refactor: add --chip for chip type check; fix 0x0c command; refine error handling

CHANGELOG.md

@@ -13,10 +13,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support WCH-Link firmware 2.9, some raw commands are changed
 - Support Flash protect and unprotect (#14)
 - Fix stuck for CH5xx devices, due to unsppported read ram rom split command
+- Add `--chip` option to specify chip type
+- Check probe type when doing mode-switch
 
 ### Fixed
 
 - Constraint regs for riscv32ec variant
+- Wrong 0x0c command interpretation, this should be a set chip speed command
+
+### Changed
+
+- Refine error messages
 
 ## [0.0.4] - 2023-07-01
 

src/commands.rs

@@ -181,6 +181,7 @@ impl Command for SetFlashProtected {
 }
 
 /// Get Chip UID, the UID is also avaliable in the `wchisp` command.
+// ??? 0x11, 0x01, _ (riscvchip)
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
 pub enum QueryChipInfo {
     V1 = 0x09,
@@ -261,6 +262,29 @@ impl Command for Reset {
     }
 }
 
+/// (0x0c, [riscvchip, 1/2/3])
+pub struct SetTwoLineMode {
+    pub riscvchip: u8,
+    pub speed: u8, // 1, 2, 3
+}
+
+impl Command for SetTwoLineMode {
+    type Response = bool;
+    const COMMAND_ID: u8 = 0x0c;
+    fn payload(&self) -> Vec<u8> {
+        vec![self.riscvchip, self.speed]
+    }
+}
+
+impl Response for bool {
+    fn from_payload(resp: &[u8]) -> Result<Self> {
+        if resp.len() != 1 {
+            return Err(Error::InvalidPayloadLength);
+        }
+        Ok(resp[0] == 0x01) // 1 means success
+    }
+}
+
 /// DMI operations
 pub enum DmiOp {
     Nop,

src/commands/control.rs

@@ -54,7 +54,7 @@ impl fmt::Display for ProbeInfo {
     }
 }
 
-/// (0x0d, 0x02)
+/// ?SetChipType (0x0d, 0x02)
 pub struct AttachChip;
 impl Command for AttachChip {
     type Response = AttachChipResponse;
@@ -64,7 +64,7 @@ impl Command for AttachChip {
     }
 }
 
-#[derive(Debug)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct AttachChipResponse {
     pub chip_family: RiscvChip,
     pub riscvchip: u8,

src/device.rs

@@ -60,7 +60,18 @@ impl WchLink {
                     .unwrap_or(false)
             })
             .nth(nth)
-            .map_or(Err(crate::error::Error::ProbeNotFound), Ok)?;
+            .map_or(Err(crate::error::Error::ProbeNotFound), Ok);
+
+        // check if there's a device with the DAP VID/PID
+        let device = match device {
+            Ok(device) => device,
+            Err(e) => {
+                if let Ok(_) = open_usb_device(VENDOR_ID_DAP, PRODUCT_ID_DAP, nth) {
+                    return Err(crate::error::Error::ProbeModeNotSupported);
+                }
+                return Err(e);
+            }
+        };
 
         let mut device_handle = device.open()?;
 
@@ -130,9 +141,15 @@ pub fn try_switch_from_rv_to_dap(nth: usize) -> Result<()> {
     };
     let info = dev.probe_info()?;
     info!("probe info: {:?}", info);
-
-    let _ = dev.send_command(RawCommand::<0xff>(vec![0x41]));
-    Ok(())
+    if info.variant.can_switch_mode() {
+        let _ = dev.send_command(RawCommand::<0xff>(vec![0x41]));
+        Ok(())
+    } else {
+        log::error!("Cannot switch mode for WCH-LinkRV: not supported");
+        return Err(crate::Error::Custom(
+            "WCH-Link-CH549 does not support mode switch".into(),
+        ));
+    }
 }
 
 /// Switch from RV mode to DAP mode

src/error.rs

@@ -1,5 +1,7 @@
 use thiserror::Error;
 
+use crate::RiscvChip;
+
 /// Alias for a `Result` with the error type `wlink::Error`.
 pub type Result<T> = std::result::Result<T, Error>;
 
@@ -9,14 +11,18 @@ pub enum Error {
     Custom(String),
     #[error("USB error: {0}")]
     Rusb(#[from] rusb::Error),
-    #[error("WCH-Link not found or not in RV mode, please check your connection or use mode-switch tool to switch to RV mode")]
+    #[error("WCH-Link not found, please check your connection")]
     ProbeNotFound,
+    #[error("WCH-Link is connected, but is not in RV mode")]
+    ProbeModeNotSupported,
     #[error("Unknown WCH-Link variant: {0}")]
     UnknownLinkVariant(u8),
     #[error("Unknown RISC-V Chip: 0x{0:02x}")]
     UnknownChip(u8),
     #[error("Probe is not attached to an MCU, or debug is not enabled. (hint: use wchisp to enable debug)")]
     NotAttached,
+    #[error("Chip mismatch: expected {0:?}, got {1:?}")]
+    ChipMismatch(RiscvChip, RiscvChip),
     #[error("WCH-Link underlying protocol error: {0:#04x} {1:#04x?}")]
     Protocol(u8, Vec<u8>),
     #[error("Invalid payload length")]

