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[/] [xulalx25soc/] [trunk/] [sw/] [usbi.cpp] - Blame information for rev 73

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////////////////////////////////////////////////////////////////////////////////
//
// Filename:    usbi.cpp
//
// Project:     XuLA2 board
//
// Purpose:     Creates a USB port, similar to a serial port, out of the
//              XuLA2 JTAG interface S/W.
//
//
// Creator:     Dan Gisselquist, Ph.D.
//              Gisselquist Technology, LLC
//
////////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2015, Gisselquist Technology, LLC
//
// This program is free software (firmware): 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 3 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 MERCHANTIBILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// License:     GPL, v3, as defined and found on www.gnu.org,
//              http://www.gnu.org/licenses/gpl.html
//
//
////////////////////////////////////////////////////////////////////////////////
//
//
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
// #include <usb.h>
 
#include <libusb.h>
 
#include "llcomms.h"
#include "usbi.h"
 
// Walk us through the JTAG Chain:
//      5-1's to go to test/reset
//      0        to go to Run-Test/Idle
//      1       to go to select-dr-scan
//      1       to go to select-ir-scan
//      0        to go to capture-ir
//      0        to go to shift-ir
//      (6-bit code 0x02 through TDI to IR, while sending 0-bits to TMS)
//      1       to leave shift IR and go to exit1-ir
//      1       to go to update-ir
//      1       to go to select-dr-scan
//      0        to go to capture-dr
//      0        to go to shift-dr
#define RESET_JTAG_LEN  12
static const char       RESET_TO_USER_DR[RESET_JTAG_LEN] = {
        JTAG_CMD,
        21, // clocks
        0,0,0,     // Also clocks, higher order bits
        PUT_TMS_MASK | PUT_TDI_MASK, // flags
        (char)(0x0df),  // TMS: Five ones, then one zero, and two ones -- low bits first
        0x00,   // TDI: irrelevant here
        (char)0x80,     // TMS: two zeros, then six zeros
        0x08,   // TDI: user command #1, bit reversed
        0x03,   // TMS: three ones, then two zeros
        0x00    // TDI byte -- irrelevant here
        //
        // 0xc0, // TDI byte -- user command #2
        // 0x40,        // TDI: user command #1
        // 0x0c, // TDI byte -- user command #2, bit reversed
};
 
//
//      TMS: 
#define TX_DR_LEN       12
static const    char    TX_DR_BITS[TX_DR_LEN] = {
        JTAG_CMD,
        48, // clocks
        0,0,0,     // Also clocks, higher order bits
        PUT_TDI_MASK, // flags
        (char)0x0ff, 0, 0, 0, 0, 0   // Six data bytes
        // module_id = 255
        // 32'h(payload.length)
        // payload
        // module_id + payload.len + num_result_bits, length=32 + payload ???
};
 
//
//      TMS: 
//      
#define REQ_RX_LEN      6
static const    char    REQ_RX_BITS[REQ_RX_LEN] = {
        JTAG_CMD,
        (const char)((USB_PKTLEN-REQ_RX_LEN)*8), // bits-requested
        0,0,0,     // Also clocks, higher order bits
        GET_TDO_MASK|TDI_VAL_MASK, // flags:TDI is kept low here, so no TDI flag
        // No data given, since there's no info to send or receive
        // Leave the result in shift-DR mode
};
 
/*
#define RETURN_TO_RESET_LEN     7
static const char       RETURN_TO_RESET[RETURN_TO_RESET_LEN] = {
        JTAG_CMD,
        5, // clocks
        0,0,0,  // Also clocks, higher order bits
        PUT_TMS_MASK, // flags
        (char)0x0ff, // Five ones
};
*/
 
