diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hwmon/w83795.c | 80 |
1 files changed, 57 insertions, 23 deletions
diff --git a/drivers/hwmon/w83795.c b/drivers/hwmon/w83795.c index c7f6b1fd0899..6596303566e1 100644 --- a/drivers/hwmon/w83795.c +++ b/drivers/hwmon/w83795.c @@ -48,6 +48,7 @@ MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended"); #define W83795_REG_VENDORID 0xfd #define W83795_REG_CHIPID 0xfe #define W83795_REG_DEVICEID 0xfb +#define W83795_REG_DEVICEID_A 0xff #define W83795_REG_I2C_ADDR 0xfc #define W83795_REG_CONFIG 0x01 @@ -1684,11 +1685,31 @@ static void w83795_init_client(struct i2c_client *client) w83795_read(client, W83795_REG_CONFIG) | 0x01); } +static int w83795_get_device_id(struct i2c_client *client) +{ + int device_id; + + device_id = i2c_smbus_read_byte_data(client, W83795_REG_DEVICEID); + + /* Special case for rev. A chips; can't be checked first because later + revisions emulate this for compatibility */ + if (device_id < 0 || (device_id & 0xf0) != 0x50) { + int alt_id; + + alt_id = i2c_smbus_read_byte_data(client, + W83795_REG_DEVICEID_A); + if (alt_id == 0x50) + device_id = alt_id; + } + + return device_id; +} + /* Return 0 if detection is successful, -ENODEV otherwise */ static int w83795_detect(struct i2c_client *client, struct i2c_board_info *info) { - u8 tmp, bank; + int bank, vendor_id, device_id, expected, i2c_addr, config; struct i2c_adapter *adapter = client->adapter; unsigned short address = client->addr; const char *chip_name; @@ -1696,32 +1717,44 @@ static int w83795_detect(struct i2c_client *client, if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; bank = i2c_smbus_read_byte_data(client, W83795_REG_BANKSEL); + if (bank < 0 || (bank & 0x7c)) { + dev_dbg(&adapter->dev, + "w83795: Detection failed at addr 0x%02hx, check %s\n", + address, "bank"); + return -ENODEV; + } - tmp = bank & 0x80 ? 0x5c : 0xa3; /* Check Nuvoton vendor ID */ - if (tmp != i2c_smbus_read_byte_data(client, - W83795_REG_VENDORID)) { - pr_debug("w83795: Detection failed at check " - "vendor id\n"); + vendor_id = i2c_smbus_read_byte_data(client, W83795_REG_VENDORID); + expected = bank & 0x80 ? 0x5c : 0xa3; + if (vendor_id != expected) { + dev_dbg(&adapter->dev, + "w83795: Detection failed at addr 0x%02hx, check %s\n", + address, "vendor id"); return -ENODEV; } - /* If Nuvoton chip, address of chip and W83795_REG_I2C_ADDR - should match */ - if ((bank & 0x07) == 0 - && (i2c_smbus_read_byte_data(client, W83795_REG_I2C_ADDR) & 0x7f) != - address) { - pr_debug("w83795: Detection failed at check " - "i2c addr\n"); + /* Check device ID */ + device_id = w83795_get_device_id(client) | + (i2c_smbus_read_byte_data(client, W83795_REG_CHIPID) << 8); + if ((device_id >> 4) != 0x795) { + dev_dbg(&adapter->dev, + "w83795: Detection failed at addr 0x%02hx, check %s\n", + address, "device id\n"); return -ENODEV; } - /* Determine the chip type now */ - if (0x79 != i2c_smbus_read_byte_data(client, - W83795_REG_CHIPID)) { - pr_debug("w83795: Detection failed at check " - "chip id\n"); - return -ENODEV; + /* If Nuvoton chip, address of chip and W83795_REG_I2C_ADDR + should match */ + if ((bank & 0x07) == 0) { + i2c_addr = i2c_smbus_read_byte_data(client, + W83795_REG_I2C_ADDR); + if ((i2c_addr & 0x7f) != address) { + dev_dbg(&adapter->dev, + "w83795: Detection failed at addr 0x%02hx, " + "check %s\n", address, "i2c addr"); + return -ENODEV; + } } /* Check 795 chip type: 795G or 795ADG @@ -1731,14 +1764,15 @@ static int w83795_detect(struct i2c_client *client, if ((bank & 0x07) != 0) i2c_smbus_write_byte_data(client, W83795_REG_BANKSEL, bank & ~0x07); - if (W83795_REG_CONFIG_CONFIG48 & - i2c_smbus_read_byte_data(client, W83795_REG_CONFIG)) { + config = i2c_smbus_read_byte_data(client, W83795_REG_CONFIG); + if (config & W83795_REG_CONFIG_CONFIG48) chip_name = "w83795adg"; - } else { + else chip_name = "w83795g"; - } strlcpy(info->type, chip_name, I2C_NAME_SIZE); + dev_info(&adapter->dev, "Found %s rev. %c at 0x%02hx\n", chip_name, + 'A' + (device_id & 0xf), address); return 0; } |