diff options
| author | Bin Meng <bmeng.cn@gmail.com> | 2015-10-22 19:13:29 -0700 |
|---|---|---|
| committer | Bin Meng <bmeng.cn@gmail.com> | 2015-11-13 06:46:18 -0800 |
| commit | bffeed0158bc5114a9542ff83c716e352841dcfb (patch) | |
| tree | 460a39e8b90674fece73d48cceabad4cca37e134 /arch/x86 | |
| parent | 0a2ea0206815bab1db1285108d013c7627b68bd9 (diff) | |
x86: Initialize i8254 timer counter 1
Initialize counter 1, used to refresh request signal. This is
required for legacy purpose as some codes like vgabios utilizes
counter 1 to provide delay functionality.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/lib/pcat_timer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/lib/pcat_timer.c b/arch/x86/lib/pcat_timer.c index ce15818ec27..347cdda9f6b 100644 --- a/arch/x86/lib/pcat_timer.c +++ b/arch/x86/lib/pcat_timer.c @@ -9,11 +9,21 @@ #include <asm/io.h> #include <asm/i8254.h> +#define TIMER1_VALUE 18 /* 15.6us */ #define TIMER2_VALUE 0x0a8e /* 440Hz */ int pcat_timer_init(void) { /* + * Initialize counter 1, used to refresh request signal. + * This is required for legacy purpose as some codes like + * vgabios utilizes counter 1 to provide delay functionality. + */ + outb(PIT_CMD_CTR1 | PIT_CMD_LOW | PIT_CMD_MODE2, + PIT_BASE + PIT_COMMAND); + outb(TIMER1_VALUE, PIT_BASE + PIT_T1); + + /* * Initialize counter 2, used to drive the speaker. * To start a beep, set both bit0 and bit1 of port 0x61. * To stop it, clear both bit0 and bit1 of port 0x61. |