USBI::USBI(void) {
        int     config;
 
        m_total_nread = 0;
 
        if (0 != libusb_init(&m_usb_context)) {
                fprintf(stderr, "Error initializing the USB library\n");
                perror("O/S Err:");
                exit(-1);
        }
 
        m_xula_usb_device = libusb_open_device_with_vid_pid(m_usb_context,
                VENDOR_ID, PRODUCT_ID);
        if (!m_xula_usb_device) {
                fprintf(stderr, "Could not open XuLA device\n");
                perror("O/S Err:");
 
                libusb_exit(m_usb_context);
                exit(-1);
        }
 
        if (0 != libusb_get_configuration(m_xula_usb_device, &config)) {
                fprintf(stderr, "Could not get configuration\n");
                perror("O/S Err:");
 
                libusb_close(m_xula_usb_device);
                libusb_exit(m_usb_context);
                exit(-1);
        }
 
        if (0 != libusb_claim_interface(m_xula_usb_device, XESS_INTERFACE)) {
                fprintf(stderr, "Could not claim interface\n");
                perror("O/S Err:");
 
                libusb_close(m_xula_usb_device);
                libusb_exit(m_usb_context);
                exit(-1);
        }
 
        unsigned char   abuf[RESET_JTAG_LEN];
        int     actual_length = RESET_JTAG_LEN, r;
 
        memcpy(abuf, RESET_TO_USER_DR, RESET_JTAG_LEN);
        r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,
                abuf, RESET_JTAG_LEN, &actual_length, 4);
        if ((r!=0)||(actual_length != RESET_JTAG_LEN)) {
                // Try clearing the queue twice, then doing this
                do {
                        r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,
                                (unsigned char *)m_rxbuf, USB_PKTLEN, &actual_length, 20);
                } while((r==0)&&(actual_length > 0));
 
                r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,
                        abuf, RESET_JTAG_LEN, &actual_length, 4);
                if ((r != 0)||(actual_length != RESET_JTAG_LEN)) {
                        printf("Some error took place requesting RESET_TO_USER_DR\n");
                        printf("r = %d, actual_length = %d (vs %d requested)\n",
                                r, actual_length, RESET_JTAG_LEN);
                        perror("O/S Err");
                        exit(-2);
                }
        }
 
        // Initialize our read FIFO
        m_rbeg = m_rend = 0;
 
        flush_read();
}
 
void    USBI::close(void) {
        // Release our interface
        if (0 != libusb_release_interface(m_xula_usb_device, XESS_INTERFACE)) {
                fprintf(stderr, "Could not release interface\n");
                perror("O/S Err:");
 
                libusb_close(m_xula_usb_device);
                libusb_exit(m_usb_context);
                exit(-1);
        }
 
        // And then close our device with
        libusb_close(m_xula_usb_device);
 
        // And just before exiting, we free our USB context
        libusb_exit(m_usb_context);
}
 
void    USBI::write(char *buf, int len) {
        int     r, actual_length;
 
        if (len >= USB_PKTLEN) {
                const int       nv = USB_PKTLEN/2-1;
                for(int pos=0; pos<len; pos+=nv)
                        write(&buf[pos], (len-pos>nv)?(nv):len-pos);
        } else {
                memset(m_txbuf, 0, len+6);
                m_txbuf[0] = JTAG_CMD;
                m_txbuf[1] = len * 8;
                m_txbuf[2] = 0;
                m_txbuf[3] = 0;
                m_txbuf[4] = 0;
                m_txbuf[5] = PUT_TDI_MASK | GET_TDO_MASK;
 
                for(int i=0; i<len; i++)
                        m_txbuf[6+i] = buf[i];
                // printf("WRITE::(buf=%*s, %d)\n", len, buf, len);
                r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,
                        (unsigned char*)m_txbuf, len+6, &actual_length, 0);
                if ((r!=0)||(actual_length != len+6)) {
                        printf("WRITE::(buf, %d) -- ERR\n", len+6);
                        printf("r = %d, actual_length = %d (!= %d requested)\n", r,
                                actual_length, len+6);
 
                        if (r == -7) {
                                r = libusb_bulk_transfer(m_xula_usb_device,
                                        XESS_ENDPOINT_OUT,
                                        (unsigned char*)m_txbuf, len+6,
                                        &actual_length, 2);
                                if ((r!=0)||(actual_length != len+6)) {
                                        printf("WRITE::(buf, %d) -- ERR\n", len+6);
                                        printf("r = %d, actual_length = %d (!= %d requested)\n", r,
                                                actual_length, len+6);
                                        perror("O/S Err");
 
                                        exit(-2);
                                }
                        } else {
                                perror("O/S Err");
                                exit(-2);
                        }
                }
 
