Messages in this thread |  | | Date | Wed, 10 Feb 2010 07:55:04 -0600 | From | Bill Gatliff <> | Subject | Re: [PWM PATCH 1/7] API to consolidate PWM devices behind a common user and kernel interface |
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H Hartley Sweeten wrote: >> +int pwm_set_polarity(struct pwm_channel *p, >> + int active_high) >> +{ >> + struct pwm_channel_config c = { >> + .config_mask = PWM_CONFIG_POLARITY, >> + .polarity = active_high, >> + }; >> + return pwm_config(p, &c); >> +} >> +EXPORT_SYMBOL(pwm_set_polarity); >> > > Has the 'polarity' logic been verified? > > pwm_set_polarity takes an active high flag that is passed to pwm_config. > A write to the sysfs 'polarity' file passes the value directly to pwm_config. > A read from the sysfs 'polarity' file returns struct pwm_channel ->active_low. > > Seems like a mis-match in logic. >
It was. And on top of that, none of the drivers were reflecting their polarity in their pwm_channel structures.
I renamed the channel structure variable to active_high for consistency, and updated each of the drivers to set that value consistent with their actual polarities.
Very good catch.
b.g.
-- Bill Gatliff Embedded systems training and consulting http://billgatliff.com bgat@billgatliff.com
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