*/
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/interrupt.h>
#include <linux/init.h>
#include <asm/hardware.h>
#include <asm/mach/irq.h>
#include <asm/mach/map.h>
+#include <asm/mach/time.h>
+
#define IRQ_MASK 0xfe000000 /* read */
#define IRQ_MSET 0xfe000000 /* write */
#define IRQ_STAT 0xff000000 /* read */
iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
}
+
+#define PIT_CTRL (PIT_BASE + 0x0d)
+#define PIT_T2 (PIT_BASE + 0x09)
+#define PIT_T1 (PIT_BASE + 0x05)
+#define PIT_T0 (PIT_BASE + 0x01)
+
+/*
+ * This is the rate at which your MCLK signal toggles (in Hz)
+ * This was measured on a 10 digit frequency counter sampling
+ * over 1 second.
+ */
+#define MCLK 47894000
+
+/*
+ * This is the rate at which the PIT timers get clocked
+ */
+#define CLKBY7 (MCLK / 7)
+
+/*
+ * This is the counter value. We tick at 200Hz on this platform.
+ */
+#define COUNT ((CLKBY7 + (HZ / 2)) / HZ)
+
+/*
+ * Get the time offset from the system PIT. Note that if we have missed an
+ * interrupt, then the PIT counter will roll over (ie, be negative).
+ * This actually works out to be convenient.
+ */
+static unsigned long ebsa110_gettimeoffset(void)
+{
+ unsigned long offset, count;
+
+ __raw_writeb(0x40, PIT_CTRL);
+ count = __raw_readb(PIT_T1);
+ count |= __raw_readb(PIT_T1) << 8;
+
+ /*
+ * If count > COUNT, make the number negative.
+ */
+ if (count > COUNT)
+ count |= 0xffff0000;
+
+ offset = COUNT;
+ offset -= count;
+
+ /*
+ * `offset' is in units of timer counts. Convert
+ * offset to units of microseconds.
+ */
+ offset = offset * (1000000 / HZ) / COUNT;
+
+ return offset;
+}
+
+static irqreturn_t
+ebsa110_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ u32 count;
+
+ /* latch and read timer 1 */
+ __raw_writeb(0x40, PIT_CTRL);
+ count = __raw_readb(PIT_T1);
+ count |= __raw_readb(PIT_T1) << 8;
+
+ count += COUNT;
+
+ __raw_writeb(count & 0xff, PIT_T1);
+ __raw_writeb(count >> 8, PIT_T1);
+
+ timer_tick(regs);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction ebsa110_timer_irq = {
+ .name = "EBSA110 Timer Tick",
+ .flags = SA_INTERRUPT,
+ .handler = ebsa110_timer_interrupt
+};
+
+/*
+ * Set up timer interrupt.
+ */
+static void __init ebsa110_init_time(void)
+{
+ /*
+ * Timer 1, mode 2, LSB/MSB
+ */
+ __raw_writeb(0x70, PIT_CTRL);
+ __raw_writeb(COUNT & 0xff, PIT_T1);
+ __raw_writeb(COUNT >> 8, PIT_T1);
+
+ gettimeoffset = ebsa110_gettimeoffset;
+
+ setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
+}
+
MACHINE_START(EBSA110, "EBSA110")
MAINTAINER("Russell King")
BOOT_MEM(0x00000000, 0xe0000000, 0xe0000000)
SOFT_REBOOT
MAPIO(ebsa110_map_io)
INITIRQ(ebsa110_init_irq)
+ INITTIME(ebsa110_init_time)
MACHINE_END