examples/async.c : Short example using async read/write

[libftdi] / examples / async.c

diff --git a/examples/async.c b/examples/async.c
new file mode 100644 (file)
index 0000000..08457b9
--- /dev/null
+++ b/examples/async.c
@@ -0,0 +1,147 @@
+/* LIBFTDI EEPROM access example
+
+   This program is distributed under the GPL, version 2
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <ftdi.h>
+
+int main(int argc, char **argv)
+{
+    struct ftdi_context *ftdi;
+    int do_read = 0;
+    int do_write = 0;
+    int i, f, retval;
+
+    if ((ftdi = ftdi_new()) == 0)
+    {
+        fprintf(stderr, "Failed to allocate ftdi structure :%s \n",
+                ftdi_get_error_string(ftdi));
+        return EXIT_FAILURE;
+    }
+
+    while ((i = getopt(argc, argv, "brw")) != -1)
+    {
+        switch (i)
+        {
+            case 'b':
+                do_read = 1;
+                do_write = 1;
+                break;
+            case 'r':
+                do_read = 1;
+                break;
+            case 'w':
+                do_write  = 1;
+                break;
+            default:
+                fprintf(stderr, "usage: %s [options]\n", *argv);
+                fprintf(stderr, "\t-b do synchronous read and write\n");
+                fprintf(stderr, "\t-r do synchronous read\n");
+                fprintf(stderr, "\t-w do synchronous write\n");
+                retval = -1;
+                goto done;
+        }
+    }
+
+    // Select first interface
+    ftdi_set_interface(ftdi, INTERFACE_ANY);
+
+    struct ftdi_device_list *devlist;
+    int res;
+    if ((res = ftdi_usb_find_all(ftdi, &devlist, 0, 0)) < 0)
+    {
+        fprintf(stderr, "No FTDI with default VID/PID found\n");
+        retval =  EXIT_FAILURE;
+        goto do_deinit;
+    }
+    if (res > 0)
+    {
+        int i = 1;
+        f = ftdi_usb_open_dev(ftdi, devlist[0].dev);
+        if (f < 0)
+        {
+            fprintf(stderr, "Unable to open device %d: (%s)",
+                    i, ftdi_get_error_string(ftdi));
+            retval = -1;
+            goto do_deinit;
+        }
+    }
+    else
+    {
+        fprintf(stderr, "No devices found\n");
+        retval = -1;
+        goto do_deinit;
+    }
+    ftdi_list_free(&devlist);
+    int err = ftdi_usb_purge_buffers(ftdi);
+    if (err != 0) {
+        fprintf(stderr, "ftdi_usb_purge_buffer: %d: %s\n",
+                err, ftdi_get_error_string(ftdi));
+        retval = -1;
+        goto do_deinit;
+    }
+    /* Reset MPSSE controller. */
+    err = ftdi_set_bitmode(ftdi, 0,  BITMODE_RESET);
+    if (err != 0) {
+        fprintf(stderr, "ftdi_set_bitmode: %d: %s\n",
+                err, ftdi_get_error_string(ftdi));
+        retval = -1;
+        goto do_deinit;
+   }
+    /* Enable MPSSE controller. Pin directions are set later.*/
+    err = ftdi_set_bitmode(ftdi, 0, BITMODE_MPSSE);
+    if (err != 0) {
+        fprintf(stderr, "ftdi_set_bitmode: %d: %s\n",
+                err, ftdi_get_error_string(ftdi));
+        return -1;
+    }
+    uint8_t ftdi_init[15] = {TCK_DIVISOR, 0x00, 0x00,
+                             SET_BITS_HIGH, 0, 0xff,
+                             GET_BITS_HIGH,
+                             SET_BITS_HIGH, 0x55, 0xff,
+                             GET_BITS_HIGH,
+                             SET_BITS_HIGH, 0xaa, 0xff,
+                             GET_BITS_HIGH};
+    struct ftdi_transfer_control *tc_read;
+    struct ftdi_transfer_control *tc_write;
+    uint8_t data[3];
+    if (do_read) {
+        tc_read = ftdi_read_data_submit(ftdi, data, 3);
+    }
+    if (do_write) {
+        tc_write = ftdi_write_data_submit(ftdi, ftdi_init, 15);
+        int transfer = ftdi_transfer_data_done(tc_write);
+        printf("Async write %d\n", transfer);
+    } else {
+        int written = ftdi_write_data(ftdi, ftdi_init, 15);
+        if (written != 15) {
+            printf("Sync write failed\n");
+        }
+    }
+    if (do_read) {
+        int transfer = ftdi_transfer_data_done(tc_read);
+        printf("Async Read %d\n", transfer);
+    } else {
+        int index = 0;
+        while (index < 3) {
+            int res = ftdi_read_data(ftdi, data + index, 3 - index);
+            if (res < 0) {
+                printf("Async read failure at %d\n", index);
+            } else {
+                index += res;
+            }
+        }
+    }
+    printf("Read %02x %02x %02x\n", data[0], data[1], data[2]);
+done:
+    ftdi_usb_close(ftdi);
+do_deinit:
+    ftdi_free(ftdi);
+    return retval;
+}