diff options
author | Bin Meng <bmeng.cn@gmail.com> | 2015-10-22 19:13:30 -0700 |
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committer | Bin Meng <bmeng.cn@gmail.com> | 2015-11-13 06:46:18 -0800 |
commit | da3fe247591e17dead357f05f69124c54aa13a01 (patch) | |
tree | b508cd98120839f343e77980f4c02f8c5b151e0f /arch/x86/lib/i8254.c | |
parent | bffeed0158bc5114a9542ff83c716e352841dcfb (diff) |
x86: Rename pcat_ to i8254 and i8259 accordingly
Rename pcat_timer.c to i8254.c and pcat_interrupts.c to i8259.c,
to match their header file names (i8254.h and i8259.h).
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86/lib/i8254.c')
-rw-r--r-- | arch/x86/lib/i8254.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/x86/lib/i8254.c b/arch/x86/lib/i8254.c new file mode 100644 index 0000000000..46a4245289 --- /dev/null +++ b/arch/x86/lib/i8254.c @@ -0,0 +1,37 @@ +/* + * (C) Copyright 2002 + * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/i8254.h> + +#define TIMER1_VALUE 18 /* 15.6us */ +#define TIMER2_VALUE 0x0a8e /* 440Hz */ + +int i8254_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. + */ + 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); + + return 0; +} |