drivers/misc/hdpuftrs/hdpu_nexus.c

   1 /*
   2  *      Sky Nexus Register Driver
   3  *
   4  *      Copyright (C) 2002 Brian Waite
   5  *
   6  *      This driver allows reading the Nexus register
   7  *      It exports the /proc/sky_chassis_id and also
   8  *      /proc/sky_slot_id pseudo-file for status information.
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/kernel.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/hdpu_features.h>
  21
  22 #include <linux/platform_device.h>
  23
  24 static int hdpu_nexus_probe(struct platform_device *pdev);
  25 static int hdpu_nexus_remove(struct platform_device *pdev);
  26
  27 static struct proc_dir_entry *hdpu_slot_id;
  28 static struct proc_dir_entry *hdpu_chassis_id;
  29 static int slot_id = -1;
  30 static int chassis_id = -1;
  31
  32 static struct platform_driver hdpu_nexus_driver = {
  33         .probe = hdpu_nexus_probe,
  34         .remove = hdpu_nexus_remove,
  35         .driver = {
  36                 .name = HDPU_NEXUS_NAME,
  37         },
  38 };
  39
  40 int hdpu_slot_id_read(char *buffer, char **buffer_location, off_t offset,
  41                       int buffer_length, int *zero, void *ptr)
  42 {
  43
  44         if (offset > 0)
  45                 return 0;
  46         return sprintf(buffer, "%d\n", slot_id);
  47 }
  48
  49 int hdpu_chassis_id_read(char *buffer, char **buffer_location, off_t offset,
  50                          int buffer_length, int *zero, void *ptr)
  51 {
  52
  53         if (offset > 0)
  54                 return 0;
  55         return sprintf(buffer, "%d\n", chassis_id);
  56 }
  57
  58 static int hdpu_nexus_probe(struct platform_device *pdev)
  59 {
  60         struct resource *res;
  61
  62         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  63         int *nexus_id_addr;
  64         nexus_id_addr =
  65             ioremap(res->start, (unsigned long)(res->end - res->start));
  66         if (nexus_id_addr) {
  67                 slot_id = (*nexus_id_addr >> 8) & 0x1f;
  68                 chassis_id = *nexus_id_addr & 0xff;
  69                 iounmap(nexus_id_addr);
  70         } else
  71                 printk("Could not map slot id\n");
  72         hdpu_slot_id = create_proc_entry("sky_slot_id", 0666, &proc_root);
  73         hdpu_slot_id->read_proc = hdpu_slot_id_read;
  74
  75         hdpu_chassis_id = create_proc_entry("sky_chassis_id", 0666, &proc_root);
  76         hdpu_chassis_id->read_proc = hdpu_chassis_id_read;
  77         return 0;
  78 }
  79
  80 static int hdpu_nexus_remove(struct platform_device *pdev)
  81 {
  82         slot_id = -1;
  83         chassis_id = -1;
  84         remove_proc_entry("sky_slot_id", &proc_root);
  85         remove_proc_entry("sky_chassis_id", &proc_root);
  86         hdpu_slot_id = 0;
  87         hdpu_chassis_id = 0;
  88         return 0;
  89 }
  90
  91 static int __init nexus_init(void)
  92 {
  93         int rc;
  94         rc = platform_driver_register(&hdpu_nexus_driver);
  95         return rc;
  96 }
  97
  98 static void __exit nexus_exit(void)
  99 {
 100         platform_driver_unregister(&hdpu_nexus_driver);
 101 }
 102
 103 module_init(nexus_init);
 104 module_exit(nexus_exit);
 105
 106 MODULE_AUTHOR("Brian Waite");
 107 MODULE_LICENSE("GPL");