diff --git a/arch/arm/mach-pxa/include/mach/regs-ost.h b/arch/arm/mach-pxa/include/mach/regs-ost.h
index a3e5f86ef67..628819995c5 100644
--- a/arch/arm/mach-pxa/include/mach/regs-ost.h
+++ b/arch/arm/mach-pxa/include/mach/regs-ost.h
@@ -7,17 +7,17 @@
  * OS Timer & Match Registers
  */
 
-#define OSMR0		__REG(0x40A00000)  /* */
-#define OSMR1		__REG(0x40A00004)  /* */
-#define OSMR2		__REG(0x40A00008)  /* */
-#define OSMR3		__REG(0x40A0000C)  /* */
-#define OSMR4		__REG(0x40A00080)  /* */
-#define OSCR		__REG(0x40A00010)  /* OS Timer Counter Register */
-#define OSCR4		__REG(0x40A00040)  /* OS Timer Counter Register */
-#define OMCR4		__REG(0x40A000C0)  /* */
-#define OSSR		__REG(0x40A00014)  /* OS Timer Status Register */
-#define OWER		__REG(0x40A00018)  /* OS Timer Watchdog Enable Register */
-#define OIER		__REG(0x40A0001C)  /* OS Timer Interrupt Enable Register */
+#define OSMR0		io_p2v(0x40A00000)  /* */
+#define OSMR1		io_p2v(0x40A00004)  /* */
+#define OSMR2		io_p2v(0x40A00008)  /* */
+#define OSMR3		io_p2v(0x40A0000C)  /* */
+#define OSMR4		io_p2v(0x40A00080)  /* */
+#define OSCR		io_p2v(0x40A00010)  /* OS Timer Counter Register */
+#define OSCR4		io_p2v(0x40A00040)  /* OS Timer Counter Register */
+#define OMCR4		io_p2v(0x40A000C0)  /* */
+#define OSSR		io_p2v(0x40A00014)  /* OS Timer Status Register */
+#define OWER		io_p2v(0x40A00018)  /* OS Timer Watchdog Enable Register */
+#define OIER		io_p2v(0x40A0001C)  /* OS Timer Interrupt Enable Register */
 
 #define OSSR_M3		(1 << 3)	/* Match status channel 3 */
 #define OSSR_M2		(1 << 2)	/* Match status channel 2 */
diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
index b4528899ef0..3fab583755d 100644
--- a/arch/arm/mach-pxa/reset.c
+++ b/arch/arm/mach-pxa/reset.c
@@ -77,9 +77,10 @@ static void do_gpio_reset(void)
 static void do_hw_reset(void)
 {
 	/* Initialize the watchdog and let it fire */
-	OWER = OWER_WME;
-	OSSR = OSSR_M3;
-	OSMR3 = OSCR + 368640;	/* ... in 100 ms */
+	writel_relaxed(OWER_WME, OWER);
+	writel_relaxed(OSSR_M3, OSSR);
+	/* ... in 100 ms */
+	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
 }
 
 void pxa_restart(char mode, const char *cmd)
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index 3d6c9bd90de..4bc47d63698 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -35,7 +35,7 @@
 
 static u32 notrace pxa_read_sched_clock(void)
 {
-	return OSCR;
+	return readl_relaxed(OSCR);
 }
 
 
@@ -47,8 +47,8 @@ pxa_ost0_interrupt(int irq, void *dev_id)
 	struct clock_event_device *c = dev_id;
 
 	/* Disarm the compare/match, signal the event. */
-	OIER &= ~OIER_E0;
-	OSSR = OSSR_M0;
+	writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+	writel_relaxed(OSSR_M0, OSSR);
 	c->event_handler(c);
 
 	return IRQ_HANDLED;
@@ -59,10 +59,10 @@ pxa_osmr0_set_next_event(unsigned long delta, struct clock_event_device *dev)
 {
 	unsigned long next, oscr;
 
