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 #define BCM2835_PADS_GPIO_0_27          (BCM2835_PERI_BASE + 0x100000)
  37 #define BCM2835_PADS_GPIO_0_27_OFFSET   (0x2c / 4)
  38
  39 /* GPIO setup macros */
  40 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
  41 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
  42 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
  43                 INP_GPIO(g);                                            \
  44                 *(pio_base+((g)/10)) |=  ((m)<<(((g)%10)*3)); } while (0)
  45 #define OUT_GPIO(g) SET_MODE_GPIO(g, 1)
  46
  47 #define GPIO_SET (*(pio_base+7))  /* sets   bits which are 1, ignores bits which are 0 */
  48 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
  49 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
  50
  51 static int dev_mem_fd;
  52 static volatile uint32_t *pio_base;
  53
  54 static int bcm2835gpio_read(void);
  55 static void bcm2835gpio_write(int tck, int tms, int tdi);
  56 static void bcm2835gpio_reset(int trst, int srst);
  57
  58 static int bcm2835gpio_init(void);
  59 static int bcm2835gpio_quit(void);
  60
  61 static struct bitbang_interface bcm2835gpio_bitbang = {
  62         .read = bcm2835gpio_read,
  63         .write = bcm2835gpio_write,
  64         .reset = bcm2835gpio_reset,
  65         .blink = NULL
  66 };
  67
  68 /* GPIO numbers for each signal. Negative values are invalid */
  69 static int tck_gpio = -1;
  70 static int tck_gpio_mode;
  71 static int tms_gpio = -1;
  72 static int tms_gpio_mode;
  73 static int tdi_gpio = -1;
  74 static int tdi_gpio_mode;
  75 static int tdo_gpio = -1;
  76 static int tdo_gpio_mode;
  77 static int trst_gpio = -1;
  78 static int trst_gpio_mode;
  79 static int srst_gpio = -1;
  80 static int srst_gpio_mode;
  81
  82 /* Transition delay coefficients */
  83 static int speed_coeff = 113714;
  84 static int speed_offset = 28;
  85 static unsigned int jtag_delay;
  86
  87 static int bcm2835gpio_read(void)
  88 {
  89         return !!(GPIO_LEV & 1<<tdo_gpio);
  90 }
  91
  92 static void bcm2835gpio_write(int tck, int tms, int tdi)
  93 {
  94         uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
  95         uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
  96
  97         GPIO_SET = set;
  98         GPIO_CLR = clear;
  99
 100         for (unsigned int i = 0; i < jtag_delay; i++)
 101                 asm volatile ("");
 102 }
 103
 104 /* (1) assert or (0) deassert reset lines */
 105 static void bcm2835gpio_reset(int trst, int srst)
 106 {
 107         uint32_t set = 0;
 108         uint32_t clear = 0;
 109
 110         if (trst_gpio > 0) {
 111                 set |= !trst<<trst_gpio;
 112                 clear |= trst<<trst_gpio;
 113         }
 114
 115         if (srst_gpio > 0) {
 116                 set |= !srst<<srst_gpio;
 117                 clear |= srst<<srst_gpio;
 118         }
 119
 120         GPIO_SET = set;
 121         GPIO_CLR = clear;
 122 }
 123
 124 static int bcm2835gpio_khz(int khz, int *jtag_speed)
 125 {
 126         if (!khz) {
 127                 LOG_DEBUG("RCLK not supported");
 128                 return ERROR_FAIL;
 129         }
 130         *jtag_speed = speed_coeff/khz - speed_offset;
 131         if (*jtag_speed < 0)
 132                 *jtag_speed = 0;
 133         return ERROR_OK;
 134 }
 135
 136 static int bcm2835gpio_speed_div(int speed, int *khz)
 137 {
 138         *khz = speed_coeff/(speed + speed_offset);
 139         return ERROR_OK;
 140 }
 141
 142 static int bcm2835gpio_speed(int speed)
 143 {
 144         jtag_delay = speed;
 145         return ERROR_OK;
 146 }
 147
 148 static int is_gpio_valid(int gpio)
 149 {
 150         return gpio >= 0 && gpio <= 53;
 151 }
 152
 153 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
 154 {
 155         if (CMD_ARGC == 4) {
 156                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 157                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio);
 158                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio);
 159                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio);
 160         } else if (CMD_ARGC != 0) {
 161                 return ERROR_COMMAND_SYNTAX_ERROR;
 162         }
 163
