Added a Sync FIFO read example

examples/read.rs

@@ -0,0 +1,82 @@
+//! A test script, puts an e.g. FT232H into synchronous FIFO mode and reads data from it.
+//! You will likely need to set (245) FIFO mode in eeprom, first; see FTDI's programmer.
+//! You MAY also need to `sudo rmmod ftdi_sio`, try that if it can't find/open the device.
+//! Assumes data is being streamed; won't block.
+
+extern crate ftdi;
+
+use std::{io::Read, time::Instant, convert::TryInto, convert::TryFrom};
+use std::cmp::min;
+
+const RX_BUF_SIZE: usize = 0x100000;
+const MAX_PRINT_SIZE: usize = 0x10;
+// const MAX_PRINT_SIZE: usize = 0x1000000;
+const ITER: i32 = 0x01;
+
+fn main() {
+    println!("Starting tester...");
+    let device = ftdi::find_by_vid_pid(0x0403, 0x6014) // FT232H
+        .interface(ftdi::Interface::A)
+        .open();
+
+    if let Ok(mut device) = device {
+        println!("Device found and opened");
+        device.usb_reset().unwrap();
+        device.usb_purge_buffers().unwrap();
+        device.set_latency_timer(2).unwrap();
+
+        // Missing: set_usb_parameters
+        device.usb_set_event_char(None).unwrap();
+        device.usb_set_error_char(None).unwrap();
+        // Missing: set_timeouts
+        //ft.set_latency_timer(Duration::from_millis(16))?;
+        //ft.set_flow_control_rts_cts()?;
+        device.set_bitmode(0x00, ftdi::BitMode::Reset).unwrap();
+        device.set_bitmode(0x00, ftdi::BitMode::Syncff).unwrap(); // Synchronous FIFO
+
+        let mut rx_buf: Vec<u8> = vec![0; RX_BUF_SIZE];
+
+        let mut total_us: u128 = 0;
+        let mut total_bytes: u128 = 0;
+        for _ in 0..ITER {
+            print!("...");
+            let now = Instant::now();
+            let ret = device.read(&mut rx_buf).unwrap();
+            let t: u128 = now.elapsed().as_micros();
+            let z: u128 = (ret * 1000000).try_into().unwrap();
+            total_us += t;
+            total_bytes += u128::try_from(ret).unwrap();
+
+            println!("{ret} @ {} = {} B/s", t, z/t);
+
+            let n = min(ret, MAX_PRINT_SIZE);
+            print!("rx: ");
+            if n < ret {
+                for i in 0..n {
+                    print!("{:02X}", rx_buf[i]);
+                }
+                print!("...");
+                for i in (ret-n)..ret {
+                    print!("{:02X}", rx_buf[i]);
+                }
+            } else {
+                for i in 0..n {
+                    print!("{:02X}", rx_buf[i]);
+                }
+            }
+
+            println!();
+            println!();
+        }
+
+        let t: u128 = total_us;
+        let z: u128 = (total_bytes * 1000000).try_into().unwrap();
+        println!("total {total_bytes} @ {} = {} B/s", t, z/t); // Doesn't account for print time, buffering means this may be incorrect
+
+        println!();
+
+        println!("Testing finished");
+    } else {
+        println!("Cannot find/open device, runtime tests are NOP");
+    }
+}