LXR linux/drivers/misc/atmel

   1#include <linux/atmel_tc.h>
   2#include <linux/clk.h>
   3#include <linux/err.h>
   4#include <linux/init.h>
   5#include <linux/io.h>
   6#include <linux/ioport.h>
   7#include <linux/kernel.h>
   8#include <linux/platform_device.h>
   9
  10/* Number of bytes to reserve for the iomem resource */
  11#define ATMEL_TC_IOMEM_SIZE     256
  12
  13
  14/*
  15 * This is a thin library to solve the problem of how to portably allocate
  16 * one of the TC blocks.  For simplicity, it doesn't currently expect to
  17 * share individual timers between different drivers.
  18 */
  19
  20#if defined(CONFIG_AVR32)
  21/* AVR32 has these divide PBB */
  22const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
  23EXPORT_SYMBOL(atmel_tc_divisors);
  24
  25#elif defined(CONFIG_ARCH_AT91)
  26/* AT91 has these divide MCK */
  27const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
  28EXPORT_SYMBOL(atmel_tc_divisors);
  29
  30#endif
  31
  32static DEFINE_SPINLOCK(tc_list_lock);
  33static LIST_HEAD(tc_list);
  34
  35/**
  36 * atmel_tc_alloc - allocate a specified TC block
  37 * @block: which block to allocate
  38 * @name: name to be associated with the iomem resource
  39 *
  40 * Caller allocates a block.  If it is available, a pointer to a
  41 * pre-initialized struct atmel_tc is returned. The caller can access
  42 * the registers directly through the "regs" field.
  43 */
  44struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
  45{
  46        struct atmel_tc         *tc;
  47        struct platform_device  *pdev = NULL;
  48        struct resource         *r;
  49
  50        spin_lock(&tc_list_lock);
  51        list_for_each_entry(tc, &tc_list, node) {
  52                if (tc->pdev->id == block) {
  53                        pdev = tc->pdev;
  54                        break;
  55                }
  56        }
  57
  58        if (!pdev || tc->iomem)
  59                goto fail;
  60
  61        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  62        r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name);
  63        if (!r)
  64                goto fail;
  65
  66        tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE);
  67        if (!tc->regs)
  68                goto fail_ioremap;
  69
  70        tc->iomem = r;
  71
  72out:
  73        spin_unlock(&tc_list_lock);
  74        return tc;
  75
  76fail_ioremap:
  77        release_resource(r);
  78fail:
  79        tc = NULL;
  80        goto out;
  81}
  82EXPORT_SYMBOL_GPL(atmel_tc_alloc);
  83
  84/**
  85 * atmel_tc_free - release a specified TC block
  86 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
  87 *
  88 * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
  89 * registers, invalidating the resource returned by that routine and
  90 * making the TC available to other drivers.
  91 */
  92void atmel_tc_free(struct atmel_tc *tc)
  93{
  94        spin_lock(&tc_list_lock);
  95        if (tc->regs) {
  96                iounmap(tc->regs);
  97                release_resource(tc->iomem);
  98                tc->regs = NULL;
  99                tc->iomem = NULL;
 100        }
 101        spin_unlock(&tc_list_lock);
 102}
 103EXPORT_SYMBOL_GPL(atmel_tc_free);
 104
 105static int __init tc_probe(struct platform_device *pdev)
 106{
 107        struct atmel_tc *tc;
 108        struct clk      *clk;
 109        int             irq;
 110
 111        if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
 112                return -EINVAL;
 113
 114        irq = platform_get_irq(pdev, 0);
 115        if (irq < 0)
 116                return -EINVAL;
 117
 118        tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
 119        if (!tc)
 120                return -ENOMEM;
 121
 122        tc->pdev = pdev;
 123
 124        clk = clk_get(&pdev->dev, "t0_clk");
 125        if (IS_ERR(clk)) {
 126                kfree(tc);
 127                return -EINVAL;
 128        }
 129
 130        tc->clk[0] = clk;
 131        tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
 132        if (IS_ERR(tc->clk[1]))
 133                tc->clk[1] = clk;
 134        tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
 135        if (IS_ERR(tc->clk[2]))
 136                tc->clk[2] = clk;
 137
 138        tc->irq[0] = irq;
 139        tc->irq[1] = platform_get_irq(pdev, 1);
 140        if (tc->irq[1] < 0)
 141                tc->irq[1] = irq;
 142        tc->irq[2] = platform_get_irq(pdev, 2);
 143        if (tc->irq[2] < 0)
 144                tc->irq[2] = irq;
 145
 146        spin_lock(&tc_list_lock);
 147        list_add_tail(&tc->node, &tc_list);
 148        spin_unlock(&tc_list_lock);
 149
 150        return 0;
 151}
 152
 153static struct platform_driver tc_driver = {
 154        .driver.name    = "atmel_tcb",
 155};
 156
 157static int __init tc_init(void)
 158{
 159        return platform_driver_probe(&tc_driver, tc_probe);
 160}
 161arch_initcall(tc_init);
 162