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);