diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/m68knommu/platform/5307/pit.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/m68knommu/platform/5307/pit.c')
-rw-r--r-- | arch/m68knommu/platform/5307/pit.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/5307/pit.c b/arch/m68knommu/platform/5307/pit.c new file mode 100644 index 00000000000..a9b2c2e7e28 --- /dev/null +++ b/arch/m68knommu/platform/5307/pit.c @@ -0,0 +1,88 @@ +/***************************************************************************/ + +/* + * pit.c -- Motorola ColdFire PIT timer. Currently this type of + * hardware timer only exists in the Motorola ColdFire + * 5270/5271 and 5282 CPUs. + * + * Copyright (C) 1999-2004, Greg Ungerer (gerg@snapgear.com) + * Copyright (C) 2001-2004, SnapGear Inc. (www.snapgear.com) + * + */ + +/***************************************************************************/ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/param.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <asm/irq.h> +#include <asm/coldfire.h> +#include <asm/mcfpit.h> +#include <asm/mcfsim.h> + +/***************************************************************************/ + +void coldfire_pit_tick(void) +{ + volatile struct mcfpit *tp; + + /* Reset the ColdFire timer */ + tp = (volatile struct mcfpit *) (MCF_IPSBAR + MCFPIT_BASE1); + tp->pcsr |= MCFPIT_PCSR_PIF; +} + +/***************************************************************************/ + +void coldfire_pit_init(irqreturn_t (*handler)(int, void *, struct pt_regs *)) +{ + volatile unsigned char *icrp; + volatile unsigned long *imrp; + volatile struct mcfpit *tp; + + request_irq(MCFINT_VECBASE + MCFINT_PIT1, handler, SA_INTERRUPT, + "ColdFire Timer", NULL); + + icrp = (volatile unsigned char *) (MCF_IPSBAR + MCFICM_INTC0 + + MCFINTC_ICR0 + MCFINT_PIT1); + *icrp = 0x2b; /* PIT1 with level 5, priority 3 */ + + imrp = (volatile unsigned long *) (MCF_IPSBAR + MCFICM_INTC0 + MCFINTC_IMRH); + *imrp &= ~(1 << (MCFINT_PIT1 - 32)); + + /* Set up PIT timer 1 as poll clock */ + tp = (volatile struct mcfpit *) (MCF_IPSBAR + MCFPIT_BASE1); + tp->pcsr = MCFPIT_PCSR_DISABLE; + + tp->pmr = ((MCF_CLK / 2) / 64) / HZ; + tp->pcsr = MCFPIT_PCSR_EN | MCFPIT_PCSR_PIE | MCFPIT_PCSR_OVW | + MCFPIT_PCSR_RLD | MCFPIT_PCSR_CLK64; +} + +/***************************************************************************/ + +unsigned long coldfire_pit_offset(void) +{ + volatile struct mcfpit *tp; + volatile unsigned long *ipr; + unsigned long pmr, pcntr, offset; + + tp = (volatile struct mcfpit *) (MCF_IPSBAR + MCFPIT_BASE1); + ipr = (volatile unsigned long *) (MCF_IPSBAR + MCFICM_INTC0 + MCFINTC_IPRH); + + pmr = *(&tp->pmr); + pcntr = *(&tp->pcntr); + + /* + * If we are still in the first half of the upcount and a + * timer interupt is pending, then add on a ticks worth of time. + */ + offset = ((pmr - pcntr) * (1000000 / HZ)) / pmr; + if ((offset < (1000000 / HZ / 2)) && (*ipr & (1 << (MCFINT_PIT1 - 32)))) + offset += 1000000 / HZ; + return offset; +} + +/***************************************************************************/ |