diff options
Diffstat (limited to 'drivers/i2c/chips/eeprom.c')
| -rw-r--r-- | drivers/i2c/chips/eeprom.c | 81 |
1 files changed, 40 insertions, 41 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c index 7dee001e5133..373ea8d8fe8f 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 @@ -78,7 +72,7 @@ static struct i2c_driver eeprom_driver = { 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 +87,12 @@ 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; @@ -159,24 +150,33 @@ static struct bin_attribute eeprom_attr = { static int eeprom_attach_adapter(struct i2c_adapter *adapter) { + if (!(adapter->class & (I2C_CLASS_DDC | I2C_CLASS_SPD))) + return 0; return i2c_probe(adapter, &addr_data, eeprom_detect); } /* This function is called by i2c_probe */ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind) { - struct i2c_client *new_client; + struct i2c_client *client; struct eeprom_data *data; int err = 0; - /* There are three ways we can read the EEPROM data: + /* 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) && address >= 0x51) + goto exit; + + /* There are four 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)) + (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)) goto exit; if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { @@ -184,50 +184,49 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind) goto exit; } - new_client = &data->client; + 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; + i2c_set_clientdata(client, data); + client->addr = address; + client->adapter = adapter; + client->driver = &eeprom_driver; /* Fill in the remaining client fields */ - strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE); - data->valid = 0; + strlcpy(client->name, "eeprom", I2C_NAME_SIZE); mutex_init(&data->update_lock); data->nature = UNKNOWN; /* Tell the I2C layer a new client has arrived */ - if ((err = i2c_attach_client(new_client))) + if ((err = i2c_attach_client(client))) goto exit_kfree; /* Detect the Vaio nature of EEPROMs. We use the "PCG-" or "VGN-" prefix as the signature. */ - if (address == 0x57) { + if (address == 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; return 0; exit_detach: - i2c_detach_client(new_client); + i2c_detach_client(client); exit_kfree: kfree(data); exit: |