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 #include <asm/io.h>
  24
  25 static int hdpu_nexus_probe(struct platform_device *pdev);
  26 static int hdpu_nexus_remove(struct platform_device *pdev);
  27
  28 static struct proc_dir_entry *hdpu_slot_id;
  29 static struct proc_dir_entry *hdpu_chassis_id;
  30 static int slot_id = -1;
  31 static int chassis_id = -1;
  32
  33 static struct platform_driver hdpu_nexus_driver = {
  34         .probe = hdpu_nexus_probe,
  35         .remove = hdpu_nexus_remove,
  36         .driver = {
  37                 .name = HDPU_NEXUS_NAME,
  38         },
  39 };
  40
  41 int hdpu_slot_id_read(char *buffer, char **buffer_location, off_t offset,
  42                       int buffer_length, int *zero, void *ptr)
  43 {
  44         if (offset > 0)
  45                 return 0;
  46
  47         return sprintf(buffer, "%d\n", slot_id);
  48 }
  49
  50 int hdpu_chassis_id_read(char *buffer, char **buffer_location, off_t offset,
  51                          int buffer_length, int *zero, void *ptr)
  52 {
  53         if (offset > 0)
  54                 return 0;
  55
  56         return sprintf(buffer, "%d\n", chassis_id);
  57 }
  58
  59 static int hdpu_nexus_probe(struct platform_device *pdev)
  60 {
  61         struct resource *res;
  62         int *nexus_id_addr;
  63
  64         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  65         if (!res) {
  66                 printk(KERN_ERR "sky_nexus: "
  67                        "Invalid memory resource.\n");
  68                 return -EINVAL;
  69         }
  70         nexus_id_addr = ioremap(res->start,
  71                                 (unsigned long)(res->end - res->start));
  72         if (nexus_id_addr) {
  73                 slot_id = (*nexus_id_addr >> 8) & 0x1f;
  74                 chassis_id = *nexus_id_addr & 0xff;
  75                 iounmap(nexus_id_addr);
  76         } else {
  77                 printk(KERN_ERR "sky_nexus: Could not map slot id\n");
  78         }
  79
  80         hdpu_slot_id = create_proc_entry("sky_slot_id", 0666, &proc_root);
  81         hdpu_slot_id->read_proc = hdpu_slot_id_read;
  82
  83         hdpu_chassis_id = create_proc_entry("sky_chassis_id", 0666, &proc_root);
  84         hdpu_chassis_id->read_proc = hdpu_chassis_id_read;
  85
  86         return 0;
  87 }
  88
  89 static int hdpu_nexus_remove(struct platform_device *pdev)
  90 {
  91         slot_id = -1;
  92         chassis_id = -1;
  93
  94         remove_proc_entry("sky_slot_id", &proc_root);
  95         remove_proc_entry("sky_chassis_id", &proc_root);
  96
  97         hdpu_slot_id = 0;
  98         hdpu_chassis_id = 0;
  99
 100         return 0;
 101 }
 102
 103 static int __init nexus_init(void)
 104 {
 105         return platform_driver_register(&hdpu_nexus_driver);
 106 }
 107
 108 static void __exit nexus_exit(void)
 109 {
 110         platform_driver_unregister(&hdpu_nexus_driver);
 111 }
 112
 113 module_init(nexus_init);
 114 module_exit(nexus_exit);
 115
 116 MODULE_AUTHOR("Brian Waite");
 117 MODULE_LICENSE("GPL");