                // Try to read back however many bytes we can
                r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,
                        (unsigned char*)m_rxbuf, USB_PKTLEN, &actual_length, 20);
                if ((r==0)&&(actual_length > 0)) {
                        push_fifo(m_rxbuf, actual_length);
                } else {
                        printf("Some error took place in receiving\n");
                        perror("O/S Err");
                }
        }
}
 
int     USBI::read(char *buf, int len) {
        return read(buf, len, 4);
}
 
int     USBI::read(char *buf, int len, int timeout_ms) {
        int     left = len, nr=0;
 
        // printf("USBI::read(%d) (FIFO is %d-%d)\n", len, m_rend, m_rbeg);
        nr = pop_fifo(buf, left);
        left -= nr;
 
        while(left > 0) {
                raw_read(left, timeout_ms);
                nr = pop_fifo(&buf[len-left], left);
                left -= nr;
 
                // printf("\tWHILE (nr = %d, LEFT = %d, len=%d)\n", nr, left, len);
                if (nr == 0)
                        break;
        }
 
        // printf("READ %d characters (%d req, %d left)\n", len-left, len, left);
        return len-left;
}
 
void    USBI::raw_read(const int clen, int timeout_ms) {
        int     avail = (m_rbeg - m_rend)&(RCV_BUFMASK), actual_length;
        int     len = clen;
        if (len > RCV_BUFMASK-avail)
                len = RCV_BUFMASK-avail;
        if (len > 26)
                len = 26;
 
        // printf("USBI::RAW-READ(%d, was %d)\n", len, clen);
        memcpy(m_txbuf, REQ_RX_BITS, REQ_RX_LEN);
 
        // I have chased process hangs to this line, but have no more
        // information than that somewhere within libusb_bulk_transfer,
        // libusb_handle_events_completed,
        // libusb_handle_events_timeout_completed, ?, poll(), there seems
        // to be a bug.
        //
        // I'm not certain if the bug is in the Linux kernel, or in the 
        // Xess tools.  I will note that, when a followup attempt is made
        // to read from the device, previously unread data may still get dumped
        // to it.  Therefore, be careful to clear the device upon starting
        // any process.
        //
        // fprintf(stderr, "[");
        int r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,
                (unsigned char *)m_txbuf, REQ_RX_LEN, &actual_length,
                timeout_ms);
        // fprintf(stderr, "]");
 
        if ((r==0)&&(actual_length == REQ_RX_LEN)) {
        } else if (r == -7) {
                // Nothing to read in the timeout provided
                // We'll have to request this data again ... later
                return;
        } else {
                printf("READ(WRITE,READ-REQ) -- ERR\n");
                printf("r = %d, actual_length = %d (!= %d requested)\n", r,
                        actual_length, len+6);
                perror("O/S Err");
                exit(-2);
        }
 
        // Try to read back however many bytes we can
        r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,
                (unsigned char *)m_rxbuf, USB_PKTLEN, &actual_length, 0);
        if ((r==0)&&(actual_length > 0)) {
                /*
                printf("RAW-READ() -> %d Read\n", actual_length);
                for(int i=0; i<actual_length; i++)
                        printf("%02x ", m_rxbuf[i] & 0x0ff);
                printf("\n");
                */
                push_fifo(m_rxbuf, actual_length);
        } else if (r == -7) {
                // Nothing to read in the timeout provided
                // Return, adding nothing to our FIFO
        } else {
                printf("Some error took place in receiving\n");
                perror("O/S Err");
        }
 
        // fprintf(stderr, "\tUSBI::RAW-READ() -- COMPLETE (%d avail)\n",
                // (m_rbeg-m_rend)&(RCV_BUFMASK));
}
 
void    USBI::flush_read(void) {
        while(poll(4)) {
                m_rbeg = m_rend = 0;
        }
}
 
void    USBI::push_fifo(char *buf, int len) {
        char    last = 0;
        char    *sptr = buf;
 
        // printf("Pushing %d items onto FIFO (%d - %d)\n", len, m_rend, m_rbeg);
        if (m_rbeg != m_rend)
                last = m_rbuf[m_rend];
        for(int i=0; i<len; i++) {
                char v = *sptr++;
                if (((v & 0x80)||((unsigned char)v < 0x10))&&(v == last)) {
                        // printf("\tSkipping: %02x\n", v & 0x0ff);
                } else if ((unsigned char)v == 0x0ff) {
                } else {
                        m_rbuf[m_rbeg] = v;
                        m_rbeg = (m_rbeg+1)&(RCV_BUFMASK);
                        // printf("\tPushing: %02x\n", v & 0x0ff);
                } last = v;
        }
}
 
int     USBI::pop_fifo(char *buf, int len) {
        int     avail = (m_rbeg - m_rend)&(RCV_BUFMASK);
        int     left = len;
        int     nr = 0;
 
