diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-21 14:02:55 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-21 14:02:55 -0700 |
commit | afd8c40431cc9e3b468a506cbf9957ffca3466fe (patch) | |
tree | 7d5b54557a67de132d62fcb0b43184a4969644d0 /drivers/hwmon/lm75.c | |
parent | 366f7e7a79b19bd8c4e8f55fdf12b81538d1a7a4 (diff) | |
parent | c0046867f34bb81ec3f237ebbc5241ae678b8379 (diff) |
Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
hwmon: (ads1015) Make gain and datarate configurable
hwmon: (ads1015) Drop dynamic attribute group
hwmon: Add support for Texas Instruments ADS1015
hwmon: New driver for SMSC SCH5627
hwmon: (abituguru*) Update my email address
hwmon: (lm75) Speed up detection
hwmon: (lm75) Add detection of the National Semiconductor LM75A
hp_accel: Fix driver name
Move lis3lv02d drivers to drivers/misc
Move hp_accel to drivers/platform/x86
Let Kconfig handle lis3lv02d dependencies
hwmon: (sht15) Fix integer overflow in humidity calculation
hwmon: (sht15) Spelling fix
hwmon: (w83795) Document pin mapping
Diffstat (limited to 'drivers/hwmon/lm75.c')
-rw-r--r-- | drivers/hwmon/lm75.c | 66 |
1 files changed, 45 insertions, 21 deletions
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index f36eb80d227f..ef902d5d06ab 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -232,13 +232,16 @@ static const struct i2c_device_id lm75_ids[] = { }; MODULE_DEVICE_TABLE(i2c, lm75_ids); +#define LM75A_ID 0xA1 + /* Return 0 if detection is successful, -ENODEV otherwise */ static int lm75_detect(struct i2c_client *new_client, struct i2c_board_info *info) { struct i2c_adapter *adapter = new_client->adapter; int i; - int cur, conf, hyst, os; + int conf, hyst, os; + bool is_lm75a = 0; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) @@ -250,37 +253,58 @@ static int lm75_detect(struct i2c_client *new_client, addresses 0x04-0x07 returning the last read value. The cycling+unused addresses combination is not tested, since it would significantly slow the detection down and would - hardly add any value. */ + hardly add any value. - /* Unused addresses */ - cur = i2c_smbus_read_word_data(new_client, 0); - conf = i2c_smbus_read_byte_data(new_client, 1); - hyst = i2c_smbus_read_word_data(new_client, 2); - if (i2c_smbus_read_word_data(new_client, 4) != hyst - || i2c_smbus_read_word_data(new_client, 5) != hyst - || i2c_smbus_read_word_data(new_client, 6) != hyst - || i2c_smbus_read_word_data(new_client, 7) != hyst) - return -ENODEV; - os = i2c_smbus_read_word_data(new_client, 3); - if (i2c_smbus_read_word_data(new_client, 4) != os - || i2c_smbus_read_word_data(new_client, 5) != os - || i2c_smbus_read_word_data(new_client, 6) != os - || i2c_smbus_read_word_data(new_client, 7) != os) - return -ENODEV; + The National Semiconductor LM75A is different than earlier + LM75s. It has an ID byte of 0xaX (where X is the chip + revision, with 1 being the only revision in existence) in + register 7, and unused registers return 0xff rather than the + last read value. */ /* Unused bits */ + conf = i2c_smbus_read_byte_data(new_client, 1); if (conf & 0xe0) return -ENODEV; + /* First check for LM75A */ + if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { + /* LM75A returns 0xff on unused registers so + just to be sure we check for that too. */ + if (i2c_smbus_read_byte_data(new_client, 4) != 0xff + || i2c_smbus_read_byte_data(new_client, 5) != 0xff + || i2c_smbus_read_byte_data(new_client, 6) != 0xff) + return -ENODEV; + is_lm75a = 1; + hyst = i2c_smbus_read_byte_data(new_client, 2); + os = i2c_smbus_read_byte_data(new_client, 3); + } else { /* Traditional style LM75 detection */ + /* Unused addresses */ + hyst = i2c_smbus_read_byte_data(new_client, 2); + if (i2c_smbus_read_byte_data(new_client, 4) != hyst + || i2c_smbus_read_byte_data(new_client, 5) != hyst + || i2c_smbus_read_byte_data(new_client, 6) != hyst + || i2c_smbus_read_byte_data(new_client, 7) != hyst) + return -ENODEV; + os = i2c_smbus_read_byte_data(new_client, 3); + if (i2c_smbus_read_byte_data(new_client, 4) != os + || i2c_smbus_read_byte_data(new_client, 5) != os + || i2c_smbus_read_byte_data(new_client, 6) != os + || i2c_smbus_read_byte_data(new_client, 7) != os) + return -ENODEV; + } + /* Addresses cycling */ - for (i = 8; i < 0xff; i += 8) { + for (i = 8; i <= 248; i += 40) { if (i2c_smbus_read_byte_data(new_client, i + 1) != conf - || i2c_smbus_read_word_data(new_client, i + 2) != hyst - || i2c_smbus_read_word_data(new_client, i + 3) != os) + || i2c_smbus_read_byte_data(new_client, i + 2) != hyst + || i2c_smbus_read_byte_data(new_client, i + 3) != os) + return -ENODEV; + if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) + != LM75A_ID) return -ENODEV; } - strlcpy(info->type, "lm75", I2C_NAME_SIZE); + strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); return 0; } |