From d221874806cbbbc125966f9a588b0747ca79efd5 Mon Sep 17 00:00:00 2001
From: morgan <mc@m-labs.hk>
Date: Fri, 24 Jan 2025 13:36:11 +0800
Subject: [PATCH] cxp fw: refactor

---
 src/libboard_artiq/src/cxp.rs | 40 +++++++++++++----------------------
 1 file changed, 15 insertions(+), 25 deletions(-)

diff --git a/src/libboard_artiq/src/cxp.rs b/src/libboard_artiq/src/cxp.rs
index 30f2254..c55969b 100644
--- a/src/libboard_artiq/src/cxp.rs
+++ b/src/libboard_artiq/src/cxp.rs
@@ -31,7 +31,6 @@ const VERSION_SUPPORTED: u32 = 0x4044;
 const VERSION_USED: u32 = 0x4048;
 
 // Setup const
-const CXP_CHANNELS: u8 = CXP_LEN as u8;
 // TEST: result
 // Currently, multilane/channel is not working properly in gateware due to buffer overflow issue
 // only single lane @ 0x800 max pak size or dual lane 256 max pak size is working
@@ -97,9 +96,8 @@ pub fn setup() -> Result<bool, Error> {
 
 fn scan_active_channels() -> u8 {
     let mut active_channels: u8 = 0;
-    for ch in 0..CXP_CHANNELS {
-        if unsafe { (CXP[ch as usize].rx_ready_read)() } == 1 {
-            // info!("ch#{} is up <---------------------------------", ch);
+    for ch in 0..CXP_LEN {
+        if unsafe { (CXP[ch].rx_ready_read)() } == 1 {
             active_channels += 1;
         }
     }
@@ -115,8 +113,8 @@ fn discover_camera(timer: &mut GlobalTimer) -> Result<(), Error> {
 
         // Section 12.1.2 (CXP-001-2021)
         // send ConnectionReset on all channels -> wait 200ms -> scan for active channels
-        for ch in 0..CXP_CHANNELS {
-            write_bytes_no_ack(ch, CONNECTION_RESET, &1_u32.to_be_bytes(), false)?;
+        for ch in 0..CXP_LEN {
+            write_bytes_no_ack(ch as u8, CONNECTION_RESET, &1_u32.to_be_bytes(), false)?;
         }
         timer.delay_ms(200);
 
@@ -155,8 +153,8 @@ fn check_connection_topology(active_channels: u8) -> Result<(), Error> {
 }
 
 fn negotiate_active_channels(timer: &mut GlobalTimer) -> Result<u8, Error> {
-    let mut available_chs = read_u32(MASTER_CHANNEL, CONNECTION_CFG_DEFAULT, false)? >> 16;
-    available_chs = available_chs.min(CXP_CHANNELS as u32);
+    let max_camera_chs = read_u32(MASTER_CHANNEL, CONNECTION_CFG_DEFAULT, false)? >> 16;
+    let available_chs = max_camera_chs.min(CXP_LEN as u32);
 
     // activate channels on camera but preserve the discovery linerate
     let current_cfg = read_u32(MASTER_CHANNEL, CONNECTION_CFG, false)?;
@@ -168,35 +166,33 @@ fn negotiate_active_channels(timer: &mut GlobalTimer) -> Result<u8, Error> {
     )?;
 
     timer.delay_ms(200);
-    let active_channels = scan_active_channels();
-    check_connection_topology(active_channels)?;
+    let active_chs = scan_active_channels();
+    check_connection_topology(active_chs)?;
 
-    if available_chs > active_channels as u32 {
+    if available_chs > active_chs as u32 {
         info!(
             "Only detected {} channel(s), disabling excess channels on camera",
-            active_channels
+            active_chs
         );
         write_u32(
             MASTER_CHANNEL,
             CONNECTION_CFG,
-            current_cfg & 0xFFFF | ((active_channels as u32) << 16),
+            current_cfg & 0xFFFF | ((active_chs as u32) << 16),
             false,
         )?;
 
         timer.delay_ms(200);
         // check no active channels are down after the cfg change
-        if active_channels != scan_active_channels() {
+        if active_chs != scan_active_channels() {
             return Err(Error::ConnectionLost);
         }
     }
-    Ok(active_channels)
+    Ok(active_chs)
 }
 
 fn set_host_connection_id() -> Result<(), Error> {
-    // TODO: not mandatory??
+    info!("setting host connection id to = {}", HOST_CONNECTION_ID);
     write_u32(MASTER_CHANNEL, MASTER_HOST_CONNECTION_ID, HOST_CONNECTION_ID, false)?;
-    let reg = read_u32(MASTER_CHANNEL, MASTER_HOST_CONNECTION_ID, false)?;
-    info!("host connection id set as = {}", reg);
     Ok(())
 }
 
@@ -234,7 +230,7 @@ fn negotiate_cxp_version() -> Result<bool, Error> {
 }
 
 fn negotiate_pak_max_size(with_tag: bool) -> Result<(), Error> {
-    // TODO: set MAX CONTROL packet size?
+    // DEBUG: print control & stream packet size
     let reg = read_u32(MASTER_CHANNEL, CONTROL_PACKET_SIZE_MAX, with_tag)?;
     info!("Max CTRL PAK size = {:#010X}", reg);
 
@@ -388,11 +384,5 @@ fn camera_setup(timer: &mut GlobalTimer) -> Result<bool, Error> {
 
     test_channels_stability(active_channels, cxp_v2_or_greater, timer)?;
 
-    // unsafe{
-    //     // don't set two identical routingid, the router cannot handle it
-    //     // it can handle it after adding the priority decoder
-    //     cxp_frame_pipeline::buffer_1_routingid_write(0x00);
-    // }
-
     Ok(cxp_v2_or_greater)
 }