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authorTomek CEDRO <cederom@tlen.pl>2011-06-16 08:13:07 +0000
committerTomek CEDRO <cederom@tlen.pl>2011-06-16 08:13:07 +0000
commit7f2221958dbc6bda0e51df87e80aa5a9c5140914 (patch)
tree81126d7063987659cac3878d1ada58d8f153f39e
parent37eeba8e0473b961b20c7a305a251515b241a34c (diff)
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FT2232_DRIVER: Added bitbang() implementation backend to drive signals on FT2*32 chip.
-rw-r--r--src/jtag/drivers/ft2232.c107
1 files changed, 104 insertions, 3 deletions
diff --git a/src/jtag/drivers/ft2232.c b/src/jtag/drivers/ft2232.c
index 38ead566..d16d4d6a 100644
--- a/src/jtag/drivers/ft2232.c
+++ b/src/jtag/drivers/ft2232.c
@@ -1,9 +1,9 @@
-/***************************************************************************
+/**************************************************************************
* Copyright (C) 2009 by Øyvind Harboe *
-* Øyvind Harboe <oyvind.harboe@zylin.com> *
+* Øyvind Harboe <oyvind.harboe@zylin.com> *
* *
* Copyright (C) 2009 by SoftPLC Corporation. http://softplc.com *
-* Dick Hollenbeck <dick@softplc.com> *
+* Dick Hollenbeck <dick@softplc.com> *
* *
* Copyright (C) 2004, 2006 by Dominic Rath *
* Dominic.Rath@gmx.de *
@@ -11,6 +11,9 @@
* Copyright (C) 2008 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
+* Copyright (C) 2011 Tomasz Boleslaw CEDRO *
+* cederom@tlen.pl, http://www.tomek.cedro.info *
+* *
* 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 *
@@ -81,6 +84,7 @@
/* project specific includes */
#include <jtag/interface.h>
+#include <interface/interface.h>
#include <transport/transport.h>
#include <helper/time_support.h>
@@ -594,6 +598,102 @@ static int ft2232_read(uint8_t* buf, uint32_t size, uint32_t* bytes_read)
return ERROR_OK;
}
+/** Generic IO BITBANG Port Manipulation Routine.
+ * It can read and write port state using signal names. Each interface have its
+ * own specific signal names and fields. This function works on those fields
+ * and based on their values talks to the FT*232 chip on the interface device.
+ * ft2232 drivers use {low,high}_{output,direction} global variables to remember
+ * port direction and value, so we need to work on them as well not to change
+ * any other pin with our bit-baning performed only on selected pins.
+ * The function name 'bitbang' reflects ability to change selected pin states.
+ *
+ * @Note: FT2232 has special mechanism called MPSSE for serial communications
+ * that is far more efficient than pure 'bitbang' mode on this device family.
+ * Although our function is named 'bitbang' it does not use bitbang mode.
+ * MPSSE command send value and port bytes on port write, but does not on read.
+ * This happens every time we want to change pin value, so we need to use cache.
+ * On write we want to OR direction mask already set by init() procedure
+ * to mark bit-mask output. On read we want to clear bits given by mask
+ * to mark them input. To read we need to write/update port state first.
+ * Long story short: to read data we first need to set pins to input.
+ *
+ * @Warning: reading and writing will set pin direction input or output,
+ * so it is possible to disable basic data output pins with bad masking,
+ * but also gives chance to create and manage full TCL signal description,
+ * that can be used to take advantage of some additional interface hardware
+ * features installed on some devices (i.e. ADC, power supply, etc).
+ * This gives new way of signal handling that is still backward-compatible.
+ *
+ * \param *device void pointer to pass additional driver information to the routine.
+ * \param signal is the string representation of the signal mask stored in layout structure.
+ * \param GETnSET if zero then perform read operation, write otherwise.
+ * \param *value is the pointer that holds the value.
+ * \return ERROR_OK on success, or ERROR_FAIL on failure.
