target/linux/ixp4xx/patches-2.6.27/294-eeprom_new_notifier.patch

   1 --- a/drivers/i2c/chips/eeprom.c
   2 +++ b/drivers/i2c/chips/eeprom.c
   3 @@ -27,6 +27,8 @@
   4  #include <linux/jiffies.h>
   5  #include <linux/i2c.h>
   6  #include <linux/mutex.h>
   7 +#include <linux/notifier.h>
   8 +#include <linux/eeprom.h>
   9
  10  /* Addresses to scan */
  11  static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
  12 @@ -35,25 +37,7 @@
  13  /* Insmod parameters */
  14  I2C_CLIENT_INSMOD_1(eeprom);
  15
  16 -
  17 -/* Size of EEPROM in bytes */
  18 -#define EEPROM_SIZE            256
  19 -
  20 -/* possible types of eeprom devices */
  21 -enum eeprom_nature {
  22 -       UNKNOWN,
  23 -       VAIO,
  24 -};
  25 -
  26 -/* Each client has this additional data */
  27 -struct eeprom_data {
  28 -       struct mutex update_lock;
  29 -       u8 valid;                       /* bitfield, bit!=0 if slice is valid */
  30 -       unsigned long last_updated[8];  /* In jiffies, 8 slices */
  31 -       u8 data[EEPROM_SIZE];           /* Register values */
  32 -       enum eeprom_nature nature;
  33 -};
  34 -
  35 +ATOMIC_NOTIFIER_HEAD(eeprom_chain);
  36
  37  static void eeprom_update_client(struct i2c_client *client, u8 slice)
  38  {
  39 @@ -178,6 +162,7 @@
  40         i2c_set_clientdata(client, data);
  41         mutex_init(&data->update_lock);
  42         data->nature = UNKNOWN;
  43 +       data->attr = &eeprom_attr;
  44
  45         /* Detect the Vaio nature of EEPROMs.
  46            We use the "PCG-" or "VGN-" prefix as the signature. */
  47 @@ -202,6 +187,9 @@
  48         if (err)
  49                 goto exit_kfree;
  50
  51 +       /* call the notifier chain */
  52 +       atomic_notifier_call_chain(&eeprom_chain, EEPROM_REGISTER, data);
  53 +
  54         return 0;
  55
  56  exit_kfree:
  57 @@ -236,6 +224,41 @@
  58         .address_data   = &addr_data,
  59  };
  60
  61 +/**
  62 + * register_eeprom_notifier - register a 'user' of EEPROM devices.
  63 + * @nb: pointer to notifier info structure
  64 + *
  65 + * Registers a callback function to be called upon detection
  66 + * of an EEPROM device.  Detection invokes the 'add' callback
  67 + * with the kobj of the mutex and a bin_attribute which allows
  68 + * read from the EEPROM.  The intention is that the notifier
  69 + * will be able to read system configuration from the notifier.
  70 + *
  71 + * Only EEPROMs detected *after* the addition of the notifier
  72 + * are notified.  I.e. EEPROMs already known to the system
  73 + * will not be notified - add the notifier from board level
  74 + * code!
  75 + */
  76 +int register_eeprom_notifier(struct notifier_block *nb)
  77 +{
  78 +       return atomic_notifier_chain_register(&eeprom_chain, nb);
  79 +}
  80 +
  81 +/**
  82 + *     unregister_eeprom_notifier - unregister a 'user' of EEPROM devices.
  83 + *     @old: pointer to notifier info structure
  84 + *
  85 + *     Removes a callback function from the list of 'users' to be
  86 + *     notified upon detection of EEPROM devices.
  87 + */
  88 +int unregister_eeprom_notifier(struct notifier_block *nb)
  89 +{
  90 +       return atomic_notifier_chain_unregister(&eeprom_chain, nb);
  91 +}
  92 +
  93 +EXPORT_SYMBOL_GPL(register_eeprom_notifier);
  94 +EXPORT_SYMBOL_GPL(unregister_eeprom_notifier);
  95 +
  96  static int __init eeprom_init(void)
  97  {
  98         return i2c_add_driver(&eeprom_driver);
  99 --- /dev/null
 100 +++ b/include/linux/eeprom.h
 101 @@ -0,0 +1,71 @@
 102 +#ifndef _LINUX_EEPROM_H
 103 +#define _LINUX_EEPROM_H
 104 +/*
 105 + *  EEPROM notifier header
 106 + *
 107 + *  Copyright (C) 2006 John Bowler
 108 + */
 109 +
 110 +/*
 111 + * This program is free software; you can redistribute it and/or modify
 112 + * it under the terms of the GNU General Public License as published by
 113 + * the Free Software Foundation; either version 2 of the License, or
 114 + * (at your option) any later version.
 115 + *
 116 + * This program is distributed in the hope that it will be useful,
 117 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 118 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 119 + * GNU General Public License for more details.
 120 + *
 121 + * You should have received a copy of the GNU General Public License
 122 + * along with this program; if not, write to the Free Software
 123 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 124 + */
 125 +
 126 +#ifndef __KERNEL__
 127 +#error This is a kernel header
 128 +#endif
 129 +
 130 +#include <linux/list.h>
 131 +#include <linux/kobject.h>
 132 +#include <linux/sysfs.h>
 133 +
 134 +/* Size of EEPROM in bytes */
 135 +#define EEPROM_SIZE             256
 136 +
 137 +/* possible types of eeprom devices */
 138 +enum eeprom_nature {
 139 +       UNKNOWN,
 140 +       VAIO,
 141 +};
 142 +
 143 +/* Each client has this additional data */
 144 +struct eeprom_data {
 145 +       struct i2c_client client;
 146 +       struct mutex update_lock;
 147 +       u8 valid;                       /* bitfield, bit!=0 if slice is valid */
 148 +       unsigned long last_updated[8];  /* In jiffies, 8 slices */
 149 +       u8 data[EEPROM_SIZE];           /* Register values */
 150 +       enum eeprom_nature nature;
 151 +       struct bin_attribute *attr;
 152 +};
 153 +
 154 +/*
 155 + * This is very basic.
 156 + *
 157 + * If an EEPROM is detected on the I2C bus (this only works for
 158 + * I2C EEPROMs) the notifier chain  is called with
 159 + * both the I2C information and the kobject for the sysfs
 160 + * device which has been registers.  It is then possible to
 161 + * read from the device via the bin_attribute::read method
 162 + * to extract configuration information.
 163 + *
 164 + * Register the notifier in the board level code, there is no
 165 + * need to unregister it but you can if you want (it will save
 166 + * a little bit or kernel memory to do so).
 167 + */
 168 +
 169 +extern int register_eeprom_notifier(struct notifier_block *nb);
 170 +extern int unregister_eeprom_notifier(struct notifier_block *nb);
 171 +
 172 +#endif /* _LINUX_EEPROM_H */
 173 --- a/include/linux/notifier.h
 174 +++ b/include/linux/notifier.h
 175 @@ -256,5 +256,8 @@
 176  #define VT_UPDATE              0x0004 /* A bigger update occurred */
 177  #define VT_PREWRITE            0x0005 /* A char is about to be written to the console */
 178
 179 +/* eeprom notifier chain */
 180 +#define EEPROM_REGISTER                0x0001
 181 +
 182  #endif /* __KERNEL__ */
 183  #endif /* _LINUX_NOTIFIER_H */