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