On Wed, Jun 24, 2020 at 12:04:24PM +0000, Roy Im wrote:
> Hello Uwe,
>
> On Tue, June 23, 2020 11:41 PM, Uwe Kleine-König wrote:
> >
> > Hello,
> >
> > On Mon, Jun 15, 2020 at 08:40:23PM +0900, Roy Im wrote:
> > > Adds support for the Dialog DA7280 LRA/ERM Haptic Driver with multiple
> > > mode and integrated waveform memory and wideband support.
> > > It communicates via an I2C bus to the device.
> > >
> > > Signed-off-by: Roy Im <roy.im.opensource@xxxxxxxxxxx>
> >
> > Just some picky comments below.
> >
> > > + error = pwm_apply_state(haptics->pwm_dev, &state);
> > > + if (error)
> > > + dev_err(haptics->dev,
> > > + "failed to apply pwm state: %pE\n",
> > > + ERR_PTR(error));
> >
> > You can save some horizontal space here by dropping the \n after the first comma. (There are a few more occurences.)
> >
> Ok, is this what you want?
> error = pwm_apply_state(haptics->pwm_dev, &state);
> if (error)
> dev_err(haptics->dev, "failed to apply pwm state: %pE\n",
> ERR_PTR(error));
Yes, that's what I meant.
> > > + return error;
> > > +}
> > > +[...]
> > > +
> > > + /* Sync up PWM state and ensure it is off. */
> > > + pwm_init_state(haptics->pwm_dev, &state);
> > > + state.enabled = false;
> > > + error = pwm_apply_state(haptics->pwm_dev, &state);
> > > + if (error) {
> > > + dev_err(dev,
> > > + "failed to apply initial PWM state: %pE\n",
> > > + ERR_PTR(error));
> > > + return error;
> > > + }
> > > +
> > > + /* Check PWM Period, it must be in 10k ~ 250kHz */
> >
> > The unit of a PWM period is in (nano)seconds, to it cannot be in the range [10kHz, 250kHz]. (Is this too picky?)
>
> No, it isn't. The 'Period' should be changed to 'frequency', I will fix this as below.
>
> /* Check PWM frequency, valid range: 10k ~ 250kHz */
Much better.
> >
> > > + period2freq = 1000000 / state.period;
> > > + if (period2freq < DA7280_MIN_PWM_FREQ_KHZ ||
> > > + period2freq > DA7280_MAX_PWM_FREQ_KHZ) {
> > > + dev_err(dev, "Not supported PWM frequency(%d)\n",
> > > + period2freq);
> >
> > Doesn't the compiler warn here about period2freq being unsigned and %d being for signed int values?
> >
> > For my (non-native) English ear s/Not supported/Unsupported/ sounds better. Also my eyes would be pleases by a space
> > before the opening brace.
>
> I didn't see any warning message, but I will change/improve them to proper one and the log as below.
>
> period2freq = 1000000 / state.period;
> if (period2freq < DA7280_MIN_PWM_FREQ_KHZ ||
> period2freq > DA7280_MAX_PWM_FREQ_KHZ) {
> dev_err(dev, "Unsupported PWM frequency (%u)\n",
> period2freq);
> return -EINVAL;
> }
> If you look ok, let me update this so.
looks fine.
Note that you don't need the division if you check for:
if (state.period > 100000 || state.period < 4000) {
...
(maybe the compiler is already clever enough to get rid of the division
for you, but then the check is:
if (state.period > 100000 || state.period < 3985) {
because of rounding errors.)
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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