trace MAX5970 status/faults/max current/max voltage on V12 rails

[bcantrill]

No description provided.

[mkeeter]

I'd vote to explicitly log errors here, since they could be interesting. Something like

Suggested change

	ringbuf_entry!(Trace::Max5970 {
	sensor,
	status0: match dev.read_reg(Register::status0) {
	Ok(reg) => reg,
	_ => return,
	},
	status3: match dev.read_reg(Register::status3) {
	Ok(reg) => reg,
	_ => return,
	},
	fault0: match dev.read_reg(Register::fault0) {
	Ok(reg) => reg,
	_ => return,
	},
	fault1: match dev.read_reg(Register::fault1) {
	Ok(reg) => reg,
	_ => return,
	},
	fault2: match dev.read_reg(Register::fault2) {
	Ok(reg) => reg,
	_ => return,
	},
	max_current: match dev.max_iout() {
	Ok(Amperes(amps)) => amps,
	_ => return,
	},
	max_voltage: volts,
	});
	// Helper function to read a register or log the failure
	let f = |reg| match dev.read_reg(reg) {
	Ok(reg) => Some(reg),
	Err(err) => {
	ringbuf_entry!(Trace::Max5970ReadFailed { reg, err });
	None
	}
	};
	let Some(status0) = f(Register::status0) else { return; };
	let Some(status3) = f(Register::status3) else { return; };
	let Some(fault0) = f(Register::fault0) else { return; };
	let Some(fault1) = f(Register::fault1) else { return; };
	let Some(fault2) = f(Register::fault2) else { return; };
	let max_current = match dev.max_iout() {
	Ok(Amperes(amps)) => amps,
	Err(err) => {
	ringbuf_entry!(Trace::Max5970MaxCurrentFailed { err });
	return;
	}
	};
	ringbuf_entry!(Trace::Max5970 {
	sensor,
	status0,
	status3,
	fault0,
	fault1,
	fault2,
	max_current,
	max_voltage: volts,
	});

along with two new ringbuf variants:

diff --git a/task/power/src/main.rs b/task/power/src/main.rs
index cd5b0623..93a77268 100644
--- a/task/power/src/main.rs
+++ b/task/power/src/main.rs
@@ -48,6 +48,13 @@ enum Trace {
         max_current: f32,
         max_voltage: f32,
     },
+    Max5970ReadFailed {
+        reg: drv_i2c_devices::max5970::Register,
+        err: ResponseCode,
+    },
+    Max5970MaxCurrentFailed {
+        err: ResponseCode,
+    },
     None,
 }

[bcantrill]

I have mixed feelings about this because I don't want to flood the ring buffer with a failed device and miss the PGs on others. (We will be able to deduce failures by the absence of expected devices.)