ARM: at91: time: move the system timer driver to drivers/clocksource

Import at91rm9200_time.c from mach-at91 as timer-atmel-st.c. Further cleanup is
required to get rid of the mach-at91 headers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

3 files changed, 2 insertions, 254 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 4da6bae047f3..24b59c75f6af 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -77,6 +77,7 @@ if SOC_SAM_V4_V5
 config SOC_AT91RM9200
         bool "AT91RM9200"
         select ATMEL_AIC_IRQ
+        select ATMEL_ST
         select COMMON_CLK_AT91
         select CPU_ARM920T
         select GENERIC_CLOCKEVENTS
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index ea54c9824d89..38aaef7b994e 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -7,7 +7,7 @@ obj-y		:= soc.o
 obj-$(CONFIG_SOC_AT91SAM9)      += sam9_smc.o
 
 # CPU-specific support
-obj-$(CONFIG_SOC_AT91RM9200)    += at91rm9200.o at91rm9200_time.o
+obj-$(CONFIG_SOC_AT91RM9200)    += at91rm9200.o
 obj-$(CONFIG_SOC_AT91SAM9)      += at91sam9.o
 obj-$(CONFIG_SOC_SAMA5)         += sama5.o
 
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
deleted file mode 100644
index 7d062ab32674..000000000000
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ /dev/null
@@ -1,253 +0,0 @@
-/*
- * linux/arch/arm/mach-at91/at91rm9200_time.c
- *
- *  Copyright (C) 2003 SAN People
- *  Copyright (C) 2003 ATMEL
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#include <linux/kernel.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/clockchips.h>
-#include <linux/export.h>
-#include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
-
-#include <asm/mach/time.h>
-
-#include <mach/at91_st.h>
-#include <mach/hardware.h>
-
-static unsigned long last_crtr;
-static u32 irqmask;
-static struct clock_event_device clkevt;
-
-#define RM9200_TIMER_LATCH      ((AT91_SLOW_CLOCK + HZ/2) / HZ)
-
-/*
- * The ST_CRTR is updated asynchronously to the master clock ... but
- * the updates as seen by the CPU don't seem to be strictly monotonic.
- * Waiting until we read the same value twice avoids glitching.
- */
-static inline unsigned long read_CRTR(void)
-{
-        unsigned long x1, x2;
-
-        x1 = at91_st_read(AT91_ST_CRTR);
-        do {
-                x2 = at91_st_read(AT91_ST_CRTR);
-                if (x1 == x2)
-                        break;
-                x1 = x2;
-        } while (1);
-        return x1;
-}
-
-/*
- * IRQ handler for the timer.
- */
-static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
-{
-        u32     sr = at91_st_read(AT91_ST_SR) & irqmask;
-
-        /*
-         * irqs should be disabled here, but as the irq is shared they are only
-         * guaranteed to be off if the timer irq is registered first.
-         */
-        WARN_ON_ONCE(!irqs_disabled());
-
-        /* simulate "oneshot" timer with alarm */
-        if (sr & AT91_ST_ALMS) {
-                clkevt.event_handler(&clkevt);
-                return IRQ_HANDLED;
-        }
-
-        /* periodic mode should handle delayed ticks */
-        if (sr & AT91_ST_PITS) {
-                u32     crtr = read_CRTR();
-
-                while (((crtr - last_crtr) & AT91_ST_CRTV) >= RM9200_TIMER_LATCH) {
-                        last_crtr += RM9200_TIMER_LATCH;
-                        clkevt.event_handler(&clkevt);
-                }
-                return IRQ_HANDLED;
-        }
-
-        /* this irq is shared ... */
-        return IRQ_NONE;
-}
-
-static struct irqaction at91rm9200_timer_irq = {
-        .name           = "at91_tick",
-        .flags          = IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
-        .handler        = at91rm9200_timer_interrupt,
-        .irq            = NR_IRQS_LEGACY + AT91_ID_SYS,
-};
-
-static cycle_t read_clk32k(struct clocksource *cs)
-{
-        return read_CRTR();
-}
-
-static struct clocksource clk32k = {
-        .name           = "32k_counter",
-        .rating         = 150,
-        .read           = read_clk32k,
-        .mask           = CLOCKSOURCE_MASK(20),
-        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static void
-clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
-{
-        /* Disable and flush pending timer interrupts */
-        at91_st_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS);
