[fpga-boss] add command to reset FPGA from FTDI chip (#2426)

* [fpga-boss] fix comment

Signed-off-by: Tim Trippel <ttrippel@google.com>

* [fpga-boss] make `sdwire` and `usbsdmux` nonmandatory args

Not all subcommands require these args to be set. Refactor the code such
that only subcommands that use these args require them.

Signed-off-by: Tim Trippel <ttrippel@google.com>

* [fpga-boss] add command to reset FPGA from FTDI chip

Currently the only way to reset the FPGA board was to also toggle the SD
card mux which, as a byproduct, also toggled the FPGA reset. This adds a
dedicated FPGA reset command to fpga-boss.

Signed-off-by: Tim Trippel <ttrippel@google.com>

---------

Signed-off-by: Tim Trippel <ttrippel@google.com>

Author: timothytrippel

ci-tools/fpga-boss/src/fpga_jtag.rs

@@ -33,7 +33,7 @@ impl FpgaJtag {
                 // Set PS_POR_B high, PS_SRST_B low
                 self.ftdi.write_all_data(&[0x8d])?;
 
-                // wait a bi
+                // wait a bit
                 std::thread::sleep(Duration::from_millis(1));
 
                 // Set PS_POR_B and PS_SRST_B pins high

ci-tools/fpga-boss/src/main.rs

@@ -55,6 +55,8 @@ fn cli() -> clap::Command<'static> {
             .arg(arg!(<IMAGE_FILENAME>).value_parser(value_parser!(PathBuf))))
         .subcommand(clap::Command::new("console")
             .about("Tail the UART output from zcu104"))
+        .subcommand(clap::Command::new("reset_fpga")
+            .about("Reset FPGA SoC using FTDI on zcu104 by toggle POR_B reset."))
         .subcommand(clap::Command::new("reset_ftdi")
             .about("Reset FTDI chip on zcu104"))
         .subcommand(clap::Command::new("serve")
@@ -235,6 +237,21 @@ fn log_uart_until_helper<R: BufRead>(
     Err(Error::new(ErrorKind::UnexpectedEof, "unexpected EOF"))
 }
 
+fn get_sd_mux(
+    sdwire: Option<&OsString>,
+    usbsdmux: Option<&OsString>,
+) -> anyhow::Result<Box<dyn SdMux>> {
+    match (sdwire, usbsdmux) {
+        (Some(sdwire), None) => {
+            Ok(Box::new(SDWire::open(String::from(sdwire.to_str().unwrap()))?) as Box<dyn SdMux>)
+        }
+        (None, Some(usbsdmux)) => Ok(Box::new(UsbsdMux::open(String::from(
+            usbsdmux.to_str().unwrap(),
+        ))?) as Box<dyn SdMux>),
+        _ => Err(anyhow!("One of --sdwire or --usbsdmux required")),
+    }
+}
+
 fn main_impl() -> anyhow::Result<()> {
     let matches = cli().get_matches();
     let sdwire = matches.get_one::<OsString>("sdwire");
@@ -259,19 +276,10 @@ fn main_impl() -> anyhow::Result<()> {
             .cloned()
     };
 
-    let mut sd_mux: Box<dyn SdMux> = match (sdwire, usbsdmux) {
-        (Some(sdwire), None) => {
-            Box::new(SDWire::open(String::from(sdwire.to_str().unwrap()))?) as Box<dyn SdMux>
-        }
-        (None, Some(usbsdmux)) => {
-            Box::new(UsbsdMux::open(String::from(usbsdmux.to_str().unwrap()))?) as Box<dyn SdMux>
-        }
-        _ => return Err(anyhow!("One of --sdwire or --usbsdmux required")),
-    };
-
     let get_fpga_ftdi = || FpgaJtag::open(get_zcu104_path()?);
     match matches.subcommand() {
         Some(("mode", sub_matches)) => {
+            let mut sd_mux = get_sd_mux(sdwire, usbsdmux)?;
             let mut fpga = get_fpga_ftdi();
             match sub_matches.get_one::<SdMuxTarget>("MODE").unwrap() {
                 SdMuxTarget::Dut => {
@@ -292,6 +300,16 @@ fn main_impl() -> anyhow::Result<()> {
                 }
             }
         }
+        Some(("reset_fpga", _)) => {
+            let mut fpga = get_fpga_ftdi();
+            if let Ok(fpga) = &mut fpga {
+                fpga.set_reset(FpgaReset::Reset)?;
+                std::thread::sleep(Duration::from_millis(1));
+                fpga.set_reset(FpgaReset::Run)?;
+            } else {
+                return Err(anyhow!("Error: failed to connect to FTDI chip."));
+            }
+        }
         Some(("reset_ftdi", _)) => {
             let mut fpga = get_fpga_ftdi()?;
             fpga.ftdi.reset()?;
@@ -334,6 +352,7 @@ fn main_impl() -> anyhow::Result<()> {
             println!();
         }
         Some(("flash", sub_matches)) => {
+            let mut sd_mux = get_sd_mux(sdwire, usbsdmux)?;
             let mut fpga = get_fpga_ftdi();
             let sd_dev_path = sd_mux.get_sd_dev_path()?;
             if let Ok(fpga) = &mut fpga {
@@ -363,6 +382,7 @@ fn main_impl() -> anyhow::Result<()> {
         }
 
         Some(("serve", sub_matches)) => {
+            let mut sd_mux = get_sd_mux(sdwire, usbsdmux)?;
             // Reuse the previous token if we never connect to GitHub.
             // This avoids creating a bunch of offline runners if the FPGA fails to establish a
             // connection.