drivers/uio/uio_pdrv.c

   1 /*
   2  * drivers/uio/uio_pdrv.c
   3  *
   4  * Copyright (C) 2008 by Digi International Inc.
   5  * All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11 #include <linux/platform_device.h>
  12 #include <linux/uio_driver.h>
  13 #include <linux/stringify.h>
  14 #include <linux/slab.h>
  15
  16 #define DRIVER_NAME "uio_pdrv"
  17
  18 struct uio_platdata {
  19         struct uio_info *uioinfo;
  20 };
  21
  22 static int uio_pdrv_probe(struct platform_device *pdev)
  23 {
  24         struct uio_info *uioinfo = pdev->dev.platform_data;
  25         struct uio_platdata *pdata;
  26         struct uio_mem *uiomem;
  27         int ret = -ENODEV;
  28         int i;
  29
  30         if (!uioinfo || !uioinfo->name || !uioinfo->version) {
  31                 dev_dbg(&pdev->dev, "%s: err_uioinfo\n", __func__);
  32                 goto err_uioinfo;
  33         }
  34
  35         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
  36         if (!pdata) {
  37                 ret = -ENOMEM;
  38                 dev_dbg(&pdev->dev, "%s: err_alloc_pdata\n", __func__);
  39                 goto err_alloc_pdata;
  40         }
  41
  42         pdata->uioinfo = uioinfo;
  43
  44         uiomem = &uioinfo->mem[0];
  45
  46         for (i = 0; i < pdev->num_resources; ++i) {
  47                 struct resource *r = &pdev->resource[i];
  48
  49                 if (r->flags != IORESOURCE_MEM)
  50                         continue;
  51
  52                 if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
  53                         dev_warn(&pdev->dev, "device has more than "
  54                                         __stringify(MAX_UIO_MAPS)
  55                                         " I/O memory resources.\n");
  56                         break;
  57                 }
  58
  59                 uiomem->memtype = UIO_MEM_PHYS;
  60                 uiomem->addr = r->start;
  61                 uiomem->size = resource_size(r);
  62                 ++uiomem;
  63         }
  64
  65         while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
  66                 uiomem->size = 0;
  67                 ++uiomem;
  68         }
  69
  70         pdata->uioinfo->priv = pdata;
  71
  72         ret = uio_register_device(&pdev->dev, pdata->uioinfo);
  73
  74         if (ret) {
  75                 kfree(pdata);
  76 err_alloc_pdata:
  77 err_uioinfo:
  78                 return ret;
  79         }
  80
  81         platform_set_drvdata(pdev, pdata);
  82
  83         return 0;
  84 }
  85
  86 static int uio_pdrv_remove(struct platform_device *pdev)
  87 {
  88         struct uio_platdata *pdata = platform_get_drvdata(pdev);
  89
  90         uio_unregister_device(pdata->uioinfo);
  91
  92         kfree(pdata);
  93
  94         return 0;
  95 }
  96
  97 static struct platform_driver uio_pdrv = {
  98         .probe = uio_pdrv_probe,
  99         .remove = uio_pdrv_remove,
 100         .driver = {
 101                 .name = DRIVER_NAME,
 102                 .owner = THIS_MODULE,
 103         },
 104 };
 105
 106 static int __init uio_pdrv_init(void)
 107 {
 108         return platform_driver_register(&uio_pdrv);
 109 }
 110
 111 static void __exit uio_pdrv_exit(void)
 112 {
 113         platform_driver_unregister(&uio_pdrv);
 114 }
 115 module_init(uio_pdrv_init);
 116 module_exit(uio_pdrv_exit);
 117
 118 MODULE_AUTHOR("Uwe Kleine-Koenig");
 119 MODULE_DESCRIPTION("Userspace I/O platform driver");
 120 MODULE_LICENSE("GPL v2");
 121 MODULE_ALIAS("platform:" DRIVER_NAME);