        // printf("Attempting to pop %d items from FIFO (%d - %d)\n",
        //              len, m_rend, m_rbeg);
        while((avail > 0)&&(left > 0)) {
                int ln = RCV_BUFLEN-m_rend;
                if (ln > left)
                        ln = left;
                if (ln > avail)
                        ln = avail;
                memcpy(&buf[len-left], &m_rbuf[m_rend], ln);
                left   -= ln;
                avail  -= ln;
                m_rend  = (m_rend + ln)&(RCV_BUFMASK);
                nr     += ln;
 
        //      printf("P:");
        //      for(int i=0; i<ln; i++)
        //              printf("%02x ", buf[len-left-ln+i]);
        } // printf("\n");
 
        /*
        if (nr > 0)
                printf("\tPopped %d items, buf[0] = %02x (%d - %d)\n",
                        nr, buf[0], m_rend, m_rbeg);
        else
                printf("\tPopped nothing, %d - %d\n", m_rend, m_rbeg);
        */
 
        return nr;
}
 
bool    USBI::poll(unsigned ms) {
        int     avail = (m_rbeg-m_rend)&(RCV_BUFMASK);
        bool    r = true;
 
        // printf("POLL request\n");
 
        if ((avail < 2)&&((avail<1)||(m_rbuf[m_rend]&0x80)||(m_rbuf[m_rend]<0x10))) {
                raw_read(4,ms);
                avail = (m_rbeg-m_rend)&(RCV_BUFMASK);
                // printf("%d availabe\n", avail);
 
                char    v = (m_rbuf[(m_rbeg-1)&(RCV_BUFMASK)]);
                while(((v&0x80)==0)&&((unsigned)v>=0x10)&&(avail < RCV_BUFMASK-32)) {
                        raw_read(26,ms);
                        avail = (m_rbeg-m_rend)&(RCV_BUFMASK);
                }
                if (avail < 1)
                        r = false;
                else if ((avail==1)&&((m_rbuf[m_rend]&0x80)||(m_rbuf[m_rend]<0x10)))
                        r = false;
        }
 
        // printf("USBI::poll() -> %s (%d avail)\n", (r)?"true":"false", avail);
        return r;
}

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[/] [xulalx25soc/] [trunk/] [sw/] [usbi.cpp] - Blame information for rev 73

