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 static int imx_gpio_reset(int trst, int srst);
  88
  89 static int imx_gpio_swdio_read(void);
  90 static void imx_gpio_swdio_drive(bool is_output);
  91
  92 static int imx_gpio_init(void);
  93 static int imx_gpio_quit(void);
  94
  95 static struct bitbang_interface imx_gpio_bitbang = {
  96         .read = imx_gpio_read,
  97         .write = imx_gpio_write,
  98         .reset = imx_gpio_reset,
  99         .swdio_read = imx_gpio_swdio_read,
 100         .swdio_drive = imx_gpio_swdio_drive,
 101         .blink = NULL
 102 };
 103
 104 /* GPIO numbers for each signal. Negative values are invalid */
 105 static int tck_gpio = -1;
 106 static int tck_gpio_mode;
 107 static int tms_gpio = -1;
 108 static int tms_gpio_mode;
 109 static int tdi_gpio = -1;
 110 static int tdi_gpio_mode;
 111 static int tdo_gpio = -1;
 112 static int tdo_gpio_mode;
 113 static int trst_gpio = -1;
 114 static int trst_gpio_mode;
 115 static int srst_gpio = -1;
 116 static int srst_gpio_mode;
 117 static int swclk_gpio = -1;
 118 static int swclk_gpio_mode;
 119 static int swdio_gpio = -1;
 120 static int swdio_gpio_mode;
 121
 122 /* Transition delay coefficients. Tuned for IMX6UL 528MHz. Adjusted
 123  * experimentally for:10kHz, 100Khz, 500KHz. Speeds above 800Khz are impossible
 124  * to reach via memory mapped method (at least for IMX6UL@528MHz).
 125  * Measured mmap raw GPIO toggling speed on IMX6UL@528MHz: 1.3MHz.
 126  */
 127 static int speed_coeff = 50000;
 128 static int speed_offset = 100;
 129 static unsigned int jtag_delay;
 130
 131 static bb_value_t imx_gpio_read(void)
 132 {
 133         return gpio_level(tdo_gpio) ? BB_HIGH : BB_LOW;
 134 }
 135
 136 static int imx_gpio_write(int tck, int tms, int tdi)
 137 {
 138         tms ? gpio_set(tms_gpio) : gpio_clear(tms_gpio);
 139         tdi ? gpio_set(tdi_gpio) : gpio_clear(tdi_gpio);
 140         tck ? gpio_set(tck_gpio) : gpio_clear(tck_gpio);
 141
 142         for (unsigned int i = 0; i < jtag_delay; i++)
 143                 asm volatile ("");
 144
 145         return ERROR_OK;
 146 }
 147
 148 static int imx_gpio_swd_write(int tck, int tms, int tdi)
 149 {
 150         tdi ? gpio_set(swdio_gpio) : gpio_clear(swdio_gpio);
 151         tck ? gpio_set(swclk_gpio) : gpio_clear(swclk_gpio);
 152
 153         for (unsigned int i = 0; i < jtag_delay; i++)
 154                 asm volatile ("");
 155
 156         return ERROR_OK;
 157 }
 158
 159 /* (1) assert or (0) deassert reset lines */
 160 static int imx_gpio_reset(int trst, int srst)
 161 {
 162         if (trst_gpio != -1)
 163                 trst ? gpio_clear(trst_gpio) : gpio_set(trst_gpio);
 164
 165         if (srst_gpio != -1)
 166                 srst ? gpio_clear(srst_gpio) : gpio_set(srst_gpio);
 167
 168         return ERROR_OK;
 169 }
 170
 171 static void imx_gpio_swdio_drive(bool is_output)
 172 {
 173         if (is_output)
 174                 gpio_mode_output_set(swdio_gpio);
 175         else
 176                 gpio_mode_input_set(swdio_gpio);
 177 }
 178
 179 static int imx_gpio_swdio_read(void)
 180 {
 181         return gpio_level(swdio_gpio);
 182 }
 183
 184 static int imx_gpio_khz(int khz, int *jtag_speed)
 185 {
 186         if (!khz) {
 187                 LOG_DEBUG("RCLK not supported");
 188                 return ERROR_FAIL;
 189         }
 190         *jtag_speed = speed_coeff/khz - speed_offset;
 191         if (*jtag_speed < 0)
 192                 *jtag_speed = 0;
 193         return ERROR_OK;
 194 }
 195
 196 static int imx_gpio_speed_div(int speed, int *khz)
 197 {
 198         *khz = speed_coeff/(speed + speed_offset);
 199         return ERROR_OK;
 200 }
 201
 202 static int imx_gpio_speed(int speed)
 203 {
 204         jtag_delay = speed;
 205         return ERROR_OK;
 206 }
 207
 208 static int is_gpio_valid(int gpio)
 209 {
 210         return gpio >= 0 && gpio < 32 * IMX_GPIO_REGS_COUNT;
 211 }
 212
 213 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionums)
 214 {
 215         if (CMD_ARGC == 4) {
 216                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 217                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 218                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 219                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 220         } else if (CMD_ARGC != 0) {
