Introduce newer .apply function in pwm_ops to replace legacy operations
including enable, disable, config and set_polarity.
This guarantees atomic changes of the pwm controller configuration.
Signed-off-by: Song Chen <[email protected]>
---
v2:
1, define duty_cycle and period as u64 in gb_pwm_config_operation.
2, define duty and period as u64 in gb_pwm_config_request.
3, disable before configuring duty and period if the eventual goal
is a disabled state.
v3:
Regarding duty_cycle and period, I read more discussion in this thread,
min, warn or -EINVAL, seems no perfect way acceptable for everyone.
How about we limit their value to INT_MAX and throw a warning at the
same time when they are wrong?
v4:
1, explain why legacy operations are replaced.
2, cap the value of period and duty to U32_MAX.
v5:
1, revise commit message.
v6:
1, revise commit message.
2, explain why capping the value of period and duty to U32_MAX in
comment.
---
drivers/staging/greybus/pwm.c | 64 ++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 24 deletions(-)
diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c
index 891a6a672378..ad20ec24031e 100644
--- a/drivers/staging/greybus/pwm.c
+++ b/drivers/staging/greybus/pwm.c
@@ -204,43 +204,59 @@ 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)
+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;
+ u64 period = state->period;
+ u64 duty_cycle = state->duty_cycle;
struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
- return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns);
-};
+ /* 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;
+ }
-static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
- enum pwm_polarity polarity)
-{
- struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
+ if (!state->enabled) {
+ if (enabled)
+ gb_pwm_disable_operation(pwmc, pwm->hwpwm);
+ return 0;
+ }
- return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
-};
+ /*
+ * Set period and duty cycle
+ *
+ * PWM privodes 64-bit period and duty_cycle, but greybus only accepts
+ * 32-bit, so their values have to be limited to U32_MAX.
+ */
+ if (period > U32_MAX)
+ period = U32_MAX;
-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);
+ if (duty_cycle > period)
+ duty_cycle = period;
- return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
-};
+ err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
+ if (err)
+ return err;
-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 (!enabled)
+ return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
- gb_pwm_disable_operation(pwmc, pwm->hwpwm);
-};
+ return 0;
+}
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
hi Alex,
On 2022/3/18 下午8:15, Alex Elder wrote:
> On 3/18/22 4:57 AM, Song Chen wrote:
>> Introduce newer .apply function in pwm_ops to replace legacy operations
>> including enable, disable, config and set_polarity.
>>
>> This guarantees atomic changes of the pwm controller configuration.
>>
>> Signed-off-by: Song Chen <[email protected]>
>
> I had another comment suggestion but you've been through enough.
> Thanks for working this to completion.
sorry about that, i probably missed it somehow. Thanks for the
understanding.
Song
>
> Reviewed-by: Alex Elder <[email protected]>
>
>>
>> ---
>> v2:
>> 1, define duty_cycle and period as u64 in gb_pwm_config_operation.
>> 2, define duty and period as u64 in gb_pwm_config_request.
>> 3, disable before configuring duty and period if the eventual goal
>> is a disabled state.
>>
>> v3:
>> Regarding duty_cycle and period, I read more discussion in this thread,
>> min, warn or -EINVAL, seems no perfect way acceptable for everyone.
>> How about we limit their value to INT_MAX and throw a warning at the
>> same time when they are wrong?
>>
>> v4:
>> 1, explain why legacy operations are replaced.
>> 2, cap the value of period and duty to U32_MAX.
>>
>> v5:
>> 1, revise commit message.
>>
>> v6:
>> 1, revise commit message.
>> 2, explain why capping the value of period and duty to U32_MAX in
>> comment.