 164         command_print(CMD_CTX,
 165                         "BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdi = %d",
 166                         tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
 167
 168         return ERROR_OK;
 169 }
 170
 171 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tck)
 172 {
 173         if (CMD_ARGC == 1)
 174                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
 175
 176         command_print(CMD_CTX, "BCM2835 GPIO config: tck = %d", tck_gpio);
 177         return ERROR_OK;
 178 }
 179
 180 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tms)
 181 {
 182         if (CMD_ARGC == 1)
 183                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
 184
 185         command_print(CMD_CTX, "BCM2835 GPIO config: tms = %d", tms_gpio);
 186         return ERROR_OK;
 187 }
 188
 189 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdo)
 190 {
 191         if (CMD_ARGC == 1)
 192                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
 193
 194         command_print(CMD_CTX, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
 195         return ERROR_OK;
 196 }
 197
 198 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_tdi)
 199 {
 200         if (CMD_ARGC == 1)
 201                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
 202
 203         command_print(CMD_CTX, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
 204         return ERROR_OK;
 205 }
 206
 207 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_srst)
 208 {
 209         if (CMD_ARGC == 1)
 210                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
 211
 212         command_print(CMD_CTX, "BCM2835 GPIO config: srst = %d", srst_gpio);
 213         return ERROR_OK;
 214 }
 215
 216 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionum_trst)
 217 {
 218         if (CMD_ARGC == 1)
 219                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
 220
 221         command_print(CMD_CTX, "BCM2835 GPIO config: trst = %d", trst_gpio);
 222         return ERROR_OK;
 223 }
 224
 225 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
 226 {
 227         if (CMD_ARGC == 2) {
 228                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
 229                 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
 230         }
 231         return ERROR_OK;
 232 }
 233
 234 static const struct command_registration bcm2835gpio_command_handlers[] = {
 235         {
 236                 .name = "bcm2835gpio_jtag_nums",
 237                 .handler = &bcm2835gpio_handle_jtag_gpionums,
 238                 .mode = COMMAND_CONFIG,
 239                 .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
 240                 .usage = "(tck tms tdi tdo)* ",
 241         },
 242         {
 243                 .name = "bcm2835gpio_tck_num",
 244                 .handler = &bcm2835gpio_handle_jtag_gpionum_tck,
 245                 .mode = COMMAND_CONFIG,
 246                 .help = "gpio number for tck.",
 247         },
 248         {
 249                 .name = "bcm2835gpio_tms_num",
 250                 .handler = &bcm2835gpio_handle_jtag_gpionum_tms,
 251                 .mode = COMMAND_CONFIG,
 252                 .help = "gpio number for tms.",
 253         },
 254         {
 255                 .name = "bcm2835gpio_tdo_num",
 256                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
 257                 .mode = COMMAND_CONFIG,
 258                 .help = "gpio number for tdo.",
 259         },
 260         {
 261                 .name = "bcm2835gpio_tdi_num",
 262                 .handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
 263                 .mode = COMMAND_CONFIG,
 264                 .help = "gpio number for tdi.",
 265         },
 266         {
 267                 .name = "bcm2835gpio_srst_num",
 268                 .handler = &bcm2835gpio_handle_jtag_gpionum_srst,
 269                 .mode = COMMAND_CONFIG,
 270                 .help = "gpio number for srst.",
 271         },
 272         {
 273                 .name = "bcm2835gpio_trst_num",
 274                 .handler = &bcm2835gpio_handle_jtag_gpionum_trst,
 275                 .mode = COMMAND_CONFIG,
 276                 .help = "gpio number for trst.",