-	OIER |= OIER_E0;
-	next = OSCR + delta;
-	OSMR0 = next;
-	oscr = OSCR;
+	writel_relaxed(readl_relaxed(OIER) | OIER_E0, OIER);
+	next = readl_relaxed(OSCR) + delta;
+	writel_relaxed(next, OSMR0);
+	oscr = readl_relaxed(OSCR);
 
 	return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
 }
@@ -72,15 +72,15 @@ pxa_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *dev)
 {
 	switch (mode) {
 	case CLOCK_EVT_MODE_ONESHOT:
-		OIER &= ~OIER_E0;
-		OSSR = OSSR_M0;
+		writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+		writel_relaxed(OSSR_M0, OSSR);
 		break;
 
 	case CLOCK_EVT_MODE_UNUSED:
 	case CLOCK_EVT_MODE_SHUTDOWN:
 		/* initializing, released, or preparing for suspend */
-		OIER &= ~OIER_E0;
-		OSSR = OSSR_M0;
+		writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+		writel_relaxed(OSSR_M0, OSSR);
 		break;
 
 	case CLOCK_EVT_MODE_RESUME:
@@ -108,8 +108,8 @@ static void __init pxa_timer_init(void)
 {
 	unsigned long clock_tick_rate = get_clock_tick_rate();
 
-	OIER = 0;
-	OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
+	writel_relaxed(0, OIER);
+	writel_relaxed(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR);
 
 	setup_sched_clock(pxa_read_sched_clock, 32, clock_tick_rate);
 
@@ -122,7 +122,7 @@ static void __init pxa_timer_init(void)
 
 	setup_irq(IRQ_OST0, &pxa_ost0_irq);
 
-	clocksource_mmio_init(&OSCR, "oscr0", clock_tick_rate, 200, 32,
+	clocksource_mmio_init(OSCR, "oscr0", clock_tick_rate, 200, 32,
 		clocksource_mmio_readl_up);
 	clockevents_register_device(&ckevt_pxa_osmr0);
 }
@@ -132,12 +132,12 @@ static unsigned long osmr[4], oier, oscr;
 
 static void pxa_timer_suspend(void)
 {
-	osmr[0] = OSMR0;
-	osmr[1] = OSMR1;
-	osmr[2] = OSMR2;
-	osmr[3] = OSMR3;
-	oier = OIER;
-	oscr = OSCR;
+	osmr[0] = readl_relaxed(OSMR0);
+	osmr[1] = readl_relaxed(OSMR1);
+	osmr[2] = readl_relaxed(OSMR2);
+	osmr[3] = readl_relaxed(OSMR3);
+	oier = readl_relaxed(OIER);
+	oscr = readl_relaxed(OSCR);
 }
 
 static void pxa_timer_resume(void)
@@ -151,12 +151,12 @@ static void pxa_timer_resume(void)
 	if (osmr[0] - oscr < MIN_OSCR_DELTA)
 		osmr[0] += MIN_OSCR_DELTA;
 
-	OSMR0 = osmr[0];
-	OSMR1 = osmr[1];
-	OSMR2 = osmr[2];
-	OSMR3 = osmr[3];
-	OIER = oier;
-	OSCR = oscr;
+	writel_relaxed(osmr[0], OSMR0);
+	writel_relaxed(osmr[1], OSMR1);
+	writel_relaxed(osmr[2], OSMR2);
+	writel_relaxed(osmr[3], OSMR3);
+	writel_relaxed(oier, OIER);
+	writel_relaxed(oscr, OSCR);
 }
 #else
 #define pxa_timer_suspend NULL
diff --git a/arch/arm/mach-sa1100/assabet.c b/arch/arm/mach-sa1100/assabet.c
index d1dc7f1a239..d673211f121 100644
--- a/arch/arm/mach-sa1100/assabet.c
+++ b/arch/arm/mach-sa1100/assabet.c
@@ -362,7 +362,7 @@ static void __init assabet_init(void)
 static void __init map_sa1100_gpio_regs( void )
 {
 	unsigned long phys = __PREG(GPLR) & PMD_MASK;
-	unsigned long virt = io_p2v(phys);
+	unsigned long virt = (unsigned long)io_p2v(phys);
 	int prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO);
 	pmd_t *pmd;
 
