Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/arm/mach-gemini/time.c
10817 views
1
/*

2
 *  Copyright (C) 2001-2006 Storlink, Corp.

3
 *  Copyright (C) 2008-2009 Paulius Zaleckas <[email protected]>

4
 *

5
 * This program is free software; you can redistribute it and/or modify

6
 * it under the terms of the GNU General Public License as published by

7
 * the Free Software Foundation; either version 2 of the License, or

8
 * (at your option) any later version.

9
 */

10
#include <linux/interrupt.h>

11
#include <linux/irq.h>

12
#include <linux/io.h>

13
#include <mach/hardware.h>

14
#include <mach/global_reg.h>

15
#include <asm/mach/time.h>

16


17
/*

18
 * Register definitions for the timers

19
 */

20
#define TIMER_COUNT(BASE_ADDR)		(BASE_ADDR  + 0x00)

21
#define TIMER_LOAD(BASE_ADDR)		(BASE_ADDR  + 0x04)

22
#define TIMER_MATCH1(BASE_ADDR)		(BASE_ADDR  + 0x08)

23
#define TIMER_MATCH2(BASE_ADDR)		(BASE_ADDR  + 0x0C)

24
#define TIMER_CR(BASE_ADDR)		(BASE_ADDR  + 0x30)

25


26
#define TIMER_1_CR_ENABLE		(1 << 0)

27
#define TIMER_1_CR_CLOCK		(1 << 1)

28
#define TIMER_1_CR_INT			(1 << 2)

29
#define TIMER_2_CR_ENABLE		(1 << 3)

30
#define TIMER_2_CR_CLOCK		(1 << 4)

31
#define TIMER_2_CR_INT			(1 << 5)

32
#define TIMER_3_CR_ENABLE		(1 << 6)

33
#define TIMER_3_CR_CLOCK		(1 << 7)

34
#define TIMER_3_CR_INT			(1 << 8)

35


36
/*

37
 * IRQ handler for the timer

38
 */

39
static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)

40
{

41
	timer_tick();

42


43
	return IRQ_HANDLED;

44
}

45


46
static struct irqaction gemini_timer_irq = {

47
	.name		= "Gemini Timer Tick",

48
	.flags		= IRQF_DISABLED | IRQF_TIMER,

49
	.handler	= gemini_timer_interrupt,

50
};

51


52
/*

53
 * Set up timer interrupt, and return the current time in seconds.

54
 */

55
void __init gemini_timer_init(void)

56
{

57
	unsigned int tick_rate, reg_v;

58


59
	reg_v = __raw_readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));

60
	tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000;

61


62
	printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);

63


64
	tick_rate /= 6;		/* APB bus run AHB*(1/6) */

65


66
	switch(reg_v & CPU_AHB_RATIO_MASK) {

67
	case CPU_AHB_1_1:

68
		printk(KERN_CONT "(1/1)\n");

69
		break;

70
	case CPU_AHB_3_2:

71
		printk(KERN_CONT "(3/2)\n");

72
		break;

73
	case CPU_AHB_24_13:

74
		printk(KERN_CONT "(24/13)\n");

75
		break;

76
	case CPU_AHB_2_1:

77
		printk(KERN_CONT "(2/1)\n");

78
		break;

79
	}

80


81
	/*

82
	 * Make irqs happen for the system timer

83
	 */

84
	setup_irq(IRQ_TIMER2, &gemini_timer_irq);

85
	/* Start the timer */

86
	__raw_writel(tick_rate / HZ, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));

87
	__raw_writel(tick_rate / HZ, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));

88
	__raw_writel(TIMER_2_CR_ENABLE | TIMER_2_CR_INT, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));

89
}

90


91