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