| /* |
| 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. |
| |
| 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. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/jiffies.h> |
| #include <linux/i2c.h> |
| |
| /* Addresses to scan */ |
| static unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, |
| 0x55, 0x56, 0x57, I2C_CLIENT_END }; |
| |
| /* Insmod parameters */ |
| I2C_CLIENT_INSMOD_1(eeprom); |
| |
| |
| /* 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 i2c_client client; |
| struct semaphore update_lock; |
| u8 valid; /* bitfield, bit!=0 if slice is valid */ |
| unsigned long last_updated[8]; /* In jiffies, 8 slices */ |
| u8 data[EEPROM_SIZE]; /* Register values */ |
| enum eeprom_nature nature; |
| }; |
| |
| |
| 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 void eeprom_update_client(struct i2c_client *client, u8 slice) |
| { |
| struct eeprom_data *data = i2c_get_clientdata(client); |
| int i, j; |
| |
| down(&data->update_lock); |
| |
| if (!(data->valid & (1 << slice)) || |
| time_after(jiffies, data->last_updated[slice] + 300 * HZ)) { |
| dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice); |
| |
| if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { |
| for (i = slice << 5; i < (slice + 1) << 5; 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, 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) |
| goto exit; |
| data->data[i] = (u8) j; |
| } |
| } |
| data->last_updated[slice] = jiffies; |
| data->valid |= (1 << slice); |
| } |
| 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); |
| u8 slice; |
| |
| if (off > EEPROM_SIZE) |
| return 0; |
| if (off + count > EEPROM_SIZE) |
| count = EEPROM_SIZE - off; |
| |
| /* Only refresh slices which contain requested bytes */ |
| for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++) |
| eeprom_update_client(client, slice); |
| |
| /* Hide Vaio security settings to regular users (16 first bytes) */ |
| if (data->nature == VAIO && off < 16 && !capable(CAP_SYS_ADMIN)) { |
| size_t in_row1 = 16 - off; |
| in_row1 = min(in_row1, count); |
| memset(buf, 0, in_row1); |
| if (count - in_row1 > 0) |
| memcpy(buf + in_row1, &data->data[16], count - in_row1); |
| } else { |
| memcpy(buf, &data->data[off], count); |
| } |
| |
| return count; |
| } |
| |
| static struct bin_attribute eeprom_attr = { |
| .attr = { |
| .name = "eeprom", |
| .mode = S_IRUGO, |
| .owner = THIS_MODULE, |
| }, |
| .size = EEPROM_SIZE, |
| .read = eeprom_read, |
| }; |
| |
| static int eeprom_attach_adapter(struct i2c_adapter *adapter) |
| { |
| return i2c_probe(adapter, &addr_data, eeprom_detect); |
| } |
| |
| /* This function is called by i2c_probe */ |
| int eeprom_detect(struct i2c_adapter *adapter, int address, int kind) |
| { |
| struct i2c_client *new_client; |
| struct eeprom_data *data; |
| int err = 0; |
| |
| /* There are three 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)) |
| goto exit; |
| |
| if (!(data = kmalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| memset(data, 0, sizeof(struct eeprom_data)); |
| |
| new_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; |
| |
| /* Fill in the remaining client fields */ |
| strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE); |
| data->valid = 0; |
| init_MUTEX(&data->update_lock); |
| data->nature = UNKNOWN; |
| |
| /* Tell the I2C layer a new client has arrived */ |
| if ((err = i2c_attach_client(new_client))) |
| 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(new_client) == 'C' |
| && i2c_smbus_read_byte(new_client) == 'G' |
| && i2c_smbus_read_byte(new_client) == '-') { |
| dev_info(&new_client->dev, "Vaio EEPROM detected, " |
| "enabling password protection\n"); |
| data->nature = VAIO; |
| } |
| } |
| |
| /* create the sysfs eeprom file */ |
| sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr); |
| |
| return 0; |
| |
| exit_kfree: |
| kfree(data); |
| exit: |
| return err; |
| } |
| |
| static int eeprom_detach_client(struct i2c_client *client) |
| { |
| int err; |
| |
| err = i2c_detach_client(client); |
| if (err) |
| return err; |
| |
| kfree(i2c_get_clientdata(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); |