diff --git a/arch/arm/mach-sa1100/cpu-sa1100.c b/arch/arm/mach-sa1100/cpu-sa1100.c
index 19b2053f5af..e8f4d1e1923 100644
--- a/arch/arm/mach-sa1100/cpu-sa1100.c
+++ b/arch/arm/mach-sa1100/cpu-sa1100.c
@@ -87,6 +87,7 @@
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
+#include <linux/io.h>
 
 #include <asm/cputype.h>
 
diff --git a/arch/arm/mach-sa1100/cpu-sa1110.c b/arch/arm/mach-sa1100/cpu-sa1110.c
index 675bf8ef97e..48c45b0c92b 100644
--- a/arch/arm/mach-sa1100/cpu-sa1110.c
+++ b/arch/arm/mach-sa1100/cpu-sa1110.c
@@ -19,6 +19,7 @@
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
diff --git a/arch/arm/mach-sa1100/include/mach/SA-1100.h b/arch/arm/mach-sa1100/include/mach/SA-1100.h
index 3f2d1b60188..0ac6cc08a19 100644
--- a/arch/arm/mach-sa1100/include/mach/SA-1100.h
+++ b/arch/arm/mach-sa1100/include/mach/SA-1100.h
@@ -830,14 +830,14 @@
  *              	(read/write).
  */
 
-#define OSMR0  		__REG(0x90000000)  /* OS timer Match Reg. 0 */
-#define OSMR1  		__REG(0x90000004)  /* OS timer Match Reg. 1 */
-#define OSMR2  		__REG(0x90000008)  /* OS timer Match Reg. 2 */
-#define OSMR3  		__REG(0x9000000c)  /* OS timer Match Reg. 3 */
-#define OSCR   	__REG(0x90000010)  /* OS timer Counter Reg. */
-#define OSSR   	__REG(0x90000014	)  /* OS timer Status Reg. */
-#define OWER   	__REG(0x90000018	)  /* OS timer Watch-dog Enable Reg. */
-#define OIER   	__REG(0x9000001C	)  /* OS timer Interrupt Enable Reg. */
+#define OSMR0  		io_p2v(0x90000000)  /* OS timer Match Reg. 0 */
+#define OSMR1  		io_p2v(0x90000004)  /* OS timer Match Reg. 1 */
+#define OSMR2  		io_p2v(0x90000008)  /* OS timer Match Reg. 2 */
+#define OSMR3  		io_p2v(0x9000000c)  /* OS timer Match Reg. 3 */
+#define OSCR   		io_p2v(0x90000010)  /* OS timer Counter Reg. */
+#define OSSR   		io_p2v(0x90000014)  /* OS timer Status Reg. */
+#define OWER   		io_p2v(0x90000018)  /* OS timer Watch-dog Enable Reg. */
+#define OIER  	 	io_p2v(0x9000001C)  /* OS timer Interrupt Enable Reg. */
 
 #define OSSR_M(Nb)	        	/* Match detected [0..3]           */ \
                 	(0x00000001 << (Nb))
diff --git a/arch/arm/mach-sa1100/include/mach/gpio.h b/arch/arm/mach-sa1100/include/mach/gpio.h
index a38fc4f5424..6a9eecf3137 100644
--- a/arch/arm/mach-sa1100/include/mach/gpio.h
+++ b/arch/arm/mach-sa1100/include/mach/gpio.h
@@ -24,6 +24,7 @@
 #ifndef __ASM_ARCH_SA1100_GPIO_H
 #define __ASM_ARCH_SA1100_GPIO_H
 
+#include <linux/io.h>
 #include <mach/hardware.h>
 #include <asm/irq.h>
 #include <asm-generic/gpio.h>
diff --git a/arch/arm/mach-sa1100/include/mach/hardware.h b/arch/arm/mach-sa1100/include/mach/hardware.h
index 99f5856d8de..cbedd75a9d6 100644
--- a/arch/arm/mach-sa1100/include/mach/hardware.h
+++ b/arch/arm/mach-sa1100/include/mach/hardware.h
@@ -32,7 +32,7 @@
 #define PIO_START       0x80000000	/* physical start of IO space */
 
 #define io_p2v( x )             \
-   ( (((x)&0x00ffffff) | (((x)&0x30000000)>>VIO_SHIFT)) + VIO_BASE )
+   IOMEM( (((x)&0x00ffffff) | (((x)&0x30000000)>>VIO_SHIFT)) + VIO_BASE )
 #define io_v2p( x )             \
    ( (((x)&0x00ffffff) | (((x)&(0x30000000>>VIO_SHIFT))<<VIO_SHIFT)) + PIO_START )
 
@@ -47,6 +47,8 @@
 #define CPU_SA1110_ID	(0x6901b110)
 #define CPU_SA1110_MASK	(0xfffffff0)
 
+#define __MREG(x)	IOMEM(io_p2v(x))
+
 #ifndef __ASSEMBLY__
 
 #include <asm/cputype.h>
@@ -56,7 +58,7 @@
 #define cpu_is_sa1100()	((read_cpuid_id() & CPU_SA1100_MASK) == CPU_SA1100_ID)
 #define cpu_is_sa1110()	((read_cpuid_id() & CPU_SA1110_MASK) == CPU_SA1110_ID)
 
-# define __REG(x)	(*((volatile unsigned long *)io_p2v(x)))
+# define __REG(x)	(*((volatile unsigned long __iomem *)io_p2v(x)))
 # define __PREG(x)	(io_v2p((unsigned long)&(x)))
 
 static inline unsigned long get_clock_tick_rate(void)
diff --git a/arch/arm/mach-sa1100/include/mach/uncompress.h b/arch/arm/mach-sa1100/include/mach/uncompress.h
index 6cb39ddde65..5cf71da60e4 100644
--- a/arch/arm/mach-sa1100/include/mach/uncompress.h
+++ b/arch/arm/mach-sa1100/include/mach/uncompress.h
@@ -8,6 +8,8 @@
 
 #include "hardware.h"
 
+#define IOMEM(x)	(x)
+
 /*
  * The following code assumes the serial port has already been
  * initialized by the bootloader.  We search for the first enabled
diff --git a/arch/arm/mach-sa1100/irq.c b/arch/arm/mach-sa1100/irq.c
index 516ccc25d7f..2124f1fc2fb 100644
--- a/arch/arm/mach-sa1100/irq.c
+++ b/arch/arm/mach-sa1100/irq.c
@@ -12,6 +12,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/ioport.h>
 #include <linux/syscore_ops.h>
diff --git a/arch/arm/mach-sa1100/jornada720_ssp.c b/arch/arm/mach-sa1100/jornada720_ssp.c
index b412fc09c80..7f07f08d896 100644
--- a/arch/arm/mach-sa1100/jornada720_ssp.c
+++ b/arch/arm/mach-sa1100/jornada720_ssp.c
@@ -18,6 +18,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
+#include <linux/io.h>
 
 #include <mach/hardware.h>
 #include <mach/jornada720.h>
diff --git a/arch/arm/mach-sa1100/leds-cerf.c b/arch/arm/mach-sa1100/leds-cerf.c
index 040540fb7d8..30fc3b2bf55 100644
--- a/arch/arm/mach-sa1100/leds-cerf.c
+++ b/arch/arm/mach-sa1100/leds-cerf.c
@@ -4,6 +4,7 @@
  * Author: ???
  */
 #include <linux/init.h>
+#include <linux/io.h>
 
