diff options
| author | Simon Glass <sjg@chromium.org> | 2019-02-16 20:24:58 -0700 |
|---|---|---|
| committer | Bin Meng <bmeng.cn@gmail.com> | 2019-02-20 15:27:09 +0800 |
| commit | 79a5be820d9b187a1d8617d6a1cb65392448322d (patch) | |
| tree | db2de64e2bced1305e1c0a8512c84cfc0c39d42d /arch/x86/lib/i8254.c | |
| parent | 6744c0d6525e9fb9b5c7fc0d7b66c0d0cbdf6177 (diff) | |
sound: x86: Add beeping support in i8254
Adjust the code to allow beeping at different frequencies, using a
calculated value for timer 2.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Diffstat (limited to 'arch/x86/lib/i8254.c')
| -rw-r--r-- | arch/x86/lib/i8254.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/arch/x86/lib/i8254.c b/arch/x86/lib/i8254.c index 1f1012488c..d0227954b1 100644 --- a/arch/x86/lib/i8254.c +++ b/arch/x86/lib/i8254.c @@ -8,8 +8,20 @@ #include <asm/io.h> #include <asm/i8254.h> -#define TIMER1_VALUE 18 /* 15.6us */ -#define TIMER2_VALUE 0x0a8e /* 440Hz */ +#define TIMER1_VALUE 18 /* 15.6us */ +#define BEEP_FREQUENCY_HZ 440 +#define SYSCTL_PORTB 0x61 +#define PORTB_BEEP_ENABLE 0x3 + +static void i8254_set_beep_freq(uint frequency_hz) +{ + uint countdown; + + countdown = PIT_TICK_RATE / frequency_hz; + + outb(countdown & 0xff, PIT_BASE + PIT_T2); + outb((countdown >> 8) & 0xff, PIT_BASE + PIT_T2); +} int i8254_init(void) { @@ -29,8 +41,23 @@ int i8254_init(void) */ outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3, PIT_BASE + PIT_COMMAND); - outb(TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2); - outb(TIMER2_VALUE >> 8, PIT_BASE + PIT_T2); + i8254_set_beep_freq(BEEP_FREQUENCY_HZ); + + return 0; +} + +int i8254_enable_beep(uint frequency_hz) +{ + if (!frequency_hz) + return -EINVAL; + + i8254_set_beep_freq(frequency_hz); + setio_8(SYSCTL_PORTB, PORTB_BEEP_ENABLE); return 0; } + +void i8254_disable_beep(void) +{ + clrio_8(SYSCTL_PORTB, PORTB_BEEP_ENABLE); +} |