| 1 | /* Libftdi example for asynchronous read/write. |
| 2 | |
| 3 | This program is distributed under the GPL, version 2 |
| 4 | */ |
| 5 | |
| 6 | /* This program switches to MPSSE mode, and sets and then reads back |
| 7 | * the high byte 3 times with three different values. |
| 8 | * The expected read values are hard coded in ftdi_init |
| 9 | * with 0x00, 0x55 and 0xaa |
| 10 | * |
| 11 | * Make sure that that nothing else drives some bit of the high byte |
| 12 | * or expect a collision for a very short time and some differences |
| 13 | * in the data read back. |
| 14 | * |
| 15 | * Result should be the same without any option or with either |
| 16 | * -r or -w or -b. |
| 17 | */ |
| 18 | |
| 19 | |
| 20 | #include <stdio.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <string.h> |
| 23 | #include <ctype.h> |
| 24 | #include <unistd.h> |
| 25 | #include <getopt.h> |
| 26 | #include <ftdi.h> |
| 27 | |
| 28 | int main(int argc, char **argv) |
| 29 | { |
| 30 | struct ftdi_context *ftdi; |
| 31 | int do_read = 0; |
| 32 | int do_write = 0; |
| 33 | int i, f, retval; |
| 34 | |
| 35 | if ((ftdi = ftdi_new()) == 0) |
| 36 | { |
| 37 | fprintf(stderr, "Failed to allocate ftdi structure :%s \n", |
| 38 | ftdi_get_error_string(ftdi)); |
| 39 | return EXIT_FAILURE; |
| 40 | } |
| 41 | |
| 42 | while ((i = getopt(argc, argv, "brw")) != -1) |
| 43 | { |
| 44 | switch (i) |
| 45 | { |
| 46 | case 'b': |
| 47 | do_read = 1; |
| 48 | do_write = 1; |
| 49 | break; |
| 50 | case 'r': |
| 51 | do_read = 1; |
| 52 | break; |
| 53 | case 'w': |
| 54 | do_write = 1; |
| 55 | break; |
| 56 | default: |
| 57 | fprintf(stderr, "usage: %s [options]\n", *argv); |
| 58 | fprintf(stderr, "\t-b do synchronous read and write\n"); |
| 59 | fprintf(stderr, "\t-r do synchronous read\n"); |
| 60 | fprintf(stderr, "\t-w do synchronous write\n"); |
| 61 | retval = -1; |
| 62 | goto done; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | /* Select first free interface */ |
| 67 | ftdi_set_interface(ftdi, INTERFACE_ANY); |
| 68 | |
| 69 | struct ftdi_device_list *devlist; |
| 70 | int res; |
| 71 | if ((res = ftdi_usb_find_all(ftdi, &devlist, 0, 0)) < 0) |
| 72 | { |
| 73 | fprintf(stderr, "No FTDI with default VID/PID found\n"); |
| 74 | retval = EXIT_FAILURE; |
| 75 | goto do_deinit; |
| 76 | } |
| 77 | if (res > 0) |
| 78 | { |
| 79 | int i = 1; |
| 80 | f = ftdi_usb_open_dev(ftdi, devlist[0].dev); |
| 81 | if (f < 0) |
| 82 | { |
| 83 | fprintf(stderr, "Unable to open device %d: (%s)", |
| 84 | i, ftdi_get_error_string(ftdi)); |
| 85 | retval = -1; |
| 86 | goto do_deinit; |
| 87 | } |
| 88 | } |
| 89 | else |
| 90 | { |
| 91 | fprintf(stderr, "No devices found\n"); |
| 92 | retval = -1; |
| 93 | goto do_deinit; |
| 94 | } |
| 95 | ftdi_list_free(&devlist); |
| 96 | int err = ftdi_tcioflush(ftdi); |
| 97 | if (err != 0) { |
