On Thu, Feb 24, 2011 at 10:45:52AM +0100, Jean Delvare wrote:
> 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.
I will have to go see what that entails. I thought I had done a decent
job following the existing style. :)
--
Len Sorensen
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