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 4da6bae..24b59c7 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 ea54c98..38aaef7 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 7d062ab..0000000
--- 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);