| 98 | fprintf(stderr, "ftdi_tcioflush: %d: %s\n", |
| 99 | err, ftdi_get_error_string(ftdi)); |
| 100 | retval = -1; |
| 101 | goto do_deinit; |
| 102 | } |
| 103 | /* Reset MPSSE controller. */ |
| 104 | err = ftdi_set_bitmode(ftdi, 0, BITMODE_RESET); |
| 105 | if (err != 0) { |
| 106 | fprintf(stderr, "ftdi_set_bitmode: %d: %s\n", |
| 107 | err, ftdi_get_error_string(ftdi)); |
| 108 | retval = -1; |
| 109 | goto do_deinit; |
| 110 | } |
| 111 | /* Enable MPSSE controller. Pin directions are set later.*/ |
| 112 | err = ftdi_set_bitmode(ftdi, 0, BITMODE_MPSSE); |
| 113 | if (err != 0) { |
| 114 | fprintf(stderr, "ftdi_set_bitmode: %d: %s\n", |
| 115 | err, ftdi_get_error_string(ftdi)); |
| 116 | return -1; |
| 117 | } |
| 118 | #define DATA_TO_READ 3 |
| 119 | uint8_t ftdi_init[] = {TCK_DIVISOR, 0x00, 0x00, |
| 120 | /* Set High byte to zero.*/ |
| 121 | SET_BITS_HIGH, 0, 0xff, |
| 122 | GET_BITS_HIGH, |
| 123 | /* Set High byte to 0x55.*/ |
| 124 | SET_BITS_HIGH, 0x55, 0xff, |
| 125 | GET_BITS_HIGH, |
| 126 | /* Set High byte to 0xaa.*/ |
| 127 | SET_BITS_HIGH, 0xaa, 0xff, |
| 128 | GET_BITS_HIGH, |
| 129 | /* Set back to high impedance.*/ |
| 130 | SET_BITS_HIGH, 0x00, 0x00 }; |
| 131 | struct ftdi_transfer_control *tc_read; |
| 132 | struct ftdi_transfer_control *tc_write; |
| 133 | uint8_t data[3]; |
| 134 | if (do_read) { |
| 135 | tc_read = ftdi_read_data_submit(ftdi, data, DATA_TO_READ); |
| 136 | } |
| 137 | if (do_write) { |
| 138 | tc_write = ftdi_write_data_submit(ftdi, ftdi_init, sizeof(ftdi_init)); |
| 139 | int transfer = ftdi_transfer_data_done(tc_write); |
| 140 | if (transfer != sizeof(ftdi_init)) { |
| 141 | printf("Async write failed : %d\n", transfer); |
| 142 | } |
| 143 | } else { |
| 144 | int written = ftdi_write_data(ftdi, ftdi_init, sizeof(ftdi_init)); |
| 145 | if (written != sizeof(ftdi_init)) { |
| 146 | printf("Sync write failed: %d\n", written); |
| 147 | } |
| 148 | } |
| 149 | if (do_read) { |
| 150 | int transfer = ftdi_transfer_data_done(tc_read); |
| 151 | if (transfer != DATA_TO_READ) { |
| 152 | printf("Async Read failed:%d\n", transfer); |
| 153 | } |
| 154 | } else { |
| 155 | int index = 0; |
| 156 | ftdi->usb_read_timeout = 1; |
| 157 | int i = 1000; /* Fail if read did not succeed in 1 second.*/ |
| 158 | while (i--) { |
| 159 | int res = ftdi_read_data(ftdi, data + index, 3 - index); |
| 160 | if (res < 0) { |
| 161 | printf("Async read failure at %d\n", index); |
| 162 | } else { |
| 163 | index += res; |
| 164 | } |
| 165 | if (res == 3) { |
| 166 | break; |
| 167 | } |
| 168 | } |
| 169 | if (i < 1) { |
| 170 | printf("Async read unsuccessful\n"); |
| 171 | } |
| 172 | } |
| 173 | printf("Read %02x %02x %02x\n", data[0], data[1], data[2]); |
| 174 | done: |
| 175 | ftdi_usb_close(ftdi); |
| 176 | do_deinit: |
| 177 | ftdi_free(ftdi); |
| 178 | return retval; |
| 179 | } |