 221                 return ERROR_COMMAND_SYNTAX_ERROR;
 222         }
 223
 224         command_print(CMD,
 225                         "imx_gpio GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
 226                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 227
 228         return ERROR_OK;
 229 }
 230
 231 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tck)
 232 {
 233         if (CMD_ARGC == 1)
 234                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 235
 236         command_print(CMD, "imx_gpio GPIO config: tck = %d", tck_gpio);
 237         return ERROR_OK;
 238 }
 239
 240 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tms)
 241 {
 242         if (CMD_ARGC == 1)
 243                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 244
 245         command_print(CMD, "imx_gpio GPIO config: tms = %d", tms_gpio);
 246         return ERROR_OK;
 247 }
 248
 249 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tdo)
 250 {
 251         if (CMD_ARGC == 1)
 252                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 253
 254         command_print(CMD, "imx_gpio GPIO config: tdo = %d", tdo_gpio);
 255         return ERROR_OK;
 256 }
 257
 258 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_tdi)
 259 {
 260         if (CMD_ARGC == 1)
 261                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 262
 263         command_print(CMD, "imx_gpio GPIO config: tdi = %d", tdi_gpio);
 264         return ERROR_OK;
 265 }
 266
 267 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_srst)
 268 {
 269         if (CMD_ARGC == 1)
 270                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 271
 272         command_print(CMD, "imx_gpio GPIO config: srst = %d", srst_gpio);
 273         return ERROR_OK;
 274 }
 275
 276 COMMAND_HANDLER(imx_gpio_handle_jtag_gpionum_trst)
 277 {
 278         if (CMD_ARGC == 1)
 279                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 280
 281         command_print(CMD, "imx_gpio GPIO config: trst = %d", trst_gpio);
 282         return ERROR_OK;
 283 }
 284
 285 COMMAND_HANDLER(imx_gpio_handle_swd_gpionums)
 286 {
 287         if (CMD_ARGC == 2) {
 288                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 289                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio);
 290         } else if (CMD_ARGC != 0) {
 291                 return ERROR_COMMAND_SYNTAX_ERROR;
 292         }
 293
 294         command_print(CMD,
 295                         "imx_gpio GPIO nums: swclk = %d, swdio = %d",
 296                         swclk_gpio, swdio_gpio);
 297
 298         return ERROR_OK;
 299 }
 300
 301 COMMAND_HANDLER(imx_gpio_handle_swd_gpionum_swclk)
 302 {
 303         if (CMD_ARGC == 1)
 304                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
 305
 306         command_print(CMD, "imx_gpio num: swclk = %d", swclk_gpio);
 307         return ERROR_OK;
 308 }
 309
 310 COMMAND_HANDLER(imx_gpio_handle_swd_gpionum_swdio)
 311 {
 312         if (CMD_ARGC == 1)
 313                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
 314
 315         command_print(CMD, "imx_gpio num: swdio = %d", swdio_gpio);
 316         return ERROR_OK;
 317 }
 318
 319 COMMAND_HANDLER(imx_gpio_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_CTX, "imx_gpio: speed_coeffs = %d, speed_offset = %d",
 327                                   speed_coeff, speed_offset);
 328         return ERROR_OK;
 329 }
 330
 331 COMMAND_HANDLER(imx_gpio_handle_peripheral_base)
 332 {
 333         if (CMD_ARGC == 1)
 334                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], imx_gpio_peri_base);
 335
 336         command_print(CMD_CTX, "imx_gpio: peripheral_base = 0x%08x",
 337                                   imx_gpio_peri_base);
 338         return ERROR_OK;
 339 }
 340
 341 static const struct command_registration imx_gpio_command_handlers[] = {
 342         {
 343                 .name = "imx_gpio_jtag_nums",
 344                 .handler = &imx_gpio_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 = "imx_gpio_tck_num",
 351                 .handler = &imx_gpio_handle_jtag_gpionum_tck,
 352                 .mode = COMMAND_CONFIG,