Line No.	Rev	Author	Line
1	5	dgisselq	`////////////////////////////////////////////////////////////////////////////////`
2			`//`
3	11	dgisselq	`// Filename: usbi.cpp`
4	5	dgisselq	`//`
5			`// Project: XuLA2 board`
6			`//`
7			`// Purpose: Creates a USB port, similar to a serial port, out of the`
8			`// XuLA2 JTAG interface S/W.`
9			`//`
10			`//`
11			`// Creator: Dan Gisselquist, Ph.D.`
12			`// Gisselquist Technology, LLC`
13			`//`
14			`////////////////////////////////////////////////////////////////////////////////`
15			`//`
16			`// Copyright (C) 2015, Gisselquist Technology, LLC`
17			`//`
18			`// This program is free software (firmware): you can redistribute it and/or`
19			`// modify it under the terms of the GNU General Public License as published`
20			`// by the Free Software Foundation, either version 3 of the License, or (at`
21			`// your option) any later version.`
22			`//`
23			`// This program is distributed in the hope that it will be useful, but WITHOUT`
24			`// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or`
25			`// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License`
26			`// for more details.`
27			`//`
28			`// License: GPL, v3, as defined and found on www.gnu.org,`
29			`// http://www.gnu.org/licenses/gpl.html`
30			`//`
31			`//`
32			`////////////////////////////////////////////////////////////////////////////////`
33			`//`
34			`//`
35			`#include <stdio.h>`
36			`#include <stdlib.h>`
37			`#include <unistd.h>`
38			`#include <string.h>`
39			`#include <ctype.h>`
40			`// #include <usb.h>`
41
42			`#include <libusb.h>`
43
44			`#include "llcomms.h"`
45			`#include "usbi.h"`
46
47			`// Walk us through the JTAG Chain:`
48			`// 5-1's to go to test/reset`
49			`// 0 to go to Run-Test/Idle`
50			`// 1 to go to select-dr-scan`
51			`// 1 to go to select-ir-scan`
52			`// 0 to go to capture-ir`
53			`// 0 to go to shift-ir`
54			`// (6-bit code 0x02 through TDI to IR, while sending 0-bits to TMS)`
55			`// 1 to leave shift IR and go to exit1-ir`
56			`// 1 to go to update-ir`
57			`// 1 to go to select-dr-scan`
58			`// 0 to go to capture-dr`
59			`// 0 to go to shift-dr`
60			`#define RESET_JTAG_LEN 12`
61			`static const char RESET_TO_USER_DR[RESET_JTAG_LEN] = {`
62			`JTAG_CMD,`
63			`21, // clocks`
64			`0,0,0, // Also clocks, higher order bits`
65			`PUT_TMS_MASK \| PUT_TDI_MASK, // flags`
66			`(char)(0x0df), // TMS: Five ones, then one zero, and two ones -- low bits first`
67			`0x00, // TDI: irrelevant here`
68			`(char)0x80, // TMS: two zeros, then six zeros`
69			`0x08, // TDI: user command #1, bit reversed`
70			`0x03, // TMS: three ones, then two zeros`
71			`0x00 // TDI byte -- irrelevant here`
72			`//`
73			`// 0xc0, // TDI byte -- user command #2`
74			`// 0x40, // TDI: user command #1`
75			`// 0x0c, // TDI byte -- user command #2, bit reversed`
76			`};`
77
78			`//`
79			`// TMS:`
80			`#define TX_DR_LEN 12`
81			`static const char TX_DR_BITS[TX_DR_LEN] = {`
82			`JTAG_CMD,`
83			`48, // clocks`
84			`0,0,0, // Also clocks, higher order bits`
85			`PUT_TDI_MASK, // flags`
86			`(char)0x0ff, 0, 0, 0, 0, 0 // Six data bytes`
87			`// module_id = 255`
88			`// 32'h(payload.length)`
89			`// payload`
90			`// module_id + payload.len + num_result_bits, length=32 + payload ???`
91			`};`
92
93			`//`
94			`// TMS:`
95			`//`
96			`#define REQ_RX_LEN 6`
97			`static const char REQ_RX_BITS[REQ_RX_LEN] = {`
98			`JTAG_CMD,`
99			`(const char)((USB_PKTLEN-REQ_RX_LEN)*8), // bits-requested`
100			`0,0,0, // Also clocks, higher order bits`
101			`GET_TDO_MASK\|TDI_VAL_MASK, // flags:TDI is kept low here, so no TDI flag`
