/* * Copyright (C) 2001-2006 Storlink, Corp. * Copyright (C) 2008-2009 Paulius Zaleckas * * 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. */ #include #include #include #include #include #include #include #include /* * Register definitions for the timers */ #define TIMER1_BASE GEMINI_TIMER_BASE #define TIMER2_BASE (GEMINI_TIMER_BASE + 0x10) #define TIMER3_BASE (GEMINI_TIMER_BASE + 0x20) #define TIMER_COUNT(BASE) (IO_ADDRESS(BASE) + 0x00) #define TIMER_LOAD(BASE) (IO_ADDRESS(BASE) + 0x04) #define TIMER_MATCH1(BASE) (IO_ADDRESS(BASE) + 0x08) #define TIMER_MATCH2(BASE) (IO_ADDRESS(BASE) + 0x0C) #define TIMER_CR (IO_ADDRESS(GEMINI_TIMER_BASE) + 0x30) #define TIMER_INTR_STATE (IO_ADDRESS(GEMINI_TIMER_BASE) + 0x34) #define TIMER_INTR_MASK (IO_ADDRESS(GEMINI_TIMER_BASE) + 0x38) #define TIMER_1_CR_ENABLE (1 << 0) #define TIMER_1_CR_CLOCK (1 << 1) #define TIMER_1_CR_INT (1 << 2) #define TIMER_2_CR_ENABLE (1 << 3) #define TIMER_2_CR_CLOCK (1 << 4) #define TIMER_2_CR_INT (1 << 5) #define TIMER_3_CR_ENABLE (1 << 6) #define TIMER_3_CR_CLOCK (1 << 7) #define TIMER_3_CR_INT (1 << 8) #define TIMER_1_CR_UPDOWN (1 << 9) #define TIMER_2_CR_UPDOWN (1 << 10) #define TIMER_3_CR_UPDOWN (1 << 11) #define TIMER_DEFAULT_FLAGS (TIMER_1_CR_UPDOWN | \ TIMER_3_CR_ENABLE | \ TIMER_3_CR_UPDOWN) #define TIMER_1_INT_MATCH1 (1 << 0) #define TIMER_1_INT_MATCH2 (1 << 1) #define TIMER_1_INT_OVERFLOW (1 << 2) #define TIMER_2_INT_MATCH1 (1 << 3) #define TIMER_2_INT_MATCH2 (1 << 4) #define TIMER_2_INT_OVERFLOW (1 << 5) #define TIMER_3_INT_MATCH1 (1 << 6) #define TIMER_3_INT_MATCH2 (1 << 7) #define TIMER_3_INT_OVERFLOW (1 << 8) #define TIMER_INT_ALL_MASK 0x1ff static unsigned int tick_rate; static int gemini_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { u32 cr; /* Setup the match register */ cr = readl(TIMER_COUNT(TIMER1_BASE)); writel(cr + cycles, TIMER_MATCH1(TIMER1_BASE)); if (readl(TIMER_COUNT(TIMER1_BASE)) - cr > cycles) return -ETIME; return 0; } static int gemini_timer_shutdown(struct clock_event_device *evt) { u32 cr; /* * Disable also for oneshot: the set_next() call will arm the timer * instead. */ /* Stop timer and interrupt. */ cr = readl(TIMER_CR); cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT); writel(cr, TIMER_CR); /* Setup counter start from 0 */ writel(0, TIMER_COUNT(TIMER1_BASE)); writel(0, TIMER_LOAD(TIMER1_BASE)); /* enable interrupt */ cr = readl(TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_MATCH1; writel(cr, TIMER_INTR_MASK); /* start the timer */ cr = readl(TIMER_CR); cr |= TIMER_1_CR_ENABLE; writel(cr, TIMER_CR); return 0; } static int gemini_timer_set_periodic(struct clock_event_device *evt) { u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ); u32 cr; /* Stop timer and interrupt */ cr = readl(TIMER_CR); cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT); writel(cr, TIMER_CR); /* Setup timer to fire at 1/HT intervals. */ cr = 0xffffffff - (period - 1); writel(cr, TIMER_COUNT(TIMER1_BASE)); writel(cr, TIMER_LOAD(TIMER1_BASE)); /* enable interrupt on overflow */ cr = readl(TIMER_INTR_MASK); cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2); cr |= TIMER_1_INT_OVERFLOW; writel(cr, TIMER_INTR_MASK); /* Start the timer */ cr = readl(TIMER_CR); cr |= TIMER_1_CR_ENABLE; cr |= TIMER_1_CR_INT; writel(cr, TIMER_CR); return 0; } /* Use TIMER1 as clock event */ static struct clock_event_device gemini_clockevent = { .name = "TIMER1", /* Reasonably fast and accurate clock event */ .rating = 300, .shift = 32, .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, .set_next_event = gemini_timer_set_next_event, .set_state_shutdown = gemini_timer_shutdown, .set_state_periodic = gemini_timer_set_periodic, .set_state_oneshot = gemini_timer_shutdown, .tick_resume = gemini_timer_shutdown, }; /* * IRQ handler for the timer */ static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id) { struct clock_event_device *evt = &gemini_clockevent; evt->event_handler(evt); return IRQ_HANDLED; } static struct irqaction gemini_timer_irq = { .name = "Gemini Timer Tick", .flags = IRQF_TIMER, .handler = gemini_timer_interrupt, }; /* * Set up timer interrupt, and return the current time in seconds. */ void __init gemini_timer_init(void) { u32 reg_v; reg_v = readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS)); tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000; printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000); tick_rate /= 6; /* APB bus run AHB*(1/6) */ switch(reg_v & CPU_AHB_RATIO_MASK) { case CPU_AHB_1_1: printk(KERN_CONT "(1/1)\n"); break; case CPU_AHB_3_2: printk(KERN_CONT "(3/2)\n"); break; case CPU_AHB_24_13: printk(KERN_CONT "(24/13)\n"); break; case CPU_AHB_2_1: printk(KERN_CONT "(2/1)\n"); break; } /* * Reset the interrupt mask and status */ writel(TIMER_INT_ALL_MASK, TIMER_INTR_MASK); writel(0, TIMER_INTR_STATE); writel(TIMER_DEFAULT_FLAGS, TIMER_CR); /* * Setup clockevent timer (interrupt-driven.) */ writel(0, TIMER_COUNT(TIMER1_BASE)); writel(0, TIMER_LOAD(TIMER1_BASE)); writel(0, TIMER_MATCH1(TIMER1_BASE)); writel(0, TIMER_MATCH2(TIMER1_BASE)); setup_irq(IRQ_TIMER1, &gemini_timer_irq); gemini_clockevent.cpumask = cpumask_of(0); clockevents_config_and_register(&gemini_clockevent, tick_rate, 1, 0xffffffff); }