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Commit b720f732 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[PATCH] ARM: Convert ARM timer implementations to use readl/writel 



Convert ARMs timer implementations to use readl/writel instead of accessing
the registers via a struct.

People have recently asked if accessing timers via a structure is the
"right way" and its not the Linux way.  So fix this code to conform to
"The Linux Way"(tm).

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 6904b246

arch/arm/mach-integrator/core.c

+14 −28
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <asm/irq.h>

#include <asm/io.h>

#include <asm/hardware/amba.h>

#include <asm/hardware/arm_timer.h>

#include <asm/arch/cm.h>

#include <asm/system.h>

#include <asm/leds.h>
@@ -156,16 +157,6 @@ EXPORT_SYMBOL(cm_control); 
#define TICKS2USECS(x)	((x) / TICKS_PER_uSEC)

#endif



/*

 * What does it look like?

 */

typedef struct TimerStruct {

	unsigned long TimerLoad;

	unsigned long TimerValue;

	unsigned long TimerControl;

	unsigned long TimerClear;

} TimerStruct_t;



static unsigned long timer_reload;



/*
@@ -174,7 +165,6 @@ static unsigned long timer_reload; 
 */

unsigned long integrator_gettimeoffset(void)

{

	volatile TimerStruct_t *timer1 = (TimerStruct_t *)TIMER1_VA_BASE;

	unsigned long ticks1, ticks2, status;



	/*
@@ -183,11 +173,11 @@ unsigned long integrator_gettimeoffset(void) 
	 * an interrupt.  We get around this by ensuring that the

	 * counter has not reloaded between our two reads.

	 */

	ticks2 = timer1->TimerValue & 0xffff;

	ticks2 = readl(TIMER1_VA_BASE + TIMER_VALUE) & 0xffff;

	do {

		ticks1 = ticks2;

		status = __raw_readl(VA_IC_BASE + IRQ_RAW_STATUS);

		ticks2 = timer1->TimerValue & 0xffff;

		ticks2 = readl(TIMER1_VA_BASE + TIMER_VALUE) & 0xffff;

	} while (ticks2 > ticks1);



	/*
@@ -213,20 +203,19 @@ unsigned long integrator_gettimeoffset(void) 
static irqreturn_t

integrator_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)

{

	volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE;



	write_seqlock(&xtime_lock);



	/*

	 * clear the interrupt

	 */

	timer1->TimerClear = 1;

	writel(1, TIMER1_VA_BASE + TIMER_INTCLR);



	/*

	 * the clock tick routines are only processed on the

	 * primary CPU

	 */

	if (hard_smp_processor_id() == 0) {

		nmi_tick();

		timer_tick(regs);

#ifdef CONFIG_SMP

		smp_send_timer();
@@ -256,32 +245,29 @@ static struct irqaction integrator_timer_irq = { 
 */

void __init integrator_time_init(unsigned long reload, unsigned int ctrl)

{

	volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *)TIMER0_VA_BASE;

	volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE;

	volatile TimerStruct_t *timer2 = (volatile TimerStruct_t *)TIMER2_VA_BASE;

	unsigned int timer_ctrl = 0x80 | 0x40;	/* periodic */

	unsigned int timer_ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;



	timer_reload = reload;

	timer_ctrl |= ctrl;



	if (timer_reload > 0x100000) {

		timer_reload >>= 8;

		timer_ctrl |= 0x08; /* /256 */

		timer_ctrl |= TIMER_CTRL_DIV256;

	} else if (timer_reload > 0x010000) {

		timer_reload >>= 4;

		timer_ctrl |= 0x04; /* /16 */

		timer_ctrl |= TIMER_CTRL_DIV16;

	}



	/*

	 * Initialise to a known state (all timers off)

	 */

	timer0->TimerControl = 0;

	timer1->TimerControl = 0;

	timer2->TimerControl = 0;

	writel(0, TIMER0_VA_BASE + TIMER_CTRL);

	writel(0, TIMER1_VA_BASE + TIMER_CTRL);

	writel(0, TIMER2_VA_BASE + TIMER_CTRL);



	timer1->TimerLoad    = timer_reload;

	timer1->TimerValue   = timer_reload;

	timer1->TimerControl = timer_ctrl;

	writel(timer_reload, TIMER1_VA_BASE + TIMER_LOAD);

	writel(timer_reload, TIMER1_VA_BASE + TIMER_VALUE);

	writel(timer_ctrl, TIMER1_VA_BASE + TIMER_CTRL);



	/*

	 * Make irqs happen for the system timer

arch/arm/mach-versatile/core.c

+24 −37
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <asm/mach-types.h>

#include <asm/hardware/amba.h>

#include <asm/hardware/amba_clcd.h>

#include <asm/hardware/arm_timer.h>

#include <asm/hardware/icst307.h>



#include <asm/mach/arch.h>
@@ -788,38 +789,25 @@ void __init versatile_init(void) 
 */

#define TIMER_INTERVAL	(TICKS_PER_uSEC * mSEC_10)

#if TIMER_INTERVAL >= 0x100000

#define TIMER_RELOAD	(TIMER_INTERVAL >> 8)		/* Divide by 256 */

#define TIMER_CTRL	0x88				/* Enable, Clock / 256 */

#define TIMER_RELOAD	(TIMER_INTERVAL >> 8)

#define TIMER_DIVISOR	(TIMER_CTRL_DIV256)

#define TICKS2USECS(x)	(256 * (x) / TICKS_PER_uSEC)

#elif TIMER_INTERVAL >= 0x10000

#define TIMER_RELOAD	(TIMER_INTERVAL >> 4)		/* Divide by 16 */

#define TIMER_CTRL	0x84				/* Enable, Clock / 16 */

#define TIMER_DIVISOR	(TIMER_CTRL_DIV16)

#define TICKS2USECS(x)	(16 * (x) / TICKS_PER_uSEC)

#else

#define TIMER_RELOAD	(TIMER_INTERVAL)

#define TIMER_CTRL	0x80				/* Enable */

#define TIMER_DIVISOR	(TIMER_CTRL_DIV1)

#define TICKS2USECS(x)	((x) / TICKS_PER_uSEC)

#endif



#define TIMER_CTRL_IE	(1 << 5)	/* Interrupt Enable */



/*

 * What does it look like?

