[lm-sensors] [PATCH 4/6] hwmon: (f75375s) Fix hysteresis register access for the F75387

Nikolaus Schulz mail at microschulz.de
Thu Feb 23 19:59:09 CET 2012


On Wed, Feb 22, 2012 at 05:25:44PM -0800, Guenter Roeck wrote:
> On Wed, Feb 22, 2012 at 05:18:47PM -0500, Nikolaus Schulz wrote:
> > The F75387 stores its temperature hysteresis in a different register than
> > the other chips supported by that driver.
> > 
> > Signed-off-by: Nikolaus Schulz <mail at microschulz.de>
> > ---
> >  drivers/hwmon/f75375s.c |   36 ++++++++++++++++++++++++++++++------
> >  1 files changed, 30 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
> > index 944937c..3b06abf 100644
> > --- a/drivers/hwmon/f75375s.c
> > +++ b/drivers/hwmon/f75375s.c
> > @@ -65,6 +65,7 @@ enum chips { f75373, f75375, f75387 };
> >  #define F75387_REG_TEMP11_LSB(nr)	(0x1a + (nr))
> >  #define F75375_REG_TEMP_HIGH(nr)	(0x28 + (nr) * 2)
> >  #define F75375_REG_TEMP_HYST(nr)	(0x29 + (nr) * 2)
> > +#define F75387_REG_TEMP_HYST		0x62
> >  
> >  #define F75375_REG_FAN(nr)		(0x16 + (nr) * 2)
> >  #define F75375_REG_FAN_MIN(nr)		(0x2C + (nr) * 2)
> > @@ -183,23 +184,34 @@ static struct f75375_data *f75375_update_device(struct device *dev)
> >  	struct i2c_client *client = to_i2c_client(dev);
> >  	struct f75375_data *data = i2c_get_clientdata(client);
> >  	int nr;
> > +	u8 f75387_hyst_reg = 0;
> >  
> >  	mutex_lock(&data->update_lock);
> >  
> >  	/* Limit registers cache is refreshed after 60 seconds */
> >  	if (time_after(jiffies, data->last_limits + 60 * HZ)
> >  		|| !data->valid) {
> > +		if (data->kind == f75387)
> > +			f75387_hyst_reg =
> > +				f75375_read8(client, F75387_REG_TEMP_HYST);
> >  		for (nr = 0; nr < 2; nr++) {
> >  			data->temp_high[nr] =
> >  				f75375_read8(client, F75375_REG_TEMP_HIGH(nr));
> > -			data->temp_max_hyst[nr] =
> > -				f75375_read8(client, F75375_REG_TEMP_HYST(nr));
> >  			data->fan_max[nr] =
> >  				f75375_read16(client, F75375_REG_FAN_FULL(nr));
> >  			data->fan_min[nr] =
> >  				f75375_read16(client, F75375_REG_FAN_MIN(nr));
> >  			data->fan_target[nr] =
> >  				f75375_read16(client, F75375_REG_FAN_EXP(nr));
> > +			if (data->kind == f75387) {
> > +				data->temp_max_hyst[nr] =
> > +					data->temp_high[nr] -
> > +					(0xf & f75387_hyst_reg);
> 
> I really hate it when people put the constant first, and consider it confusing.
> Please change.

Ok.

> Besides, you can do the masking above, when f75387_hyst_reg is read. 
> This way it only needs to be done once.

Correct.

I didn't do that because there is also some fan-specific information
encoded in that register, and I am working on code that uses it.  But
until that code is posted, the register should be masked beforehand.
I'll update the patch accordingly.

> > +			} else {
> > +				data->temp_max_hyst[nr] =
> > +					f75375_read8(client,
> > +						F75375_REG_TEMP_HYST(nr));
> > +			}
> >  		}
> >  		for (nr = 0; nr < 4; nr++) {
> >  			data->in_max[nr] =
> > @@ -599,11 +611,23 @@ static ssize_t set_temp_max_hyst(struct device *dev,
> >  	if (err < 0)
> >  		return err;
> >  
> > -	val = SENSORS_LIMIT(TEMP_TO_REG(val), 0, 127);
> > +	val = TEMP_TO_REG(val);
> >  	mutex_lock(&data->update_lock);
> > -	data->temp_max_hyst[nr] = val;
> > -	f75375_write8(client, F75375_REG_TEMP_HYST(nr),
> > -		data->temp_max_hyst[nr]);
> > +	if (data->kind == f75387) {
> > +		u8 regval;
> > +		val = SENSORS_LIMIT(val,
> > +				data->temp_high[nr] - 0xf,
> > +				data->temp_high[nr]);
> > +		data->temp_max_hyst[nr] = val;
> > +		regval = f75375_read8(client, F75387_REG_TEMP_HYST);
> > +		regval &= 0xf0;
> > +		regval |= data->temp_high[nr] - val;
> > +		f75375_write8(client, F75387_REG_TEMP_HYST, regval);
> 
> Unless I am missing something, this affects the other hysteresis values as well,
> since there is really only a single hysteresis register.

That's correct.

> If so, you have to set
> data->valid to 0 to ensure that temp_max_hyst[] is updated with the next read cycle.

Good catch!

I will post an updated patch.

> > +	} else {
> > +		val = SENSORS_LIMIT(val, 0, 127);
> > +		data->temp_max_hyst[nr] = val;
> > +		f75375_write8(client, F75375_REG_TEMP_HYST(nr), val);
> > +	}
> >  	mutex_unlock(&data->update_lock);
> >  	return count;
> >  }
> > -- 
> > 1.7.9.1




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