1 files changed, 40 insertions, 41 deletions

diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 7dee001e5133..373ea8d8fe8f 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -1,15 +1,9 @@
 /*
-    eeprom.c - Part of lm_sensors, Linux kernel modules for hardware
-               monitoring
     Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
                                Philip Edelbrock <phil@netroedge.com>
     Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
     Copyright (C) 2003 IBM Corp.
-
-    2004-01-16  Jean Delvare <khali@linux-fr.org>
-    Divide the eeprom in 32-byte (arbitrary) slices. This significantly
-    speeds sensors up, as well as various scripts using the eeprom
-    module.
+    Copyright (C) 2004 Jean Delvare <khali@linux-fr.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -78,7 +72,7 @@ static struct i2c_driver eeprom_driver = {
 static void eeprom_update_client(struct i2c_client *client, u8 slice)
 {
         struct eeprom_data *data = i2c_get_clientdata(client);
-        int i, j;
+        int i;
 
         mutex_lock(&data->update_lock);
 
@@ -93,15 +87,12 @@ static void eeprom_update_client(struct i2c_client *client, u8 slice)
                                                         != 32)
                                         goto exit;
                 } else {
-                        if (i2c_smbus_write_byte(client, slice << 5)) {
-                                dev_dbg(&client->dev, "eeprom read start has failed!\n");
-                                goto exit;
-                        }
-                        for (i = slice << 5; i < (slice + 1) << 5; i++) {
-                                j = i2c_smbus_read_byte(client);
-                                if (j < 0)
+                        for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
+                                int word = i2c_smbus_read_word_data(client, i);
+                                if (word < 0)
                                         goto exit;
-                                data->data[i] = (u8) j;
+                                data->data[i] = word & 0xff;
+                                data->data[i + 1] = word >> 8;
                         }
                 }
                 data->last_updated[slice] = jiffies;
@@ -159,24 +150,33 @@ static struct bin_attribute eeprom_attr = {
 
 static int eeprom_attach_adapter(struct i2c_adapter *adapter)
 {
+        if (!(adapter->class & (I2C_CLASS_DDC | I2C_CLASS_SPD)))
+                return 0;
         return i2c_probe(adapter, &addr_data, eeprom_detect);
 }
 
 /* This function is called by i2c_probe */
 static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
 {
-        struct i2c_client *new_client;
+        struct i2c_client *client;
         struct eeprom_data *data;
         int err = 0;
 
-        /* There are three ways we can read the EEPROM data:
+        /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
+           addresses 0x50-0x57, but we only care about 0x50. So decline
+           attaching to addresses >= 0x51 on DDC buses */
+        if (!(adapter->class & I2C_CLASS_SPD) && address >= 0x51)
+                goto exit;
+
+        /* There are four ways we can read the EEPROM data:
            (1) I2C block reads (faster, but unsupported by most adapters)
-           (2) Consecutive byte reads (100% overhead)
-           (3) Regular byte data reads (200% overhead)
-           The third method is not implemented by this driver because all
-           known adapters support at least the second. */
-        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA
-                                            | I2C_FUNC_SMBUS_BYTE))
+           (2) Word reads (128% overhead)
+           (3) Consecutive byte reads (88% overhead, unsafe)
+           (4) Regular byte data reads (265% overhead)
+           The third and fourth methods are not implemented by this driver
+           because all known adapters support one of the first two. */
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
+         && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
                 goto exit;
 
         if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
@@ -184,50 +184,49 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
                 goto exit;
         }
 
-        new_client = &data->client;
+        client = &data->client;
         memset(data->data, 0xff, EEPROM_SIZE);
-        i2c_set_clientdata(new_client, data);
-        new_client->addr = address;
-        new_client->adapter = adapter;
-        new_client->driver = &eeprom_driver;
-        new_client->flags = 0;
+        i2c_set_clientdata(client, data);
+        client->addr = address;
+        client->adapter = adapter;
+        client->driver = &eeprom_driver;
 
         /* Fill in the remaining client fields */
-        strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE);
-        data->valid = 0;
+        strlcpy(client->name, "eeprom", I2C_NAME_SIZE);
         mutex_init(&data->update_lock);
         data->nature = UNKNOWN;
 
         /* Tell the I2C layer a new client has arrived */
-        if ((err = i2c_attach_client(new_client)))
+        if ((err = i2c_attach_client(client)))
                 goto exit_kfree;
 
         /* Detect the Vaio nature of EEPROMs.
            We use the "PCG-" or "VGN-" prefix as the signature. */
-        if (address == 0x57) {
+        if (address == 0x57
+         && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
                 char name[4];
 
-                name[0] = i2c_smbus_read_byte_data(new_client, 0x80);
-                name[1] = i2c_smbus_read_byte(new_client);
-                name[2] = i2c_smbus_read_byte(new_client);
-                name[3] = i2c_smbus_read_byte(new_client);
+                name[0] = i2c_smbus_read_byte_data(client, 0x80);
+                name[1] = i2c_smbus_read_byte_data(client, 0x81);
+                name[2] = i2c_smbus_read_byte_data(client, 0x82);
+                name[3] = i2c_smbus_read_byte_data(client, 0x83);
 
                 if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
-                        dev_info(&new_client->dev, "Vaio EEPROM detected, "
+                        dev_info(&client->dev, "Vaio EEPROM detected, "
                                  "enabling privacy protection\n");
                         data->nature = VAIO;
                 }
         }
 
         /* create the sysfs eeprom file */
-        err = sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
+        err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
         if (err)
                 goto exit_detach;
 
         return 0;
 
 exit_detach:
-        i2c_detach_client(new_client);
+        i2c_detach_client(client);
 exit_kfree:
         kfree(data);
 exit: