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kernel/linux-imx6_3.14.28/arch/mips/bcm63xx/timer.c 4.4 KB
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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_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
  ");
  		return ret;
  	}
  
  	return 0;
  }
  
  arch_initcall(bcm63xx_timer_init);