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path: root/drivers/i2c
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Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/chips/eeprom.c39
1 files changed, 19 insertions, 20 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c
index 213a9f98dec..9a81252a721 100644
--- a/drivers/i2c/chips/eeprom.c
+++ b/drivers/i2c/chips/eeprom.c
@@ -78,7 +78,7 @@ 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 +93,12 @@ 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;
@@ -177,14 +174,15 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
if (!(adapter->class & I2C_CLASS_SPD) && address >= 0x51)
goto exit;
- /* There are three ways we can read the EEPROM data:
+ /* 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))) {
@@ -212,13 +210,14 @@ static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
/* 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[1] = i2c_smbus_read_byte_data(new_client, 0x81);
+ name[2] = i2c_smbus_read_byte_data(new_client, 0x82);
+ name[3] = i2c_smbus_read_byte_data(new_client, 0x83);
if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
dev_info(&new_client->dev, "Vaio EEPROM detected, "