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