[PATCH] add pit timer for m68knommu/5282 CPU support

This code supports the PIT timer of the 5282 ColdFire.

This new timer device is completely different to the previous ColdFire
timer device.

diff --git a/arch/m68knommu/platform/5282/pit.c b/arch/m68knommu/platform/5282/pit.c
new file mode 100644 (file)
index 0000000..d3bbca3
--- /dev/null
+++ b/arch/m68knommu/platform/5282/pit.c
@@ -0,0 +1,86 @@
+/***************************************************************************/
+
+/*
+ *     pit.c -- Motorola ColdFire PIT timer. Currently this type of
+ *              hardware timer only exists in the Motorola ColdFire
+ *              5282 CPU.
+ *
+ *     Copyright (C) 1999-2003, Greg Ungerer (gerg@snapgear.com)
+ *     Copyright (C) 2001-2003, 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 <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(void (*handler)(int, void *, struct pt_regs *))
+{
+       volatile unsigned char *icrp;
+       volatile unsigned long *imrp;
+       volatile struct mcfpit *tp;
+
+       request_irq(64+55, 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 << (55 - 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 = ((pcntr * (1000000 / HZ)) / pmr);
+       if ((offset < (1000000 / HZ / 2)) && (*ipr & (1 << (55 - 32))))
+               offset += 1000000 / HZ;
+       return offset;  
+}
+
+/***************************************************************************/