drivers/w1/w1_smem.c

   1 /*
   2  *      w1_smem.c
   3  *
   4  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the smems of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <asm/types.h>
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/device.h>
  28 #include <linux/types.h>
  29
  30 #include "w1.h"
  31 #include "w1_io.h"
  32 #include "w1_int.h"
  33 #include "w1_family.h"
  34
  35 MODULE_LICENSE("GPL");
  36 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
  37 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, 64bit memory family.");
  38
  39 static ssize_t w1_smem_read_name(struct device *, struct device_attribute *attr, char *);
  40 static ssize_t w1_smem_read_bin(struct kobject *, char *, loff_t, size_t);
  41
  42 static struct w1_family_ops w1_smem_fops = {
  43         .rname = &w1_smem_read_name,
  44         .rbin = &w1_smem_read_bin,
  45 };
  46
  47 static ssize_t w1_smem_read_name(struct device *dev, struct device_attribute *attr, char *buf)
  48 {
  49         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  50
  51         return sprintf(buf, "%s\n", sl->name);
  52 }
  53
  54 static ssize_t w1_smem_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
  55 {
  56         struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
  57                                            struct w1_slave, dev);
  58         int i;
  59
  60         atomic_inc(&sl->refcnt);
  61         if (down_interruptible(&sl->master->mutex)) {
  62                 count = 0;
  63                 goto out_dec;
  64         }
  65
  66         if (off > W1_SLAVE_DATA_SIZE) {
  67                 count = 0;
  68                 goto out;
  69         }
  70         if (off + count > W1_SLAVE_DATA_SIZE) {
  71                 count = 0;
  72                 goto out;
  73         }
  74         for (i = 0; i < 8; ++i)
  75                 count += sprintf(buf + count, "%02x ", ((u8 *)&sl->reg_num)[i]);
  76         count += sprintf(buf + count, "\n");
  77
  78 out:
  79         up(&sl->master->mutex);
  80 out_dec:
  81         atomic_dec(&sl->refcnt);
  82
  83         return count;
  84 }
  85
  86 static struct w1_family w1_smem_family_01 = {
  87         .fid = W1_FAMILY_SMEM_01,
  88         .fops = &w1_smem_fops,
  89 };
  90
  91 static struct w1_family w1_smem_family_81 = {
  92         .fid = W1_FAMILY_SMEM_81,
  93         .fops = &w1_smem_fops,
  94 };
  95
  96 static int __init w1_smem_init(void)
  97 {
  98         int err;
  99
 100         err = w1_register_family(&w1_smem_family_01);
 101         if (err)
 102                 return err;
 103
 104         err = w1_register_family(&w1_smem_family_81);
 105         if (err) {
 106                 w1_unregister_family(&w1_smem_family_01);
 107                 return err;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static void __exit w1_smem_fini(void)
 114 {
 115         w1_unregister_family(&w1_smem_family_01);
 116         w1_unregister_family(&w1_smem_family_81);
 117 }
 118
 119 module_init(w1_smem_init);
 120 module_exit(w1_smem_fini);