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authorStefan Reinauer <reinauer@chromium.org>2011-10-25 14:15:57 -0700
committerPatrick Georgi <patrick@georgi-clan.de>2011-10-27 10:49:41 +0200
commitbbfc9c449f61fc553bdea797b2f77af9d9420ccf (patch)
tree27b3e6bf005de6b0a3ec3d9b80e065d810d768cb /payloads/libpayload/drivers/speaker.c
parent6eb8bef25e6ab4d44b0f0549a12b05bde943dcae (diff)
downloadcoreboot-bbfc9c449f61fc553bdea797b2f77af9d9420ccf.tar.xz
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 <reinauer@google.com> Reviewed-on: http://review.coreboot.org/337 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
Diffstat (limited to 'payloads/libpayload/drivers/speaker.c')
-rw-r--r--payloads/libpayload/drivers/speaker.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/payloads/libpayload/drivers/speaker.c b/payloads/libpayload/drivers/speaker.c
index 3b3a750318..3a561bcbfa 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);