1/* 2 * Copyright (C) 2001-2006 Storlink, Corp. 3 * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> 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 */ 39static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id) 40{ 41 timer_tick(); 42 43 return IRQ_HANDLED; 44} 45 46static 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 */ 55void __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