GNU Linux-libre 4.19.286-gnu1
[releases.git] / arch / mips / bcm63xx / timer.c
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
21 static DEFINE_RAW_SPINLOCK(timer_reg_lock);
22 static DEFINE_RAW_SPINLOCK(timer_data_lock);
23 static struct clk *periph_clk;
24
25 static struct timer_data {
26         void    (*cb)(void *);
27         void    *data;
28 } timer_data[BCM63XX_TIMER_COUNT];
29
30 static 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
57 int 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
79 EXPORT_SYMBOL(bcm63xx_timer_enable);
80
81 int 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
103 EXPORT_SYMBOL(bcm63xx_timer_disable);
104
105 int 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
123 out:
124         raw_spin_unlock_irqrestore(&timer_data_lock, flags);
125         return ret;
126 }
127
128 EXPORT_SYMBOL(bcm63xx_timer_register);
129
130 void 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
142 EXPORT_SYMBOL(bcm63xx_timer_unregister);
143
144 unsigned int bcm63xx_timer_countdown(unsigned int countdown_us)
145 {
146         return (clk_get_rate(periph_clk) / (1000 * 1000)) * countdown_us;
147 }
148
149 EXPORT_SYMBOL(bcm63xx_timer_countdown);
150
151 int 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
179 EXPORT_SYMBOL(bcm63xx_timer_set);
180
181 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, "periph");
193         if (IS_ERR(periph_clk))
194                 return -ENODEV;
195
196         irq = bcm63xx_get_irq_number(IRQ_TIMER);
197         ret = request_irq(irq, timer_interrupt, 0, "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
206 arch_initcall(bcm63xx_timer_init);