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_set(trst_gpio) : gpio_clear(trst_gpio);
 164
 165         if (srst_gpio != -1)
 166                 srst ? gpio_set(srst_gpio) : gpio_clear(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_CTX,
 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_CTX, "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_CTX, "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_CTX, "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_CTX, "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_CTX, "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_CTX, "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_CTX,
 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_CTX, "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_CTX, "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         return ERROR_OK;
 326 }
 327
 328 COMMAND_HANDLER(imx_gpio_handle_peripheral_base)
 329 {
 330         if (CMD_ARGC == 1)
 331                 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], imx_gpio_peri_base);
 332         return ERROR_OK;
 333 }
 334
 335 static const struct command_registration imx_gpio_command_handlers[] = {
 336         {
 337                 .name = "imx_gpio_jtag_nums",
 338                 .handler = &imx_gpio_handle_jtag_gpionums,
 339                 .mode = COMMAND_CONFIG,
 340                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 341                 .usage = "(tck tms tdi tdo)* ",
 342         },
 343         {
 344                 .name = "imx_gpio_tck_num",
 345                 .handler = &imx_gpio_handle_jtag_gpionum_tck,
 346                 .mode = COMMAND_CONFIG,
 347                 .help = "gpio number for tck.",
 348         },
 349         {
 350                 .name = "imx_gpio_tms_num",
 351                 .handler = &imx_gpio_handle_jtag_gpionum_tms,
 352                 .mode = COMMAND_CONFIG,
 353                 .help = "gpio number for tms.",
 354         },
 355         {
 356                 .name = "imx_gpio_tdo_num",
 357                 .handler = &imx_gpio_handle_jtag_gpionum_tdo,
 358                 .mode = COMMAND_CONFIG,
 359                 .help = "gpio number for tdo.",
 360         },
 361         {
 362                 .name = "imx_gpio_tdi_num",
 363                 .handler = &imx_gpio_handle_jtag_gpionum_tdi,
 364                 .mode = COMMAND_CONFIG,
 365                 .help = "gpio number for tdi.",
 366         },
 367         {
 368                 .name = "imx_gpio_swd_nums",
 369                 .handler = &imx_gpio_handle_swd_gpionums,
 370                 .mode = COMMAND_CONFIG,
 371                 .help = "gpio numbers for swclk, swdio. (in that order)",
 372                 .usage = "(swclk swdio)* ",
 373         },
 374         {
 375                 .name = "imx_gpio_swclk_num",
 376                 .handler = &imx_gpio_handle_swd_gpionum_swclk,
 377                 .mode = COMMAND_CONFIG,
 378                 .help = "gpio number for swclk.",
 379         },
 380         {
 381                 .name = "imx_gpio_swdio_num",
 382                 .handler = &imx_gpio_handle_swd_gpionum_swdio,
 383                 .mode = COMMAND_CONFIG,
 384                 .help = "gpio number for swdio.",
 385         },
 386         {
 387                 .name = "imx_gpio_srst_num",
 388                 .handler = &imx_gpio_handle_jtag_gpionum_srst,
 389                 .mode = COMMAND_CONFIG,
 390                 .help = "gpio number for srst.",
 391         },
 392         {
 393                 .name = "imx_gpio_trst_num",
 394                 .handler = &imx_gpio_handle_jtag_gpionum_trst,
 395                 .mode = COMMAND_CONFIG,
 396                 .help = "gpio number for trst.",
 397         },
 398         {
 399                 .name = "imx_gpio_speed_coeffs",
 400                 .handler = &imx_gpio_handle_speed_coeffs,
 401                 .mode = COMMAND_CONFIG,
 402                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 403         },
 404         {
 405                 .name = "imx_gpio_peripheral_base",
 406                 .handler = &imx_gpio_handle_peripheral_base,
 407                 .mode = COMMAND_CONFIG,
 408                 .help = "peripheral base to access GPIOs (0x0209c000 for most IMX).",
 409         },
 410
 411         COMMAND_REGISTRATION_DONE
 412 };
 413
 414 static const char * const imx_gpio_transports[] = { "jtag", "swd", NULL };
 415
 416 struct jtag_interface imx_gpio_interface = {
 417         .name = "imx_gpio",
 418         .supported = DEBUG_CAP_TMS_SEQ,
 419         .execute_queue = bitbang_execute_queue,
 420         .transports = imx_gpio_transports,
 421         .swd = &bitbang_swd,
 422         .speed = imx_gpio_speed,
 423         .khz = imx_gpio_khz,
 424         .speed_div = imx_gpio_speed_div,
 425         .commands = imx_gpio_command_handlers,
 426         .init = imx_gpio_init,
 427         .quit = imx_gpio_quit,
 428 };
 429
