[PATCH 1/3] Add support for GMT G72/G763 PWM fan controller

[linux@roeck-us.net (Guenter Roeck)]

On Fri, Apr 19, 2013 at 01:30:51PM +0200, Arnaud Ebalard wrote:
> Hi,
> 
> Andrew Lunn <andrew@lunn.ch> writes:
> 
> > Hi Arnaud
> >
> >> +static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
> >> +static DEVICE_ATTR(pwm1_polarity, S_IWUSR | S_IRUGO,
> >> +		   get_pwm_polarity, set_pwm_polarity);
> >> +static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO,
> >> +		   get_pwm_mode, set_pwm_mode);
> >> +static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
> >> +		   get_speed_control_mode, set_speed_control_mode);
> >> +static DEVICE_ATTR(pwm1_freq, S_IWUSR | S_IRUGO,
> >> +		   get_pwm_freq, set_pwm_freq);
> >> +
> >> +static DEVICE_ATTR(fan1_input, S_IRUGO, get_fan_rpm, NULL);
> >> +static DEVICE_ATTR(fan1_alarm, S_IRUGO, get_fan_ooc, NULL);
> >> +static DEVICE_ATTR(fan1_alarm_detection, S_IWUSR | S_IRUGO,
> >> +		   get_fan_ooc_detection, set_fan_ooc_detection);
> >> +static DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_failure, NULL);
> >> +static DEVICE_ATTR(fan1_fault_detection, S_IWUSR | S_IRUGO,
> >> +		   get_fan_failure_detection, set_fan_failure_detection);
> >> +static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
> >> +		   get_fan_target, set_fan_target);
> >> +static DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO,
> >> +		   get_fan_pulses, set_fan_pulses);
> >> +static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO,
> >> +		   get_fan_clk_div, set_fan_clk_div);
> >> +static DEVICE_ATTR(fan1_gear_mode, S_IWUSR | S_IRUGO,
> >> +		   get_fan_gear_mode, set_fan_gear_mode);
> >> +static DEVICE_ATTR(fan1_startup_voltage, S_IWUSR | S_IRUGO,
> >> +		   get_fan_startup_voltage, set_fan_startup_voltage);
> >
> > It is normal to use SENSOR_ATTR, not DEVICE_ATTR. Take a look at the
> > existing fan drivers.
> 
> I will take a look and use SENSOR_ATTR if it is the expected way. For
> the records, the g760a.c which I used as basis uses DEVICE_ATTR ;-)
> 
You only need SENSOR_ATTR if you have an index parameter. Otherwise DEVICE_ATTR
is just fine. I would actually reject the patch if I notice that it uses
SENSOR_ATTR without need for a parameter. Besides, in the context used,
it would probably be SENSOR_DEVICE_ATTR.

> > I also think a lot of these are not needed. They are fixed properties
> > of the board and cannot change dynamically. They are set once using DT
> > and user space does not need to care.
> 
> I added those knobs for a simple reason: I don't have all the various
> characteristics of the target platform I am working on (Netgear
> ReadyNAS Duo v2) and needed to be able to test various values w/o
> rebooting to get those rights. I thought this knobs would be useful for
> people with the same issue (for instance, the new ReadyNAS 102 also has
> a G762) and would not hurt.
> 
Testing is not a reason to add non-standard attributes.

Thanks,
Guenter

> Anyway, I will split the patch in two parts and keep the useless knobs
> on my side.
> 
> Thanks for your feedback,
> 
> Cheers,
> 
> a+
>