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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6/arch/arm/mach-ns9xxx/
1/*
2 * arch/arm/mach-ns9xxx/time-ns9360.c
3 *
4 * Copyright (C) 2006,2007 by Digi International Inc.
5 * All rights reserved.
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 */
11#include <linux/jiffies.h>
12#include <linux/interrupt.h>
13#include <linux/irq.h>
14#include <linux/stringify.h>
15#include <linux/clocksource.h>
16#include <linux/clockchips.h>
17
18#include <mach/processor-ns9360.h>
19#include <mach/regs-sys-ns9360.h>
20#include <mach/irqs.h>
21#include <mach/system.h>
22#include "generic.h"
23
24#define TIMER_CLOCKSOURCE 0
25#define TIMER_CLOCKEVENT 1
26static u32 latch;
27
28static cycle_t ns9360_clocksource_read(struct clocksource *cs)
29{
30	return __raw_readl(SYS_TR(TIMER_CLOCKSOURCE));
31}
32
33static struct clocksource ns9360_clocksource = {
34	.name	= "ns9360-timer" __stringify(TIMER_CLOCKSOURCE),
35	.rating	= 300,
36	.read	= ns9360_clocksource_read,
37	.mask	= CLOCKSOURCE_MASK(32),
38	.shift	= 20,
39	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
40};
41
42static void ns9360_clockevent_setmode(enum clock_event_mode mode,
43		struct clock_event_device *clk)
44{
45	u32 tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
46
47	switch (mode) {
48	case CLOCK_EVT_MODE_PERIODIC:
49		__raw_writel(latch, SYS_TRC(TIMER_CLOCKEVENT));
50		REGSET(tc, SYS_TCx, REN, EN);
51		REGSET(tc, SYS_TCx, INTS, EN);
52		REGSET(tc, SYS_TCx, TEN, EN);
53		break;
54
55	case CLOCK_EVT_MODE_ONESHOT:
56		REGSET(tc, SYS_TCx, REN, DIS);
57		REGSET(tc, SYS_TCx, INTS, EN);
58
59		/* fall through */
60
61	case CLOCK_EVT_MODE_UNUSED:
62	case CLOCK_EVT_MODE_SHUTDOWN:
63	case CLOCK_EVT_MODE_RESUME:
64	default:
65		REGSET(tc, SYS_TCx, TEN, DIS);
66		break;
67	}
68
69	__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
70}
71
72static int ns9360_clockevent_setnextevent(unsigned long evt,
73		struct clock_event_device *clk)
74{
75	u32 tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
76
77	if (REGGET(tc, SYS_TCx, TEN)) {
78		REGSET(tc, SYS_TCx, TEN, DIS);
79		__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
80	}
81
82	REGSET(tc, SYS_TCx, TEN, EN);
83
84	__raw_writel(evt, SYS_TRC(TIMER_CLOCKEVENT));
85
86	__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
87
88	return 0;
89}
90
91static struct clock_event_device ns9360_clockevent_device = {
92	.name		= "ns9360-timer" __stringify(TIMER_CLOCKEVENT),
93	.shift		= 20,
94	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
95	.set_mode	= ns9360_clockevent_setmode,
96	.set_next_event	= ns9360_clockevent_setnextevent,
97};
98
99static irqreturn_t ns9360_clockevent_handler(int irq, void *dev_id)
100{
101	int timerno = irq - IRQ_NS9360_TIMER0;
102	u32 tc;
103
104	struct clock_event_device *evt = &ns9360_clockevent_device;
105
106	/* clear irq */
107	tc = __raw_readl(SYS_TC(timerno));
108	if (REGGET(tc, SYS_TCx, REN) == SYS_TCx_REN_DIS) {
109		REGSET(tc, SYS_TCx, TEN, DIS);
110		__raw_writel(tc, SYS_TC(timerno));
111	}
112	REGSET(tc, SYS_TCx, INTC, SET);
113	__raw_writel(tc, SYS_TC(timerno));
114	REGSET(tc, SYS_TCx, INTC, UNSET);
115	__raw_writel(tc, SYS_TC(timerno));
116
117	evt->event_handler(evt);
118
119	return IRQ_HANDLED;
120}
121
122static struct irqaction ns9360_clockevent_action = {
123	.name		= "ns9360-timer" __stringify(TIMER_CLOCKEVENT),
124	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
125	.handler	= ns9360_clockevent_handler,
126};
127
128static void __init ns9360_timer_init(void)
129{
130	int tc;
131
132	tc = __raw_readl(SYS_TC(TIMER_CLOCKSOURCE));
133	if (REGGET(tc, SYS_TCx, TEN)) {
134		REGSET(tc, SYS_TCx, TEN, DIS);
135		__raw_writel(tc, SYS_TC(TIMER_CLOCKSOURCE));
136	}
137
138	__raw_writel(0, SYS_TRC(TIMER_CLOCKSOURCE));
139
140	REGSET(tc, SYS_TCx, TEN, EN);
141	REGSET(tc, SYS_TCx, TDBG, STOP);
142	REGSET(tc, SYS_TCx, TLCS, CPU);
143	REGSET(tc, SYS_TCx, TM, IEE);
144	REGSET(tc, SYS_TCx, INTS, DIS);
145	REGSET(tc, SYS_TCx, UDS, UP);
146	REGSET(tc, SYS_TCx, TSZ, 32);
147	REGSET(tc, SYS_TCx, REN, EN);
148
149	__raw_writel(tc, SYS_TC(TIMER_CLOCKSOURCE));
150
151	ns9360_clocksource.mult = clocksource_hz2mult(ns9360_cpuclock(),
152			ns9360_clocksource.shift);
153
154	clocksource_register(&ns9360_clocksource);
155
156	latch = SH_DIV(ns9360_cpuclock(), HZ, 0);
157
158	tc = __raw_readl(SYS_TC(TIMER_CLOCKEVENT));
159	REGSET(tc, SYS_TCx, TEN, DIS);
160	REGSET(tc, SYS_TCx, TDBG, STOP);
161	REGSET(tc, SYS_TCx, TLCS, CPU);
162	REGSET(tc, SYS_TCx, TM, IEE);
163	REGSET(tc, SYS_TCx, INTS, DIS);
164	REGSET(tc, SYS_TCx, UDS, DOWN);
165	REGSET(tc, SYS_TCx, TSZ, 32);
166	REGSET(tc, SYS_TCx, REN, EN);
167	__raw_writel(tc, SYS_TC(TIMER_CLOCKEVENT));
168
169	ns9360_clockevent_device.mult = div_sc(ns9360_cpuclock(),
170			NSEC_PER_SEC, ns9360_clockevent_device.shift);
171	ns9360_clockevent_device.max_delta_ns =
172		clockevent_delta2ns(-1, &ns9360_clockevent_device);
173	ns9360_clockevent_device.min_delta_ns =
174		clockevent_delta2ns(1, &ns9360_clockevent_device);
175
176	ns9360_clockevent_device.cpumask = cpumask_of(0);
177	clockevents_register_device(&ns9360_clockevent_device);
178
179	setup_irq(IRQ_NS9360_TIMER0 + TIMER_CLOCKEVENT,
180			&ns9360_clockevent_action);
181}
182
183struct sys_timer ns9360_timer = {
184	.init = ns9360_timer_init,
185};
186