Messages in this thread | | | Date | Mon, 28 Jan 2013 10:36:07 +0100 | From | Florian Vaussard <> | Subject | Re: [PATCH v2 1/3] pwm: Add pwm_cansleep() as exported API to users |
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Hello,
Le 28/01/2013 09:45, Peter Ujfalusi a écrit : > hi Thierry, > > On 01/26/2013 06:40 AM, Thierry Reding wrote: >>> + * @pwm: PWM device >>> + * >>> + * It returns nonzero if accessing the PWM can sleep. >>> + */ >>> +int pwm_cansleep(struct pwm_device *pwm) >> >> I actually liked pwm_can_sleep() better. I find it to be more consistent >> with the naming of other function names. It would furthermore match the >> field name. > > I was looking at the GPIO API to suggest this name change, but you are right > we should be consistent with the PWM API here. > Sorry Florian. >
No problem, I agree with the PWM API consistency.
>> >>> +{ >>> + return pwm->chip->can_sleep; >>> +} >>> +EXPORT_SYMBOL_GPL(pwm_cansleep); >> >> Would it make sense to check for NULL pointers here? I guess that >> passing NULL into the function could be considered a programming error >> and an oops would be okay, but in that case there's no point in making >> the function return an int. Also see my next comment. > > While it is unlikely to happen it is better to be safe, something like this > will do: > > return pwm ? pwm->chip->can_sleep : 0; >
Ok. And what about:
BUG_ON(pwm == NULL); return pwm->chip->can_sleep;
>> >>> + >>> #ifdef CONFIG_DEBUG_FS >>> static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) >>> { >>> diff --git a/include/linux/pwm.h b/include/linux/pwm.h >>> index 70655a2..e2cb5c7 100644 >>> --- a/include/linux/pwm.h >>> +++ b/include/linux/pwm.h >>> @@ -146,6 +146,8 @@ struct pwm_ops { >>> * @base: number of first PWM controlled by this chip >>> * @npwm: number of PWMs controlled by this chip >>> * @pwms: array of PWM devices allocated by the framework >>> + * @can_sleep: flag must be set iff config()/enable()/disable() methods sleep, >>> + * as they must while accessing PWM chips over I2C or SPI >>> */ >>> struct pwm_chip { >>> struct device *dev; >>> @@ -159,6 +161,7 @@ struct pwm_chip { >>> struct pwm_device * (*of_xlate)(struct pwm_chip *pc, >>> const struct of_phandle_args *args); >>> unsigned int of_pwm_n_cells; >>> + unsigned int can_sleep:1; >> >> What's the reason for making this a bitfield? Couldn't we just use a >> bool instead? > > I have also overlooked this. In my version I had the can_sleep as bool also. >
Ok for a bool.
Thank you for your reviews. I will send a v3 sometimes today.
Cheers, Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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