drivers/misc/atmel_tclib.c

   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 #include <linux/module.h>
  10 #include <linux/slab.h>
  11 #include <linux/export.h>
  12 #include <linux/of.h>
  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 */
  22 const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
  23 EXPORT_SYMBOL(atmel_tc_divisors);
  24
  25 #elif defined(CONFIG_ARCH_AT91)
  26 /* AT91 has these divide MCK */
  27 const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
  28 EXPORT_SYMBOL(atmel_tc_divisors);
  29
  30 #endif
  31
  32 static DEFINE_SPINLOCK(tc_list_lock);
  33 static 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  */
  44 struct 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         size_t                  size;
  50
  51         spin_lock(&tc_list_lock);
  52         list_for_each_entry(tc, &tc_list, node) {
  53                 if (tc->pdev->dev.of_node) {
  54                         if (of_alias_get_id(tc->pdev->dev.of_node, "tcb")
  55                                         == block) {
  56                                 pdev = tc->pdev;
  57                                 break;
  58                         }
  59                 } else if (tc->pdev->id == block) {
  60                         pdev = tc->pdev;
  61                         break;
  62                 }
  63         }
  64
  65         if (!pdev || tc->iomem)
  66                 goto fail;
  67
  68         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  69         if (!r)
  70                 goto fail;
  71
  72         size = resource_size(r);
  73         r = request_mem_region(r->start, size, name);
  74         if (!r)
  75                 goto fail;
  76
  77         tc->regs = ioremap(r->start, size);
  78         if (!tc->regs)
  79                 goto fail_ioremap;
  80
  81         tc->iomem = r;
  82
  83 out:
  84         spin_unlock(&tc_list_lock);
  85         return tc;
  86
  87 fail_ioremap:
  88         release_mem_region(r->start, size);
  89 fail:
  90         tc = NULL;
  91         goto out;
  92 }
  93 EXPORT_SYMBOL_GPL(atmel_tc_alloc);
  94
  95 /**
  96  * atmel_tc_free - release a specified TC block
  97  * @tc: Timer/counter block that was returned by atmel_tc_alloc()
  98  *
  99  * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
 100  * registers, invalidating the resource returned by that routine and
 101  * making the TC available to other drivers.
 102  */
 103 void atmel_tc_free(struct atmel_tc *tc)
 104 {
 105         spin_lock(&tc_list_lock);
 106         if (tc->regs) {
 107                 iounmap(tc->regs);
 108                 release_mem_region(tc->iomem->start, resource_size(tc->iomem));
 109                 tc->regs = NULL;
 110                 tc->iomem = NULL;
 111         }
 112         spin_unlock(&tc_list_lock);
 113 }
 114 EXPORT_SYMBOL_GPL(atmel_tc_free);
 115
 116 #if defined(CONFIG_OF)
 117 static struct atmel_tcb_config tcb_rm9200_config = {
 118         .counter_width = 16,
 119 };
 120
 121 static struct atmel_tcb_config tcb_sam9x5_config = {
 122         .counter_width = 32,
 123 };
 124
 125 static const struct of_device_id atmel_tcb_dt_ids[] = {
 126         {
 127                 .compatible = "atmel,at91rm9200-tcb",
 128                 .data = &tcb_rm9200_config,
 129         }, {
 130                 .compatible = "atmel,at91sam9x5-tcb",
 131                 .data = &tcb_sam9x5_config,
 132         }, {
 133                 /* sentinel */
 134         }
 135 };
 136
 137 MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
 138 #endif
 139
 140 static int __init tc_probe(struct platform_device *pdev)
 141 {
 142         struct atmel_tc *tc;
 143         struct clk      *clk;
 144         int             irq;
 145
 146         if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
 147                 return -EINVAL;
 148
 149         irq = platform_get_irq(pdev, 0);
 150         if (irq < 0)
 151                 return -EINVAL;
 152
 153         tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
 154         if (!tc)
 155                 return -ENOMEM;
 156
 157         tc->pdev = pdev;
 158
 159         clk = clk_get(&pdev->dev, "t0_clk");
 160         if (IS_ERR(clk)) {
 161                 kfree(tc);
 162                 return -EINVAL;
 163         }
 164
 165         /* Now take SoC information if available */
 166         if (pdev->dev.of_node) {
 167                 const struct of_device_id *match;
 168                 match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
 169                 if (match)
 170                         tc->tcb_config = match->data;
 171         }
 172
 173         tc->clk[0] = clk;
 174         tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
 175         if (IS_ERR(tc->clk[1]))
 176                 tc->clk[1] = clk;
 177         tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
 178         if (IS_ERR(tc->clk[2]))
 179                 tc->clk[2] = clk;
 180
 181         tc->irq[0] = irq;
 182         tc->irq[1] = platform_get_irq(pdev, 1);
 183         if (tc->irq[1] < 0)
 184                 tc->irq[1] = irq;
 185         tc->irq[2] = platform_get_irq(pdev, 2);
 186         if (tc->irq[2] < 0)
 187                 tc->irq[2] = irq;
 188
 189         spin_lock(&tc_list_lock);
 190         list_add_tail(&tc->node, &tc_list);
 191         spin_unlock(&tc_list_lock);
 192
 193         return 0;
 194 }
 195
 196 static struct platform_driver tc_driver = {
 197         .driver = {
 198                 .name   = "atmel_tcb",
 199                 .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
 200         },
 201 };
 202
 203 static int __init tc_init(void)
 204 {
 205         return platform_driver_probe(&tc_driver, tc_probe);
 206 }
 207 arch_initcall(tc_init);