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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
*/
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
#include <bcm63xx_timer.h>
#include <bcm63xx_regs.h>
static DEFINE_SPINLOCK(timer_reg_lock);
static DEFINE_SPINLOCK(timer_data_lock);
static struct clk *periph_clk;
static struct timer_data {
void (*cb)(void *);
void *data;
} timer_data[BCM63XX_TIMER_COUNT];
static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
u32 stat;
int i;
spin_lock(&timer_reg_lock);
stat = bcm_timer_readl(TIMER_IRQSTAT_REG);
bcm_timer_writel(stat, TIMER_IRQSTAT_REG);
spin_unlock(&timer_reg_lock);
for (i = 0; i < BCM63XX_TIMER_COUNT; i++) {
if (!(stat & TIMER_IRQSTAT_TIMER_CAUSE(i)))
continue;
spin_lock(&timer_data_lock);
if (!timer_data[i].cb) {
spin_unlock(&timer_data_lock);
continue;
}
timer_data[i].cb(timer_data[i].data);
spin_unlock(&timer_data_lock);
}
return IRQ_HANDLED;
}
int bcm63xx_timer_enable(int id)
{
u32 reg;
unsigned long flags;
if (id >= BCM63XX_TIMER_COUNT)
return -EINVAL;
spin_lock_irqsave(&timer_reg_lock, flags);
reg = bcm_timer_readl(TIMER_CTLx_REG(id));
reg |= TIMER_CTL_ENABLE_MASK;
bcm_timer_writel(reg, TIMER_CTLx_REG(id));
reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
reg |= TIMER_IRQSTAT_TIMER_IR_EN(id);
bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
spin_unlock_irqrestore(&timer_reg_lock, flags);
return 0;
}
EXPORT_SYMBOL(bcm63xx_timer_enable);
int bcm63xx_timer_disable(int id)
{
u32 reg;
unsigned long flags;
if (id >= BCM63XX_TIMER_COUNT)
return -EINVAL;
spin_lock_irqsave(&timer_reg_lock, flags);
reg = bcm_timer_readl(TIMER_CTLx_REG(id));
reg &= ~TIMER_CTL_ENABLE_MASK;
bcm_timer_writel(reg, TIMER_CTLx_REG(id));
reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
reg &= ~TIMER_IRQSTAT_TIMER_IR_EN(id);
bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
spin_unlock_irqrestore(&timer_reg_lock, flags);
return 0;
}
EXPORT_SYMBOL(bcm63xx_timer_disable);
int bcm63xx_timer_register(int id, void (*callback)(void *data), void *data)
{
unsigned long flags;
int ret;
if (id >= BCM63XX_TIMER_COUNT || !callback)
return -EINVAL;
ret = 0;
spin_lock_irqsave(&timer_data_lock, flags);
if (timer_data[id].cb) {
ret = -EBUSY;
goto out;
}
timer_data[id].cb = callback;
timer_data[id].data = data;
out:
spin_unlock_irqrestore(&timer_data_lock, flags);
return ret;
}
EXPORT_SYMBOL(bcm63xx_timer_register);
void bcm63xx_timer_unregister(int id)
{
unsigned long flags;
if (id >= BCM63XX_TIMER_COUNT)
return;
spin_lock_irqsave(&timer_data_lock, flags);
timer_data[id].cb = NULL;
spin_unlock_irqrestore(&timer_data_lock, flags);
}
EXPORT_SYMBOL(bcm63xx_timer_unregister);
unsigned int bcm63xx_timer_countdown(unsigned int countdown_us)
{
return (clk_get_rate(periph_clk) / (1000 * 1000)) * countdown_us;
}
EXPORT_SYMBOL(bcm63xx_timer_countdown);
int bcm63xx_timer_set(int id, int monotonic, unsigned int countdown_us)
{
u32 reg, countdown;
unsigned long flags;
if (id >= BCM63XX_TIMER_COUNT)
return -EINVAL;
countdown = bcm63xx_timer_countdown(countdown_us);
if (countdown & ~TIMER_CTL_COUNTDOWN_MASK)
return -EINVAL;
spin_lock_irqsave(&timer_reg_lock, flags);
reg = bcm_timer_readl(TIMER_CTLx_REG(id));
if (monotonic)
reg &= ~TIMER_CTL_MONOTONIC_MASK;
else
reg |= TIMER_CTL_MONOTONIC_MASK;
reg &= ~TIMER_CTL_COUNTDOWN_MASK;
reg |= countdown;
bcm_timer_writel(reg, TIMER_CTLx_REG(id));
spin_unlock_irqrestore(&timer_reg_lock, flags);
return 0;
}
EXPORT_SYMBOL(bcm63xx_timer_set);
int bcm63xx_timer_init(void)
{
int ret, irq;
u32 reg;
reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
reg &= ~TIMER_IRQSTAT_TIMER0_IR_EN;
reg &= ~TIMER_IRQSTAT_TIMER1_IR_EN;
reg &= ~TIMER_IRQSTAT_TIMER2_IR_EN;
bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
periph_clk = clk_get(NULL, "periph");
if (IS_ERR(periph_clk))
return -ENODEV;
irq = bcm63xx_get_irq_number(IRQ_TIMER);
ret = request_irq(irq, timer_interrupt, 0, "bcm63xx_timer", NULL);
if (ret) {
printk(KERN_ERR "bcm63xx_timer: failed to register irq\n");
return ret;
}
return 0;
}
arch_initcall(bcm63xx_timer_init);
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