-        at91_st_read(AT91_ST_SR);
-
-        last_crtr = read_CRTR();
-        switch (mode) {
-        case CLOCK_EVT_MODE_PERIODIC:
-                /* PIT for periodic irqs; fixed rate of 1/HZ */
-                irqmask = AT91_ST_PITS;
-                at91_st_write(AT91_ST_PIMR, RM9200_TIMER_LATCH);
-                break;
-        case CLOCK_EVT_MODE_ONESHOT:
-                /* ALM for oneshot irqs, set by next_event()
-                 * before 32 seconds have passed
-                 */
-                irqmask = AT91_ST_ALMS;
-                at91_st_write(AT91_ST_RTAR, last_crtr);
-                break;
-        case CLOCK_EVT_MODE_SHUTDOWN:
-        case CLOCK_EVT_MODE_UNUSED:
-        case CLOCK_EVT_MODE_RESUME:
-                irqmask = 0;
-                break;
-        }
-        at91_st_write(AT91_ST_IER, irqmask);
-}
-
-static int
-clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
-{
-        u32             alm;
-        int             status = 0;
-
-        BUG_ON(delta < 2);
-
-        /* The alarm IRQ uses absolute time (now+delta), not the relative
-         * time (delta) in our calling convention.  Like all clockevents
-         * using such "match" hardware, we have a race to defend against.
-         *
-         * Our defense here is to have set up the clockevent device so the
-         * delta is at least two.  That way we never end up writing RTAR
-         * with the value then held in CRTR ... which would mean the match
-         * wouldn't trigger until 32 seconds later, after CRTR wraps.
-         */
-        alm = read_CRTR();
-
-        /* Cancel any pending alarm; flush any pending IRQ */
-        at91_st_write(AT91_ST_RTAR, alm);
-        at91_st_read(AT91_ST_SR);
-
-        /* Schedule alarm by writing RTAR. */
-        alm += delta;
-        at91_st_write(AT91_ST_RTAR, alm);
-
-        return status;
-}
-
-static struct clock_event_device clkevt = {
-        .name           = "at91_tick",
-        .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-        .rating         = 150,
-        .set_next_event = clkevt32k_next_event,
-        .set_mode       = clkevt32k_mode,
-};
-
-void __iomem *at91_st_base;
-EXPORT_SYMBOL_GPL(at91_st_base);
-
-static const struct of_device_id at91rm9200_st_timer_ids[] = {
-        { .compatible = "atmel,at91rm9200-st" },
-        { /* sentinel */ }
-};
-
-static int __init of_at91rm9200_st_init(void)
-{
-        struct device_node *np;
-        int ret;
-
-        np = of_find_matching_node(NULL, at91rm9200_st_timer_ids);
-        if (!np)
-                goto err;
-
-        at91_st_base = of_iomap(np, 0);
-        if (!at91_st_base)
-                goto node_err;
-
-        /* Get the interrupts property */
-        ret = irq_of_parse_and_map(np, 0);
-        if (!ret)
-                goto ioremap_err;
-        at91rm9200_timer_irq.irq = ret;
-
-        of_node_put(np);
-
-        return 0;
-
-ioremap_err:
-        iounmap(at91_st_base);
-node_err:
-        of_node_put(np);
-err:
-        return -EINVAL;
-}
-
-/*
- * ST (system timer) module supports both clockevents and clocksource.
- */
-static void __init atmel_st_timer_init(struct device_node *node)
-{
-        /* For device tree enabled device: initialize here */
-        of_at91rm9200_st_init();
-
-        /* Disable all timer interrupts, and clear any pending ones */
-        at91_st_write(AT91_ST_IDR,
-                AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
-        at91_st_read(AT91_ST_SR);
-
-        /* Make IRQs happen for the system timer */
-        setup_irq(at91rm9200_timer_irq.irq, &at91rm9200_timer_irq);
-
-        /* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
-         * directly for the clocksource and all clockevents, after adjusting
-         * its prescaler from the 1 Hz default.
-         */
-        at91_st_write(AT91_ST_RTMR, 1);
-
-        /* Setup timer clockevent, with minimum of two ticks (important!!) */
-        clkevt.cpumask = cpumask_of(0);
-        clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK,
-                                        2, AT91_ST_ALMV);
-
-        /* register clocksource */
-        clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);
-}
-CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
-                       atmel_st_timer_init);