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
  15 #define DRIVER_NAME "uio_pdrv"
  16
  17 struct uio_platdata {
  18         struct uio_info *uioinfo;
  19 };
  20
  21 static int uio_pdrv_probe(struct platform_device *pdev)
  22 {
  23         struct uio_info *uioinfo = pdev->dev.platform_data;
  24         struct uio_platdata *pdata;
  25         struct uio_mem *uiomem;
  26         int ret = -ENODEV;
  27         int i;
  28
  29         if (!uioinfo || !uioinfo->name || !uioinfo->version) {
  30                 dev_dbg(&pdev->dev, "%s: err_uioinfo\n", __func__);
  31                 goto err_uioinfo;
  32         }
  33
  34         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
  35         if (!pdata) {
  36                 ret = -ENOMEM;
  37                 dev_dbg(&pdev->dev, "%s: err_alloc_pdata\n", __func__);
  38                 goto err_alloc_pdata;
  39         }
  40
  41         pdata->uioinfo = uioinfo;
  42
  43         uiomem = &uioinfo->mem[0];
  44
  45         for (i = 0; i < pdev->num_resources; ++i) {
  46                 struct resource *r = &pdev->resource[i];
  47
  48                 if (r->flags != IORESOURCE_MEM)
  49                         continue;
  50
  51                 if (uiomem >= &uioinfo->mem[MAX_UIO_MAPS]) {
  52                         dev_warn(&pdev->dev, "device has more than "
  53                                         __stringify(MAX_UIO_MAPS)
  54                                         " I/O memory resources.\n");
  55                         break;
  56                 }
  57
  58                 uiomem->memtype = UIO_MEM_PHYS;
  59                 uiomem->addr = r->start;
  60                 uiomem->size = r->end - r->start + 1;
  61                 ++uiomem;
  62         }
  63
  64         while (uiomem < &uioinfo->mem[MAX_UIO_MAPS]) {
  65                 uiomem->size = 0;
  66                 ++uiomem;
  67         }
  68
  69         pdata->uioinfo->priv = pdata;
  70
  71         ret = uio_register_device(&pdev->dev, pdata->uioinfo);
  72
  73         if (ret) {
  74                 kfree(pdata);
  75 err_alloc_pdata:
  76 err_uioinfo:
  77                 return ret;
  78         }
  79
  80         platform_set_drvdata(pdev, pdata);
  81
  82         return 0;
  83 }
  84
  85 static int uio_pdrv_remove(struct platform_device *pdev)
  86 {
  87         struct uio_platdata *pdata = platform_get_drvdata(pdev);
  88
  89         uio_unregister_device(pdata->uioinfo);
  90
  91         kfree(pdata);
  92
  93         return 0;
  94 }
  95
  96 static struct platform_driver uio_pdrv = {
  97         .probe = uio_pdrv_probe,
  98         .remove = uio_pdrv_remove,
  99         .driver = {
 100                 .name = DRIVER_NAME,
 101                 .owner = THIS_MODULE,
 102         },
 103 };
 104
 105 static int __init uio_pdrv_init(void)
 106 {
 107         return platform_driver_register(&uio_pdrv);
 108 }
 109
 110 static void __exit uio_pdrv_exit(void)
 111 {
 112         platform_driver_unregister(&uio_pdrv);
 113 }
 114 module_init(uio_pdrv_init);
 115 module_exit(uio_pdrv_exit);
 116
 117 MODULE_AUTHOR("Uwe Kleine-Koenig");
 118 MODULE_DESCRIPTION("Userspace I/O platform driver");
 119 MODULE_LICENSE("GPL v2");
 120 MODULE_ALIAS("platform:" DRIVER_NAME);