diff options
Diffstat (limited to 'drivers/i2c/chips/eeprom.c')
-rw-r--r-- | drivers/i2c/chips/eeprom.c | 143 |
1 files changed, 65 insertions, 78 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c index 7dee001..2c27193 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); |