 #include <mach/hardware.h>
 #include <asm/leds.h>
diff --git a/arch/arm/mach-sa1100/leds-lart.c b/arch/arm/mach-sa1100/leds-lart.c
index a51830c60e5..50a5b143b46 100644
--- a/arch/arm/mach-sa1100/leds-lart.c
+++ b/arch/arm/mach-sa1100/leds-lart.c
@@ -10,6 +10,7 @@
  *  pace of the LED.
  */
 #include <linux/init.h>
+#include <linux/io.h>
 
 #include <mach/hardware.h>
 #include <asm/leds.h>
diff --git a/arch/arm/mach-sa1100/pm.c b/arch/arm/mach-sa1100/pm.c
index 690cf0ce5c0..6645d1e31f1 100644
--- a/arch/arm/mach-sa1100/pm.c
+++ b/arch/arm/mach-sa1100/pm.c
@@ -23,6 +23,7 @@
  * 				Storage is local on the stack now.
  */
 #include <linux/init.h>
+#include <linux/io.h>
 #include <linux/suspend.h>
 #include <linux/errno.h>
 #include <linux/time.h>
diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c
index 6af26e8d55e..80702c9ecc7 100644
--- a/arch/arm/mach-sa1100/time.c
+++ b/arch/arm/mach-sa1100/time.c
@@ -22,7 +22,7 @@
 
 static u32 notrace sa1100_read_sched_clock(void)
 {
-	return OSCR;
+	return readl_relaxed(OSCR);
 }
 
 #define MIN_OSCR_DELTA 2
@@ -32,8 +32,8 @@ static irqreturn_t sa1100_ost0_interrupt(int irq, void *dev_id)
 	struct clock_event_device *c = dev_id;
 
 	/* Disarm the compare/match, signal the event. */
-	OIER &= ~OIER_E0;
-	OSSR = OSSR_M0;
+	writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+	writel_relaxed(OSSR_M0, OSSR);
 	c->event_handler(c);
 
 	return IRQ_HANDLED;
@@ -44,10 +44,10 @@ sa1100_osmr0_set_next_event(unsigned long delta, struct clock_event_device *c)
 {
 	unsigned long next, oscr;
 
-	OIER |= OIER_E0;
-	next = OSCR + delta;
-	OSMR0 = next;
-	oscr = OSCR;
+	writel_relaxed(readl_relaxed(OIER) | OIER_E0, OIER);
+	next = readl_relaxed(OSCR) + delta;
+	writel_relaxed(next, OSMR0);
+	oscr = readl_relaxed(OSCR);
 
 	return (signed)(next - oscr) <= MIN_OSCR_DELTA ? -ETIME : 0;
 }
@@ -59,8 +59,8 @@ sa1100_osmr0_set_mode(enum clock_event_mode mode, struct clock_event_device *c)
 	case CLOCK_EVT_MODE_ONESHOT:
 	case CLOCK_EVT_MODE_UNUSED:
 	case CLOCK_EVT_MODE_SHUTDOWN:
-		OIER &= ~OIER_E0;
-		OSSR = OSSR_M0;
+		writel_relaxed(readl_relaxed(OIER) & ~OIER_E0, OIER);
+		writel_relaxed(OSSR_M0, OSSR);
 		break;
 
 	case CLOCK_EVT_MODE_RESUME:
@@ -86,8 +86,8 @@ static struct irqaction sa1100_timer_irq = {
 
 static void __init sa1100_timer_init(void)
 {
-	OIER = 0;
-	OSSR = OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3;
+	writel_relaxed(0, OIER);
+	writel_relaxed(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR);
 
 	setup_sched_clock(sa1100_read_sched_clock, 32, 3686400);
 
@@ -100,7 +100,7 @@ static void __init sa1100_timer_init(void)
 
 	setup_irq(IRQ_OST0, &sa1100_timer_irq);
 
