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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/chips/eeprom.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/i2c/chips/eeprom.c')
-rw-r--r-- | drivers/i2c/chips/eeprom.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c new file mode 100644 index 0000000..cbdfa2d --- /dev/null +++ b/drivers/i2c/chips/eeprom.c @@ -0,0 +1,264 @@ +/* + 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/config.h> +#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> +#include <linux/i2c-sensor.h> + +/* Addresses to scan */ +static unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, + 0x55, 0x56, 0x57, I2C_CLIENT_END }; +static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; + +/* Insmod parameters */ +SENSORS_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_detect(adapter, &addr_data, eeprom_detect); +} + +/* This function is called by i2c_detect */ +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; + + /* 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 (!(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; + + /* prevent 24RF08 corruption */ + i2c_smbus_write_quick(new_client, 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) { + dev_err(&client->dev, "Client deregistration failed, client not detached.\n"); + 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); |