Re: [PATCH v2 2/7] hwmon: (lm90) Introduce device feature bits

[Jean Delvare <khali@linux-fr.org>]

On Thu, 9 Sep 2010 06:25:45 -0700, Guenter Roeck wrote:
> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
> ---
>  drivers/hwmon/lm90.c |   38 +++++++++++++++++++++++++-------------
>  1 files changed, 25 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
> index aafed28..a81a053 100644
> --- a/drivers/hwmon/lm90.c
> +++ b/drivers/hwmon/lm90.c
> @@ -142,7 +142,11 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, adt7461, max6680, max6646,
>  /*
>   * Device flags
>   */
> -#define LM90_FLAG_ADT7461_EXT		0x01	/* ADT7461 extended mode */
> +#define LM90_FLAG_ADT7461_EXT	0x01	/* ADT7461 extended mode	*/
> +/* Device features */
> +#define	LM90_HAVE_OFFSET	0x02	/* temperature offset register	*/
> +#define	LM90_HAVE_LOCAL_EXT	0x04	/* extended local temperature	*/
> +#define	LM90_HAVE_REM_LIMIT_EXT	0x08	/* extended remote limit	*/

Please always use a space, not a tab, between #define and the symbol
name.

When defining bit values, I suggest using the following notation:

#define LM90_HAVE_OFFSET	(1 << 2)	/* temperature offset register	*/
#define LM90_HAVE_LOCAL_EXT	(1 << 3)	/* extended local temperature	*/

It is more immediately obvious that you have a bit vector.

>  
>  /*
>   * Functions declaration
> @@ -462,17 +466,16 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
>  	mutex_lock(&data->update_lock);
>  	if (data->kind == adt7461)
>  		data->temp11[nr] = temp_to_u16_adt7461(data, val);
> -	else if (data->kind == max6657 || data->kind == max6680)
> -		data->temp11[nr] = temp_to_s8(val) << 8;
>  	else if (data->kind == max6646)
>  		data->temp11[nr] = temp_to_u8(val) << 8;
> +	else if (!(data->flags & LM90_HAVE_REM_LIMIT_EXT))

It would be more efficient to swap the last two statements to avoid the
negation.

> +		data->temp11[nr] = temp_to_s8(val) << 8;
>  	else
>  		data->temp11[nr] = temp_to_s16(val);
>  
>  	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
>  				  data->temp11[nr] >> 8);
> -	if (data->kind != max6657 && data->kind != max6680
> -	    && data->kind != max6646)
> +	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
>  		i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
>  					  data->temp11[nr] & 0xff);
>  	mutex_unlock(&data->update_lock);
> @@ -847,6 +850,17 @@ static int lm90_probe(struct i2c_client *new_client,
>  		break;
>  	}
>  
> +	/* Set chip capabilities */
> +	if (data->kind != max6657 && data->kind != max6646)
> +		data->flags |= LM90_HAVE_OFFSET;
> +
> +	if (data->kind == max6657 || data->kind == max6646)
> +		data->flags |= LM90_HAVE_LOCAL_EXT;
> +
> +	if (data->kind != max6657 && data->kind != max6646
> +	    && data->kind != max6680)
> +		data->flags |= LM90_HAVE_REM_LIMIT_EXT;
> +
>  	/* Initialize the LM90 chip */
>  	lm90_init_client(new_client);
>  
> @@ -859,7 +873,7 @@ static int lm90_probe(struct i2c_client *new_client,
>  		if (err)
>  			goto exit_remove_files;
>  	}
> -	if (data->kind != max6657 && data->kind != max6646) {
> +	if (data->flags & LM90_HAVE_OFFSET) {
>  		err = device_create_file(&new_client->dev,
>  					&sensor_dev_attr_temp2_offset.dev_attr);
>  		if (err)
> @@ -925,7 +939,7 @@ static int lm90_remove(struct i2c_client *client)
>  	hwmon_device_unregister(data->hwmon_dev);
>  	sysfs_remove_group(&client->dev.kobj, &lm90_group);
>  	device_remove_file(&client->dev, &dev_attr_pec);
> -	if (data->kind != max6657 && data->kind != max6646)
> +	if (data->flags & LM90_HAVE_OFFSET)
>  		device_remove_file(&client->dev,
>  				   &sensor_dev_attr_temp2_offset.dev_attr);
>  
> @@ -1019,7 +1033,7 @@ static struct lm90_data *lm90_update_device(struct device *dev)
>  		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
>  		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
>  
> -		if (data->kind == max6657 || data->kind == max6646) {
> +		if (data->flags & LM90_HAVE_LOCAL_EXT) {
>  			lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
>  				    MAX6657_REG_R_LOCAL_TEMPL,
>  				    &data->temp11[4]);
> @@ -1033,22 +1047,20 @@ static struct lm90_data *lm90_update_device(struct device *dev)
>  
>  		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
>  			data->temp11[1] = h << 8;
> -			if (data->kind != max6657 && data->kind != max6680
> -			 && data->kind != max6646
> +			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
>  			 && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
>  					  &l) == 0)
>  				data->temp11[1] |= l;
>  		}
>  		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
>  			data->temp11[2] = h << 8;
> -			if (data->kind != max6657 && data->kind != max6680
> -			 && data->kind != max6646
> +			if ((data->flags & LM90_HAVE_REM_LIMIT_EXT)
>  			 && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
>  					  &l) == 0)
>  				data->temp11[2] |= l;
>  		}
>  
> -		if (data->kind != max6657 && data->kind != max6646) {
> +		if (data->flags & LM90_HAVE_OFFSET) {
>  			if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
>  					  &h) == 0
>  			 && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,

Other than these minor implementation details, the changes look good, I
like them.

-- 
Jean Delvare