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 *, char *);
  40 static ssize_t w1_smem_read_val(struct device *, char *);
  41 static ssize_t w1_smem_read_bin(struct kobject *, char *, loff_t, size_t);
  42
  43 static struct w1_family_ops w1_smem_fops = {
  44         .rname = &w1_smem_read_name,
  45         .rbin = &w1_smem_read_bin,
  46         .rval = &w1_smem_read_val,
  47         .rvalname = "id",
  48 };
  49
  50 static ssize_t w1_smem_read_name(struct device *dev, char *buf)
  51 {
  52         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  53
  54         return sprintf(buf, "%s\n", sl->name);
  55 }
  56
  57 static ssize_t w1_smem_read_val(struct device *dev, char *buf)
  58 {
  59         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  60         int i;
  61         ssize_t count = 0;
  62
  63         for (i = 0; i < 8; ++i)
  64                 count += sprintf(buf + count, "%02x ", ((u8 *)&sl->reg_num)[i]);
  65         count += sprintf(buf + count, "\n");
  66
  67         return count;
  68 }
  69
  70 static ssize_t w1_smem_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
  71 {
  72         struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
  73                                                 struct w1_slave, dev);
  74         int i;
  75
  76         atomic_inc(&sl->refcnt);
  77         if (down_interruptible(&sl->master->mutex)) {
  78                 count = 0;
  79                 goto out_dec;
  80         }
  81
  82         if (off > W1_SLAVE_DATA_SIZE) {
  83                 count = 0;
  84                 goto out;
  85         }
  86         if (off + count > W1_SLAVE_DATA_SIZE) {
  87                 count = 0;
  88                 goto out;
  89         }
  90         for (i = 0; i < 8; ++i)
  91                 count += sprintf(buf + count, "%02x ", ((u8 *)&sl->reg_num)[i]);
  92         count += sprintf(buf + count, "\n");
  93
  94 out:
  95         up(&sl->master->mutex);
  96 out_dec:
  97         atomic_dec(&sl->refcnt);
  98
  99         return count;
 100 }
 101
 102 static struct w1_family w1_smem_family = {
 103         .fid = W1_FAMILY_SMEM,
 104         .fops = &w1_smem_fops,
 105 };
 106
 107 static int __init w1_smem_init(void)
 108 {
 109         return w1_register_family(&w1_smem_family);
 110 }
 111
 112 static void __exit w1_smem_fini(void)
 113 {
 114         w1_unregister_family(&w1_smem_family);
 115 }
 116
 117 module_init(w1_smem_init);
 118 module_exit(w1_smem_fini);