1 files changed, 217 insertions, 0 deletions

diff --git a/arch/avr32/mach-at32ap/time-tc.c b/arch/avr32/mach-at32ap/time-tc.c
new file mode 100644
index 000000000000..7ac0e94d8ed5
--- /dev/null
+++ b/arch/avr32/mach-at32ap/time-tc.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2004-2007 Atmel Corporation
+ *
+ * Based on MIPS implementation arch/mips/kernel/time.c
+ *   Copyright 2001 MontaVista Software Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/time.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel_stat.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/profile.h>
+#include <linux/sysdev.h>
+#include <linux/err.h>
+
+#include <asm/div64.h>
+#include <asm/sysreg.h>
+#include <asm/io.h>
+#include <asm/sections.h>
+
+#include <asm/arch/time.h>
+
+/* how many counter cycles in a jiffy? */
+static u32 cycles_per_jiffy;
+
+/* the count value for the next timer interrupt */
+static u32 expirelo;
+
+/* the I/O registers of the TC module */
+static void __iomem *ioregs;
+
+cycle_t read_cycle_count(void)
+{
+        return (cycle_t)timer_read(ioregs, 0, CV);
+}
+
+struct clocksource clocksource_avr32 = {
+        .name           = "avr32",
+        .rating         = 342,
+        .read           = read_cycle_count,
+        .mask           = CLOCKSOURCE_MASK(16),
+        .shift          = 16,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void avr32_timer_ack(void)
+{
+        u16 count = expirelo;
+
+        /* Ack this timer interrupt and set the next one, use a u16
+         * variable so it will wrap around correctly */
+        count += cycles_per_jiffy;
+        expirelo = count;
+        timer_write(ioregs, 0, RC, expirelo);
+
+        /* Check to see if we have missed any timer interrupts */
+        count = timer_read(ioregs, 0, CV);
+        if ((count - expirelo) < 0x7fff) {
+                expirelo = count + cycles_per_jiffy;
+                timer_write(ioregs, 0, RC, expirelo);
+        }
+}
+
+u32 avr32_hpt_read(void)
+{
+        return timer_read(ioregs, 0, CV);
+}
+
+static int avr32_timer_calc_div_and_set_jiffies(struct clk *pclk)
+{
+        unsigned int cycles_max = (clocksource_avr32.mask + 1) / 2;
+        unsigned int divs[] = { 4, 8, 16, 32 };
+        int divs_size = sizeof(divs) / sizeof(*divs);
+        int i = 0;
+        unsigned long count_hz;
+        unsigned long shift;
+        unsigned long mult;
+        int clock_div = -1;
+        u64 tmp;
+
+        shift = clocksource_avr32.shift;
+
+        do {
+                count_hz = clk_get_rate(pclk) / divs[i];
+                mult = clocksource_hz2mult(count_hz, shift);
+                clocksource_avr32.mult = mult;
+
+                tmp = TICK_NSEC;
+                tmp <<= shift;
+                tmp += mult / 2;
+                do_div(tmp, mult);
+
+                cycles_per_jiffy = tmp;
+        } while (cycles_per_jiffy > cycles_max && ++i < divs_size);
+
+        clock_div = i + 1;
+
+        if (clock_div > divs_size) {
+                pr_debug("timer: could not calculate clock divider\n");
+                return -EFAULT;
+        }
+
+        /* Set the clock divider */
+        timer_write(ioregs, 0, CMR, TIMER_BF(CMR_TCCLKS, clock_div));
+
+        return 0;
+}
+
+int avr32_hpt_init(unsigned int count)
+{
+        struct resource *regs;
+        struct clk *pclk;
+        int irq = -1;
+        int ret = 0;
+
+        ret = -ENXIO;
+
+        irq = platform_get_irq(&at32_systc0_device, 0);
+        if (irq < 0) {
+                pr_debug("timer: could not get irq\n");
+                goto out_error;
+        }
+
+        pclk = clk_get(&at32_systc0_device.dev, "pclk");
+        if (IS_ERR(pclk)) {
+                pr_debug("timer: could not get clk: %ld\n", PTR_ERR(pclk));
+                goto out_error;
+        }
+
+        regs = platform_get_resource(&at32_systc0_device, IORESOURCE_MEM, 0);
+        if (!regs) {
+                pr_debug("timer: could not get resource\n");
+                goto out_error_clk;
+        }
+
+        ioregs = ioremap(regs->start, regs->end - regs->start + 1);
+        if (!ioregs) {
+                pr_debug("timer: could not get ioregs\n");
+                goto out_error_clk;
+        }
+
+        ret = avr32_timer_calc_div_and_set_jiffies(pclk);
+        if (ret)
+                goto out_error_io;
+
+        ret = setup_irq(irq, &timer_irqaction);
+        if (ret) {
+                pr_debug("timer: could not request irq %d: %d\n",
+                                irq, ret);
+                goto out_error_io;
+        }
+
+        expirelo = (timer_read(ioregs, 0, CV) / cycles_per_jiffy + 1)
+                * cycles_per_jiffy;
+
+        /* Enable clock and interrupts on RC compare */
+        timer_write(ioregs, 0, CCR, TIMER_BIT(CCR_CLKEN));
+        timer_write(ioregs, 0, IER, TIMER_BIT(IER_CPCS));
+        /* Set cycles to first interrupt */
+        timer_write(ioregs, 0,  RC, expirelo);
+
+        printk(KERN_INFO "timer: AT32AP system timer/counter at 0x%p irq %d\n",
+                        ioregs, irq);
+
+        return 0;
+
+out_error_io:
+        iounmap(ioregs);
+out_error_clk:
+        clk_put(pclk);
+out_error:
+        return ret;
+}
+
+int avr32_hpt_start(void)
+{
+        timer_write(ioregs, 0, CCR, TIMER_BIT(CCR_SWTRG));
+        return 0;
+}
+
+irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+        unsigned int sr = timer_read(ioregs, 0, SR);
+
+        if (sr & TIMER_BIT(SR_CPCS)) {
+                /* ack timer interrupt and try to set next interrupt */
+                avr32_timer_ack();
+
+                /*
+                 * Call the generic timer interrupt handler
+                 */
+                write_seqlock(&xtime_lock);
+                do_timer(1);
+                write_sequnlock(&xtime_lock);
+
+                /*
+                 * In UP mode, we call local_timer_interrupt() to do profiling
+                 * and process accounting.
+                 *
+                 * SMP is not supported yet.
+                 */
+                local_timer_interrupt(irq, dev_id);
+
+                return IRQ_HANDLED;
+        }
+
+        return IRQ_NONE;
+}