* [PATCH] staging: greybus: introduce pwm_ops::apply @ 2022-02-10 9:05 Song Chen 2022-02-10 10:03 ` Uwe Kleine-König 0 siblings, 1 reply; 5+ messages in thread From: Song Chen @ 2022-02-10 9:05 UTC (permalink / raw) To: johan, elder, gregkh, thierry.reding, u.kleine-koenig, lee.jones, greybus-dev, linux-staging, linux-kernel, linux-pwm Cc: Song Chen Introduce apply in pwm_ops to replace legacy operations, like enable, disable, config and set_polarity. Signed-off-by: Song Chen <chensong_2000@189.cn> --- drivers/staging/greybus/pwm.c | 46 +++++++++++++++-------------------- 1 file changed, 19 insertions(+), 27 deletions(-) diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c index 891a6a672378..e1889cf979b2 100644 --- a/drivers/staging/greybus/pwm.c +++ b/drivers/staging/greybus/pwm.c @@ -204,43 +204,35 @@ static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); } -static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) -{ - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); - - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); -}; - -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, - enum pwm_polarity polarity) +static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { + int ret; struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); -}; - -static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); + /* set period and duty cycle*/ + ret = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); + if (ret) + return ret; - return gb_pwm_enable_operation(pwmc, pwm->hwpwm); -}; + /* set polarity */ + ret = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity); + if (ret) + return ret; -static void gb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); + /* enable/disable */ + if (state->enabled) + ret = gb_pwm_enable_operation(pwmc, pwm->hwpwm); + else + ret = gb_pwm_disable_operation(pwmc, pwm->hwpwm); - gb_pwm_disable_operation(pwmc, pwm->hwpwm); -}; + return ret; +} static const struct pwm_ops gb_pwm_ops = { .request = gb_pwm_request, .free = gb_pwm_free, - .config = gb_pwm_config, - .set_polarity = gb_pwm_set_polarity, - .enable = gb_pwm_enable, - .disable = gb_pwm_disable, + .apply = gb_pwm_apply, .owner = THIS_MODULE, }; -- 2.25.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] staging: greybus: introduce pwm_ops::apply 2022-02-10 9:05 [PATCH] staging: greybus: introduce pwm_ops::apply Song Chen @ 2022-02-10 10:03 ` Uwe Kleine-König 2022-02-11 3:06 ` Song Chen 0 siblings, 1 reply; 5+ messages in thread From: Uwe Kleine-König @ 2022-02-10 10:03 UTC (permalink / raw) To: Song Chen Cc: johan, elder, gregkh, thierry.reding, lee.jones, greybus-dev, linux-staging, linux-kernel, linux-pwm [-- Attachment #1: Type: text/plain, Size: 2228 bytes --] On Thu, Feb 10, 2022 at 05:05:02PM +0800, Song Chen wrote: > Introduce apply in pwm_ops to replace legacy operations, > like enable, disable, config and set_polarity. > > Signed-off-by: Song Chen <chensong_2000@189.cn> > --- > drivers/staging/greybus/pwm.c | 46 +++++++++++++++-------------------- > 1 file changed, 19 insertions(+), 27 deletions(-) > > diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c > index 891a6a672378..e1889cf979b2 100644 > --- a/drivers/staging/greybus/pwm.c > +++ b/drivers/staging/greybus/pwm.c > @@ -204,43 +204,35 @@ static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) > gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); > } > > -static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > - int duty_ns, int period_ns) > -{ > - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > - > - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); > -}; > - > -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, > - enum pwm_polarity polarity) > +static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > + const struct pwm_state *state) > { > + int ret; > struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > > - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); > -}; > - > -static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > -{ > - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > + /* set period and duty cycle*/ > + ret = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); gb_pwm_config_operation's 3rd parameter is an u32, so you're loosing bits here as state->duty_cycle is a u64. Ditto for period. Also it would be nice if you go from .duty_cycle = A, .period = B, .enabled = 1 to .duty_cycle = C, .period = D, .enabled = 0 that C/D wasn't visible on the output pin. So please disable earlier (but keep enable at the end). Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] staging: greybus: introduce pwm_ops::apply 2022-02-10 10:03 ` Uwe Kleine-König @ 2022-02-11 3:06 ` Song Chen 2022-02-11 7:16 ` Uwe Kleine-König 0 siblings, 1 reply; 5+ messages in thread From: Song Chen @ 2022-02-11 3:06 UTC (permalink / raw) To: Uwe Kleine-König Cc: johan, elder, gregkh, thierry.reding, lee.jones, greybus-dev, linux-staging, linux-kernel, linux-pwm 在 2022/2/10 18:03, Uwe Kleine-König 写道: > On Thu, Feb 10, 2022 at 05:05:02PM +0800, Song Chen wrote: >> Introduce apply in pwm_ops to replace legacy operations, >> like enable, disable, config and set_polarity. >> >> Signed-off-by: Song Chen <chensong_2000@189.cn> >> --- >> drivers/staging/greybus/pwm.c | 46 +++++++++++++++-------------------- >> 1 file changed, 19 insertions(+), 27 deletions(-) >> >> diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c >> index 891a6a672378..e1889cf979b2 100644 >> --- a/drivers/staging/greybus/pwm.c >> +++ b/drivers/staging/greybus/pwm.c >> @@ -204,43 +204,35 @@ static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) >> gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); >> } >> >> -static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, >> - int duty_ns, int period_ns) >> -{ >> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >> - >> - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); >> -}; >> - >> -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, >> - enum pwm_polarity polarity) >> +static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, >> + const struct pwm_state *state) >> { >> + int ret; >> struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >> >> - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); >> -}; >> - >> -static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) >> -{ >> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >> + /* set period and duty cycle*/ >> + ret = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); > > gb_pwm_config_operation's 3rd parameter is an u32, so you're loosing > bits here as state->duty_cycle is a u64. Ditto for period. originally, pwm_apply_state --> pwm_apply_legacy --> gb_pwm_config --> gb_pwm_config_operation is also loosing bits, does it mean greybus can live with that? Or redefine gb_pwm_config_request, switch duty and period to __le64? > > Also it would be nice if you go from > > .duty_cycle = A, .period = B, .enabled = 1 > > to > > .duty_cycle = C, .period = D, .enabled = 0 > > that C/D wasn't visible on the output pin. So please disable earlier > (but keep enable at the end). sorry, i don't quite understand this part, but is below code looking good to you? static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { int err; bool enabled = pwm->state.enabled; struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); /* set polarity */ if (state->polarity != pwm->state.polarity) { if (enabled) { gb_pwm_disable_operation(pwmc, pwm->hwpwm); enabled = false; } err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity); if (err) return err; } if (!state->enabled) { if (enabled) gb_pwm_disable_operation(pwmc, pwm->hwpwm); return 0; } /* set period and duty cycle*/ err = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); if (err) return err; /* enable/disable */ if (!enabled) return gb_pwm_enable_operation(pwmc, pwm->hwpwm); return 0; } > > Best regards > Uwe > ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] staging: greybus: introduce pwm_ops::apply 2022-02-11 3:06 ` Song Chen @ 2022-02-11 7:16 ` Uwe Kleine-König 2022-02-11 7:48 ` Song Chen 0 siblings, 1 reply; 5+ messages in thread From: Uwe Kleine-König @ 2022-02-11 7:16 UTC (permalink / raw) To: Song Chen Cc: johan, elder, gregkh, thierry.reding, lee.jones, greybus-dev, linux-staging, linux-kernel, linux-pwm [-- Attachment #1: Type: text/plain, Size: 4646 bytes --] Hello , On Fri, Feb 11, 2022 at 11:06:33AM +0800, Song Chen wrote: > 在 2022/2/10 18:03, Uwe Kleine-König 写道: > > On Thu, Feb 10, 2022 at 05:05:02PM +0800, Song Chen wrote: > > > Introduce apply in pwm_ops to replace legacy operations, > > > like enable, disable, config and set_polarity. > > > > > > Signed-off-by: Song Chen <chensong_2000@189.cn> > > > --- > > > drivers/staging/greybus/pwm.c | 46 +++++++++++++++-------------------- > > > 1 file changed, 19 insertions(+), 27 deletions(-) > > > > > > diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c > > > index 891a6a672378..e1889cf979b2 100644 > > > --- a/drivers/staging/greybus/pwm.c > > > +++ b/drivers/staging/greybus/pwm.c > > > @@ -204,43 +204,35 @@ static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) > > > gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); > > > } > > > -static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, > > > - int duty_ns, int period_ns) > > > -{ > > > - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > > > - > > > - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); > > > -}; > > > - > > > -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, > > > - enum pwm_polarity polarity) > > > +static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > > > + const struct pwm_state *state) > > > { > > > + int ret; > > > struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > > > - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); > > > -}; > > > - > > > -static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) > > > -{ > > > - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > > > + /* set period and duty cycle*/ > > > + ret = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); > > > > gb_pwm_config_operation's 3rd parameter is an u32, so you're loosing > > bits here as state->duty_cycle is a u64. Ditto for period. > > originally, pwm_apply_state --> pwm_apply_legacy --> gb_pwm_config --> > gb_pwm_config_operation is also loosing bits, does it mean greybus can live > with that? This is true, I tried to address that, but Thierry had concerns. (https://lore.kernel.org/all/20210312212119.1342666-1-u.kleine-koenig@pengutronix.de/ was the patch I suggested.) > Or redefine gb_pwm_config_request, switch duty and period to __le64? Don't use __le64, this is only for representing (little endian) register values. u64 would be the right one. > > Also it would be nice if you go from > > > > .duty_cycle = A, .period = B, .enabled = 1 > > > > to > > > > .duty_cycle = C, .period = D, .enabled = 0 > > > > that C/D wasn't visible on the output pin. So please disable earlier > > (but keep enable at the end). > > sorry, i don't quite understand this part, To reexplain: If your hardware is configured for .duty_cycle = A, .period = B, .enabled = 1 and pwm_apply is called with .duty_cycle = C, .period = D, .enabled = 0 you configured the registers for .duty_cycle and .period first and only then disable the PWM. This usually results in glitches because the hardware shortly runs with .duty_cycle = C, .period = D, .enabled = 1 . So the idea is, to disable before configuring duty and period if the eventual goal is a disabled state. > but is below code looking good to > you? > > static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > const struct pwm_state *state) > { > int err; > bool enabled = pwm->state.enabled; > struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); > > /* set polarity */ > if (state->polarity != pwm->state.polarity) { > if (enabled) { > gb_pwm_disable_operation(pwmc, pwm->hwpwm); > enabled = false; > } > err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity); > if (err) > return err; > } > > if (!state->enabled) { > if (enabled) > gb_pwm_disable_operation(pwmc, pwm->hwpwm); > return 0; > } > > /* set period and duty cycle*/ > err = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); > if (err) > return err; > > /* enable/disable */ > if (!enabled) > return gb_pwm_enable_operation(pwmc, pwm->hwpwm); > > return 0; > } This looks good. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] staging: greybus: introduce pwm_ops::apply 2022-02-11 7:16 ` Uwe Kleine-König @ 2022-02-11 7:48 ` Song Chen 0 siblings, 0 replies; 5+ messages in thread From: Song Chen @ 2022-02-11 7:48 UTC (permalink / raw) To: Uwe Kleine-König Cc: johan, elder, gregkh, thierry.reding, lee.jones, greybus-dev, linux-staging, linux-kernel, linux-pwm Hello Uwe, Thanks for the explain, now i can understand it better. So, if redefining period and duty as u64 in gb_pwm_config_request is an acceptable solution, i will send patch v2. BR Song 在 2022/2/11 15:16, Uwe Kleine-König 写道: > Hello , > > On Fri, Feb 11, 2022 at 11:06:33AM +0800, Song Chen wrote: >> 在 2022/2/10 18:03, Uwe Kleine-König 写道: >>> On Thu, Feb 10, 2022 at 