 277         },
 278         {
 279                 .name = "bcm2835gpio_speed_coeffs",
 280                 .handler = &bcm2835gpio_handle_speed_coeffs,
 281                 .mode = COMMAND_CONFIG,
 282                 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
 283         },
 284         COMMAND_REGISTRATION_DONE
 285 };
 286
 287 struct jtag_interface bcm2835gpio_interface = {
 288         .name = "bcm2835gpio",
 289         .supported = DEBUG_CAP_TMS_SEQ,
 290         .execute_queue = bitbang_execute_queue,
 291         .transports = jtag_only,
 292         .speed = bcm2835gpio_speed,
 293         .khz = bcm2835gpio_khz,
 294         .speed_div = bcm2835gpio_speed_div,
 295         .commands = bcm2835gpio_command_handlers,
 296         .init = bcm2835gpio_init,
 297         .quit = bcm2835gpio_quit,
 298 };
 299
 300 static int bcm2835gpio_init(void)
 301 {
 302         bitbang_interface = &bcm2835gpio_bitbang;
 303
 304         if (!is_gpio_valid(tdo_gpio) || !is_gpio_valid(tdi_gpio) ||
 305                 !is_gpio_valid(tck_gpio) || !is_gpio_valid(tms_gpio) ||
 306                 (trst_gpio != -1 && !is_gpio_valid(trst_gpio)) ||
 307                 (srst_gpio != -1 && !is_gpio_valid(srst_gpio)))
 308                 return ERROR_JTAG_INIT_FAILED;
 309
 310         dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
 311         if (dev_mem_fd < 0) {
 312                 perror("open");
 313                 return ERROR_JTAG_INIT_FAILED;
 314         }
 315
 316         pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 317                                 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
 318
 319         if (pio_base == MAP_FAILED) {
 320                 perror("mmap");
 321                 close(dev_mem_fd);
 322                 return ERROR_JTAG_INIT_FAILED;
 323         }
 324
 325         static volatile uint32_t *pads_base;
 326         pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
 327                                 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
 328
 329         if (pads_base == MAP_FAILED) {
 330                 perror("mmap");
 331                 close(dev_mem_fd);
 332                 return ERROR_JTAG_INIT_FAILED;
 333         }
 334
 335         /* set 16mA drive strength */
 336         pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000018 + 7;
 337
 338         tdo_gpio_mode = MODE_GPIO(tdo_gpio);
 339         tdi_gpio_mode = MODE_GPIO(tdi_gpio);
 340         tck_gpio_mode = MODE_GPIO(tck_gpio);
 341         tms_gpio_mode = MODE_GPIO(tms_gpio);
 342         /*
 343          * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
 344          * as outputs.  Drive TDI and TCK low, and TMS/TRST/SRST high.
 345          */
 346         INP_GPIO(tdo_gpio);
 347
 348         GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio;
 349         GPIO_SET = 1<<tms_gpio;
 350
 351         OUT_GPIO(tdi_gpio);
 352         OUT_GPIO(tck_gpio);
 353         OUT_GPIO(tms_gpio);
 354         if (trst_gpio != -1) {
 355                 trst_gpio_mode = MODE_GPIO(trst_gpio);
 356                 GPIO_SET = 1 << trst_gpio;
 357                 OUT_GPIO(trst_gpio);
 358         }
 359         if (srst_gpio != -1) {
 360                 srst_gpio_mode = MODE_GPIO(srst_gpio);
 361                 GPIO_SET = 1 << srst_gpio;
 362                 OUT_GPIO(srst_gpio);
 363         }
 364
 365         LOG_DEBUG("saved pinmux settings: tck %d tms %d tdi %d "
 366                   "tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
 367                   tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
 368
 369         return ERROR_OK;
 370 }
 371
 372 static int bcm2835gpio_quit(void)
 373 {
 374         SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
 375         SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
 376         SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
 377         SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
 378         if (trst_gpio != -1)
 379                 SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
 380         if (srst_gpio != -1)
 381                 SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
 382
 383         return ERROR_OK;
 384 }