[ARM] pxa: add base support for Marvell's PXA168 processor line

"""The Marvell® PXA168 processor is the first in a family of application
processors targeted at mass market opportunities in computing and consumer
devices. It balances high computing and multimedia performance with low
power consumption to support extended battery life, and includes a wealth
of integrated peripherals to reduce overall BOM cost .... """

See http://www.marvell.com/featured/pxa168.jsp for more information.

  1. Marvell Mohawk core is a hybrid of xscale3 and its own ARM core,
     there are many enhancements like instructions for flushing the
     whole D-cache, and so on

  2. Clock reuses Russell's common clkdev, and added the basic support
     for UART1/2.

  3. Devices are a bit different from the 'mach-pxa' way, the platform
     devices are now dynamically allocated only when necessary (i.e.
     when pxa_register_device() is called). Description for each device
     are stored in an array of 'struct pxa_device_desc'. Now that:

     a. this array of device description is marked with __initdata and
        can be freed up system is fully up

     b. which means board code has to add all needed devices early in
        his initializing function

     c. platform specific data can now be marked as __initdata since
        they are allocated and copied by platform_device_add_data()

  4. only the basic UART1/2/3 are added, more devices will come later.

Signed-off-by: Jason Chagas <chagas@marvell.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>

1 files changed, 199 insertions, 0 deletions

diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
new file mode 100644
index 000000000000..b03a6eda7419
--- /dev/null
+++ b/arch/arm/mach-mmp/time.c
@@ -0,0 +1,199 @@
+/*
+ * linux/arch/arm/mach-mmp/time.c
+ *
+ *   Support for clocksource and clockevents
+ *
+ * Copyright (C) 2008 Marvell International Ltd.
+ * All rights reserved.
+ *
+ *   2008-04-11: Jason Chagas <Jason.chagas@marvell.com>
+ *   2008-10-08: Bin Yang <bin.yang@marvell.com>
+ *
+ * The timers module actually includes three timers, each timer with upto
+ * three match comparators. Timer #0 is used here in free-running mode as
+ * the clock source, and match comparator #1 used as clock event device.
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/cnt32_to_63.h>
+
+#include <mach/addr-map.h>
+#include <mach/regs-timers.h>
+#include <mach/irqs.h>
+
+#include "clock.h"
+
+#define TIMERS_VIRT_BASE        TIMERS1_VIRT_BASE
+
+#define MAX_DELTA               (0xfffffffe)
+#define MIN_DELTA               (16)
+
+#define TCR2NS_SCALE_FACTOR     10
+
+static unsigned long tcr2ns_scale;
+
+static void __init set_tcr2ns_scale(unsigned long tcr_rate)
+{
+        unsigned long long v = 1000000000ULL << TCR2NS_SCALE_FACTOR;
+        do_div(v, tcr_rate);
+        tcr2ns_scale = v;
+        /*
+         * We want an even value to automatically clear the top bit
+         * returned by cnt32_to_63() without an additional run time
+         * instruction. So if the LSB is 1 then round it up.
+         */
+        if (tcr2ns_scale & 1)
+                tcr2ns_scale++;
+}
+
+/*
+ * FIXME: the timer needs some delay to stablize the counter capture
+ */
+static inline uint32_t timer_read(void)
+{
+        int delay = 100;
+
+        __raw_writel(1, TIMERS_VIRT_BASE + TMR_CVWR(0));
+
+        while (delay--)
+                cpu_relax();
+
+        return __raw_readl(TIMERS_VIRT_BASE + TMR_CVWR(0));
+}
+
+unsigned long long sched_clock(void)
+{
+        unsigned long long v = cnt32_to_63(timer_read());
+        return (v * tcr2ns_scale) >> TCR2NS_SCALE_FACTOR;
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *c = dev_id;
+
+        /* disable and clear pending interrupt status */
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
+        __raw_writel(0x1, TIMERS_VIRT_BASE + TMR_ICR(0));
+        c->event_handler(c);
+        return IRQ_HANDLED;
+}
+
+static int timer_set_next_event(unsigned long delta,
+                                struct clock_event_device *dev)
+{
+        unsigned long flags, next;
+
+        local_irq_save(flags);
+
+        /* clear pending interrupt status and enable */
+        __raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
+        __raw_writel(0x01, TIMERS_VIRT_BASE + TMR_IER(0));
+
+        next = timer_read() + delta;
+        __raw_writel(next, TIMERS_VIRT_BASE + TMR_TN_MM(0, 0));
+
+        local_irq_restore(flags);
+        return 0;
+}
+
+static void timer_set_mode(enum clock_event_mode mode,
+                           struct clock_event_device *dev)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        switch (mode) {
+        case CLOCK_EVT_MODE_ONESHOT:
+        case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                /* disable the matching interrupt */
+                __raw_writel(0x00, TIMERS_VIRT_BASE + TMR_IER(0));
+                break;
+        case CLOCK_EVT_MODE_RESUME:
+        case CLOCK_EVT_MODE_PERIODIC:
+                break;
+        }
+        local_irq_restore(flags);
+}
+
+static struct clock_event_device ckevt = {
+        .name           = "clockevent",
+        .features       = CLOCK_EVT_FEAT_ONESHOT,
+        .shift          = 32,
+        .rating         = 200,
+        .set_next_event = timer_set_next_event,
+        .set_mode       = timer_set_mode,
+};
+
+static cycle_t clksrc_read(void)
+{
+        return timer_read();
+}
+
+static struct clocksource cksrc = {
+        .name           = "clocksource",
+        .shift          = 20,
+        .rating         = 200,
+        .read           = clksrc_read,
+        .mask           = CLOCKSOURCE_MASK(32),
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init timer_config(void)
+{
+        uint32_t ccr = __raw_readl(TIMERS_VIRT_BASE + TMR_CCR);
+        uint32_t cer = __raw_readl(TIMERS_VIRT_BASE + TMR_CER);
+        uint32_t cmr = __raw_readl(TIMERS_VIRT_BASE + TMR_CMR);
+
+        __raw_writel(cer & ~0x1, TIMERS_VIRT_BASE + TMR_CER); /* disable */
+
+        ccr &= TMR_CCR_CS_0(0x3);
+        __raw_writel(ccr, TIMERS_VIRT_BASE + TMR_CCR);
+
+        /* free-running mode */
+        __raw_writel(cmr | 0x01, TIMERS_VIRT_BASE + TMR_CMR);
+
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* free-running */
+        __raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(0));  /* clear status */
+        __raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
+
+        /* enable timer counter */
+        __raw_writel(cer | 0x01, TIMERS_VIRT_BASE + TMR_CER);
+}
+
+static struct irqaction timer_irq = {
+        .name           = "timer",
+        .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+        .handler        = timer_interrupt,
+        .dev_id         = &ckevt,
+};
+
+void __init timer_init(int irq)
+{
+        timer_config();
+
+        set_tcr2ns_scale(CLOCK_TICK_RATE);
+
+        ckevt.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, ckevt.shift);
+        ckevt.max_delta_ns = clockevent_delta2ns(MAX_DELTA, &ckevt);
+        ckevt.min_delta_ns = clockevent_delta2ns(MIN_DELTA, &ckevt);
+        ckevt.cpumask = cpumask_of(0);
+
+        cksrc.mult = clocksource_hz2mult(CLOCK_TICK_RATE, cksrc.shift);
+
+        setup_irq(irq, &timer_irq);
+
+        clocksource_register(&cksrc);
+        clockevents_register_device(&ckevt);
+}