| Message ID | 1459368249-13241-9-git-send-email-boris.brezillon@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Mar 30, 2016 at 10:03:31PM +0200, Boris Brezillon wrote: > The PWM framework has clarified the concept of reference PWM config > (the platform dependent config retrieved from the DT or the PWM > lookup table) and real PWM state. > > Use pwm_get_args() when the PWM user wants to retrieve this reference > config and not the current state. > > This is part of the rework allowing the PWM framework to support > hardware readout and expose real PWM state even when the PWM has > just been requested (before the user calls pwm_config/enable/disable()). > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > drivers/hwmon/pwm-fan.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index 3e23003..82c5656 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -40,15 +40,18 @@ struct pwm_fan_ctx { > > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > + struct pwm_args pargs = { }; Hi Boris, I guess I am missing some context; sorry for that. Unfortunately, I did not easily find an explanation, so please bear with me. Two questions: Why do we need a local copy of struct pwm_args instead of a pointer to it ? If it can change while being used, isn't it inconsistent anyway ? Also, assuming the local copy is necessary, why initialize pargs ? After all, pwm_get_args() just overwrites it. Thanks, Guenter > unsigned long duty; > int ret = 0; > > + pwm_get_args(ctx->pwm, &pargs); > + > mutex_lock(&ctx->lock); > if (ctx->pwm_value == pwm) > goto exit_set_pwm_err; > > - duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM); > - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); > + duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM); > + ret = pwm_config(ctx->pwm, duty, pargs.period); > if (ret) > goto exit_set_pwm_err; > > @@ -214,6 +217,7 @@ static int pwm_fan_of_get_cooling_data(struct device *dev, > static int pwm_fan_probe(struct platform_device *pdev) > { > struct thermal_cooling_device *cdev; > + struct pwm_args pargs = { }; > struct pwm_fan_ctx *ctx; > struct device *hwmon; > int duty_cycle; > @@ -234,10 +238,11 @@ static int pwm_fan_probe(struct platform_device *pdev) > platform_set_drvdata(pdev, ctx); > > /* Set duty cycle to maximum allowed */ > - duty_cycle = ctx->pwm->period - 1; > + pwm_get_args(ctx->pwm, &pargs); > + duty_cycle = pargs.period - 1; > ctx->pwm_value = MAX_PWM; > > - ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period); > + ret = pwm_config(ctx->pwm, duty_cycle, pargs.period); > if (ret) { > dev_err(&pdev->dev, "Failed to configure PWM\n"); > return ret; > @@ -303,14 +308,16 @@ static int pwm_fan_suspend(struct device *dev) > static int pwm_fan_resume(struct device *dev) > { > struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > + struct pwm_args pargs = { }; > unsigned long duty; > int ret; > > if (ctx->pwm_value == 0) > return 0; > > - duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM); > - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); > + pwm_get_args(ctx->pwm, &pargs); > + duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM); > + ret = pwm_config(ctx->pwm, duty, pargs.period); > if (ret) > return ret; > return pwm_enable(ctx->pwm); > -- > 2.5.0 >
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 3e23003..82c5656 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -40,15 +40,18 @@ struct pwm_fan_ctx { static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { + struct pwm_args pargs = { }; unsigned long duty; int ret = 0; + pwm_get_args(ctx->pwm, &pargs); + mutex_lock(&ctx->lock); if (ctx->pwm_value == pwm) goto exit_set_pwm_err; - duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM); - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); + duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM); + ret = pwm_config(ctx->pwm, duty, pargs.period); if (ret) goto exit_set_pwm_err; @@ -214,6 +217,7 @@ static int pwm_fan_of_get_cooling_data(struct device *dev, static int pwm_fan_probe(struct platform_device *pdev) { struct thermal_cooling_device *cdev; + struct pwm_args pargs = { }; struct pwm_fan_ctx *ctx; struct device *hwmon; int duty_cycle; @@ -234,10 +238,11 @@ static int pwm_fan_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ctx); /* Set duty cycle to maximum allowed */ - duty_cycle = ctx->pwm->period - 1; + pwm_get_args(ctx->pwm, &pargs); + duty_cycle = pargs.period - 1; ctx->pwm_value = MAX_PWM; - ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period); + ret = pwm_config(ctx->pwm, duty_cycle, pargs.period); if (ret) { dev_err(&pdev->dev, "Failed to configure PWM\n"); return ret; @@ -303,14 +308,16 @@ static int pwm_fan_suspend(struct device *dev) static int pwm_fan_resume(struct device *dev) { struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + struct pwm_args pargs = { }; unsigned long duty; int ret; if (ctx->pwm_value == 0) return 0; - duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM); - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); + pwm_get_args(ctx->pwm, &pargs); + duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM); + ret = pwm_config(ctx->pwm, duty, pargs.period); if (ret) return ret; return pwm_enable(ctx->pwm);
The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state. Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state. This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- drivers/hwmon/pwm-fan.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)