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
timer_interrupt(int irq,void * dev_id)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
bcm63xx_timer_enable(int id)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
bcm63xx_timer_disable(int id)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
bcm63xx_timer_register(int id,void (* callback)(void * data),void * data)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
bcm63xx_timer_unregister(int id)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
bcm63xx_timer_countdown(unsigned int countdown_us)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
bcm63xx_timer_set(int id,int monotonic,unsigned int countdown_us)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
bcm63xx_timer_init(void)181 static 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);
207