 */

typedef struct TimerStruct {

	unsigned long TimerLoad;

	unsigned long TimerValue;

	unsigned long TimerControl;

	unsigned long TimerClear;

} TimerStruct_t;



/*

 * Returns number of ms since last clock interrupt.  Note that interrupts

 * will have been disabled by do_gettimeoffset()

 */

static unsigned long versatile_gettimeoffset(void)

{

	volatile TimerStruct_t *timer0 = (TimerStruct_t *)TIMER0_VA_BASE;

	unsigned long ticks1, ticks2, status;



	/*
@@ -828,11 +816,11 @@ static unsigned long versatile_gettimeoffset(void) 
	 * an interrupt.  We get around this by ensuring that the

	 * counter has not reloaded between our two reads.

	 */

	ticks2 = timer0->TimerValue & 0xffff;

	ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;

	do {

		ticks1 = ticks2;

		status = __raw_readl(VA_IC_BASE + VIC_IRQ_RAW_STATUS);

		ticks2 = timer0->TimerValue & 0xffff;

		ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;

	} while (ticks2 > ticks1);



	/*
@@ -859,12 +847,10 @@ static unsigned long versatile_gettimeoffset(void) 
 */

static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)

{

	volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *)TIMER0_VA_BASE;



	write_seqlock(&xtime_lock);



	// ...clear the interrupt

	timer0->TimerClear = 1;

	writel(1, TIMER0_VA_BASE + TIMER_INTCLR);



	timer_tick(regs);
@@ -884,31 +870,32 @@ static struct irqaction versatile_timer_irq = { 
 */

static void __init versatile_timer_init(void)

{

	volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *)TIMER0_VA_BASE;

	volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE;

	volatile TimerStruct_t *timer2 = (volatile TimerStruct_t *)TIMER2_VA_BASE;

	volatile TimerStruct_t *timer3 = (volatile TimerStruct_t *)TIMER3_VA_BASE;

	u32 val;



	/* 

	 * set clock frequency: 

	 *	VERSATILE_REFCLK is 32KHz

	 *	VERSATILE_TIMCLK is 1MHz

	 */

	*(volatile unsigned int *)IO_ADDRESS(VERSATILE_SCTL_BASE) |= 

	  ((VERSATILE_TIMCLK << VERSATILE_TIMER1_EnSel) | (VERSATILE_TIMCLK << VERSATILE_TIMER2_EnSel) | 

	   (VERSATILE_TIMCLK << VERSATILE_TIMER3_EnSel) | (VERSATILE_TIMCLK << VERSATILE_TIMER4_EnSel));

	val = readl(IO_ADDRESS(VERSATILE_SCTL_BASE));

	writel((VERSATILE_TIMCLK << VERSATILE_TIMER1_EnSel) |

	       (VERSATILE_TIMCLK << VERSATILE_TIMER2_EnSel) | 

	       (VERSATILE_TIMCLK << VERSATILE_TIMER3_EnSel) |

	       (VERSATILE_TIMCLK << VERSATILE_TIMER4_EnSel) | val,

	       IO_ADDRESS(VERSATILE_SCTL_BASE));



	/*

	 * Initialise to a known state (all timers off)

	 */

	timer0->TimerControl = 0;

	timer1->TimerControl = 0;

	timer2->TimerControl = 0;

	timer3->TimerControl = 0;



	timer0->TimerLoad    = TIMER_RELOAD;

	timer0->TimerValue   = TIMER_RELOAD;

	timer0->TimerControl = TIMER_CTRL | 0x40 | TIMER_CTRL_IE;  /* periodic + IE */

	writel(0, TIMER0_VA_BASE + TIMER_CTRL);

	writel(0, TIMER1_VA_BASE + TIMER_CTRL);

	writel(0, TIMER2_VA_BASE + TIMER_CTRL);

	writel(0, TIMER3_VA_BASE + TIMER_CTRL);



	writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);

	writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_VALUE);

	writel(TIMER_DIVISOR | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC |

	       TIMER_CTRL_IE, TIMER0_VA_BASE + TIMER_CTRL);



	/* 

	 * Make irqs happen for the system timer

include/asm-arm/hardware/arm_timer.h

0 → 100644
+21 −0
Original line number Diff line number Diff line 
#ifndef __ASM_ARM_HARDWARE_ARM_TIMER_H

#define __ASM_ARM_HARDWARE_ARM_TIMER_H



#define TIMER_LOAD	0x00

#define TIMER_VALUE	0x04

#define TIMER_CTRL	0x08

#define TIMER_CTRL_ONESHOT	(1 << 0)

#define TIMER_CTRL_32BIT	(1 << 1)

#define TIMER_CTRL_DIV1		(0 << 2)

#define TIMER_CTRL_DIV16	(1 << 2)

#define TIMER_CTRL_DIV256	(2 << 2)

#define TIMER_CTRL_IE		(1 << 5)	/* Interrupt Enable (versatile only) */

#define TIMER_CTRL_PERIODIC	(1 << 6)

#define TIMER_CTRL_ENABLE	(1 << 7)



#define TIMER_INTCLR	0x0c

#define TIMER_RIS	0x10

#define TIMER_MIS	0x14

#define TIMER_BGLOAD	0x18



#endif