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, };
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
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
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@pengutr... 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
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@pengutr... 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
-
Song Chen -
Uwe Kleine-König