>> ---
>> drivers/staging/greybus/pwm.c | 64 ++++++++++++++++++++++-------------
>> 1 file changed, 40 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/staging/greybus/pwm.c
>> b/drivers/staging/greybus/pwm.c
>> index 891a6a672378..ad20ec24031e 100644
>> --- a/drivers/staging/greybus/pwm.c
>> +++ b/drivers/staging/greybus/pwm.c
>> @@ -204,43 +204,59 @@ 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)
>> +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;
>> + u64 period = state->period;
>> + u64 duty_cycle = state->duty_cycle;
>> struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
>> - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns,
>> period_ns);
>> -};
>> + /* 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;
>> + }
>> -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct
>> pwm_device *pwm,
>> - enum pwm_polarity polarity)
>> -{
>> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
>> + if (!state->enabled) {
>> + if (enabled)
>> + gb_pwm_disable_operation(pwmc, pwm->hwpwm);
>> + return 0;
>> + }
>> - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
>> -};
>> + /*
>> + * Set period and duty cycle
>> + *
>> + * PWM privodes 64-bit period and duty_cycle, but greybus only
>> accepts
>> + * 32-bit, so their values have to be limited to U32_MAX.
>> + */
>> + if (period > U32_MAX)
>> + period = U32_MAX;
>> -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);
>> + if (duty_cycle > period)
>> + duty_cycle = period;
>> - return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
>> -};
>> + err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
>> + if (err)
>> + return err;
>> -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 (!enabled)
>> + return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
>> - gb_pwm_disable_operation(pwmc, pwm->hwpwm);
>> -};
>> + return 0;
>> +}
>> 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,
>> };
>
>
On 3/18/22 4:57 AM, Song Chen wrote:
> Introduce newer .apply function in pwm_ops to replace legacy operations
> including enable, disable, config and set_polarity.
>
> This guarantees atomic changes of the pwm controller configuration.
>
> Signed-off-by: Song Chen <[email protected]>
I had another comment suggestion but you've been through enough.
Thanks for working this to completion.
Reviewed-by: Alex Elder <[email protected]>
>
> ---
> v2:
> 1, define duty_cycle and period as u64 in gb_pwm_config_operation.
> 2, define duty and period as u64 in gb_pwm_config_request.
> 3, disable before configuring duty and period if the eventual goal
> is a disabled state.
>
> v3:
> Regarding duty_cycle and period, I read more discussion in this thread,
> min, warn or -EINVAL, seems no perfect way acceptable for everyone.
> How about we limit their value to INT_MAX and throw a warning at the
> same time when they are wrong?
>
> v4:
> 1, explain why legacy operations are replaced.
> 2, cap the value of period and duty to U32_MAX.
>
> v5:
> 1, revise commit message.
>
> v6:
> 1, revise commit message.
> 2, explain why capping the value of period and duty to U32_MAX in
> comment.
> ---
> drivers/staging/greybus/pwm.c | 64 ++++++++++++++++++++++-------------
> 1 file changed, 40 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c
> index 891a6a672378..ad20ec24031e 100644
> --- a/drivers/staging/greybus/pwm.c
> +++ b/drivers/staging/greybus/pwm.c
> @@ -204,43 +204,59 @@ 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)
> +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;
> + u64 period = state->period;
> + u64 duty_cycle = state->duty_cycle;
> struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
>
> - return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns);
> -};
> + /* 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;
> + }
>
> -static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
> - enum pwm_polarity polarity)
> -{
> - struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
> + if (!state->enabled) {
> + if (enabled)
> + gb_pwm_disable_operation(pwmc, pwm->hwpwm);
> + return 0;
> + }
>
> - return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
> -};
> + /*
> + * Set period and duty cycle
> + *
> + * PWM privodes 64-bit period and duty_cycle, but greybus only accepts
> + * 32-bit, so their values have to be limited to U32_MAX.
> + */
> + if (period > U32_MAX)
> + period = U32_MAX;
>
> -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);
> + if (duty_cycle > period)
> + duty_cycle = period;
>
> - return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
> -};
> + err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
> + if (err)
> + return err;
>
> -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 (!enabled)
> + return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
>
> - gb_pwm_disable_operation(pwmc, pwm->hwpwm);
> -};
> + return 0;
> +}
>
> 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,
> };
>
Hello,
On Fri, Mar 18, 2022 at 05:57:12PM +0800, Song Chen wrote:
> Introduce newer .apply function in pwm_ops to replace legacy operations
> including enable, disable, config and set_polarity.
>
> This guarantees atomic changes of the pwm controller configuration.
>
> Signed-off-by: Song Chen <[email protected]>
for the record: This patch was applied by Greg, I'm marking it as
"handled elsewhere" in the pwm patchwork.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | https://www.pengutronix.de/ |