--- /dev/null
+/*
+ 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.
+
+ 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* #define DEBUG */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c-sensor.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { I2C_CLIENT_END };
+static unsigned short normal_i2c_range[] = { 0x50, 0x57, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+static unsigned int normal_isa_range[] = { I2C_CLIENT_ISA_END };
+
+/* Insmod parameters */
+SENSORS_INSMOD_1(eeprom);
+
+static int checksum = 0;
+MODULE_PARM(checksum, "i");
+MODULE_PARM_DESC(checksum, "Only accept eeproms whose checksum is correct");
+
+
+/* EEPROM registers */
+#define EEPROM_REG_CHECKSUM 0x3f
+
+/* EEPROM memory types: */
+#define ONE_K 1
+#define TWO_K 2
+#define FOUR_K 3
+#define EIGHT_K 4
+#define SIXTEEN_K 5
+
+/* Size of EEPROM in bytes */
+#define EEPROM_SIZE 256
+
+/* possible types of eeprom devices */
+enum eeprom_nature {
+ UNKNOWN,
+ VAIO,
+};
+
+/* Each client has this additional data */
+struct eeprom_data {
+ struct semaphore update_lock;
+ char valid; /* !=0 if following fields are valid */
+ unsigned long last_updated; /* In jiffies */
+ u8 data[EEPROM_SIZE]; /* Register values */
+};
+
+
+static int eeprom_attach_adapter(struct i2c_adapter *adapter);
+static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind);
+static int eeprom_detach_client(struct i2c_client *client);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver eeprom_driver = {
+ .owner = THIS_MODULE,
+ .name = "eeprom",
+ .id = I2C_DRIVERID_EEPROM,
+ .flags = I2C_DF_NOTIFY,
+ .attach_adapter = eeprom_attach_adapter,
+ .detach_client = eeprom_detach_client,
+};
+
+static int eeprom_id = 0;
+
+static void eeprom_update_client(struct i2c_client *client)
+{
+ struct eeprom_data *data = i2c_get_clientdata(client);
+ int i, j;
+
+ down(&data->update_lock);
+
+ if ((jiffies - data->last_updated > 300 * HZ) |
+ (jiffies < data->last_updated) || !data->valid) {
+ dev_dbg(&client->dev, "Starting eeprom update\n");
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+ for (i=0; i < EEPROM_SIZE; i += I2C_SMBUS_I2C_BLOCK_MAX)
+ if (i2c_smbus_read_i2c_block_data(client, i, data->data + i) != I2C_SMBUS_I2C_BLOCK_MAX)
+ goto exit;
+ } else {
+ if (i2c_smbus_write_byte(client, 0)) {
+ dev_dbg(&client->dev, "eeprom read start has failed!\n");
+ goto exit;
+ }
+ for (i = 0; i < EEPROM_SIZE; i++) {
+ j = i2c_smbus_read_byte(client);
+ if (j < 0)
+ goto exit;
+ data->data[i] = (u8) j;
+ }
+ }
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+exit:
+ up(&data->update_lock);
+}
+
+static ssize_t eeprom_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj));
+ struct eeprom_data *data = i2c_get_clientdata(client);
+
+ eeprom_update_client(client);
+
+ if (off > EEPROM_SIZE)
+ return 0;
+ if (off + count > EEPROM_SIZE)
+ count = EEPROM_SIZE - off;
+
+ memcpy(buf, &data->data[off], count);
+ return count;
+}
+
+static struct bin_attribute eeprom_attr = {
+ .attr = {
+ .name = "eeprom",
+ .mode = S_IRUGO,
+ },
+ .size = EEPROM_SIZE,
+ .read = eeprom_read,
+};
+
+static int eeprom_attach_adapter(struct i2c_adapter *adapter)
+{
+ return i2c_detect(adapter, &addr_data, eeprom_detect);
+}
+
+/* This function is called by i2c_detect */
+int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+ int i, cs;
+ struct i2c_client *new_client;
+ struct eeprom_data *data;
+ enum eeprom_nature nature = UNKNOWN;
+ int err = 0;
+
+ /* Make sure we aren't probing the ISA bus!! This is just a safety check
+ at this moment; i2c_detect really won't call us. */
+#ifdef DEBUG
+ if (i2c_is_isa_adapter(adapter)) {
+ dev_dbg(&adapter->dev, " eeprom_detect called for an ISA bus adapter?!?\n");
+ return 0;
+ }
+#endif
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ goto exit;
+
+ /* OK. For now, we presume we have a valid client. We now create the
+ client structure, even though we cannot fill it completely yet.