102			`// No data given, since there's no info to send or receive`
103			`// Leave the result in shift-DR mode`
104			`};`
105
106			`/*`
107			`#define RETURN_TO_RESET_LEN 7`
108			`static const char RETURN_TO_RESET[RETURN_TO_RESET_LEN] = {`
109			`JTAG_CMD,`
110			`5, // clocks`
111			`0,0,0, // Also clocks, higher order bits`
112			`PUT_TMS_MASK, // flags`
113			`(char)0x0ff, // Five ones`
114			`};`
115			`*/`
116
117			`USBI::USBI(void) {`
118			`int config;`
119
120			`m_total_nread = 0;`
121
122			`if (0 != libusb_init(&m_usb_context)) {`
123			`fprintf(stderr, "Error initializing the USB library\n");`
124			`perror("O/S Err:");`
125			`exit(-1);`
126			`}`
127
128			`m_xula_usb_device = libusb_open_device_with_vid_pid(m_usb_context,`
129			`VENDOR_ID, PRODUCT_ID);`
130			`if (!m_xula_usb_device) {`
131			`fprintf(stderr, "Could not open XuLA device\n");`
132			`perror("O/S Err:");`
133
134			`libusb_exit(m_usb_context);`
135			`exit(-1);`
136			`}`
137
138			`if (0 != libusb_get_configuration(m_xula_usb_device, &config)) {`
139			`fprintf(stderr, "Could not get configuration\n");`
140			`perror("O/S Err:");`
141
142			`libusb_close(m_xula_usb_device);`
143			`libusb_exit(m_usb_context);`
144			`exit(-1);`
145			`}`
146
147			`if (0 != libusb_claim_interface(m_xula_usb_device, XESS_INTERFACE)) {`
148			`fprintf(stderr, "Could not claim interface\n");`
149			`perror("O/S Err:");`
150
151			`libusb_close(m_xula_usb_device);`
152			`libusb_exit(m_usb_context);`
153			`exit(-1);`
154			`}`
155
156			`unsigned char abuf[RESET_JTAG_LEN];`
157			`int actual_length = RESET_JTAG_LEN, r;`
158
159			`memcpy(abuf, RESET_TO_USER_DR, RESET_JTAG_LEN);`
160			`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,`
161			`abuf, RESET_JTAG_LEN, &actual_length, 4);`
162			`if ((r!=0)\|\|(actual_length != RESET_JTAG_LEN)) {`
163			`// Try clearing the queue twice, then doing this`
164			`do {`
165			`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,`
166			`(unsigned char *)m_rxbuf, USB_PKTLEN, &actual_length, 20);`
167			`} while((r==0)&&(actual_length > 0));`
168
169			`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,`
170			`abuf, RESET_JTAG_LEN, &actual_length, 4);`
171			`if ((r != 0)\|\|(actual_length != RESET_JTAG_LEN)) {`
172			`printf("Some error took place requesting RESET_TO_USER_DR\n");`
173			`printf("r = %d, actual_length = %d (vs %d requested)\n",`
174			`r, actual_length, RESET_JTAG_LEN);`
175			`perror("O/S Err");`
176			`exit(-2);`
177			`}`
178			`}`
179
180			`// Initialize our read FIFO`
181			`m_rbeg = m_rend = 0;`
182
183			`flush_read();`
184			`}`
185
186			`void USBI::close(void) {`
187			`// Release our interface`
188			`if (0 != libusb_release_interface(m_xula_usb_device, XESS_INTERFACE)) {`
189			`fprintf(stderr, "Could not release interface\n");`
190			`perror("O/S Err:");`
191
192			`libusb_close(m_xula_usb_device);`
193			`libusb_exit(m_usb_context);`
194			`exit(-1);`
195			`}`
196
197			`// And then close our device with`
198			`libusb_close(m_xula_usb_device);`
199
200			`// And just before exiting, we free our USB context`
201			`libusb_exit(m_usb_context);`
202			`}`
203
204			`void USBI::write(char *buf, int len) {`
205			`int r, actual_length;`
206
207			`if (len >= USB_PKTLEN) {`
208			`const int nv = USB_PKTLEN/2-1;`
209			`for(int pos=0; pos<len; pos+=nv)`
210			`write(&buf[pos], (len-pos>nv)?(nv):len-pos);`
211			`} else {`
212			`memset(m_txbuf, 0, len+6);`
213			`m_txbuf[0] = JTAG_CMD;`
214			`m_txbuf[1] = len * 8;`
215			`m_txbuf[2] = 0;`
216			`m_txbuf[3] = 0;`
217			`m_txbuf[4] = 0;`
218			`m_txbuf[5] = PUT_TDI_MASK \| GET_TDO_MASK;`
219