+ */
+int ft2232_bitbang(void *device, char *signal_name, int GETnSET, int *value){
+ uint8_t buf[3];
+ int retval, vall=0, valh=0;
+ unsigned int sigmask;
+ uint32_t bytes_written, bytes_read;
+ oocd_interface_signal_t *sig;
+
+ //First get the signal mask, or return error if signal not defined.
+ if (!(sig=oocd_interface_signal_find(signal_name))){
+ LOG_ERROR("Requested signal not found on this interface!");
+ return ERROR_FAIL;
+ }
+ // Pin mask is also related with port direction and complicates it!!!
+ sigmask=sig->mask;
+
+ if (!GETnSET){
+ // We will SET port pins selected by sigmask.
+ // Modify our pins value, but remember about other pins and their previous value
+ low_output = (low_output & ~sigmask) | ((*value & sigmask) & 0x0ff);
+ high_output = (high_output & ~(sigmask>>8)) | (((*value & sigmask)>>8) & 0x0ff);
+ // Modify our pins direction, but remember about other pins and their previous direction
+ low_direction |= sigmask & 0x0ff;
+ high_direction |= (sigmask>>8) & 0x0ff;
+ // Now send those settings to the interface chip
+ buf[0] = 0x80; //Set Data Bits LowByte
+ buf[1] = low_output;
+ buf[2] = low_direction;
+ if ((retval=ft2232_write(buf, 3, &bytes_written)) != ERROR_OK) return retval;
+ buf[0] = 0x82; //Set Data Bits HighByte
+ buf[1] = high_output;
+ buf[2] = high_direction;
+ if ((retval=ft2232_write(buf, 3, &bytes_written)) != ERROR_OK) return retval;
+ sig->value = ((high_output<<8) | low_output) & sig->mask;
+ } else {
+ // Modify our pins value, but remember about other pins and their previous value
+ // DO WE REALLY NEED TO PULL-UP PINS TO READ THEIR STATE OR SIMPLY LEAVE AS IS?
+ //low_output = (low_output & ~sigmask) | (sigmask & 0x0ff);
+ //high_output = (high_output & ~sigmask) | (sigmask>>8) & 0x0ff);
+ // Modify our pins direction to input, but remember about other pins and their previous direction
+ low_direction &= ~(sigmask);
+ high_direction &= ~(sigmask>>8);
+ // Now send those settings to the interface chip
+ // First change desired pins to input
+ buf[0] = 0x80; //Set Data Bits LowByte
+ buf[1] = low_output;
+ buf[2] = low_direction;
+ if ((retval=ft2232_write(buf, 3, &bytes_written)) != ERROR_OK) return retval;
+ buf[0] = 0x82; //Set Data Bits HighByte
+ buf[1] = high_output;
+ buf[2] = high_direction;
+ if ((retval=ft2232_write(buf, 3, &bytes_written)) != ERROR_OK) return retval;
+ // Then read pins designated by a signal mask
+ buf[0]=0x81; //Read Data Bits LowByte.
+ if ((retval=ft2232_write(buf, 1, &bytes_written)) != ERROR_OK) return retval;
+ if ((retval=ft2232_read((uint8_t *)&vall, 1, &bytes_read)) != ERROR_OK) return retval;
+ buf[0]=0x83; //Read Data Bits HighByte.
+ if ((retval=ft2232_write(buf, 1, &bytes_written)) != ERROR_OK) return retval;
+ if ((retval=ft2232_read((uint8_t *)&valh, 1, &bytes_read)) != ERROR_OK) return retval;
+ sig->value = *value = ((valh<<8)|vall) & sig->mask; //Join result bytes and apply signal bitmask
+ }
+ return ERROR_OK;
+}
+
+
static bool ft2232_device_is_highspeed(void)
{
#if BUILD_FT2232_FTD2XX == 1
@@ -4486,4 +4586,5 @@ struct jtag_interface ft2232_interface = {
.speed_div = ft2232_speed_div,
.khz = ft2232_khz,
.execute_queue = ft2232_execute_queue,
+ .bitbang = ft2232_bitbang,
};