src/jtag/drivers/bcm2835gpio.c

   1 /***************************************************************************
   2  *   Copyright (C) 2013 by Paul Fertser, fercerpav@gmail.com               *
   3  *                                                                         *
   4  *   Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
   5  *   Based on at91rm9200.c (c) Anders Larsen                               *
   6  *   and RPi GPIO examples by Gert van Loo & Dom                           *
   7  *                                                                         *
   8  *   This program is free software; you can redistribute it and/or modify  *
   9  *   it under the terms of the GNU General Public License as published by  *
  10  *   the Free Software Foundation; either version 2 of the License, or     *
  11  *   (at your option) any later version.                                   *
  12  *                                                                         *
  13  *   This program is distributed in the hope that it will be useful,       *
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  16  *   GNU General Public License for more details.                          *
  17  *                                                                         *
  18  *   You should have received a copy of the GNU General Public License     *
  19  *   along with this program; if not, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  22  ***************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <jtag/interface.h>
  29 #include "bitbang.h"
  30
  31 #include <sys/mman.h>
  32
  33 #define BCM2835_PERI_BASE       0x20000000
  34 #define BCM2835_GPIO_BASE       (BCM2835_PERI_BASE + 0x200000) /* GPIO controller */
  35
  36 /* GPIO setup macros */
  37 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  38 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  39 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  40                 INP_GPIO(g);                                            \
  41                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  42 #define OUT_GPIO(g) SET_MODE_GPIO(g, 1)
  43
  44 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  45 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  46 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  47
  48 static int dev_mem_fd;
  49 static volatile uint32_t *pio_base;
  50
  51 static int bcm2835gpio_read(void);
  52 static void bcm2835gpio_write(int tck, int tms, int tdi);
  53 static void bcm2835gpio_reset(int trst, int srst);
  54
  55 static int bcm2835gpio_init(void);
  56 static int bcm2835gpio_quit(void);
  57
  58 static struct bitbang_interface bcm2835gpio_bitbang = {
  59         .read = bcm2835gpio_read,
  60         .write = bcm2835gpio_write,
  61         .reset = bcm2835gpio_reset,
  62         .blink = NULL
  63 };
  64
  65 /* GPIO numbers for each signal. Negative values are invalid */
  66 static int tck_gpio = -1;
  67 static int tck_gpio_mode;
  68 static int tms_gpio = -1;
  69 static int tms_gpio_mode;
  70 static int tdi_gpio = -1;
  71 static int tdi_gpio_mode;
  72 static int tdo_gpio = -1;
  73 static int tdo_gpio_mode;
  74 static int trst_gpio = -1;
  75 static int trst_gpio_mode;
  76 static int srst_gpio = -1;
  77 static int srst_gpio_mode;
  78
  79 /* Transition delay coefficients */
  80 static int speed_coeff = 113714;
  81 static int speed_offset = 28;
  82 static unsigned int jtag_delay;
  83
  84 static int bcm2835gpio_read(void)
  85 {
  86         return !!(GPIO_LEV & 1<<tdo_gpio);
  87 }
  88
  89 static void bcm2835gpio_write(int tck, int tms, int tdi)
  90 {
  91         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
  92         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
  93
  94         GPIO_SET = set;
  95         GPIO_CLR = clear;
  96
  97         for (unsigned int i = 0; i < jtag_delay; i++)
  98                 asm volatile ("");
  99 }
 100
 101 /* (1) assert or (0) deassert reset lines */
 102 static void bcm2835gpio_reset(int trst, int srst)
 103 {
 104         uint32_t set = 0;
 105         uint32_t clear = 0;
 106
 107         if (trst_gpio > 0) {
 108                 set |= !trst<<trst_gpio;
 109                 clear |= trst<<trst_gpio;
 110         }
 111
 112         if (srst_gpio > 0) {
 113                 set |= !srst<<srst_gpio;
 114                 clear |= srst<<srst_gpio;
 115         }
 116
 117         GPIO_SET = set;
 118         GPIO_CLR = clear;
 119 }
 120
 121 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 122 {
 123         if (!khz) {
 124                 LOG_DEBUG("RCLK not supported");
 125                 return ERROR_FAIL;
 126         }
 127         *jtag_speed = speed_coeff/khz - speed_offset;
 128         if (*jtag_speed < 0)
 129                 *jtag_speed = 0;
 130         return ERROR_OK;
 131 }
 132
 133 static int bcm2835gpio_speed_div(int speed, int *khz)
 134 {
 135         *khz = speed_coeff/(speed + speed_offset);
 136         return ERROR_OK;
 137 }
 138
 139 static int bcm2835gpio_speed(int speed)
 140 {
 141         jtag_delay = speed;
 142         return ERROR_OK;
 143 }
 144
 145 static int is_gpio_valid(int gpio)
 146 {
 147         return gpio >= 0 && gpio <= 53;
 148 }
 149
 150 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 151 {
 152         if (CMD_ARGC == 4) {
 153                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 154                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 155                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 156                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 157         } else if (CMD_ARGC != 0) {
 158                 return ERROR_COMMAND_SYNTAX_ERROR;
 159         }
 160
 161         command_print(CMD_CTX,
 162                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdi = %d",
 163                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 164
 165         return ERROR_OK;
 166 }
 167
 168 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 169 {
 170         if (CMD_ARGC == 1)
 171                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 172
 173         command_print(CMD_CTX, "BCM2835 GPIO config: tck = %d", tck_gpio);
 174         return ERROR_OK;
 175 }
 176
 177 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 178 {
 179         if (CMD_ARGC == 1)
 180                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 181
 182         command_print(CMD_CTX, "BCM2835 GPIO config: tms = %d", tms_gpio);
 183         return ERROR_OK;
 184 }
 185
 186 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 187 {
 188         if (CMD_ARGC == 1)
 189                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 190
 191         command_print(CMD_CTX, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 192         return ERROR_OK;