-	clocksource_mmio_init(&OSCR, "oscr", CLOCK_TICK_RATE, 200, 32,
+	clocksource_mmio_init(OSCR, "oscr", CLOCK_TICK_RATE, 200, 32,
 		clocksource_mmio_readl_up);
 	clockevents_register_device(&ckevt_sa1100_osmr0);
 }
@@ -110,26 +110,26 @@ unsigned long osmr[4], oier;
 
 static void sa1100_timer_suspend(void)
 {
-	osmr[0] = OSMR0;
-	osmr[1] = OSMR1;
-	osmr[2] = OSMR2;
-	osmr[3] = OSMR3;
-	oier = OIER;
+	osmr[0] = readl_relaxed(OSMR0);
+	osmr[1] = readl_relaxed(OSMR1);
+	osmr[2] = readl_relaxed(OSMR2);
+	osmr[3] = readl_relaxed(OSMR3);
+	oier = readl_relaxed(OIER);
 }
 
 static void sa1100_timer_resume(void)
 {
-	OSSR = 0x0f;
-	OSMR0 = osmr[0];
-	OSMR1 = osmr[1];
-	OSMR2 = osmr[2];
-	OSMR3 = osmr[3];
-	OIER = oier;
+	writel_relaxed(0x0f, OSSR);
+	writel_relaxed(osmr[0], OSMR0);
+	writel_relaxed(osmr[1], OSMR1);
+	writel_relaxed(osmr[2], OSMR2);
+	writel_relaxed(osmr[3], OSMR3);
+	writel_relaxed(oier, OIER);
 
 	/*
 	 * OSMR0 is the system timer: make sure OSCR is sufficiently behind
 	 */
-	OSCR = OSMR0 - LATCH;
+	writel_relaxed(OSMR0 - LATCH, OSCR);
 }
 #else
 #define sa1100_timer_suspend NULL
diff --git a/drivers/input/touchscreen/jornada720_ts.c b/drivers/input/touchscreen/jornada720_ts.c
index d9be6eac99b..7f03d1bd916 100644
--- a/drivers/input/touchscreen/jornada720_ts.c
+++ b/drivers/input/touchscreen/jornada720_ts.c
@@ -19,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/io.h>
 
 #include <mach/hardware.h>
 #include <mach/jornada720.h>
diff --git a/drivers/pcmcia/sa1100_shannon.c b/drivers/pcmcia/sa1100_shannon.c
index decb34730bc..56ab7391560 100644
--- a/drivers/pcmcia/sa1100_shannon.c
+++ b/drivers/pcmcia/sa1100_shannon.c
@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/init.h>
+#include <linux/io.h>
 
 #include <mach/hardware.h>
 #include <asm/mach-types.h>
diff --git a/drivers/watchdog/sa1100_wdt.c b/drivers/watchdog/sa1100_wdt.c
index 54984deb856..ccd6b29e21b 100644
--- a/drivers/watchdog/sa1100_wdt.c
+++ b/drivers/watchdog/sa1100_wdt.c
@@ -54,10 +54,10 @@ static int sa1100dog_open(struct inode *inode, struct file *file)
 		return -EBUSY;
 
 	/* Activate SA1100 Watchdog timer */
-	OSMR3 = OSCR + pre_margin;
-	OSSR = OSSR_M3;
-	OWER = OWER_WME;
-	OIER |= OIER_E3;
+	writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
+	writel_relaxed(OSSR_M3, OSSR);
+	writel_relaxed(OWER_WME, OWER);
+	writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER);
 	return nonseekable_open(inode, file);
 }
 
@@ -80,7 +80,7 @@ static ssize_t sa1100dog_write(struct file *file, const char __user *data,
 {
 	if (len)
 		/* Refresh OSMR3 timer. */
-		OSMR3 = OSCR + pre_margin;
+		writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
 	return len;
 }
 
@@ -114,7 +114,7 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
 		break;
 
 	case WDIOC_KEEPALIVE:
-		OSMR3 = OSCR + pre_margin;
+		writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
 		ret = 0;
 		break;
 
@@ -129,7 +129,7 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
 		}
 
 		pre_margin = oscr_freq * time;
-		OSMR3 = OSCR + pre_margin;
+		writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
 		/*fall through*/
 
 	case WDIOC_GETTIMEOUT: