diff options
Diffstat (limited to 'kernel/arch/mips/bcm63xx/timer.c')
| -rw-r--r-- | kernel/arch/mips/bcm63xx/timer.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/kernel/arch/mips/bcm63xx/timer.c b/kernel/arch/mips/bcm63xx/timer.c new file mode 100644 index 000000000..5f1135981 --- /dev/null +++ b/kernel/arch/mips/bcm63xx/timer.c @@ -0,0 +1,205 @@ +/* + * 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_RAW_SPINLOCK(timer_reg_lock); +static DEFINE_RAW_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; + + raw_spin_lock(&timer_reg_lock); + stat = bcm_timer_readl(TIMER_IRQSTAT_REG); + bcm_timer_writel(stat, TIMER_IRQSTAT_REG); + raw_spin_unlock(&timer_reg_lock); + + for (i = 0; i < BCM63XX_TIMER_COUNT; i++) { + if (!(stat & TIMER_IRQSTAT_TIMER_CAUSE(i))) + continue; + + raw_spin_lock(&timer_data_lock); + if (!timer_data[i].cb) { + raw_spin_unlock(&timer_data_lock); + continue; + } + + timer_data[i].cb(timer_data[i].data); + raw_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; + + raw_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); + + raw_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; + + raw_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); + + raw_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; + raw_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: + raw_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; + + raw_spin_lock_irqsave(&timer_data_lock, flags); + timer_data[id].cb = NULL; + raw_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; + + raw_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)); + + raw_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); |