diff options
Diffstat (limited to 'firmware/asm/arm')
-rw-r--r-- | firmware/asm/arm/beep.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/firmware/asm/arm/beep.c b/firmware/asm/arm/beep.c new file mode 100644 index 0000000000..f3c3e2e0d2 --- /dev/null +++ b/firmware/asm/arm/beep.c | |||
@@ -0,0 +1,39 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (c) 2011 Michael Sevakis | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | /* Actually output samples into beep_buf */ | ||
23 | static FORCE_INLINE void beep_generate(uint32_t *out, int count, | ||
24 | int32_t *phase, uint32_t step, | ||
25 | uint32_t amplitude) | ||
26 | { | ||
27 | uint32_t s; | ||
28 | |||
29 | asm volatile ( | ||
30 | "1: \n" | ||
31 | "eor %3, %5, %1, asr #31 \n" | ||
32 | "subs %2, %2, #1 \n" | ||
33 | "str %3, [%0], #4 \n" | ||
34 | "add %1, %1, %4 \n" | ||
35 | "bgt 1b \n" | ||
36 | : "+r"(out), "+r"(*phase), "+r"(count), | ||
37 | "=&r"(s) | ||
38 | : "r"(step), "r"(amplitude)); | ||
39 | } | ||