touchpad: Show IC type and firmware version

Example on Framework 13:

```
> framework_tool --version
[...]
Touchpad
  IC Type:           0274
  Firmware Version: v0704
```

Signed-off-by: Daniel Schaefer <dhs@frame.work>

Author: JohnAZoidberg

framework_lib/src/commandline/mod.rs

@@ -51,6 +51,8 @@ use crate::smbios;
 use crate::smbios::ConfigDigit0;
 use crate::smbios::{dmidecode_string_val, get_smbios, is_framework};
 #[cfg(feature = "hidapi")]
+use crate::touchpad::print_touchpad_fw_ver;
+#[cfg(feature = "hidapi")]
 use crate::touchscreen::print_touchscreen_fw_ver;
 #[cfg(feature = "uefi")]
 use crate::uefi::enable_page_break;
@@ -478,6 +480,8 @@ fn print_versions(ec: &CrosEc) {
     check_camera_version();
     #[cfg(feature = "hidapi")]
     print_touchscreen_fw_ver().unwrap();
+    #[cfg(feature = "hidapi")]
+    print_touchpad_fw_ver().unwrap();
 }
 
 fn print_esrt() {

framework_lib/src/lib.rs

@@ -17,6 +17,8 @@ pub mod audio_card;
 #[cfg(feature = "rusb")]
 pub mod camera;
 #[cfg(feature = "hidapi")]
+pub mod touchpad;
+#[cfg(feature = "hidapi")]
 pub mod touchscreen;
 
 #[cfg(feature = "uefi")]

framework_lib/src/touchpad.rs

@@ -0,0 +1,58 @@
+use hidapi::{HidApi, HidDevice, HidError};
+
+pub const PIX_VID: u16 = 0x093A;
+pub const PIX_REPORT_ID: u8 = 0x43;
+
+fn read_byte(device: &HidDevice, addr: u8) -> Result<u8, HidError> {
+    device.send_feature_report(&[PIX_REPORT_ID, addr, 0x10, 0])?;
+
+    let mut buf = [0u8; 4];
+    buf[0] = PIX_REPORT_ID;
+
+    device.get_feature_report(&mut buf)?;
+    Ok(buf[3])
+}
+
+fn read_ver(device: &HidDevice) -> Result<u16, HidError> {
+    Ok(u16::from_le_bytes([
+        read_byte(device, 0xb2)?,
+        read_byte(device, 0xb3)?,
+    ]))
+}
+
+pub fn print_touchpad_fw_ver() -> Result<(), HidError> {
+    match HidApi::new() {
+        Ok(api) => {
+            for dev_info in api.device_list() {
+                let vid = dev_info.vendor_id();
+                let pid = dev_info.product_id();
+                let usage_page = dev_info.usage_page();
+
+                debug!("Found {:X}:{:X} Usage Page: {}", vid, pid, usage_page);
+                if vid != PIX_VID || (pid != 0x0274 && pid != 0x0239) {
+                    continue;
+                }
+                if usage_page != 0xFF00 {
+                    continue;
+                }
+
+                let device = dev_info.open_device(&api).unwrap();
+
+                // On Windows this value is "Control Interface", probably hijacked by the kernel driver
+                debug!(
+                    "  Product String:  {}",
+                    dev_info.product_string().unwrap_or("")
+                );
+
+                println!("Touchpad");
+                println!("  IC Type:           {:04X}", pid);
+                println!("  Firmware Version: v{:04X}", read_ver(&device)?);
+            }
+        }
+        Err(e) => {
+            eprintln!("Error: {e}");
+        }
+    };
+
+    Ok(())
+}