1 /*
2 * linux/arch/arm/mach-w90x900/time.c
3 *
4 * Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks
5 *
6 * Copyright (c) 2009 Nuvoton technology corporation
7 * All rights reserved.
8 *
9 * Wan ZongShun <mcuos.com@gmail.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 */
17
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/err.h>
23 #include <linux/clk.h>
24 #include <linux/io.h>
25 #include <linux/leds.h>
26 #include <linux/clocksource.h>
27 #include <linux/clockchips.h>
28
29 #include <asm/mach-types.h>
30 #include <asm/mach/irq.h>
31 #include <asm/mach/time.h>
32
33 #include <mach/map.h>
34 #include "regs-timer.h"
35
36 #include "nuc9xx.h"
37
38 #define RESETINT 0x1f
39 #define PERIOD (0x01 << 27)
40 #define ONESHOT (0x00 << 27)
41 #define COUNTEN (0x01 << 30)
42 #define INTEN (0x01 << 29)
43
44 #define TICKS_PER_SEC 100
45 #define PRESCALE 0x63 /* Divider = prescale + 1 */
46
47 #define TDR_SHIFT 24
48
49 static unsigned int timer0_load;
50
nuc900_clockevent_shutdown(struct clock_event_device * evt)51 static int nuc900_clockevent_shutdown(struct clock_event_device *evt)
52 {
53 unsigned int val = __raw_readl(REG_TCSR0) & ~(0x03 << 27);
54
55 __raw_writel(val, REG_TCSR0);
56 return 0;
57 }
58
nuc900_clockevent_set_oneshot(struct clock_event_device * evt)59 static int nuc900_clockevent_set_oneshot(struct clock_event_device *evt)
60 {
61 unsigned int val = __raw_readl(REG_TCSR0) & ~(0x03 << 27);
62
63 val |= (ONESHOT | COUNTEN | INTEN | PRESCALE);
64
65 __raw_writel(val, REG_TCSR0);
66 return 0;
67 }
68
nuc900_clockevent_set_periodic(struct clock_event_device * evt)69 static int nuc900_clockevent_set_periodic(struct clock_event_device *evt)
70 {
71 unsigned int val = __raw_readl(REG_TCSR0) & ~(0x03 << 27);
72
73 __raw_writel(timer0_load, REG_TICR0);
74 val |= (PERIOD | COUNTEN | INTEN | PRESCALE);
75 __raw_writel(val, REG_TCSR0);
76 return 0;
77 }
78
nuc900_clockevent_setnextevent(unsigned long evt,struct clock_event_device * clk)79 static int nuc900_clockevent_setnextevent(unsigned long evt,
80 struct clock_event_device *clk)
81 {
82 unsigned int val;
83
84 __raw_writel(evt, REG_TICR0);
85
86 val = __raw_readl(REG_TCSR0);
87 val |= (COUNTEN | INTEN | PRESCALE);
88 __raw_writel(val, REG_TCSR0);
89
90 return 0;
91 }
92
93 static struct clock_event_device nuc900_clockevent_device = {
94 .name = "nuc900-timer0",
95 .features = CLOCK_EVT_FEAT_PERIODIC |
96 CLOCK_EVT_FEAT_ONESHOT,
97 .set_state_shutdown = nuc900_clockevent_shutdown,
98 .set_state_periodic = nuc900_clockevent_set_periodic,
99 .set_state_oneshot = nuc900_clockevent_set_oneshot,
100 .tick_resume = nuc900_clockevent_shutdown,
101 .set_next_event = nuc900_clockevent_setnextevent,
102 .rating = 300,
103 };
104
105 /*IRQ handler for the timer*/
106
nuc900_timer0_interrupt(int irq,void * dev_id)107 static irqreturn_t nuc900_timer0_interrupt(int irq, void *dev_id)
108 {
109 struct clock_event_device *evt = &nuc900_clockevent_device;
110
111 __raw_writel(0x01, REG_TISR); /* clear TIF0 */
112
113 evt->event_handler(evt);
114 return IRQ_HANDLED;
115 }
116
117 static struct irqaction nuc900_timer0_irq = {
118 .name = "nuc900-timer0",
119 .flags = IRQF_TIMER | IRQF_IRQPOLL,
120 .handler = nuc900_timer0_interrupt,
121 };
122
nuc900_clockevents_init(void)123 static void __init nuc900_clockevents_init(void)
124 {
125 unsigned int rate;
126 struct clk *clk = clk_get(NULL, "timer0");
127
128 BUG_ON(IS_ERR(clk));
129
130 __raw_writel(0x00, REG_TCSR0);
131
132 clk_enable(clk);
133 rate = clk_get_rate(clk) / (PRESCALE + 1);
134
135 timer0_load = (rate / TICKS_PER_SEC);
136
137 __raw_writel(RESETINT, REG_TISR);
138 setup_irq(IRQ_TIMER0, &nuc900_timer0_irq);
139
140 nuc900_clockevent_device.cpumask = cpumask_of(0);
141
142 clockevents_config_and_register(&nuc900_clockevent_device, rate,
143 0xf, 0xffffffff);
144 }
145
nuc900_clocksource_init(void)146 static void __init nuc900_clocksource_init(void)
147 {
148 unsigned int val;
149 unsigned int rate;
150 struct clk *clk = clk_get(NULL, "timer1");
151
152 BUG_ON(IS_ERR(clk));
153
154 __raw_writel(0x00, REG_TCSR1);
155
156 clk_enable(clk);
157 rate = clk_get_rate(clk) / (PRESCALE + 1);
158
159 __raw_writel(0xffffffff, REG_TICR1);
160
161 val = __raw_readl(REG_TCSR1);
162 val |= (COUNTEN | PERIOD | PRESCALE);
163 __raw_writel(val, REG_TCSR1);
164
165 clocksource_mmio_init(REG_TDR1, "nuc900-timer1", rate, 200,
166 TDR_SHIFT, clocksource_mmio_readl_down);
167 }
168
nuc900_timer_init(void)169 void __init nuc900_timer_init(void)
170 {
171 nuc900_clocksource_init();
172 nuc900_clockevents_init();
173 }
174
