1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7 */
8
9#include <linux/kernel.h>
10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/export.h>
13#include <linux/spinlock.h>
14#include <linux/interrupt.h>
15#include <linux/clk.h>
16#include <bcm63xx_cpu.h>
17#include <bcm63xx_io.h>
18#include <bcm63xx_timer.h>
19#include <bcm63xx_regs.h>
20
21static DEFINE_RAW_SPINLOCK(timer_reg_lock);
22static DEFINE_RAW_SPINLOCK(timer_data_lock);
23static struct clk *periph_clk;
24
25static struct timer_data {
26 void (*cb)(void *);
27 void *data;
28} timer_data[BCM63XX_TIMER_COUNT];
29
30static irqreturn_t timer_interrupt(int irq, void *dev_id)
31{
32 u32 stat;
33 int i;
34
35 raw_spin_lock(&timer_reg_lock);
36 stat = bcm_timer_readl(TIMER_IRQSTAT_REG);
37 bcm_timer_writel(stat, TIMER_IRQSTAT_REG);
38 raw_spin_unlock(&timer_reg_lock);
39
40 for (i = 0; i < BCM63XX_TIMER_COUNT; i++) {
41 if (!(stat & TIMER_IRQSTAT_TIMER_CAUSE(i)))
42 continue;
43
44 raw_spin_lock(&timer_data_lock);
45 if (!timer_data[i].cb) {
46 raw_spin_unlock(&timer_data_lock);
47 continue;
48 }
49
50 timer_data[i].cb(timer_data[i].data);
51 raw_spin_unlock(&timer_data_lock);
52 }
53
54 return IRQ_HANDLED;
55}
56
57int bcm63xx_timer_enable(int id)
58{
59 u32 reg;
60 unsigned long flags;
61
62 if (id >= BCM63XX_TIMER_COUNT)
63 return -EINVAL;
64
65 raw_spin_lock_irqsave(&timer_reg_lock, flags);
66
67 reg = bcm_timer_readl(TIMER_CTLx_REG(id));
68 reg |= TIMER_CTL_ENABLE_MASK;
69 bcm_timer_writel(reg, TIMER_CTLx_REG(id));
70
71 reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
72 reg |= TIMER_IRQSTAT_TIMER_IR_EN(id);
73 bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
74
75 raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
76 return 0;
77}
78
79EXPORT_SYMBOL(bcm63xx_timer_enable);
80
81int bcm63xx_timer_disable(int id)
82{
83 u32 reg;
84 unsigned long flags;
85
86 if (id >= BCM63XX_TIMER_COUNT)
87 return -EINVAL;
88
89 raw_spin_lock_irqsave(&timer_reg_lock, flags);
90
91 reg = bcm_timer_readl(TIMER_CTLx_REG(id));
92 reg &= ~TIMER_CTL_ENABLE_MASK;
93 bcm_timer_writel(reg, TIMER_CTLx_REG(id));
94
95 reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
96 reg &= ~TIMER_IRQSTAT_TIMER_IR_EN(id);
97 bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
98
99 raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
100 return 0;
101}
102
103EXPORT_SYMBOL(bcm63xx_timer_disable);
104
105int bcm63xx_timer_register(int id, void (*callback)(void *data), void *data)
106{
107 unsigned long flags;
108 int ret;
109
110 if (id >= BCM63XX_TIMER_COUNT || !callback)
111 return -EINVAL;
112
113 ret = 0;
114 raw_spin_lock_irqsave(&timer_data_lock, flags);
115 if (timer_data[id].cb) {
116 ret = -EBUSY;
117 goto out;
118 }
119
120 timer_data[id].cb = callback;
121 timer_data[id].data = data;
122
123out:
124 raw_spin_unlock_irqrestore(&timer_data_lock, flags);
125 return ret;
126}
127
128EXPORT_SYMBOL(bcm63xx_timer_register);
129
130void bcm63xx_timer_unregister(int id)
131{
132 unsigned long flags;
133
134 if (id >= BCM63XX_TIMER_COUNT)
135 return;
136
137 raw_spin_lock_irqsave(&timer_data_lock, flags);
138 timer_data[id].cb = NULL;
139 raw_spin_unlock_irqrestore(&timer_data_lock, flags);
140}
141
142EXPORT_SYMBOL(bcm63xx_timer_unregister);
143
144unsigned int bcm63xx_timer_countdown(unsigned int countdown_us)
145{
146 return (clk_get_rate(clk: periph_clk) / (1000 * 1000)) * countdown_us;
147}
148
149EXPORT_SYMBOL(bcm63xx_timer_countdown);
150
151int bcm63xx_timer_set(int id, int monotonic, unsigned int countdown_us)
152{
153 u32 reg, countdown;
154 unsigned long flags;
155
156 if (id >= BCM63XX_TIMER_COUNT)
157 return -EINVAL;
158
159 countdown = bcm63xx_timer_countdown(countdown_us);
160 if (countdown & ~TIMER_CTL_COUNTDOWN_MASK)
161 return -EINVAL;
162
163 raw_spin_lock_irqsave(&timer_reg_lock, flags);
164 reg = bcm_timer_readl(TIMER_CTLx_REG(id));
165
166 if (monotonic)
167 reg &= ~TIMER_CTL_MONOTONIC_MASK;
168 else
169 reg |= TIMER_CTL_MONOTONIC_MASK;
170
171 reg &= ~TIMER_CTL_COUNTDOWN_MASK;
172 reg |= countdown;
173 bcm_timer_writel(reg, TIMER_CTLx_REG(id));
174
175 raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
176 return 0;
177}
178
179EXPORT_SYMBOL(bcm63xx_timer_set);
180
181static int bcm63xx_timer_init(void)
182{
183 int ret, irq;
184 u32 reg;
185
186 reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
187 reg &= ~TIMER_IRQSTAT_TIMER0_IR_EN;
188 reg &= ~TIMER_IRQSTAT_TIMER1_IR_EN;
189 reg &= ~TIMER_IRQSTAT_TIMER2_IR_EN;
190 bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
191
192 periph_clk = clk_get(NULL, id: "periph");
193 if (IS_ERR(ptr: periph_clk))
194 return -ENODEV;
195
196 irq = bcm63xx_get_irq_number(IRQ_TIMER);
197 ret = request_irq(irq, handler: timer_interrupt, flags: 0, name: "bcm63xx_timer", NULL);
198 if (ret) {
199 pr_err("%s: failed to register irq\n", __func__);
200 return ret;
201 }
202
203 return 0;
204}
205
206arch_initcall(bcm63xx_timer_init);
207

source code of linux/arch/mips/bcm63xx/timer.c