+ But it allows us to access eeprom_{read,write}_value. */
+ if (!(new_client = kmalloc(sizeof(struct i2c_client) +
+ sizeof(struct eeprom_data),
+ GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ memset(new_client, 0x00, sizeof(struct i2c_client) +
+ sizeof(struct eeprom_data));
+
+ data = (struct eeprom_data *) (new_client + 1);
+ memset(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;
+
+ /* Now, we do the remaining detection. It is not there, unless you force
+ the checksum to work out. */
+ if (checksum) {
+ /* prevent 24RF08 corruption */
+ i2c_smbus_write_quick(new_client, 0);
+ cs = 0;
+ for (i = 0; i <= 0x3e; i++)
+ cs += i2c_smbus_read_byte_data(new_client, i);
+ cs &= 0xff;
+ if (i2c_smbus_read_byte_data (new_client, EEPROM_REG_CHECKSUM) != cs)
+ goto exit_kfree;
+ }
+
+ /* Detect the Vaio nature of EEPROMs.
+ We use the "PCG-" prefix as the signature. */
+ if (address == 0x57) {
+ if (i2c_smbus_read_byte_data(new_client, 0x80) == 'P' &&
+ i2c_smbus_read_byte_data(new_client, 0x81) == 'C' &&
+ i2c_smbus_read_byte_data(new_client, 0x82) == 'G' &&
+ i2c_smbus_read_byte_data(new_client, 0x83) == '-')
+ nature = VAIO;
+ }
+
+ /* If this is a VIAO, then we only allow root to read from this file,
+ as BIOS passwords can be present here in plaintext */
+ switch (nature) {
+ case VAIO:
+ eeprom_attr.attr.mode = S_IRUSR;
+ break;
+ default:
+ eeprom_attr.attr.mode = S_IRUGO;
+ }
+
+ /* Fill in the remaining client fields */
+ strncpy(new_client->name, "eeprom", I2C_NAME_SIZE);
+ new_client->id = eeprom_id++;
+ data->valid = 0;
+ init_MUTEX(&data->update_lock);
+
+ /* Tell the I2C layer a new client has arrived */
+ if ((err = i2c_attach_client(new_client)))
+ goto exit_kfree;
+
+ /* create the sysfs eeprom file */
+ sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
+
+ return 0;
+
+exit_kfree:
+ kfree(new_client);
+exit:
+ return err;
+}
+
+static int eeprom_detach_client(struct i2c_client *client)
+{
+ int err;
+
+ err = i2c_detach_client(client);
+ if (err) {
+ dev_err(&client->dev, "Client deregistration failed, client not detached.\n");
+ return err;
+ }
+
+ kfree(client);
+
+ return 0;
+}
+
+static int __init eeprom_init(void)
+{
+ return i2c_add_driver(&eeprom_driver);
+}
+
+static void __exit eeprom_exit(void)
+{
+ i2c_del_driver(&eeprom_driver);
+}
+
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
+ "Philip Edelbrock <phil@netroedge.com> and "
+ "Greg Kroah-Hartman <greg@kroah.com>");
+MODULE_DESCRIPTION("I2C EEPROM driver");
+MODULE_LICENSE("GPL");
+
+module_init(eeprom_init);
+module_exit(eeprom_exit);
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