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path: root/drivers/i2c/chips/eeprom.c
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Diffstat (limited to 'drivers/i2c/chips/eeprom.c')
-rw-r--r--drivers/i2c/chips/eeprom.c143
1 files changed, 65 insertions, 78 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 7dee001e513..2c27193aeaa 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -1,15 +1,9 @@
/*
- 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.
+ Copyright (C) 2004 Jean Delvare <khali@linux-fr.org>
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
@@ -53,7 +47,6 @@ enum eeprom_nature {
/* Each client has this additional data */
struct eeprom_data {
- struct i2c_client client;
struct mutex update_lock;
u8 valid; /* bitfield, bit!=0 if slice is valid */
unsigned long last_updated[8]; /* In jiffies, 8 slices */
@@ -62,23 +55,10 @@ struct eeprom_data {
};
-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 = {
- .driver = {
- .name = "eeprom",
- },
- .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;
+ int i;
mutex_lock(&data->update_lock);
@@ -93,15 +73,12 @@ static void eeprom_update_client(struct i2c_client *client, u8 slice)
!= 32)
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)
+ for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
+ int word = i2c_smbus_read_word_data(client, i);
+ if (word < 0)
goto exit;
- data->data[i] = (u8) j;
+ data->data[i] = word & 0xff;
+ data->data[i + 1] = word >> 8;
}
}
data->last_updated[slice] = jiffies;
@@ -157,98 +134,108 @@ static struct bin_attribute eeprom_attr = {
.read = eeprom_read,
};
-static int eeprom_attach_adapter(struct i2c_adapter *adapter)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int eeprom_detect(struct i2c_client *client, int kind,
+ struct i2c_board_info *info)
{
- return i2c_probe(adapter, &addr_data, eeprom_detect);
+ struct i2c_adapter *adapter = client->adapter;
+
+ /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
+ addresses 0x50-0x57, but we only care about 0x50. So decline
+ attaching to addresses >= 0x51 on DDC buses */
+ if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51)
+ return -ENODEV;
+
+ /* There are four ways we can read the EEPROM data:
+ (1) I2C block reads (faster, but unsupported by most adapters)
+ (2) Word reads (128% overhead)
+ (3) Consecutive byte reads (88% overhead, unsafe)
+ (4) Regular byte data reads (265% overhead)
+ The third and fourth methods are not implemented by this driver
+ because all known adapters support one of the first two. */
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
+ && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return -ENODEV;
+
+ strlcpy(info->type, "eeprom", I2C_NAME_SIZE);
+
+ return 0;
}
-/* This function is called by i2c_probe */
-static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
+static int eeprom_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
{
- struct i2c_client *new_client;
+ struct i2c_adapter *adapter = client->adapter;
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;
+ int err;
if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
- 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;
+ i2c_set_clientdata(client, data);
mutex_init(&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-" or "VGN-" prefix as the signature. */
- if (address == 0x57) {
+ if (client->addr == 0x57
+ && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
char name[4];
- name[0] = i2c_smbus_read_byte_data(new_client, 0x80);
- name[1] = i2c_smbus_read_byte(new_client);
- name[2] = i2c_smbus_read_byte(new_client);
- name[3] = i2c_smbus_read_byte(new_client);
+ name[0] = i2c_smbus_read_byte_data(client, 0x80);
+ name[1] = i2c_smbus_read_byte_data(client, 0x81);
+ name[2] = i2c_smbus_read_byte_data(client, 0x82);
+ name[3] = i2c_smbus_read_byte_data(client, 0x83);
if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
- dev_info(&new_client->dev, "Vaio EEPROM detected, "
+ dev_info(&client->dev, "Vaio EEPROM detected, "
"enabling privacy protection\n");
data->nature = VAIO;
}
}
/* create the sysfs eeprom file */
- err = sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
+ err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
if (err)
- goto exit_detach;
+ goto exit_kfree;
return 0;
-exit_detach:
- i2c_detach_client(new_client);
exit_kfree:
kfree(data);
exit:
return err;
}
-static int eeprom_detach_client(struct i2c_client *client)
+static int eeprom_remove(struct i2c_client *client)
{
- int err;
-
sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
-
- err = i2c_detach_client(client);
- if (err)
- return err;
-
kfree(i2c_get_clientdata(client));
return 0;
}
+static const struct i2c_device_id eeprom_id[] = {
+ { "eeprom", 0 },
+ { }
+};
+
+static struct i2c_driver eeprom_driver = {
+ .driver = {
+ .name = "eeprom",
+ },
+ .probe = eeprom_probe,
+ .remove = eeprom_remove,
+ .id_table = eeprom_id,
+
+ .class = I2C_CLASS_DDC | I2C_CLASS_SPD,
+ .detect = eeprom_detect,
+ .address_data = &addr_data,
+};
+
static int __init eeprom_init(void)
{
return i2c_add_driver(&eeprom_driver);
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-29 21:51:15 +0000