| Message ID | 20220523110513.407516-3-alexander.stein@ew.tq-group.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | hwmon: pwm-fan: switch regulator dynamically | expand |
On Mon, May 23, 2022 at 01:05:09PM +0200, Alexander Stein wrote: > Instead of comparing the current to the new pwm duty to decide whether to > enable the PWM, use a dedicated flag. Also apply the new PWM duty in any > case. This is a preparation to enable/disable the regulator dynamically. > > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> > --- > drivers/hwmon/pwm-fan.c | 37 +++++++++++++++++++++++++++++-------- > 1 file changed, 29 insertions(+), 8 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index 831878daffe6..96b10d422828 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -29,10 +29,13 @@ struct pwm_fan_tach { > }; > > struct pwm_fan_ctx { > + struct device *dev; > + > struct mutex lock; > struct pwm_device *pwm; > struct pwm_state pwm_state; > struct regulator *reg_en; > + bool enabled; > > int tach_count; > struct pwm_fan_tach *tachs; > @@ -85,14 +88,21 @@ static void sample_timer(struct timer_list *t) > static int pwm_fan_power_on(struct pwm_fan_ctx *ctx) > { > struct pwm_state *state = &ctx->pwm_state; > - unsigned long period; > int ret; > > - period = state->period; > - state->duty_cycle = DIV_ROUND_UP(ctx->pwm_value * (period - 1), MAX_PWM); > + if (ctx->enabled) > + return 0; > + > state->enabled = true; > ret = pwm_apply_state(ctx->pwm, state); > + if (ret) { > + dev_err(ctx->dev, "failed to enable PWM\n"); > + goto err; There is no reason for this goto. Just return directly. > + } > > + ctx->enabled = true; > + > +err: > return ret; > } > > @@ -100,26 +110,36 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) > { > struct pwm_state *state = &ctx->pwm_state; > > + if (!ctx->enabled) > + return 0; > + ctx->enabled will initially be false. How is it known that pwm is disabled when the driver is loaded ? At the very least that warrants an explanation. > state->enabled = false; > state->duty_cycle = 0; > pwm_apply_state(ctx->pwm, state); This code is a bit inconsistent with pwm_fan_power_on(). Why check for error there, but not here ? > > + ctx->enabled = false; > + > return 0; > } > > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > + struct pwm_state *state = &ctx->pwm_state; > + unsigned long period; > int ret = 0; > > mutex_lock(&ctx->lock); > - if (ctx->pwm_value == pwm) > - goto exit_set_pwm_err; > > - if (pwm > 0) > + if (pwm > 0) { > + period = state->period; > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > + ret = pwm_apply_state(ctx->pwm, state); > + if (ret) > + goto exit_set_pwm_err; > ret = pwm_fan_power_on(ctx); > - else > + } else { > ret = pwm_fan_power_off(ctx); > - > + } > if (!ret) > ctx->pwm_value = pwm; > > @@ -326,6 +346,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > > mutex_init(&ctx->lock); > > + ctx->dev = &pdev->dev; > ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL); > if (IS_ERR(ctx->pwm)) > return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
Hello Guenter, thanks for your feedback. Am Dienstag, 30. August 2022, 15:43:38 CEST schrieb Guenter Roeck: > On Mon, May 23, 2022 at 01:05:09PM +0200, Alexander Stein wrote: > > Instead of comparing the current to the new pwm duty to decide whether to > > enable the PWM, use a dedicated flag. Also apply the new PWM duty in any > > case. This is a preparation to enable/disable the regulator dynamically. > > > > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> > > --- > > > > drivers/hwmon/pwm-fan.c | 37 +++++++++++++++++++++++++++++-------- > > 1 file changed, 29 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > > index 831878daffe6..96b10d422828 100644 > > --- a/drivers/hwmon/pwm-fan.c > > +++ b/drivers/hwmon/pwm-fan.c > > @@ -29,10 +29,13 @@ struct pwm_fan_tach { > > > > }; > > > > struct pwm_fan_ctx { > > > > + struct device *dev; > > + > > > > struct mutex lock; > > struct pwm_device *pwm; > > struct pwm_state pwm_state; > > struct regulator *reg_en; > > > > + bool enabled; > > > > int tach_count; > > struct pwm_fan_tach *tachs; > > > > @@ -85,14 +88,21 @@ static void sample_timer(struct timer_list *t) > > > > static int pwm_fan_power_on(struct pwm_fan_ctx *ctx) > > { > > > > struct pwm_state *state = &ctx->pwm_state; > > > > - unsigned long period; > > > > int ret; > > > > - period = state->period; > > - state->duty_cycle = DIV_ROUND_UP(ctx->pwm_value * (period - 1), > > MAX_PWM); > > + if (ctx->enabled) > > + return 0; > > + > > > > state->enabled = true; > > ret = pwm_apply_state(ctx->pwm, state); > > > > + if (ret) { > > + dev_err(ctx->dev, "failed to enable PWM\n"); > > + goto err; > > There is no reason for this goto. Just return directly. Sure, will do so. > > + } > > > > + ctx->enabled = true; > > + > > > > +err: > > return ret; > > > > } > > > > @@ -100,26 +110,36 @@ static int pwm_fan_power_off(struct pwm_fan_ctx > > *ctx) > > > > { > > > > struct pwm_state *state = &ctx->pwm_state; > > > > + if (!ctx->enabled) > > + return 0; > > + > > ctx->enabled will initially be false. How is it known that pwm is > disabled when the driver is loaded ? At the very least that warrants > an explanation. I'm not sure what you are concerned about. The PWM is enabled in probe unconditionally, calling __set_pwm(ctx, MAX_PWM). > > state->enabled = false; > > state->duty_cycle = 0; > > pwm_apply_state(ctx->pwm, state); > > This code is a bit inconsistent with pwm_fan_power_on(). Why check for > error there, but not here ? You are right, make sense to check in both functions. Thanks and best regards Alexander > > + ctx->enabled = false; > > + > > > > return 0; > > > > } > > > > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > > { > > > > + struct pwm_state *state = &ctx->pwm_state; > > + unsigned long period; > > > > int ret = 0; > > > > mutex_lock(&ctx->lock); > > > > - if (ctx->pwm_value == pwm) > > - goto exit_set_pwm_err; > > > > - if (pwm > 0) > > + if (pwm > 0) { > > + period = state->period; > > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > > + ret = pwm_apply_state(ctx->pwm, state); > > + if (ret) > > + goto exit_set_pwm_err; > > > > ret = pwm_fan_power_on(ctx); > > > > - else > > + } else { > > > > ret = pwm_fan_power_off(ctx); > > > > - > > + } > > > > if (!ret) > > > > ctx->pwm_value = pwm; > > > > @@ -326,6 +346,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > > > > mutex_init(&ctx->lock); > > > > + ctx->dev = &pdev->dev; > > > > ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL); > > if (IS_ERR(ctx->pwm)) > > > > return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 831878daffe6..96b10d422828 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -29,10 +29,13 @@ struct pwm_fan_tach { }; struct pwm_fan_ctx { + struct device *dev; + struct mutex lock; struct pwm_device *pwm; struct pwm_state pwm_state; struct regulator *reg_en; + bool enabled; int tach_count; struct pwm_fan_tach *tachs; @@ -85,14 +88,21 @@ static void sample_timer(struct timer_list *t) static int pwm_fan_power_on(struct pwm_fan_ctx *ctx) { struct pwm_state *state = &ctx->pwm_state; - unsigned long period; int ret; - period = state->period; - state->duty_cycle = DIV_ROUND_UP(ctx->pwm_value * (period - 1), MAX_PWM); + if (ctx->enabled) + return 0; + state->enabled = true; ret = pwm_apply_state(ctx->pwm, state); + if (ret) { + dev_err(ctx->dev, "failed to enable PWM\n"); + goto err; + } + ctx->enabled = true; + +err: return ret; } @@ -100,26 +110,36 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) { struct pwm_state *state = &ctx->pwm_state; + if (!ctx->enabled) + return 0; + state->enabled = false; state->duty_cycle = 0; pwm_apply_state(ctx->pwm, state); + ctx->enabled = false; + return 0; } static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { + struct pwm_state *state = &ctx->pwm_state; + unsigned long period; int ret = 0; mutex_lock(&ctx->lock); - if (ctx->pwm_value == pwm) - goto exit_set_pwm_err; - if (pwm > 0) + if (pwm > 0) { + period = state->period; + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + ret = pwm_apply_state(ctx->pwm, state); + if (ret) + goto exit_set_pwm_err; ret = pwm_fan_power_on(ctx); - else + } else { ret = pwm_fan_power_off(ctx); - + } if (!ret) ctx->pwm_value = pwm; @@ -326,6 +346,7 @@ static int pwm_fan_probe(struct platform_device *pdev) mutex_init(&ctx->lock); + ctx->dev = &pdev->dev; ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL); if (IS_ERR(ctx->pwm)) return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
Instead of comparing the current to the new pwm duty to decide whether to enable the PWM, use a dedicated flag. Also apply the new PWM duty in any case. This is a preparation to enable/disable the regulator dynamically. Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> --- drivers/hwmon/pwm-fan.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-)