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x86: Make sure i8254 is setup correctly before generating beeps

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The i8254 timer control IO port (0x43) should be setup correctly
by using PIT counter 2 to generate beeps, however in U-Boot other
codes like TSC driver utilizes PIT for TSC frequency calibration
and configures the counter 2 to a different mode that does not
beep. Fix this by always ensuring the PIT counter 2 is correctly
initialized so that the i8254 beeper driver works as expected.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Bin Meng 2019-02-26 01:52:19 -08:00
parent d9b59fc9ae
commit 7d0a53a40c
1 changed files with 4 additions and 0 deletions
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arch/x86/lib/i8254.c
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@ -51,6 +51,10 @@ int i8254_enable_beep(uint frequency_hz)
if (!frequency_hz)
return -EINVAL;
/* make sure i8254 is setup correctly before generating beeps */
outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
PIT_BASE + PIT_COMMAND);
i8254_set_beep_freq(frequency_hz);
setio_8(SYSCTL_PORTB, PORTB_BEEP_ENABLE);