220			`for(int i=0; i<len; i++)`
221			`m_txbuf[6+i] = buf[i];`
222	13	dgisselq	`// printf("WRITE::(buf=%*s, %d)\n", len, buf, len);`
223	5	dgisselq	`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,`
224			`(unsigned char*)m_txbuf, len+6, &actual_length, 0);`
225			`if ((r!=0)\|\|(actual_length != len+6)) {`
226			`printf("WRITE::(buf, %d) -- ERR\n", len+6);`
227			`printf("r = %d, actual_length = %d (!= %d requested)\n", r,`
228			`actual_length, len+6);`
229
230			`if (r == -7) {`
231			`r = libusb_bulk_transfer(m_xula_usb_device,`
232			`XESS_ENDPOINT_OUT,`
233			`(unsigned char*)m_txbuf, len+6,`
234			`&actual_length, 2);`
235			`if ((r!=0)\|\|(actual_length != len+6)) {`
236			`printf("WRITE::(buf, %d) -- ERR\n", len+6);`
237			`printf("r = %d, actual_length = %d (!= %d requested)\n", r,`
238			`actual_length, len+6);`
239			`perror("O/S Err");`
240
241			`exit(-2);`
242			`}`
243			`} else {`
244			`perror("O/S Err");`
245			`exit(-2);`
246			`}`
247			`}`
248
249			`// Try to read back however many bytes we can`
250			`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,`
251			`(unsigned char*)m_rxbuf, USB_PKTLEN, &actual_length, 20);`
252			`if ((r==0)&&(actual_length > 0)) {`
253			`push_fifo(m_rxbuf, actual_length);`
254			`} else {`
255			`printf("Some error took place in receiving\n");`
256			`perror("O/S Err");`
257			`}`
258			`}`
259			`}`
260
261			`int USBI::read(char *buf, int len) {`
262			`return read(buf, len, 4);`
263			`}`
264
265			`int USBI::read(char *buf, int len, int timeout_ms) {`
266			`int left = len, nr=0;`
267
268			`// printf("USBI::read(%d) (FIFO is %d-%d)\n", len, m_rend, m_rbeg);`
269			`nr = pop_fifo(buf, left);`
270			`left -= nr;`
271
272			`while(left > 0) {`
273			`raw_read(left, timeout_ms);`
274	41	dgisselq	`nr = pop_fifo(&buf[len-left], left);`
275	5	dgisselq	`left -= nr;`
276
277			`// printf("\tWHILE (nr = %d, LEFT = %d, len=%d)\n", nr, left, len);`
278			`if (nr == 0)`
279			`break;`
280			`}`
281
282			`// printf("READ %d characters (%d req, %d left)\n", len-left, len, left);`
283			`return len-left;`
284			`}`
285
286			`void USBI::raw_read(const int clen, int timeout_ms) {`
287			`int avail = (m_rbeg - m_rend)&(RCV_BUFMASK), actual_length;`
288			`int len = clen;`
289			`if (len > RCV_BUFMASK-avail)`
290			`len = RCV_BUFMASK-avail;`
291			`if (len > 26)`
292			`len = 26;`
293
294			`// printf("USBI::RAW-READ(%d, was %d)\n", len, clen);`
295			`memcpy(m_txbuf, REQ_RX_BITS, REQ_RX_LEN);`
296
297	46	dgisselq	`// I have chased process hangs to this line, but have no more`
298			`// information than that somewhere within libusb_bulk_transfer,`
299			`// libusb_handle_events_completed,`
300			`// libusb_handle_events_timeout_completed, ?, poll(), there seems`
301			`// to be a bug.`
302			`//`
303			`// I'm not certain if the bug is in the Linux kernel, or in the`
304			`// Xess tools. I will note that, when a followup attempt is made`
305			`// to read from the device, previously unread data may still get dumped`
306			`// to it. Therefore, be careful to clear the device upon starting`
307			`// any process.`
308			`//`
309			`// fprintf(stderr, "[");`
310	5	dgisselq	`int r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_OUT,`
311			`(unsigned char *)m_txbuf, REQ_RX_LEN, &actual_length,`
312			`timeout_ms);`
313	46	dgisselq	`// fprintf(stderr, "]");`
314
315	5	dgisselq	`if ((r==0)&&(actual_length == REQ_RX_LEN)) {`
316			`} else if (r == -7) {`
317			`// Nothing to read in the timeout provided`
318			`// We'll have to request this data again ... later`
319			`return;`
320			`} else {`
321			`printf("READ(WRITE,READ-REQ) -- ERR\n");`
