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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/chips/eeprom.c
downloadlwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
Linux-2.6.12-rc2v2.6.12-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.c264
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 000000000000..cbdfa2db6f7c
--- /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);