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...@gmail.com>
---
arch/x86/lib/i8254.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/lib/i8254.c b/arch/x86/lib/i8254.c
index d022795..0f97538 100644
--- a/arch/x86/lib/i8254.c
+++ b/arch/x86/lib/i8254.c
@@ -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);
--
2.7.4
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