From bbfc9c449f61fc553bdea797b2f77af9d9420ccf Mon Sep 17 00:00:00 2001 From: Stefan Reinauer Date: Tue, 25 Oct 2011 14:15:57 -0700 Subject: [PATCH] Fix libpayload speaker driver The frequency for the PC speaker has to be specified as 1193180 / frequency according to http://wiki.osdev.org/PC_Speaker Change-Id: Iaca9d45807e080efe834611e719b350680b5fb90 Signed-off-by: Stefan Reinauer Reviewed-on: http://review.coreboot.org/337 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi --- payloads/libpayload/drivers/speaker.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/payloads/libpayload/drivers/speaker.c b/payloads/libpayload/drivers/speaker.c index 3b3a75031..3a561bcbf 100644 --- a/payloads/libpayload/drivers/speaker.c +++ b/payloads/libpayload/drivers/speaker.c @@ -60,13 +60,15 @@ */ void speaker_enable(u16 freq) { + u16 reg16 = 1193180 / freq; + /* Select counter 2. Read/write LSB first, then MSB. Use mode 3 (square wave generator). Use a 16bit binary counter. */ outb(0xb6, I82C54_CONTROL_WORD_REGISTER); /* Set the desired tone frequency. */ - outb((u8)(freq & 0x00ff), I82C54_COUNTER2); /* LSB. */ - outb((u8)(freq >> 8), I82C54_COUNTER2); /* MSB. */ + outb((u8)(reg16 & 0x00ff), I82C54_COUNTER2); /* LSB. */ + outb((u8)(reg16 >> 8), I82C54_COUNTER2); /* MSB. */ /* Enable the PC speaker (set bits 0 and 1). */ outb(inb(PC_SPEAKER_PORT) | 0x03, PC_SPEAKER_PORT); -- 2.25.1