 353                 .help = "gpio number for tck.",
 354                 .usage = "[tck]",
 355         },
 356         {
 357                 .name = "imx_gpio_tms_num",
 358                 .handler = &imx_gpio_handle_jtag_gpionum_tms,
 359                 .mode = COMMAND_CONFIG,
 360                 .help = "gpio number for tms.",
 361                 .usage = "[tms]",
 362         },
 363         {
 364                 .name = "imx_gpio_tdo_num",
 365                 .handler = &imx_gpio_handle_jtag_gpionum_tdo,
 366                 .mode = COMMAND_CONFIG,
 367                 .help = "gpio number for tdo.",
 368                 .usage = "[tdo]",
 369         },
 370         {
 371                 .name = "imx_gpio_tdi_num",
 372                 .handler = &imx_gpio_handle_jtag_gpionum_tdi,
 373                 .mode = COMMAND_CONFIG,
 374                 .help = "gpio number for tdi.",
 375                 .usage = "[tdi]",
 376         },
 377         {
 378                 .name = "imx_gpio_swd_nums",
 379                 .handler = &imx_gpio_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 = "imx_gpio_swclk_num",
 386                 .handler = &imx_gpio_handle_swd_gpionum_swclk,
 387                 .mode = COMMAND_CONFIG,
 388                 .help = "gpio number for swclk.",
 389                 .usage = "[swclk]",
 390         },
 391         {
 392                 .name = "imx_gpio_swdio_num",
 393                 .handler = &imx_gpio_handle_swd_gpionum_swdio,
 394                 .mode = COMMAND_CONFIG,
 395                 .help = "gpio number for swdio.",
 396                 .usage = "[swdio]",
 397         },
 398         {
 399                 .name = "imx_gpio_srst_num",
 400                 .handler = &imx_gpio_handle_jtag_gpionum_srst,
 401                 .mode = COMMAND_CONFIG,
 402                 .help = "gpio number for srst.",
 403                 .usage = "[srst]",
 404         },
 405         {
 406                 .name = "imx_gpio_trst_num",
 407                 .handler = &imx_gpio_handle_jtag_gpionum_trst,
 408                 .mode = COMMAND_CONFIG,
 409                 .help = "gpio number for trst.",
 410                 .usage = "[trst]",
 411         },
 412         {
 413                 .name = "imx_gpio_speed_coeffs",
 414                 .handler = &imx_gpio_handle_speed_coeffs,
 415                 .mode = COMMAND_CONFIG,
 416                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 417                 .usage = "[SPEED_COEFF SPEED_OFFSET]",
 418         },
 419         {
 420                 .name = "imx_gpio_peripheral_base",
 421                 .handler = &imx_gpio_handle_peripheral_base,
 422                 .mode = COMMAND_CONFIG,
 423                 .help = "peripheral base to access GPIOs (0x0209c000 for most IMX).",
 424                 .usage = "[base]",
 425         },
 426
 427         COMMAND_REGISTRATION_DONE
 428 };
 429
 430 static const char * const imx_gpio_transports[] = { "jtag", "swd", NULL };
 431
 432 struct jtag_interface imx_gpio_interface = {
 433         .name = "imx_gpio",
 434         .supported = DEBUG_CAP_TMS_SEQ,
 435         .execute_queue = bitbang_execute_queue,
 436         .transports = imx_gpio_transports,
 437         .swd = &bitbang_swd,
 438         .speed = imx_gpio_speed,
 439         .khz = imx_gpio_khz,
 440         .speed_div = imx_gpio_speed_div,
 441         .commands = imx_gpio_command_handlers,
 442         .init = imx_gpio_init,
 443         .quit = imx_gpio_quit,
 444 };
 445
 446 static bool imx_gpio_jtag_mode_possible(void)
 447 {
 448         if (!is_gpio_valid(tck_gpio))
 449                 return 0;
 450         if (!is_gpio_valid(tms_gpio))
 451                 return 0;
 452         if (!is_gpio_valid(tdi_gpio))
 453                 return 0;
 454         if (!is_gpio_valid(tdo_gpio))
 455                 return 0;
 456         return 1;
 457 }
 458
 459 static bool imx_gpio_swd_mode_possible(void)
 460 {
 461         if (!is_gpio_valid(swclk_gpio))
 462                 return 0;
 463         if (!is_gpio_valid(swdio_gpio))
 464                 return 0;
 465         return 1;
 466 }
 467
 468 static int imx_gpio_init(void)
 469 {
 470         bitbang_interface = &imx_gpio_bitbang;
 471