322			`printf("r = %d, actual_length = %d (!= %d requested)\n", r,`
323			`actual_length, len+6);`
324			`perror("O/S Err");`
325			`exit(-2);`
326			`}`
327
328			`// Try to read back however many bytes we can`
329			`r = libusb_bulk_transfer(m_xula_usb_device, XESS_ENDPOINT_IN,`
330			`(unsigned char *)m_rxbuf, USB_PKTLEN, &actual_length, 0);`
331			`if ((r==0)&&(actual_length > 0)) {`
332			`/*`
333			`printf("RAW-READ() -> %d Read\n", actual_length);`
334			`for(int i=0; i<actual_length; i++)`
335			`printf("%02x ", m_rxbuf[i] & 0x0ff);`
336			`printf("\n");`
337			`*/`
338			`push_fifo(m_rxbuf, actual_length);`
339			`} else if (r == -7) {`
340			`// Nothing to read in the timeout provided`
341			`// Return, adding nothing to our FIFO`
342			`} else {`
343			`printf("Some error took place in receiving\n");`
344			`perror("O/S Err");`
345			`}`
346
347			`// fprintf(stderr, "\tUSBI::RAW-READ() -- COMPLETE (%d avail)\n",`
348			`// (m_rbeg-m_rend)&(RCV_BUFMASK));`
349			`}`
350
351			`void USBI::flush_read(void) {`
352			`while(poll(4)) {`
353			`m_rbeg = m_rend = 0;`
354			`}`
355			`}`
356
357			`void USBI::push_fifo(char *buf, int len) {`
358			`char last = 0;`
359			`char *sptr = buf;`
360
361			`// printf("Pushing %d items onto FIFO (%d - %d)\n", len, m_rend, m_rbeg);`
362			`if (m_rbeg != m_rend)`
363			`last = m_rbuf[m_rend];`
364			`for(int i=0; i<len; i++) {`
365			`char v = *sptr++;`
366			`if (((v & 0x80)\|\|((unsigned char)v < 0x10))&&(v == last)) {`
367			`// printf("\tSkipping: %02x\n", v & 0x0ff);`
368			`} else if ((unsigned char)v == 0x0ff) {`
369			`} else {`
370			`m_rbuf[m_rbeg] = v;`
371			`m_rbeg = (m_rbeg+1)&(RCV_BUFMASK);`
372			`// printf("\tPushing: %02x\n", v & 0x0ff);`
373			`} last = v;`
374			`}`
375			`}`
376
377			`int USBI::pop_fifo(char *buf, int len) {`
378			`int avail = (m_rbeg - m_rend)&(RCV_BUFMASK);`
379			`int left = len;`
380			`int nr = 0;`
381
382			`// printf("Attempting to pop %d items from FIFO (%d - %d)\n",`
383	41	dgisselq	`// len, m_rend, m_rbeg);`
384	5	dgisselq	`while((avail > 0)&&(left > 0)) {`
385			`int ln = RCV_BUFLEN-m_rend;`
386			`if (ln > left)`
387			`ln = left;`
388			`if (ln > avail)`
389			`ln = avail;`
390			`memcpy(&buf[len-left], &m_rbuf[m_rend], ln);`
391			`left -= ln;`
392			`avail -= ln;`
393			`m_rend = (m_rend + ln)&(RCV_BUFMASK);`
394			`nr += ln;`
395
396	41	dgisselq	`// printf("P:");`
397			`// for(int i=0; i<ln; i++)`
398			`// printf("%02x ", buf[len-left-ln+i]);`
399			`} // printf("\n");`
400
401	5	dgisselq	`/*`
402			`if (nr > 0)`
403			`printf("\tPopped %d items, buf[0] = %02x (%d - %d)\n",`
404			`nr, buf[0], m_rend, m_rbeg);`
405			`else`
406			`printf("\tPopped nothing, %d - %d\n", m_rend, m_rbeg);`
407			`*/`
408	13	dgisselq
409	5	dgisselq	`return nr;`
410			`}`
411
412			`bool USBI::poll(unsigned ms) {`
413			`int avail = (m_rbeg-m_rend)&(RCV_BUFMASK);`
414			`bool r = true;`
415
416			`// printf("POLL request\n");`
417
418			`if ((avail < 2)&&((avail<1)\|\|(m_rbuf[m_rend]&0x80)\|\|(m_rbuf[m_rend]<0x10))) {`
419			`raw_read(4,ms);`
420			`avail = (m_rbeg-m_rend)&(RCV_BUFMASK);`
421			`// printf("%d availabe\n", avail);`
422
423			`char v = (m_rbuf[(m_rbeg-1)&(RCV_BUFMASK)]);`
424			`while(((v&0x80)==0)&&((unsigned)v>=0x10)&&(avail < RCV_BUFMASK-32)) {`
425			`raw_read(26,ms);`
426			`avail = (m_rbeg-m_rend)&(RCV_BUFMASK);`
427			`}`
428			`if (avail < 1)`
429			`r = false;`
430			`else if ((avail==1)&&((m_rbuf[m_rend]&0x80)\|\|(m_rbuf[m_rend]<0x10)))`
431			`r = false;`
432			`}`
433
434			`// printf("USBI::poll() -> %s (%d avail)\n", (r)?"true":"false", avail);`
435			`return r;`
436			`}`