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Diffstat (limited to 'src/interface/bitbang.c')
| -rw-r--r-- | src/interface/bitbang.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/src/interface/bitbang.c b/src/interface/bitbang.c new file mode 100644 index 00000000..443e9aea --- /dev/null +++ b/src/interface/bitbang.c @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2011 Tomasz Boleslaw CEDRO <cederom@tlen.pl> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +/** @file Simple framework to bitbang the interface pins. + */ + +#include <helper/command.h> +#include <jtag/interface.h> +#include <interface/interface.h> +#include "bitbang.h" + +extern struct jtag_interface *jtag_interface; + +/*-----------------------------------------------------------------------*/ + +/* + * Infrastructure for Tcl interface to bitbang. + */ + +/** Bitbang framework allows operation on interface signals, operating on HEX + * values, to read and set their state. When only signal name is given then + * read operation is performed and value returned for given port mask defined + * by signal mask. Additional '=' parameter with following value with set this + * value to the port (again restricted by the signal mask). Therefore it is + * possible to set/get more than one bit/pin at once each with its own value. + * In addition label 'hi'/'set' equals value 0xFFFFFFFF, 'lo'/'clr' equals 0. + * Also note that read/write operation will affect selected port bits direction + * as reading values will switch masked bits to input while writing will make + * them outputs. This is also good way to change port behavior for some pins, + * but beware that reading output may not always bring expected results as it + * may impact device connected to that pin (i.e. Hi-Z input gives 1 undriven). + * This functionality brings new possibilities to script additional features. + */ +COMMAND_HANDLER(handle_bitbang_command) +{ + LOG_DEBUG("%s", __func__); + + if (!jtag_interface){ + LOG_ERROR("You need to setup interface first!"); + return ERROR_FAIL; + } + + if (!jtag_interface->bitbang){ + LOG_ERROR("This interface does not support bit-banging!"); + return ERROR_FAIL; + } + + if (CMD_ARGC < 1) { + LOG_ERROR("Bad syntax!"); + return ERROR_COMMAND_SYNTAX_ERROR; + } + + if (jtag_interface->signal==NULL){ + LOG_ERROR("No signals defined, see 'interface_signal' command for help."); + return ERROR_FAIL; + } + + static oocd_interface_signal_t *sig; + static unsigned int pn; + static int retval; + static char *mark, *signame, *sigval, pcmd[45]; + + // Iterate through list of command parameters + for (pn=0;pn<CMD_ARGC;pn++){ + // Make a local copy of parameter command to work on + if (!strncpy(pcmd, CMD_ARGV[pn], 45)){ + LOG_ERROR("Cannot copy parameter: %s", CMD_ARGV[pn]); + return ERROR_FAIL; + } + // Look for '=' mark to see if read or write will happen + mark=strnstr(pcmd, "=", 45); + if (!mark){ + // If no '=' was found then we read the signal value + // Check if specified signal exists + if (!(sig=oocd_interface_signal_find(pcmd))){ + LOG_ERROR("Unknown signal specified!"); + return ERROR_FAIL; + } + // Call the driver routine to do the actual signal read + retval=jtag_interface->bitbang(NULL, pcmd, 1, (int *)&sig->value); + if (retval!=ERROR_OK){ + LOG_ERROR("Unable to read signal: %s", pcmd); + return ERROR_FAIL; + } + } else { + // If '=' was found then we write specified value to the specified signal + // Get and verify the signal name first + signame=strtok(pcmd, "="); + sig=oocd_interface_signal_find(signame); + if (!sig){ + LOG_ERROR("Unknown signal specified!"); + return ERROR_FAIL; + } + // Then read the HEX value or hi (all bits one) / lo (all bits zero) + if (!(sigval=strtok(NULL, "="))){ + LOG_ERROR("No value specified! Use: hi, set, lo, clr, or HEX port value."); + return ERROR_COMMAND_SYNTAX_ERROR; + } + if (!strncmp(sigval, "hi", 2) || !strncmp(sigval, "set", 3)){ + sig->value=0xffffffff&sig->mask; + } else if (!strncmp(sigval, "lo", 2) || !strncmp(sigval, "clr", 3)){ + sig->value=0; + } else if (!sscanf(sigval, "%x", (unsigned int *)&sig->value)){ + LOG_ERROR("Bad value parameter specified (can be: hi, set, lo, clr, or direct HEX port value)"); + return ERROR_COMMAND_SYNTAX_ERROR; + } + retval=jtag_interface->bitbang(NULL, signame, 0, (int *)&sig->value); + if (retval!=ERROR_OK){ + LOG_ERROR("Unable to write signal: %s", signame); + return ERROR_FAIL; + } + } + command_print(CMD_CTX, "%s=0x%08X", sig->name, sig->value); + } + return ERROR_OK; +} + +static const struct command_registration bitbang_commands[] = { + { + .name = "bitbang", + .handler = handle_bitbang_command, + .mode = COMMAND_ANY, + .help = "Perform bit-bang operations on interface signals (mask!).", + .usage = "'signal_name' to read, 'signal_name'='port_hex_value' to write.", + }, + COMMAND_REGISTRATION_DONE +}; + +int bitbang_register_commands(struct command_context *ctx) +{ + return register_commands(ctx, NULL, bitbang_commands); +} |