1/* 2 * arch/arm/mach-netx/time.c 3 * 4 * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 8 * as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20#include <linux/init.h> 21#include <linux/interrupt.h> 22#include <linux/irq.h> 23#include <linux/clocksource.h> 24 25#include <asm/hardware.h> 26#include <asm/io.h> 27#include <asm/mach/time.h> 28#include <asm/arch/netx-regs.h> 29 30/* 31 * IRQ handler for the timer 32 */ 33static irqreturn_t 34netx_timer_interrupt(int irq, void *dev_id) 35{ 36 write_seqlock(&xtime_lock); 37 38 timer_tick(); 39 40 write_sequnlock(&xtime_lock); 41 42 /* acknowledge interrupt */ 43 writel(COUNTER_BIT(0), NETX_GPIO_IRQ); 44 45 return IRQ_HANDLED; 46} 47 48static struct irqaction netx_timer_irq = { 49 .name = "NetX Timer Tick", 50 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, 51 .handler = netx_timer_interrupt, 52}; 53 54cycle_t netx_get_cycles(void) 55{ 56 return readl(NETX_GPIO_COUNTER_CURRENT(1)); 57} 58 59static struct clocksource clocksource_netx = { 60 .name = "netx_timer", 61 .rating = 200, 62 .read = netx_get_cycles, 63 .mask = CLOCKSOURCE_MASK(32), 64 .shift = 20, 65 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 66}; 67 68/* 69 * Set up timer interrupt 70 */ 71static void __init netx_timer_init(void) 72{ 73 /* disable timer initially */ 74 writel(0, NETX_GPIO_COUNTER_CTRL(0)); 75 76 /* Reset the timer value to zero */ 77 writel(0, NETX_GPIO_COUNTER_CURRENT(0)); 78 79 writel(LATCH, NETX_GPIO_COUNTER_MAX(0)); 80 81 /* acknowledge interrupt */ 82 writel(COUNTER_BIT(0), NETX_GPIO_IRQ); 83 84 /* Enable the interrupt in the specific timer register and start timer */ 85 writel(COUNTER_BIT(0), NETX_GPIO_IRQ_ENABLE); 86 writel(NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN, 87 NETX_GPIO_COUNTER_CTRL(0)); 88 89 setup_irq(NETX_IRQ_TIMER0, &netx_timer_irq); 90 91 /* Setup timer one for clocksource */ 92 writel(0, NETX_GPIO_COUNTER_CTRL(1)); 93 writel(0, NETX_GPIO_COUNTER_CURRENT(1)); 94 writel(0xFFFFFFFF, NETX_GPIO_COUNTER_MAX(1)); 95 96 writel(NETX_GPIO_COUNTER_CTRL_RUN, 97 NETX_GPIO_COUNTER_CTRL(1)); 98 99 clocksource_netx.mult = 100 clocksource_hz2mult(CLOCK_TICK_RATE, clocksource_netx.shift); 101 clocksource_register(&clocksource_netx); 102} 103 104struct sys_timer netx_timer = { 105 .init = netx_timer_init, 106}; 107