api: add cxp api support for CTRL packet

src/libksupport/src/cxp.rs

@@ -0,0 +1,11 @@
+use libboard_artiq::cxp_proto;
+
+pub extern "C" fn cxp_readu32(channel: i32, addr: i32) {
+    // TODO: use artiq_raise like i2c?
+    cxp_proto::read_u32(channel as u8, addr as u32).expect("CXP transmission failed");
+}
+
+pub extern "C" fn cxp_writeu32(channel: i32, addr: i32, val: i32) {
+    // TODO: use artiq_raise like i2c?
+    cxp_proto::write_u32(channel as u8, addr as u32, val as u32).expect("CXP transmission failed");
+}

src/libksupport/src/kernel/api.rs

@@ -11,6 +11,8 @@ use super::{cache,
             core1::rtio_get_destination_status,
             dma, linalg,
             rpc::{rpc_recv, rpc_send, rpc_send_async}};
+#[cfg(has_cxp_phys)]
+use crate::cxp;
 use crate::{eh_artiq, i2c, rtio};
 
 extern "C" {
@@ -126,6 +128,12 @@ pub fn resolve(required: &[u8]) -> Option<u32> {
         #[cfg(has_drtio)]
         api!(subkernel_await_message = subkernel::await_message),
 
+        // CoaXPress
+        #[cfg(has_cxp_phys)]
+        api!(cxp_readu32 = cxp::cxp_readu32),
+        #[cfg(has_cxp_phys)]
+        api!(cxp_writeu32 = cxp::cxp_writeu32),
+
         // Double-precision floating-point arithmetic helper functions
         // RTABI chapter 4.1.2, Table 2
         api!(__aeabi_dadd),

src/libksupport/src/lib.rs

@@ -35,6 +35,8 @@ pub mod rtio;
 #[path = "../../../build/pl.rs"]
 pub mod pl;
 
+#[cfg(has_cxp_phys)]
+pub mod cxp;
 
 #[derive(Debug, Clone)]
 pub struct RPCException {