 472         LOG_INFO("imx_gpio GPIO JTAG/SWD bitbang driver");
 473
 474         if (imx_gpio_jtag_mode_possible()) {
 475                 if (imx_gpio_swd_mode_possible())
 476                         LOG_INFO("JTAG and SWD modes enabled");
 477                 else
 478                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 479         } else if (imx_gpio_swd_mode_possible()) {
 480                 LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
 481         } else {
 482                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
 483                 return ERROR_JTAG_INIT_FAILED;
 484         }
 485
 486         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 487         if (dev_mem_fd < 0) {
 488                 perror("open");
 489                 return ERROR_JTAG_INIT_FAILED;
 490         }
 491
 492
 493         LOG_INFO("imx_gpio mmap: pagesize: %u, regionsize: %u",
 494                         (unsigned int) sysconf(_SC_PAGE_SIZE), IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE);
 495         pio_base = mmap(NULL, IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE,
 496                                 PROT_READ | PROT_WRITE,
 497                                 MAP_SHARED, dev_mem_fd, imx_gpio_peri_base);
 498
 499         if (pio_base == MAP_FAILED) {
 500                 perror("mmap");
 501                 close(dev_mem_fd);
 502                 return ERROR_JTAG_INIT_FAILED;
 503         }
 504
 505         /*
 506          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 507          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 508          */
 509         if (imx_gpio_jtag_mode_possible()) {
 510                 tdo_gpio_mode = gpio_mode_get(tdo_gpio);
 511                 tdi_gpio_mode = gpio_mode_get(tdi_gpio);
 512                 tck_gpio_mode = gpio_mode_get(tck_gpio);
 513                 tms_gpio_mode = gpio_mode_get(tms_gpio);
 514
 515                 gpio_clear(tdi_gpio);
 516                 gpio_clear(tck_gpio);
 517                 gpio_set(tms_gpio);
 518
 519                 gpio_mode_input_set(tdo_gpio);
 520                 gpio_mode_output_set(tdi_gpio);
 521                 gpio_mode_output_set(tck_gpio);
 522                 gpio_mode_output_set(tms_gpio);
 523         }
 524         if (imx_gpio_swd_mode_possible()) {
 525                 swclk_gpio_mode = gpio_mode_get(swclk_gpio);
 526                 swdio_gpio_mode = gpio_mode_get(swdio_gpio);
 527
 528                 gpio_clear(swdio_gpio);
 529                 gpio_clear(swclk_gpio);
 530                 gpio_mode_output_set(swclk_gpio);
 531                 gpio_mode_output_set(swdio_gpio);
 532         }
 533         if (trst_gpio != -1) {
 534                 trst_gpio_mode = gpio_mode_get(trst_gpio);
 535                 gpio_set(trst_gpio);
 536                 gpio_mode_output_set(trst_gpio);
 537         }
 538         if (srst_gpio != -1) {
 539                 srst_gpio_mode = gpio_mode_get(srst_gpio);
 540                 gpio_set(srst_gpio);
 541                 gpio_mode_output_set(srst_gpio);
 542         }
 543
 544         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 545                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 546                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 547
 548         if (swd_mode) {
 549                 imx_gpio_bitbang.write = imx_gpio_swd_write;
 550                 bitbang_switch_to_swd();
 551         }
 552
 553         return ERROR_OK;
 554 }
 555
 556 static int imx_gpio_quit(void)
 557 {
 558         if (imx_gpio_jtag_mode_possible()) {
 559                 gpio_mode_set(tdo_gpio, tdo_gpio_mode);
 560                 gpio_mode_set(tdi_gpio, tdi_gpio_mode);
 561                 gpio_mode_set(tck_gpio, tck_gpio_mode);
 562                 gpio_mode_set(tms_gpio, tms_gpio_mode);
 563         }
 564         if (imx_gpio_swd_mode_possible()) {
 565                 gpio_mode_set(swclk_gpio, swclk_gpio_mode);
 566                 gpio_mode_set(swdio_gpio, swdio_gpio_mode);
 567         }
 568         if (trst_gpio != -1)
 569                 gpio_mode_set(trst_gpio, trst_gpio_mode);
 570         if (srst_gpio != -1)
 571                 gpio_mode_set(srst_gpio, srst_gpio_mode);
 572
 573         return ERROR_OK;
 574 }