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/Ethereal-msm8939-beta9/arch/mips/bcm63xx/timer.c

https://bitbucket.org/MilosStamenkovic95/etherealos
C | 205 lines | 149 code | 49 blank | 7 comment | 14 complexity | d37fc0c038b50c5e58bf7460ae6f2a52 MD5 | raw file
  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);