src/lib.rs

@@ -1,4 +1,4 @@
-use std::fmt;
+use std::{fmt, str::FromStr};
 
 pub mod commands;
 pub mod device;
@@ -39,6 +39,13 @@ impl WchLinkVariant {
             _ => Err(Error::UnknownLinkVariant(value)),
         }
     }
+
+    pub fn can_switch_mode(&self) -> bool {
+        match self {
+            WchLinkVariant::Ch549 => false,
+            _ => true,
+        }
+    }
 }
 
 impl fmt::Display for WchLinkVariant {
@@ -86,11 +93,14 @@ impl RiscvChip {
             RiscvChip::CH32V103 | RiscvChip::CH32V003 | RiscvChip::CH32V20X | RiscvChip::CH32V30X
         )
     }
-    fn can_disable_debug(&self) -> bool {
+
+    /// Very unsafe. This disables the debug interface of the chip.
+    /// Command sequence is 810e0101
+    pub fn can_disable_debug(&self) -> bool {
         matches!(self, RiscvChip::CH57X | RiscvChip::CH56X | RiscvChip::CH58X)
     }
 
-    fn reset_command(&self) -> crate::commands::Reset {
+    pub fn reset_command(&self) -> crate::commands::Reset {
         match self {
             RiscvChip::CH57X | RiscvChip::CH58X => crate::commands::Reset::Normal2,
             _ => crate::commands::Reset::Normal,
@@ -146,3 +156,21 @@ impl RiscvChip {
         }
     }
 }
+
+// for clap parser
+impl FromStr for RiscvChip {
+    type Err = Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match &*s.to_ascii_uppercase() {
+            "CH32V103" => Ok(RiscvChip::CH32V103),
+            "CH32V20X" => Ok(RiscvChip::CH32V20X),
+            "CH32V30X" => Ok(RiscvChip::CH32V30X),
+            "CH32V003" => Ok(RiscvChip::CH32V003),
+            "CH56X" => Ok(RiscvChip::CH56X),
+            "CH57X" => Ok(RiscvChip::CH57X),
+            "CH58X" => Ok(RiscvChip::CH58X),
+            _ => Err(Error::UnknownChip(0)),
+        }
+    }
+}

src/main.rs

@@ -1,7 +1,7 @@
 use std::{thread::sleep, time::Duration};
 
 use anyhow::Result;
-use wlink::{commands, device::WchLink, format::read_firmware_from_file, regs};
+use wlink::{commands, device::WchLink, format::read_firmware_from_file, regs, RiscvChip};
 
 use clap::{Parser, Subcommand};
 
@@ -20,6 +20,10 @@ struct Cli {
     #[arg(long, global = true)]
     detach: bool,
 
+    /// Specify the chip type, e.g. CH32V30X
+    #[arg(long, global = true)]
+    chip: Option<RiscvChip>,
+
     #[command(subcommand)]
     command: Option<Commands>,
 }
@@ -137,7 +141,7 @@ fn main() -> Result<()> {
         Some(command) => {
             let mut probe = WchLink::open_nth(device_index)?;
             probe.probe_info()?;
-            probe.attach_chip()?;
+            probe.attach_chip(cli.chip)?;
             match command {
                 Dump { address, length } => {
                     log::info!(

src/operations.rs

@@ -18,23 +18,36 @@ impl WchLink {
         Ok(info)
     }
     /// Attach chip and get chip info
-    pub fn attach_chip(&mut self) -> Result<()> {
+    pub fn attach_chip(&mut self, expected_chip: Option<RiscvChip>) -> Result<()> {
         if self.chip.is_some() {
             log::warn!("Chip already attached");
         }
 
-        let mut chip_info = None;
         let probe_info = self.send_command(commands::control::GetProbeInfo)?;
+
+        let mut chip_info = None;
         for _ in 0..3 {
             // self.send_command(commands::control::DetachChip)?;
 
-            // unknown command
-            // 0x07 seems to be the expected richvchip id
-            self.send_command(commands::RawCommand::<0x0c>(vec![0x07, 0x01]))?;
+            self.send_command(commands::SetTwoLineMode {
+                riscvchip: expected_chip.unwrap_or(RiscvChip::CH32V30X) as u8,
+                speed: 1, // 1 high, 2, medium, 3 low
+            })?;
 
             if let Ok(resp) = self.send_command(commands::control::AttachChip) {
                 log::info!("Attached chip: {}", resp);
                 chip_info = Some(resp);
+
+                if let Some(expected_chip) = expected_chip {
+                    if resp.chip_family != expected_chip {
+                        log::error!(
+                            "Attached chip type ({:?}) does not match expected chip type ({:?})",
+                            resp.chip_family,
+                            expected_chip
+                        );
+                        return Err(Error::ChipMismatch(expected_chip, resp.chip_family));
+                    }
+                }
                 break;
             } else {
                 log::debug!("retrying...");