 430 static bool imx_gpio_jtag_mode_possible(void)
 431 {
 432         if (!is_gpio_valid(tck_gpio))
 433                 return 0;
 434         if (!is_gpio_valid(tms_gpio))
 435                 return 0;
 436         if (!is_gpio_valid(tdi_gpio))
 437                 return 0;
 438         if (!is_gpio_valid(tdo_gpio))
 439                 return 0;
 440         return 1;
 441 }
 442
 443 static bool imx_gpio_swd_mode_possible(void)
 444 {
 445         if (!is_gpio_valid(swclk_gpio))
 446                 return 0;
 447         if (!is_gpio_valid(swdio_gpio))
 448                 return 0;
 449         return 1;
 450 }
 451
 452 static int imx_gpio_init(void)
 453 {
 454         bitbang_interface = &imx_gpio_bitbang;
 455
 456         LOG_INFO("imx_gpio GPIO JTAG/SWD bitbang driver");
 457
 458         if (imx_gpio_jtag_mode_possible()) {
 459                 if (imx_gpio_swd_mode_possible())
 460                         LOG_INFO("JTAG and SWD modes enabled");
 461                 else
 462                         LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
 463         } else if (imx_gpio_swd_mode_possible()) {
 464                 LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
 465         } else {
 466                 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
 467                 return ERROR_JTAG_INIT_FAILED;
 468         }
 469
 470         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 471         if (dev_mem_fd < 0) {
 472                 perror("open");
 473                 return ERROR_JTAG_INIT_FAILED;
 474         }
 475
 476
 477         LOG_INFO("imx_gpio mmap: pagesize: %u, regionsize: %u",
 478                         (unsigned int) sysconf(_SC_PAGE_SIZE), IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE);
 479         pio_base = mmap(NULL, IMX_GPIO_REGS_COUNT * IMX_GPIO_SIZE,
 480                                 PROT_READ | PROT_WRITE,
 481                                 MAP_SHARED, dev_mem_fd, imx_gpio_peri_base);
 482
 483         if (pio_base == MAP_FAILED) {
 484                 perror("mmap");
 485                 close(dev_mem_fd);
 486                 return ERROR_JTAG_INIT_FAILED;
 487         }
 488
 489         /*
 490          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 491          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 492          */
 493         if (imx_gpio_jtag_mode_possible()) {
 494                 tdo_gpio_mode = gpio_mode_get(tdo_gpio);
 495                 tdi_gpio_mode = gpio_mode_get(tdi_gpio);
 496                 tck_gpio_mode = gpio_mode_get(tck_gpio);
 497                 tms_gpio_mode = gpio_mode_get(tms_gpio);
 498
 499                 gpio_clear(tdi_gpio);
 500                 gpio_clear(tck_gpio);
 501                 gpio_set(tms_gpio);
 502
 503                 gpio_mode_input_set(tdo_gpio);
 504                 gpio_mode_output_set(tdi_gpio);
 505                 gpio_mode_output_set(tck_gpio);
 506                 gpio_mode_output_set(tms_gpio);
 507         }
 508         if (imx_gpio_swd_mode_possible()) {
 509                 swclk_gpio_mode = gpio_mode_get(swclk_gpio);
 510                 swdio_gpio_mode = gpio_mode_get(swdio_gpio);
 511
 512                 gpio_clear(swdio_gpio);
 513                 gpio_clear(swclk_gpio);
 514                 gpio_mode_output_set(swclk_gpio);
 515                 gpio_mode_output_set(swdio_gpio);
 516         }
 517         if (trst_gpio != -1) {
 518                 trst_gpio_mode = gpio_mode_get(trst_gpio);
 519                 gpio_set(trst_gpio);
 520                 gpio_mode_output_set(trst_gpio);
 521         }
 522         if (srst_gpio != -1) {
 523                 srst_gpio_mode = gpio_mode_get(srst_gpio);
 524                 gpio_set(srst_gpio);
 525                 gpio_mode_output_set(srst_gpio);
 526         }
 527
 528         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 529                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 530                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 531
 532         if (swd_mode) {
 533                 imx_gpio_bitbang.write = imx_gpio_swd_write;
 534                 bitbang_switch_to_swd();
 535         }
 536
 537         return ERROR_OK;
 538 }
 539
 540 static int imx_gpio_quit(void)
 541 {
 542         if (imx_gpio_jtag_mode_possible()) {
 543                 gpio_mode_set(tdo_gpio, tdo_gpio_mode);
 544                 gpio_mode_set(tdi_gpio, tdi_gpio_mode);
 545                 gpio_mode_set(tck_gpio, tck_gpio_mode);
 546                 gpio_mode_set(tms_gpio, tms_gpio_mode);
 547         }
 548         if (imx_gpio_swd_mode_possible()) {
 549                 gpio_mode_set(swclk_gpio, swclk_gpio_mode);
 550                 gpio_mode_set(swdio_gpio, swdio_gpio_mode);
 551         }
 552         if (trst_gpio != -1)
 553                 gpio_mode_set(trst_gpio, trst_gpio_mode);
 554         if (srst_gpio != -1)
 555                 gpio_mode_set(srst_gpio, srst_gpio_mode);
 556
 557         return ERROR_OK;
 558 }