184 lines
5.5 KiB
Diff
184 lines
5.5 KiB
Diff
--- a/drivers/i2c/chips/eeprom.c
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+++ b/drivers/i2c/chips/eeprom.c
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@@ -27,6 +27,8 @@
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/mutex.h>
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+#include <linux/notifier.h>
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+#include <linux/eeprom.h>
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/* Addresses to scan */
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static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
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@@ -35,25 +37,7 @@ static const unsigned short normal_i2c[]
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(eeprom);
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-
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-/* Size of EEPROM in bytes */
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-#define EEPROM_SIZE 256
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-
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-/* possible types of eeprom devices */
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-enum eeprom_nature {
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- UNKNOWN,
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- VAIO,
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-};
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-
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-/* Each client has this additional data */
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-struct eeprom_data {
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- struct mutex update_lock;
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- u8 valid; /* bitfield, bit!=0 if slice is valid */
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- unsigned long last_updated[8]; /* In jiffies, 8 slices */
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- u8 data[EEPROM_SIZE]; /* Register values */
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- enum eeprom_nature nature;
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-};
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-
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+ATOMIC_NOTIFIER_HEAD(eeprom_chain);
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static void eeprom_update_client(struct i2c_client *client, u8 slice)
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{
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@@ -178,6 +162,7 @@ static int eeprom_probe(struct i2c_clien
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i2c_set_clientdata(client, data);
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mutex_init(&data->update_lock);
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data->nature = UNKNOWN;
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+ data->attr = &eeprom_attr;
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/* Detect the Vaio nature of EEPROMs.
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We use the "PCG-" or "VGN-" prefix as the signature. */
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@@ -202,6 +187,9 @@ static int eeprom_probe(struct i2c_clien
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if (err)
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goto exit_kfree;
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+ /* call the notifier chain */
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+ atomic_notifier_call_chain(&eeprom_chain, EEPROM_REGISTER, data);
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+
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return 0;
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exit_kfree:
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@@ -236,6 +224,41 @@ static struct i2c_driver eeprom_driver =
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.address_data = &addr_data,
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};
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+/**
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+ * register_eeprom_notifier - register a 'user' of EEPROM devices.
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+ * @nb: pointer to notifier info structure
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+ *
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+ * Registers a callback function to be called upon detection
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+ * of an EEPROM device. Detection invokes the 'add' callback
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+ * with the kobj of the mutex and a bin_attribute which allows
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+ * read from the EEPROM. The intention is that the notifier
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+ * will be able to read system configuration from the notifier.
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+ *
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+ * Only EEPROMs detected *after* the addition of the notifier
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+ * are notified. I.e. EEPROMs already known to the system
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+ * will not be notified - add the notifier from board level
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+ * code!
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+ */
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+int register_eeprom_notifier(struct notifier_block *nb)
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+{
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+ return atomic_notifier_chain_register(&eeprom_chain, nb);
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+}
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+
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+/**
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+ * unregister_eeprom_notifier - unregister a 'user' of EEPROM devices.
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+ * @old: pointer to notifier info structure
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+ *
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+ * Removes a callback function from the list of 'users' to be
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+ * notified upon detection of EEPROM devices.
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+ */
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+int unregister_eeprom_notifier(struct notifier_block *nb)
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+{
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+ return atomic_notifier_chain_unregister(&eeprom_chain, nb);
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+}
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+
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+EXPORT_SYMBOL_GPL(register_eeprom_notifier);
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+EXPORT_SYMBOL_GPL(unregister_eeprom_notifier);
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+
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static int __init eeprom_init(void)
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{
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return i2c_add_driver(&eeprom_driver);
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--- /dev/null
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+++ b/include/linux/eeprom.h
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@@ -0,0 +1,71 @@
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+#ifndef _LINUX_EEPROM_H
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+#define _LINUX_EEPROM_H
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+/*
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+ * EEPROM notifier header
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+ *
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+ * Copyright (C) 2006 John Bowler
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+ */
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+
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+/*
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ *
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+ * You should have received a copy of the GNU General Public License
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+ * along with this program; if not, write to the Free Software
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+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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+ */
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+
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+#ifndef __KERNEL__
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+#error This is a kernel header
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+#endif
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+
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+#include <linux/list.h>
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+#include <linux/kobject.h>
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+#include <linux/sysfs.h>
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+
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+/* Size of EEPROM in bytes */
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+#define EEPROM_SIZE 256
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+
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+/* possible types of eeprom devices */
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+enum eeprom_nature {
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+ UNKNOWN,
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+ VAIO,
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+};
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+
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+/* Each client has this additional data */
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+struct eeprom_data {
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+ struct i2c_client client;
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+ struct mutex update_lock;
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+ u8 valid; /* bitfield, bit!=0 if slice is valid */
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+ unsigned long last_updated[8]; /* In jiffies, 8 slices */
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+ u8 data[EEPROM_SIZE]; /* Register values */
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+ enum eeprom_nature nature;
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+ struct bin_attribute *attr;
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+};
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+
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+/*
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+ * This is very basic.
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+ *
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+ * If an EEPROM is detected on the I2C bus (this only works for
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+ * I2C EEPROMs) the notifier chain is called with
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+ * both the I2C information and the kobject for the sysfs
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+ * device which has been registers. It is then possible to
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+ * read from the device via the bin_attribute::read method
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+ * to extract configuration information.
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+ *
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+ * Register the notifier in the board level code, there is no
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+ * need to unregister it but you can if you want (it will save
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+ * a little bit or kernel memory to do so).
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+ */
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+
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+extern int register_eeprom_notifier(struct notifier_block *nb);
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+extern int unregister_eeprom_notifier(struct notifier_block *nb);
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+
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+#endif /* _LINUX_EEPROM_H */
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--- a/include/linux/notifier.h
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+++ b/include/linux/notifier.h
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@@ -256,5 +256,8 @@ extern struct blocking_notifier_head reb
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#define VT_UPDATE 0x0004 /* A bigger update occurred */
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#define VT_PREWRITE 0x0005 /* A char is about to be written to the console */
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+/* eeprom notifier chain */
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+#define EEPROM_REGISTER 0x0001
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+
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#endif /* __KERNEL__ */
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#endif /* _LINUX_NOTIFIER_H */
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