From 299c3fa2ef6d4505cd2b5208fc7184b34b7a7893 Mon Sep 17 00:00:00 2001
From: Grazfather <grazfather@gmail.com>
Date: Mon, 19 Feb 2024 21:08:21 -0500
Subject: [PATCH] wip: rp2040: Add support for PIO's jmp_pin

This field is a bit tricky: It belongs to the EXECCTRL register, while
most of the other fields can determined based on the directives used in
the assembled program, this one has to be set explicitly. This makes it
so that we have to plumb some way to explicitly set the field. I did
this by making `LoadAndStartProgramOptions` take `ExecOptions`, but this
isn't perfect, because if a user sets other fields, they will be ignored
in favour of the values set in the program.
---
 board-support/raspberrypi-rp2040/src/hal/pio.zig | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/board-support/raspberrypi-rp2040/src/hal/pio.zig b/board-support/raspberrypi-rp2040/src/hal/pio.zig
index 9472728d..473f5f2e 100644
--- a/board-support/raspberrypi-rp2040/src/hal/pio.zig
+++ b/board-support/raspberrypi-rp2040/src/hal/pio.zig
@@ -83,6 +83,7 @@ pub const ClkDivOptions = struct {
 };
 
 pub const ExecOptions = struct {
+    jmp_pin: u5 = 0,
     wrap: u5 = 31,
     wrap_target: u5 = 0,
     side_pindir: bool = false,
@@ -132,6 +133,7 @@ pub const LoadAndStartProgramOptions = struct {
     clkdiv: ClkDivOptions,
     shift: ShiftOptions = .{},
     pin_mappings: PinMappingOptions = .{},
+    exec: ExecOptions = .{},
 };
 
 pub const Pio = enum(u1) {
@@ -254,10 +256,12 @@ pub const Pio = enum(u1) {
     pub fn sm_set_exec_options(self: Pio, sm: StateMachine, options: ExecOptions) void {
         const sm_regs = self.get_sm_regs(sm);
         sm_regs.execctrl.modify(.{
+            // NOTE: EXEC_STALLED is RO
             .WRAP_BOTTOM = options.wrap_target,
             .WRAP_TOP = options.wrap,
             .SIDE_PINDIR = @intFromBool(options.side_pindir),
             .SIDE_EN = @intFromBool(options.side_set_optional),
+            .JMP_PIN = options.jmp_pin,
 
             // TODO: plug in rest of the options
             // STATUS_N
@@ -265,7 +269,6 @@ pub const Pio = enum(u1) {
             // OUT_STICKY
             // INLINE_OUT_EN
             // OUT_EN_SEL
-            // JMP_PIN
             // EXEC_STALLED
         });
     }
@@ -514,6 +517,8 @@ pub const Pio = enum(u1) {
                     side_set.optional
                 else
                     false,
+
+                .jmp_pin = options.exec.jmp_pin,
             },
         });
     }