We overclock JTAG router

 /** * @file * This driver implements a bitbang jtag interface using gpio lines via * router ob BCM63XX SoC. * The aim of this driver implementation is use system GPIOs but avoid the * need for a additional kernel driver. * (Note memory mapped IO is another option, however it doesn't mix well with * the kernel gpiolib driver - which makes sense I guess.) * * A gpio is required for tck, tms, tdi and tdo. One or both of srst and trst * must be also be specified. The required jtag gpios are specified via the * bcm63xx_gpio_jtag_nums command or the relevant bcm63xx_gpio_XXX_num commang. * The srst and trst gpios are set via the bcm63xx_gpio_srst_num and * bcm63xx_gpio_trst_num respectively. GPIO numbering follows the kernel * convention of starting from 0. * * The gpios should not be in use by another entity, and must not be requested * by a kernel driver without also being exported by it (otherwise they can't * be exported by bcm63xx_). * * The bcm63xx gpio interface can only manipulate one gpio at a time, so the * bitbang write handler remembers the last state for tck, tms, tdi to avoid * superfluous writes. * For speed the bcm63xx "value" entry is opened at init and held open. * This results in considerable gains over open-write-close (45s vs 900s) * * Further work could address: * -srst and trst open drain/ push pull * -configurable active high/low for srst & trst */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <jtag/interface.h> #include "bitbang.h" #include <sys/mman.h> /* * Helper func to determine if gpio number valid * * Assume here that there will be less than 1000 gpios on a system */ static int is_gpio_valid(int gpio) { return gpio >= 0 && gpio < 32; } off_t address_dir = NULL; off_t address_val = NULL; static int dev_mem_fd = -1; static volatile uint32_t *pio_base = NULL; static volatile uint32_t *pval_base = NULL; static volatile uint32_t *pads_base = NULL; static unsigned int jtag_delay = 0; static void set_dir_gpio(const int gpio, const int direction) { if(direction) *pio_base |= 1 << gpio; else *pio_base &= ~(1 << gpio); } static void set_value_gpio(const int gpio, const int value) { if(value) *pval_base |= 1 << gpio; else *pval_base &= ~(1 << gpio); for (unsigned int i = 0; i < jtag_delay; i++) asm volatile (""); } static int read_gpio(const int gpio) { uint32_t val = *pval_base & (1 << gpio); val = val ? 1 : 0; return val; } static int setup_bcm63xx_gpio(int gpio, int is_output, int init_high) { char buf[40]; char gpiostr[4]; int ret; if (!is_gpio_valid(gpio)) return ERROR_OK; if((address_dir == NULL) || (address_val == NULL)){ perror("address of gpio register don't set"); return ERROR_FAIL; } if( dev_mem_fd < 0 ) { dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC); if (dev_mem_fd < 0) { perror("open"); return ERROR_FAIL; } const uint32_t mapped_size = getpagesize(); const off_t target_mmap = address_dir & ~(off_t)(mapped_size - 1); pads_base = mmap(NULL, mapped_size, PROT_READ | PROT_WRITE, MAP_SHARED, dev_mem_fd, target_mmap); if (pads_base == MAP_FAILED) { perror("mmap. Check correct register address."); close(dev_mem_fd); return ERROR_FAIL; } pio_base = (char*)pads_base + (unsigned)(address_dir - target_mmap); pval_base = (char*)pads_base + (unsigned)(address_val - target_mmap); } set_dir_gpio(gpio, is_output); set_value_gpio(gpio, init_high); return 0; } /* gpio numbers for each gpio. Negative values are invalid */ static int tck_gpio = -1; static int tms_gpio = -1; static int