 193 }
 194
 195 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 196 {
 197         if (CMD_ARGC == 1)
 198                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 199
 200         command_print(CMD_CTX, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 201         return ERROR_OK;
 202 }
 203
 204 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 205 {
 206         if (CMD_ARGC == 1)
 207                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 208
 209         command_print(CMD_CTX, "BCM2835 GPIO config: srst = %d", srst_gpio);
 210         return ERROR_OK;
 211 }
 212
 213 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 214 {
 215         if (CMD_ARGC == 1)
 216                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 217
 218         command_print(CMD_CTX, "BCM2835 GPIO config: trst = %d", trst_gpio);
 219         return ERROR_OK;
 220 }
 221
 222 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 223 {
 224         if (CMD_ARGC == 2) {
 225                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 226                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 227         }
 228         return ERROR_OK;
 229 }
 230
 231 static const struct command_registration bcm2835gpio_command_handlers[] = {
 232         {
 233                 .name = "bcm2835gpio_jtag_nums",
 234                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 235                 .mode = COMMAND_CONFIG,
 236                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 237                 .usage = "(tck tms tdi tdo)* ",
 238         },
 239         {
 240                 .name = "bcm2835gpio_tck_num",
 241                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 242                 .mode = COMMAND_CONFIG,
 243                 .help = "gpio number for tck.",
 244         },
 245         {
 246                 .name = "bcm2835gpio_tms_num",
 247                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 248                 .mode = COMMAND_CONFIG,
 249                 .help = "gpio number for tms.",
 250         },
 251         {
 252                 .name = "bcm2835gpio_tdo_num",
 253                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 254                 .mode = COMMAND_CONFIG,
 255                 .help = "gpio number for tdo.",
 256         },
 257         {
 258                 .name = "bcm2835gpio_tdi_num",
 259                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 260                 .mode = COMMAND_CONFIG,
 261                 .help = "gpio number for tdi.",
 262         },
 263         {
 264                 .name = "bcm2835gpio_srst_num",
 265                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 266                 .mode = COMMAND_CONFIG,
 267                 .help = "gpio number for srst.",
 268         },
 269         {
 270                 .name = "bcm2835gpio_trst_num",
 271                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 272                 .mode = COMMAND_CONFIG,
 273                 .help = "gpio number for trst.",
 274         },
 275         {
 276                 .name = "bcm2835gpio_speed_coeffs",
 277                 .handler = &bcm2835gpio_handle_speed_coeffs,
 278                 .mode = COMMAND_CONFIG,
 279                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 280         },
 281         COMMAND_REGISTRATION_DONE
 282 };
 283
 284 struct jtag_interface bcm2835gpio_interface = {
 285         .name = "bcm2835gpio",
 286         .supported = DEBUG_CAP_TMS_SEQ,
 287         .execute_queue = bitbang_execute_queue,
 288         .transports = jtag_only,
 289         .speed = bcm2835gpio_speed,
 290         .khz = bcm2835gpio_khz,
 291         .speed_div = bcm2835gpio_speed_div,
 292         .commands = bcm2835gpio_command_handlers,
 293         .init = bcm2835gpio_init,
 294         .quit = bcm2835gpio_quit,
 295 };
 296
 297 static int bcm2835gpio_init(void)
 298 {
 299         bitbang_interface = &bcm2835gpio_bitbang;
 300
 301         if (!is_gpio_valid(tdo_gpio) || !is_gpio_valid(tdi_gpio) ||
 302                 !is_gpio_valid(tck_gpio) || !is_gpio_valid(tms_gpio) ||
 303                 (trst_gpio != -1 && !is_gpio_valid(trst_gpio)) ||
 304                 (srst_gpio != -1 && !is_gpio_valid(srst_gpio)))
 305                 return ERROR_JTAG_INIT_FAILED;
 306
 307         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 308         if (dev_mem_fd < 0) {
 309                 perror("open");
 310                 return ERROR_JTAG_INIT_FAILED;
 311         }
 312
 313         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 314                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 315
 316         if (pio_base == MAP_FAILED) {
 317                 perror("mmap");
 318                 close(dev_mem_fd);
 319                 return ERROR_JTAG_INIT_FAILED;
 320         }
 321
 322         tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 323         tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 324         tck_gpio_mode = MODE_GPIO(tck_gpio);
 325         tms_gpio_mode = MODE_GPIO(tms_gpio);
 326         /*
 327          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 328          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 329          */
 330         INP_GPIO(tdo_gpio);
 331
 332         GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio;
 333         GPIO_SET = 1<<tms_gpio;
 334
 335         OUT_GPIO(tdi_gpio);
 336         OUT_GPIO(tck_gpio);
 337         OUT_GPIO(tms_gpio);
 338         if (trst_gpio != -1) {
 339                 trst_gpio_mode = MODE_GPIO(trst_gpio);
 340                 GPIO_SET = 1 << trst_gpio;
 341                 OUT_GPIO(trst_gpio);
 342         }
 343         if (srst_gpio != -1) {
 344                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 345                 GPIO_SET = 1 << srst_gpio;
 346                 OUT_GPIO(srst_gpio);
 347         }
 348
 349         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 350                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 351                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 352
 353         return ERROR_OK;
 354 }
 355
 356 static int bcm2835gpio_quit(void)
 357 {
 358         SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 359         SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 360         SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 361         SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 362         if (trst_gpio != -1)
 363                 SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 364         if (srst_gpio != -1)
 365                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 366
 367         return ERROR_OK;
 368 }