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author | Simon Glass <sjg@chromium.org> | 2013-04-17 16:13:39 +0000 |
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committer | Simon Glass <sjg@chromium.org> | 2013-05-13 13:33:21 -0700 |
commit | d0b6f247a1e7ffd06d931ca4088426134dc4e546 (patch) | |
tree | 6fb11d15dfddb6223291ef7c48fdcb4da591cacc /arch/x86/lib/pcat_timer.c | |
parent | f9083bbe784cb03940b094afe4db0bf94f312f2b (diff) | |
download | u-boot-imx-d0b6f247a1e7ffd06d931ca4088426134dc4e546.zip u-boot-imx-d0b6f247a1e7ffd06d931ca4088426134dc4e546.tar.gz u-boot-imx-d0b6f247a1e7ffd06d931ca4088426134dc4e546.tar.bz2 |
x86: Re-enable PCAT timer 2 for beeping
While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86/lib/pcat_timer.c')
-rw-r--r-- | arch/x86/lib/pcat_timer.c | 69 |
1 files changed, 3 insertions, 66 deletions
diff --git a/arch/x86/lib/pcat_timer.c b/arch/x86/lib/pcat_timer.c index b0b6637..1ca3eb9 100644 --- a/arch/x86/lib/pcat_timer.c +++ b/arch/x86/lib/pcat_timer.c @@ -24,83 +24,20 @@ #include <common.h> #include <asm/io.h> #include <asm/i8254.h> -#include <asm/ibmpc.h> -#include <asm/interrupt.h> -#define TIMER0_VALUE 0x04aa /* 1kHz 1.9318MHz / 1000 */ #define TIMER2_VALUE 0x0a8e /* 440Hz */ -static int timer_init_done; - -int timer_init(void) +int pcat_timer_init(void) { - /* initialize timer 0 and 2 - * - * Timer 0 is used to increment system_tick 1000 times/sec - * Timer 1 was used for DRAM refresh in early PC's - * Timer 2 is used to drive the speaker + /* + * initialize 2, used to drive the speaker * (to start a beep: write 3 to port 0x61, * to stop it again: write 0) */ - outb(PIT_CMD_CTR0 | PIT_CMD_BOTH | PIT_CMD_MODE2, - PIT_BASE + PIT_COMMAND); - outb(TIMER0_VALUE & 0xff, PIT_BASE + PIT_T0); - outb(TIMER0_VALUE >> 8, PIT_BASE + PIT_T0); - 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); - irq_install_handler(0, timer_isr, NULL); - unmask_irq(0); - - timer_init_done = 1; - return 0; } - -static u16 read_pit(void) -{ - u8 low; - - outb(PIT_CMD_LATCH, PIT_BASE + PIT_COMMAND); - low = inb(PIT_BASE + PIT_T0); - - return (inb(PIT_BASE + PIT_T0) << 8) | low; -} - -/* this is not very exact */ -void __udelay(unsigned long usec) -{ - int counter; - int wraps; - - if (timer_init_done) { - counter = read_pit(); - wraps = usec / 1000; - usec = usec % 1000; - - usec *= 1194; - usec /= 1000; - usec += counter; - - while (usec > 1194) { - usec -= 1194; - wraps++; - } - - while (1) { - int new_count = read_pit(); - - if (((new_count < usec) && !wraps) || wraps < 0) - break; - - if (new_count > counter) - wraps--; - - counter = new_count; - } - } - -} |