tdi_gpio = -1; static int tdo_gpio = -1; static int trst_gpio = -1; static int srst_gpio = -1; static int swclk_gpio = -1; static int swdio_gpio = -1; /* * file descriptors for /sys/class/gpio/gpioXX/value * Set up during init. */ static int tck_fd = -1; static int tms_fd = -1; static int tdi_fd = -1; static int tdo_fd = -1; static int trst_fd = -1; static int srst_fd = -1; static int swclk_fd = -1; static int swdio_fd = -1; static int last_swclk; static int last_swdio; static bool last_stored; static bool swdio_input; static void bcm63xx_gpio_swdio_drive(bool is_output) { set_dir_gpio(swdio_gpio, is_output ? 1 : 0); last_stored = false; swdio_input = !is_output; } static int bcm63xx_gpio_swdio_read(void) { return read_gpio(swdio_gpio); } static void bcm63xx_gpio_swdio_write(int swclk, int swdio) { const char one[] = "1"; const char zero[] = "0"; size_t bytes_written; if (!swdio_input) { if (!last_stored || (swdio != last_swdio)) { set_value_gpio(swdio_gpio, swdio ? 1 : 0); } } /* write swclk last */ if (!last_stored || (swclk != last_swclk)) { set_value_gpio(swclk_gpio, swclk ? 1 : 0); } last_swdio = swdio; last_swclk = swclk; last_stored = true; } /* * Bitbang interface read of TDO * * The bcm63xx value will read back either '0' or '1'. The trick here is to call * lseek to bypass buffering in the bcm63xx kernel driver. */ static int bcm63xx_gpio_read(void) { return read_gpio(tdo_gpio); } /* * Bitbang interface write of TCK, TMS, TDI * * Seeing as this is the only function where the outputs are changed, * we can cache the old value to avoid needlessly writing it. */ static void bcm63xx_gpio_write(int tck, int tms, int tdi) { if (swd_mode) { bcm63xx_gpio_swdio_write(tck, tdi); return; } const char one[] = "1"; const char zero[] = "0"; static int last_tck; static int last_tms; static int last_tdi; static int first_time; size_t bytes_written; if (!first_time) { last_tck = !tck; last_tms = !tms; last_tdi = !tdi; first_time = 1; } if (tdi != last_tdi) { set_value_gpio(tdi_gpio,tdi); } if (tms != last_tms) { set_value_gpio(tms_gpio,tms); } /* write clk last */ if (tck != last_tck) { set_value_gpio(tck_gpio,tck); } last_tdi = tdi; last_tms = tms; last_tck = tck; } /* * Bitbang interface to manipulate reset lines SRST and TRST * * (1) assert or (0) deassert reset lines */ static void bcm63xx_gpio_reset(int trst, int srst) { LOG_DEBUG("bcm63xx_gpio_reset"); const char one[] = "1"; const char zero[] = "0"; size_t bytes_written; /* assume active low */ if (srst_fd >= 0) { set_value_gpio(srst_gpio,srst); } /* assume active low */ if (trst_fd >= 0) { set_value_gpio(trst_gpio,trst); } } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionums) { if (CMD_ARGC == 4) { COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio); COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tms_gpio); COMMAND_PARSE_NUMBER(int, CMD_ARGV[2], tdi_gpio); COMMAND_PARSE_NUMBER(int, CMD_ARGV[3], tdo_gpio); } else if (CMD_ARGC != 0) { return ERROR_COMMAND_SYNTAX_ERROR; } command_print(CMD_CTX, "bcm63xx_GPIO nums: tck = %d, tms = %d, tdi = %d, tdo = %d", tck_gpio, tms_gpio, tdi_gpio, tdo_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_tck) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: tck = %d", tck_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_tms) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: tms = %d", tms_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_tdo) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: tdo = %d", tdo_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_tdi) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: tdi = %d", tdi_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_srst) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: srst = %d", srst_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_jtag_gpionum_trst) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: trst = %d", trst_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_swd_gpionums) { if (CMD_ARGC == 2) { COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio); COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], swdio_gpio); } else if (CMD_ARGC != 0) { return ERROR_COMMAND_SYNTAX_ERROR; } command_print(CMD_CTX, "bcm63xx_GPIO nums: swclk = %d, swdio = %d", swclk_gpio, swdio_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_swd_gpionum_swclk) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: swclk = %d", swclk_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_handle_swd_gpionum_swdio) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio); command_print(CMD_CTX, "bcm63xx_GPIO num: swdio = %d", swdio_gpio); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_jtag_delay) { if (CMD_ARGC == 1) COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], jtag_delay); command_print(CMD_CTX, "bcm63xx_GPIO jtag_delay:= %d tics", jtag_delay); return ERROR_OK; } COMMAND_HANDLER(bcm63xx_gpio_adresses) { if (CMD_ARGC == 2) { COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], address_dir); COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], address_val); } else if (CMD_ARGC != 0) { return ERROR_COMMAND_SYNTAX_ERROR; } command_print(CMD_CTX, "bcm63xx_GPIO address: direction = %x, value = %x", address_dir, address_val); return ERROR_OK; } static const struct command_registration bcm63xx_gpio_command_handlers[] = { { .name = "bcm63xx_gpio_jtag_nums", .handler = &bcm63xx_gpio_handle_jtag_gpionums, .mode = COMMAND_CONFIG, .help = "gpio numbers for tck, tms, tdi, tdo. (in that order)", .usage = "(tck tms tdi tdo)* ", }, { .name = "bcm63xx_gpio_tck_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_tck, .mode = COMMAND_CONFIG, .help = "gpio number for tck.", }, { .name = "bcm63xx_gpio_tms_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_tms, .mode = COMMAND_CONFIG, .help = "gpio number for tms.", }, { .name = "bcm63xx_gpio_tdo_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_tdo, .mode = COMMAND_CONFIG, .help = "gpio number for tdo.", }, { .name = "bcm63xx_gpio_tdi_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_tdi, .mode = COMMAND_CONFIG, .help = "gpio number for tdi.", }, { .name = "bcm63xx_gpio_srst_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_srst, .mode = COMMAND_CONFIG, .help = "gpio number for srst.", }, { .name = "bcm63xx_gpio_trst_num", .handler = &bcm63xx_gpio_handle_jtag_gpionum_trst, .mode = COMMAND_CONFIG, .help = "gpio number for trst.", }, { .name = "bcm63xx_gpio_swd_nums", .handler = &bcm63xx_gpio_handle_swd_gpionums, .mode = COMMAND_CONFIG, .help = "gpio numbers for swclk, swdio. (in that order)", .usage = "(swclk swdio)* ", }, { .name = "bcm63xx_gpio_swclk_num", .handler = &bcm63xx_gpio_handle_swd_gpionum_swclk, .mode = COMMAND_CONFIG, .help = "gpio number for swclk.", }, { .name = "bcm63xx_gpio_swdio_num", .handler = &bcm63xx_gpio_handle_swd_gpionum_swdio, .mode = COMMAND_CONFIG, .help = "gpio number for swdio.", }, { .name = "bcm63xx_gpio_jtag_delay", .handler = &bcm63xx_gpio_jtag_delay, .mode = COMMAND_CONFIG, .help = "qty tics gpio delay.", }, { .name = "bcm63xx_gpio_adresses", .handler = &bcm63xx_gpio_adresses, .mode = COMMAND_CONFIG, .help = "addresses for direction and value setup. (in that order)", .usage = "(address_dir address_val)* ", }, COMMAND_REGISTRATION_DONE }; static int bcm63xx_gpio_init(void); static int bcm63xx_gpio_quit(void); static const char * const bcm63xx_gpio_transports[] = { "jtag", "swd", NULL }; struct jtag_interface bcm63xxgpio_interface = { .name = "bcm63xxgpio", .supported = DEBUG_CAP_TMS_SEQ, .execute_queue = bitbang_execute_queue, .transports = bcm63xx_gpio_transports, .swd = &bitbang_swd, .commands = bcm63xx_gpio_command_handlers, .init = bcm63xx_gpio_init, .quit = bcm63xx_gpio_quit, }; static struct bitbang_interface bcm63xx_gpio_bitbang = { .read = bcm63xx_gpio_read, .write = bcm63xx_gpio_write, .reset = bcm63xx_gpio_reset, .swdio_read = bcm63xx_gpio_swdio_read, .swdio_drive = bcm63xx_gpio_swdio_drive, .blink = 0 }; static void unusing_all_gpio(void) { munmap(pads_base, sysconf(_SC_PAGE_SIZE)); close(dev_mem_fd); LOG_INFO("unusing_all_gpio\n"); } static bool bcm63xx_gpio_jtag_mode_possible(void) { if (!is_gpio_valid(tck_gpio)) return 0; if (!is_gpio_valid(tms_gpio)) return 0; if (!is_gpio_valid(tdi_gpio)) return 0; if (!is_gpio_valid(tdo_gpio)) return 0; return 1; } static bool bcm63xx_gpio_swd_mode_possible(void) { if (!is_gpio_valid(swclk_gpio)) return 0; if (!is_gpio_valid(swdio_gpio)) return 0; return 1; } static int bcm63xx_gpio_init(void) { bitbang_interface = &bcm63xx_gpio_bitbang; LOG_INFO("bcm63xx_gpio JTAG/SWD bitbang driver"); if (bcm63xx_gpio_jtag_mode_possible()) { if (bcm63xx_gpio_swd_mode_possible()) LOG_INFO("JTAG and SWD modes enabled"); else LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)"); if (!is_gpio_valid(trst_gpio) && !is_gpio_valid(srst_gpio)) { LOG_ERROR("Require at least one of trst or srst gpios to be specified"); return ERROR_JTAG_INIT_FAILED; } } else if (bcm63xx_gpio_swd_mode_possible()) { LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)"); } else { LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode"); return ERROR_JTAG_INIT_FAILED; } /* * Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST * as outputs. Drive TDI and TCK low, and TMS/TRST/SRST high. * For SWD, SWCLK and SWDIO are configures as output high. */ if (tck_gpio >= 0) { tck_fd = setup_bcm63xx_gpio(tck_gpio, 1, 0); if (tck_fd < 0) goto out_error; } if (tms_gpio >= 0) { tms_fd = setup_bcm63xx_gpio(tms_gpio, 1, 1); if (tms_fd < 0) goto out_error; } if (tdi_gpio >= 0) { tdi_fd = setup_bcm63xx_gpio(tdi_gpio, 1, 0); if (tdi_fd < 0) goto out_error; } if (tdo_gpio >= 0) { tdo_fd = setup_bcm63xx_gpio(tdo_gpio, 0, 0); if (tdo_fd < 0) goto out_error; } /* assume active low*/ if (trst_gpio >= 0) { trst_fd = setup_bcm63xx_gpio(trst_gpio, 1, 1); if (trst_fd < 0) goto out_error; } /* assume active low*/ if (srst_gpio >= 0) { srst_fd = setup_bcm63xx_gpio(srst_gpio, 1, 1); if (srst_fd < 0) goto out_error; } if (swclk_gpio >= 0) { swclk_fd = setup_bcm63xx_gpio(swclk_gpio, 1, 0); if (swclk_fd < 0) goto out_error; } if (swdio_gpio >= 0) { swdio_fd = setup_bcm63xx_gpio(swdio_gpio, 1, 0); if (swdio_fd < 0) goto out_error; } if (bcm63xx_gpio_swd_mode_possible()) { if (swd_mode) bitbang_swd_switch_seq(JTAG_TO_SWD); else bitbang_swd_switch_seq(SWD_TO_JTAG); } return ERROR_OK; out_error: unusing_all_gpio(); return ERROR_JTAG_INIT_FAILED; } static int bcm63xx_gpio_quit(void) { unusing_all_gpio(); return ERROR_OK; }