clk: Add PWM clock driver
Hi,
http://patchwork.ozlabs.org/patch/359069/
https://lkml.org/lkml/2014/6/12/186
Will the patch ever included to linux-next?
pwm_config() API could be extended to support not only period [ns] and duty [ns] time
but also frequency [Hz] and duty cycle fraction [1/1000?] (instead of time in ns) as parameters.
Then ns (rounded by pwm) to freq. conversion problem inclk_pwm_recalc_rate() usingpwm_get_period() could be avoided.
To extend the API pwm_config() can support
new flags forduty_ns and period_ns,
eg. PWM_DUTY_PERCENT and PWM_PERIOD_HZ.
best regards
Janusz
Quoted 6 lines · Janusz Użycki
Hi,
http://patchwork.ozlabs.org/patch/359069/
https://lkml.org/lkml/2014/6/12/186Will the patch ever included to linux-next?
I've never seen this patch before. From a quick look it doesn't seem like it would work as is, but the idea is certainly interesting. If somebody decides to continue work on it, please Cc me and the linux-pwm mailing list.
Quoted 10 lines
pwm_config()API could be extended to support not only period [ns] and duty [ns] time
but also frequency [Hz] and duty cycle fraction [1/1000?] (instead of time in ns) as parameters.
Then ns (rounded by pwm) to freq. conversion probleminclk_pwm_recalc_rate()usingpwm_get_period()could be avoided.
To extend the APIpwm_config()can support
new flagsforduty_nsandperiod_ns,
eg.PWM_DUTY_PERCENTandPWM_PERIOD_HZ.
Is that rounding really a problem? Also the PWM chips will most likely use the concept of period and duty-cycle internally anyway, so it will convert back from Hz/percentage to nanoseconds and fall victim to similar rounding effects.
Thierry
Quoting Thierry Reding (2014-09-23 01:51:31)
Quoted 6 lines · Janusz Użycki
Quoted 6 lines
Quoted 1 line
Will the patch ever included to linux-next?
I've never seen this patch before. From a quick look it doesn't seem like it would work as is, but the idea is certainly interesting. If somebody decides to continue work on it, please Cc me and the linux-pwm mailing list.
I just merged a gpio-controlled clock gate and I'm fine with a PWM clock output.
Janusz, how are you testing the clock driver?
Regards,
Mike
Quoted 18 lines
Quoted 11 lines
pwm_config()API could be extended to support not only period [ns] and duty [ns] time
but also frequency [Hz] and duty cycle fraction [1/1000?] (instead of time in ns) as parameters.
Then ns (rounded by pwm) to freq. conversion probleminclk_pwm_recalc_rate()usingpwm_get_period()could be avoided.
To extend the APIpwm_config()can support
new flagsforduty_nsandperiod_ns,
eg.PWM_DUTY_PERCENTandPWM_PERIOD_HZ.Is that rounding really a problem? Also the PWM chips will most likely use the concept of period and duty-cycle internally anyway, so it will convert back from Hz/percentage to nanoseconds and fall victim to similar rounding effects.
Thierry
W dniu 2014-09-27 o 22:01, Mike Turquette pisze:
Quoted 8 lines
Quoting Thierry Reding (2014-09-23 01:51:31)
Quoted 7 lines · Janusz Użycki
Quoted 6 lines
Hi,
http://patchwork.ozlabs.org/patch/359069/
https://lkml.org/lkml/2014/6/12/186Will the patch ever included to linux-next?
Quoted 8 lines
Quoted 4 lines
I've never seen this patch before. From a quick look it doesn't seem like it would work as is, but the idea is certainly interesting. If somebody decides to continue work on it, please Cc me and the linux-pwm mailing list.
I just merged a gpio-controlled clock gate and I'm fine with a PWM clock output.
Janusz, how are you testing the clock driver?
Sorry, I didn't noticed the email.
I didn't test the patch yet. However I plan to check it this year.
best regards
Janusz
Quoted 21 lines
Regards,
MikeQuoted 16 lines
Quoted 10 lines
pwm_config()API could be extended to support not only period [ns] and duty [ns] time
but also frequency [Hz] and duty cycle fraction [1/1000?] (instead of time in ns) as parameters.
Then ns (rounded by pwm) to freq. conversion probleminclk_pwm_recalc_rate()usingpwm_get_period()could be avoided.
To extend the APIpwm_config()can support
new flagsforduty_nsandperiod_ns,
eg.PWM_DUTY_PERCENTandPWM_PERIOD_HZ.Is that rounding really a problem? Also the PWM chips will most likely use the concept of period and duty-cycle internally anyway, so it will convert back from Hz/percentage to nanoseconds and fall victim to similar rounding effects.
Thierry
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Am Samstag, den 27.09.2014, 13:01 -0700 schrieb Mike Turquette:
Quoted 14 lines
Quoting Thierry Reding (2014-09-23 01:51:31)
Quoted 6 lines · Janusz Użycki
Quoted 6 lines
Quoted 1 line
Will the patch ever included to linux-next?
I've never seen this patch before. From a quick look it doesn't seem like it would work as is, but the idea is certainly interesting. If somebody decides to continue work on it, please Cc me and the linux-pwm mailing list.
Quoted 4 lines
I just merged a gpio-controlled clock gate and I'm fine with a PWM clock output.
Janusz, how are you testing the clock driver?
On the BoundaryDevices Nitrogen6X board, the master clock to the OV5640 MIPI CSI-2 sensor module has to be provided by a PWM.
regards
Philipp