk_num",
 384                 .handler = &imx_gpio_handle_swd_gpionum_swclk,
 385                 .mode = COMMAND_CONFIG,
 386                 .help = "gpio number for swclk.",
 387                 .usage = "[swclk]",
 388         },
 389         {
 390                 .name = "imx_gpio_swdio_num",
 391                 .handler = &imx_gpio_handle_swd_gpionum_swdio,
 392                 .mode = COMMAND_CONFIG,
 393                 .help = "gpio number for swdio.",
 394                 .usage = "[swdio]",
 395         },
 396         {
 397                 .name = "imx_gpio_srst_num",
 398                 .handler = &imx_gpio_handle_jtag_gpionum_srst,
 399                 .mode = COMMAND_CONFIG,
 400                 .help = "gpio number for srst.",
 401                 .usage = "[srst]",
 402         },
 403         {
 404                 .name = "imx_gpio_trst_num",
 405                 .handler = &imx_gpio_handle_jtag_gpionum_trst,
 406                 .mode = COMMAND_CONFIG,
 407                 .help = "gpio number for trst.",
 408                 .usage = "[trst]",
 409         },
 410         {
 411                 .name = "imx_gpio_speed_coeffs",
 412                 .handler = &imx_gpio_handle_speed_coeffs,
 413                 .mode = COMMAND_CONFIG,
 414                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 415                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 416         },
 417         {
 418                 .name = "imx_gpio_peripheral_base",
 419                 .handler = &imx_gpio_handle_peripheral_base,
 420                 .mode = COMMAND_CONFIG,
 421                 .help = "peripheral base to access GPIOs (0x0209c000 for most IMX).",
 422                 .usage = "[base]",
 423         },
 424
 425         COMMAND_REGISTRATION_DONE
 426 };
 427
 428 static const char * const imx_gpio_transports[] = { "jtag", "swd", NULL };
 429
 430 struct jtag_interface imx_gpio_interface = {
 431         .name = "imx_gpio",
 432         .supported = DEBUG_CAP_TMS_SEQ,
 433         .execute_queue = bitbang_execute_queue,
 434         .transports = imx_gpio_transports,
 435         .swd = &bitbang_swd,
 436         .speed = imx_gpio_speed,
 437         .khz = imx_gpio_khz,
 438         .speed_div = imx_gpio_speed_div,
 439         .commands = imx_gpio_command_handlers,
 440         .init = imx_gpio_init,
 441         .quit = imx_gpio_quit,
 442         .reset = imx_gpio_reset,
 443 };
 444
 445 static bool imx_gpio_jtag_mode_possible(void)
 446 {
 447         if (!is_gpio_valid(tck_gpio))
 448                 return 0;
 449         if (!is_gpio_valid(tms_gpio))
 450                 return 0;
 451         if (!is_gpio_valid(tdi_gpio))
 452                 return 0;
 453         if (!is_gpio_valid(tdo_gpio))
 454                 return 0;
 455         return 1;
 456 }
 457
 458 static bool imx_gpio_swd_mode_possible(void)
 459 {
 460         if (!is_gpio_valid(swclk_gpio))
 461                 return 0;
 462         if (!is_gpio_valid(swdio_gpio))
 463                 return 0;
 464         return 1;
 465 }
 466
 467 static int imx_gpio_init(void)
 468 {
 469         bitbang_interface = &imx_gpio_bitbang;
 470
 471         LOG_INFO("imx_gpio GPIO JTAG/SWD bitbang driver");
 472
 473         if (imx_gpio_jtag_mode_possible()) {
 474                 if (imx_gpio_swd_mode_possible())
 475                         LOG_INFO("JTAG and SWD modes enabled");
 476                 else
 477                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 478         } else if (imx_gpio_swd_mode_possible()) {
 479                 LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
 480         } else {
 481                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
 482                 return ERROR_JTAG_INIT_FAILED;
 483         }
 484
 485         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 486         if (dev_mem_fd < 0) {
 487                 perror("open");
 488                 return ERROR_JTAG_INIT_FAILED;
 489         }
 490
 491
 492         LOG_INFO("imx_gpio mmap: pagesize: %u, regionsize: %u",
 493                         (unsigned int) sysconf(_SC_PAGE_SIZE), IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE);
 494         pio_base = mmap(NULL, IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE,
 495                                 PROT_READ | PROT_WRITE,
 496                                 MAP_SHARED, dev_mem_fd, imx_gpio_peri_base);
 497
 498         if (pio_base == MAP_FAILED) {
 499                 perror("mmap");
 500                 close(dev_mem_fd);
 501                 return ERROR_JTAG_INIT_FAILED;
 502         }
 503
 504         /*
 505          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 506          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 507          */
 508         if (imx_gpio_jtag_mode_possible()) {
 509                 tdo_gpio_mode = gpio_mode_get(tdo_gpio);
 510                 tdi_gpio_mode = gpio_mode_get(tdi_gpio);
 511                 tck_gpio_mode = gpio_mode_get(tck_gpio);
 512                 tms_gpio_mode = gpio_mode_get(tms_gpio);
 513
 514                 gpio_clear(tdi_gpio);
 515                 gpio_clear(tck_gpio);
 516                 gpio_set(tms_gpio);
 517
 518                 gpio_mode_input_set(tdo_gpio);
 519                 gpio_mode_output_set(tdi_gpio);
 520                 gpio_mode_output_set(tck_gpio);
 521                 gpio_mode_output_set(tms_gpio);
 522         }
 523         if (imx_gpio_swd_mode_possible()) {
 524                 swclk_gpio_mode = gpio_mode_get(swclk_gpio);
 525                 swdio_gpio_mode = gpio_mode_get(swdio_gpio);
 526
 527                 gpio_clear(swdio_gpio);
 528                 gpio_clear(swclk_gpio);
 529                 gpio_mode_output_set(swclk_gpio);
 530                 gpio_mode_output_set(swdio_gpio);
 531         }
 532         if (trst_gpio != -1) {
 533                 trst_gpio_mode = gpio_mode_get(trst_gpio);
 534                 gpio_set(trst_gpio);
 535                 gpio_mode_output_set(trst_gpio);
 536         }
 537         if (srst_gpio != -1) {
 538                 srst_gpio_mode = gpio_mode_get(srst_gpio);
 539                 gpio_set(srst_gpio);
 540                 gpio_mode_output_set(srst_gpio);
 541         }
 542
 543         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 544                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 545                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 546
 547         if (swd_mode) {
 548                 imx_gpio_bitbang.write = imx_gpio_swd_write;
 549                 bitbang_switch_to_swd();
 550         }
 551
 552         return ERROR_OK;
 553 }
 554
 555 static int imx_gpio_quit(void)
 556 {
 557         if (imx_gpio_jtag_mode_possible()) {
 558                 gpio_mode_set(tdo_gpio, tdo_gpio_mode);
 559                 gpio_mode_set(tdi_gpio, tdi_gpio_mode);
 560                 gpio_mode_set(tck_gpio, tck_gpio_mode);
 561                 gpio_mode_set(tms_gpio, tms_gpio_mode);
 562         }
 563         if (imx_gpio_swd_mode_possible()) {
 564                 gpio_mode_set(swclk_gpio, swclk_gpio_mode);
 565                 gpio_mode_set(swdio_gpio, swdio_gpio_mode);
 566         }
 567         if (trst_gpio != -1)
 568                 gpio_mode_set(trst_gpio, trst_gpio_mode);
 569         if (srst_gpio != -1)
 570                 gpio_mode_set(srst_gpio, srst_gpio_mode);
 571
 572         return ERROR_OK;
 573 }