05:05:02PM +0800, Song Chen wrote: >>>> Introduce apply in pwm_ops to replace legacy operations, >>>> like enable, disable, config and set_polarity. >>>> >>>> Signed-off-by: Song Chen <chensong_2000@189.cn> >>>> --- >>>> drivers/staging/greybus/pwm.c | 46 +++++++++++++++-------------------- >>>> 1 file changed, 19 insertions(+), 27 deletions(-) >>>> >>>> diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c >>>> index 891a6a672378..e1889cf979b2 100644 >>>> --- a/drivers/staging/greybus/pwm.c >>>> +++ b/drivers/staging/greybus/pwm.c >>>> @@ -204,43 +204,35 @@ static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) >>>> gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); >>>> } >>>> -static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, >>>> - int duty_ns, int period_ns) >>>> -{ >>>> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >>>> - >>>> - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); >>>> -}; >>>> - >>>> -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, >>>> - enum pwm_polarity polarity) >>>> +static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, >>>> + const struct pwm_state *state) >>>> { >>>> + int ret; >>>> struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >>>> - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); >>>> -}; >>>> - >>>> -static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) >>>> -{ >>>> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >>>> + /* set period and duty cycle*/ >>>> + ret = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); >>> >>> gb_pwm_config_operation's 3rd parameter is an u32, so you're loosing >>> bits here as state->duty_cycle is a u64. Ditto for period. >> >> originally, pwm_apply_state --> pwm_apply_legacy --> gb_pwm_config --> >> gb_pwm_config_operation is also loosing bits, does it mean greybus can live >> with that? > > This is true, I tried to address that, but Thierry had concerns. > (https://lore.kernel.org/all/20210312212119.1342666-1-u.kleine-koenig@pengutronix.de/ > was the patch I suggested.) > >> Or redefine gb_pwm_config_request, switch duty and period to __le64? > > Don't use __le64, this is only for representing (little endian) register > values. u64 would be the right one. > >>> Also it would be nice if you go from >>> >>> .duty_cycle = A, .period = B, .enabled = 1 >>> >>> to >>> >>> .duty_cycle = C, .period = D, .enabled = 0 >>> >>> that C/D wasn't visible on the output pin. So please disable earlier >>> (but keep enable at the end). >> >> sorry, i don't quite understand this part, > > To reexplain: If your hardware is configured for > > .duty_cycle = A, .period = B, .enabled = 1 > > and pwm_apply is called with > > .duty_cycle = C, .period = D, .enabled = 0 > > you configured the registers for .duty_cycle and .period first and only > then disable the PWM. This usually results in glitches because the > hardware shortly runs with > > .duty_cycle = C, .period = D, .enabled = 1 > > . So the idea is, to disable before configuring duty and period if the > eventual goal is a disabled state. understood, thanks. > >> but is below code looking good to >> you? >> >> static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, >> const struct pwm_state *state) >> { >> int err; >> bool enabled = pwm->state.enabled; >> struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); >> >> /* set polarity */ >> if (state->polarity != pwm->state.polarity) { >> if (enabled) { >> gb_pwm_disable_operation(pwmc, pwm->hwpwm); >> enabled = false; >> } >> err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity); >> if (err) >> return err; >> } >> >> if (!state->enabled) { >> if (enabled) >> gb_pwm_disable_operation(pwmc, pwm->hwpwm); >> return 0; >> } >> >> /* set period and duty cycle*/ >> err = gb_pwm_config_operation(pwmc, pwm->hwpwm, state->duty_cycle, state->period); >> if (err) >> return err; >> >> /* enable/disable */ >> if (!enabled) >> return gb_pwm_enable_operation(pwmc, pwm->hwpwm); >> >> return 0; >> } > > This looks good. > > Best regards > Uwe > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-02-11 7:49 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-02-10 9:05 [PATCH] staging: greybus: introduce pwm_ops::apply Song Chen 2022-02-10 10:03 ` Uwe Kleine-König 2022-02-11 3:06 ` Song Chen 2022-02-11 7:16 ` Uwe Kleine-König 2022-02-11 7:48 ` Song Chen
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