From 75f8523f3a70558788186f8f2d7ca5a6f9f71194 Mon Sep 17 00:00:00 2001
From: Josh Rahm <joshuarahm@gmail.com>
Date: Wed, 18 Nov 2020 22:46:11 -0700
Subject: Change dma.h over to a regset() strategy.

Apparently people really don't like bitfields in practice,
so I have devised a compromise to retain some readability while
using bitmasks instead by writing a regset() macro.
---
 02-usart/include/common.h | 5 +++++
 1 file changed, 5 insertions(+)

(limited to '02-usart/include/common.h')

diff --git a/02-usart/include/common.h b/02-usart/include/common.h
index f9cbe06..394dc62 100644
--- a/02-usart/include/common.h
+++ b/02-usart/include/common.h
@@ -17,6 +17,8 @@
 #define __IO volatile
 #endif
 
+#define CTZ(n) __builtin_ctz(n)
+
 #define bool int
 #ifndef __cplusplus
 #define true 1
@@ -39,4 +41,7 @@
 
 typedef __IO uint32_t bits_t;
 
+#define regset(reg, mask, val) \
+  (reg = (reg & ~mask) | (val << CTZ(mask)))
+
 #endif /* COMMON_H */
-- 
cgit