On Tue, 22 Feb 2011 17:15:41 -0500, Lennart Sorensen wrote:
> On Tue, Feb 22, 2011 at 01:27:13PM -0500, Lennart Sorensen wrote:
> > I will do that. I hope to have an updated patch in a couple of hours.
>
> OK, here is an updated one:
>
> Add support for detection of LM75A using the ID register value.
>
> Signed-off-by: Len Sorensen <lsorense@xxxxxxxxxxxxxxxxxxx>
>
> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> index f36eb80..5900926 100644
> --- a/drivers/hwmon/lm75.c
> +++ b/drivers/hwmon/lm75.c
> @@ -232,6 +232,8 @@ 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)
> @@ -239,6 +241,7 @@ static int lm75_detect(struct i2c_client *new_client,
> struct i2c_adapter *adapter = new_client->adapter;
> int i;
> int cur, conf, hyst, os;
> + bool is_lm75a = 0;
>
> if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
> I2C_FUNC_SMBUS_WORD_DATA))
> @@ -250,23 +253,43 @@ 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.
> +
> + 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 existance) in
> + register 7, and unused registers return 0xff rather than the
> + last read 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;
> +
> + /* First check for LM75A */
> + if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
> + /* LM 75A 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_word_data(new_client, 2);
> + os = i2c_smbus_read_word_data(new_client, 3);
> + } else { /* Traditional style LM75 detection */
> + /* Unused addresses */
> + 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;
> + }
>
> /* Unused bits */
> if (conf & 0xe0)
> @@ -278,9 +301,14 @@ static int lm75_detect(struct i2c_client *new_client,
> || i2c_smbus_read_word_data(new_client, i + 2) != hyst
> || i2c_smbus_read_word_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);
> + if (is_lm75a)
> + strlcpy(info->type, "lm75a", I2C_NAME_SIZE);
> + else
> + strlcpy(info->type, "lm75", I2C_NAME_SIZE);
>
> return 0;
> }
>
Applied with minor style fixes, thank you.
--
Jean Delvare
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