#include <linux/atmel_tc.h>
  #include <linux/clk.h>
  #include <linux/err.h>
  #include <linux/init.h>
  #include <linux/io.h>
  #include <linux/ioport.h>
  #include <linux/kernel.h>
  #include <linux/platform_device.h>

  #include <linux/slab.h>

  #include <linux/export.h>

  
  /* Number of bytes to reserve for the iomem resource */
  #define ATMEL_TC_IOMEM_SIZE	256
  
  
  /*
   * This is a thin library to solve the problem of how to portably allocate
   * one of the TC blocks.  For simplicity, it doesn't currently expect to
   * share individual timers between different drivers.
   */
  
  #if defined(CONFIG_AVR32)
  /* AVR32 has these divide PBB */
  const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
  EXPORT_SYMBOL(atmel_tc_divisors);
  
  #elif defined(CONFIG_ARCH_AT91)
  /* AT91 has these divide MCK */
  const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
  EXPORT_SYMBOL(atmel_tc_divisors);
  
  #endif
  
  static DEFINE_SPINLOCK(tc_list_lock);
  static LIST_HEAD(tc_list);
  
  /**
   * atmel_tc_alloc - allocate a specified TC block
   * @block: which block to allocate
   * @name: name to be associated with the iomem resource
   *
   * Caller allocates a block.  If it is available, a pointer to a
   * pre-initialized struct atmel_tc is returned. The caller can access
   * the registers directly through the "regs" field.
   */
  struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
  {
  	struct atmel_tc		*tc;
  	struct platform_device	*pdev = NULL;
  	struct resource		*r;
  
  	spin_lock(&tc_list_lock);
  	list_for_each_entry(tc, &tc_list, node) {
  		if (tc->pdev->id == block) {
  			pdev = tc->pdev;
  			break;
  		}
  	}
  
  	if (!pdev || tc->iomem)
  		goto fail;
  
  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name);
  	if (!r)
  		goto fail;
  
  	tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE);
  	if (!tc->regs)
  		goto fail_ioremap;
  
  	tc->iomem = r;
  
  out:
  	spin_unlock(&tc_list_lock);
  	return tc;
  
  fail_ioremap:

  	release_mem_region(r->start, ATMEL_TC_IOMEM_SIZE);

  fail:
  	tc = NULL;
  	goto out;
  }
  EXPORT_SYMBOL_GPL(atmel_tc_alloc);
  
  /**
   * atmel_tc_free - release a specified TC block
   * @tc: Timer/counter block that was returned by atmel_tc_alloc()
   *
   * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
   * registers, invalidating the resource returned by that routine and
   * making the TC available to other drivers.
   */
  void atmel_tc_free(struct atmel_tc *tc)
  {
  	spin_lock(&tc_list_lock);
  	if (tc->regs) {
  		iounmap(tc->regs);

  		release_mem_region(tc->iomem->start, ATMEL_TC_IOMEM_SIZE);

  		tc->regs = NULL;
  		tc->iomem = NULL;
  	}
  	spin_unlock(&tc_list_lock);
  }
  EXPORT_SYMBOL_GPL(atmel_tc_free);
  
  static int __init tc_probe(struct platform_device *pdev)
  {
  	struct atmel_tc *tc;
  	struct clk	*clk;
  	int		irq;
  
  	if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
  		return -EINVAL;
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0)
  		return -EINVAL;
  
  	tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
  	if (!tc)
  		return -ENOMEM;
  
  	tc->pdev = pdev;
  
  	clk = clk_get(&pdev->dev, "t0_clk");
  	if (IS_ERR(clk)) {
  		kfree(tc);
  		return -EINVAL;
  	}
  
  	tc->clk[0] = clk;
  	tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
  	if (IS_ERR(tc->clk[1]))
  		tc->clk[1] = clk;
  	tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
  	if (IS_ERR(tc->clk[2]))
  		tc->clk[2] = clk;
  
  	tc->irq[0] = irq;
  	tc->irq[1] = platform_get_irq(pdev, 1);
  	if (tc->irq[1] < 0)
  		tc->irq[1] = irq;
  	tc->irq[2] = platform_get_irq(pdev, 2);
  	if (tc->irq[2] < 0)
  		tc->irq[2] = irq;
  
  	spin_lock(&tc_list_lock);
  	list_add_tail(&tc->node, &tc_list);
  	spin_unlock(&tc_list_lock);
  
  	return 0;
  }
  
  static struct platform_driver tc_driver = {
  	.driver.name	= "atmel_tcb",
  };
  
  static int __init tc_init(void)
  {
  	return platform_driver_probe(&tc_driver, tc_probe);
  }
  arch_initcall(tc_init);