diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hwmon/lm90.c | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 5acc12ae4e3..fa0793e684f 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -345,15 +345,63 @@ static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst, static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4); static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); +/* pec used for ADM1032 only */ +static ssize_t show_pec(struct device *dev, struct device_attribute *dummy, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC)); +} + +static ssize_t set_pec(struct device *dev, struct device_attribute *dummy, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + long val = simple_strtol(buf, NULL, 10); + + switch (val) { + case 0: + client->flags &= ~I2C_CLIENT_PEC; + break; + case 1: + client->flags |= I2C_CLIENT_PEC; + break; + default: + return -EINVAL; + } + + return count; +} + +static DEVICE_ATTR(pec, S_IWUSR | S_IRUGO, show_pec, set_pec); + /* * Real code */ +/* The ADM1032 supports PEC but not on write byte transactions, so we need + to explicitely ask for a transaction without PEC. */ +static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value) +{ + return i2c_smbus_xfer(client->adapter, client->addr, + client->flags & ~I2C_CLIENT_PEC, + I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); +} + +/* It is assumed that client->update_lock is held (unless we are in + detection or initialization steps). This matters when PEC is enabled, + because we don't want the address pointer to change between the write + byte and the read byte transactions. */ static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value) { int err; - err = i2c_smbus_read_byte_data(client, reg); + if (client->flags & I2C_CLIENT_PEC) { + err = adm1032_write_byte(client, reg); + if (err >= 0) + err = i2c_smbus_read_byte(client); + } else + err = i2c_smbus_read_byte_data(client, reg); if (err < 0) { dev_warn(&client->dev, "Register %#02x read failed (%d)\n", @@ -494,6 +542,10 @@ static int lm90_detect(struct i2c_adapter *adapter, int address, int kind) name = "lm90"; } else if (kind == adm1032) { name = "adm1032"; + /* The ADM1032 supports PEC, but only if combined + transactions are not used. */ + if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) + new_client->flags |= I2C_CLIENT_PEC; } else if (kind == lm99) { name = "lm99"; } else if (kind == lm86) { @@ -546,6 +598,9 @@ static int lm90_detect(struct i2c_adapter *adapter, int address, int kind) &sensor_dev_attr_temp2_crit_hyst.dev_attr); device_create_file(&new_client->dev, &dev_attr_alarms); + if (new_client->flags & I2C_CLIENT_PEC) + device_create_file(&new_client->dev, &dev_attr_pec); + return 0; exit_detach: |