| Message ID | 1554989411-23666-1-git-send-email-stefan.wahren@i2se.com |
|---|---|
| Headers | show |
| Series | hwmon: pwm-fan: Add RPM support | expand |
On Thu, Apr 11, 2019 at 03:30:11PM +0200, Stefan Wahren wrote: > This adds RPM support to the pwm-fan driver in order to use with > fancontrol/pwmconfig. This feature is intended for fans with a tachometer > output signal, which generate a defined number of pulses per revolution. > > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> > --- > drivers/hwmon/pwm-fan.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 103 insertions(+), 4 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index e4c5197..8c4c5ee 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -18,6 +18,7 @@ > > #include <linux/hwmon.h> > #include <linux/hwmon-sysfs.h> > +#include <linux/interrupt.h> > #include <linux/module.h> > #include <linux/mutex.h> > #include <linux/of.h> > @@ -26,6 +27,7 @@ > #include <linux/regulator/consumer.h> > #include <linux/sysfs.h> > #include <linux/thermal.h> > +#include <linux/timer.h> > > #define MAX_PWM 255 > > @@ -33,6 +35,14 @@ struct pwm_fan_ctx { > struct mutex lock; > struct pwm_device *pwm; > struct regulator *reg_en; > + > + int irq; > + atomic_t pulses; > + unsigned int rpm; > + u8 pulses_per_revolution; > + ktime_t sample_start; > + struct timer_list rpm_timer; > + > unsigned int pwm_value; > unsigned int pwm_fan_state; > unsigned int pwm_fan_max_state; > @@ -40,6 +50,32 @@ struct pwm_fan_ctx { > struct thermal_cooling_device *cdev; > }; > > +/* This handler assumes self resetting edge triggered interrupt. */ > +static irqreturn_t pulse_handler(int irq, void *dev_id) > +{ > + struct pwm_fan_ctx *ctx = dev_id; > + > + atomic_inc(&ctx->pulses); > + > + return IRQ_HANDLED; > +} > + > +static void sample_timer(struct timer_list *t) > +{ > + struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer); > + int pulses; > + u64 tmp; > + > + pulses = atomic_read(&ctx->pulses); > + atomic_sub(pulses, &ctx->pulses); > + tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60; > + do_div(tmp, ctx->pulses_per_revolution * 1000); > + ctx->rpm = tmp; > + > + ctx->sample_start = ktime_get(); > + mod_timer(&ctx->rpm_timer, jiffies + HZ); > +} > + > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > unsigned long period; > @@ -100,15 +136,47 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *attr, > return sprintf(buf, "%u\n", ctx->pwm_value); > } > > +static ssize_t rpm_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > + > + return sprintf(buf, "%u\n", ctx->rpm); > +} > > static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); > +static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0); > > static struct attribute *pwm_fan_attrs[] = { > &sensor_dev_attr_pwm1.dev_attr.attr, > + &sensor_dev_attr_fan1_input.dev_attr.attr, > NULL, > }; > > -ATTRIBUTE_GROUPS(pwm_fan); > +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, > + int n) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > + struct device_attribute *devattr; > + > + /* Hide fan_input in case no interrupt is available */ > + devattr = container_of(a, struct device_attribute, attr); Field day for static analyzers - devattr is no longer used. No need to resend. I'll let the series rest for a couple of days and then apply to hwmon-next (after removing devattr) unless there are additional comments. > + if (n == 1 && ctx->irq <= 0) > + return 0; > + > + return a->mode; > +} > + > +static const struct attribute_group pwm_fan_group = { > + .attrs = pwm_fan_attrs, > + .is_visible = pwm_fan_attrs_visible, > +}; > + > +static const struct attribute_group *pwm_fan_groups[] = { > + &pwm_fan_group, > + NULL, > +}; > > /* thermal cooling device callbacks */ > static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev, > @@ -214,6 +282,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > struct device *hwmon; > int ret; > struct pwm_state state = { }; > + u32 ppr = 2; > > ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); > if (!ctx) > @@ -233,6 +302,10 @@ static int pwm_fan_probe(struct platform_device *pdev) > > platform_set_drvdata(pdev, ctx); > > + ctx->irq = platform_get_irq(pdev, 0); > + if (ctx->irq == -EPROBE_DEFER) > + return ctx->irq; > + > ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan"); > if (IS_ERR(ctx->reg_en)) { > if (PTR_ERR(ctx->reg_en) != -ENODEV) > @@ -261,17 +334,38 @@ static int pwm_fan_probe(struct platform_device *pdev) > goto err_reg_disable; > } > > + timer_setup(&ctx->rpm_timer, sample_timer, 0); > + > + of_property_read_u32(pdev->dev.of_node, "pulses-per-revolution", &ppr); > + ctx->pulses_per_revolution = ppr; > + if (!ctx->pulses_per_revolution) { > + dev_err(&pdev->dev, "pulses-per-revolution can't be zero.\n"); > + ret = -EINVAL; > + goto err_pwm_disable; > + } > + > + if (ctx->irq > 0) { > + ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, > + pdev->name, ctx); > + if (ret) { > + dev_err(&pdev->dev, "Can't get interrupt working.\n"); > + goto err_pwm_disable; > + } > + ctx->sample_start = ktime_get(); > + mod_timer(&ctx->rpm_timer, jiffies + HZ); > + } > + > hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", > ctx, pwm_fan_groups); > if (IS_ERR(hwmon)) { > dev_err(&pdev->dev, "Failed to register hwmon device\n"); > ret = PTR_ERR(hwmon); > - goto err_pwm_disable; > + goto err_del_timer; > } > > ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); > if (ret) > - goto err_pwm_disable; > + goto err_del_timer; > > ctx->pwm_fan_state = ctx->pwm_fan_max_state; > if (IS_ENABLED(CONFIG_THERMAL)) { > @@ -282,7 +376,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > dev_err(&pdev->dev, > "Failed to register pwm-fan as cooling device"); > ret = PTR_ERR(cdev); > - goto err_pwm_disable; > + goto err_del_timer; > } > ctx->cdev = cdev; > thermal_cdev_update(cdev); > @@ -290,6 +384,9 @@ static int pwm_fan_probe(struct platform_device *pdev) > > return 0; > > +err_del_timer: > + del_timer_sync(&ctx->rpm_timer); > + > err_pwm_disable: > state.enabled = false; > pwm_apply_state(ctx->pwm, &state); > @@ -306,6 +403,8 @@ static int pwm_fan_remove(struct platform_device *pdev) > struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev); > > thermal_cooling_device_unregister(ctx->cdev); > + del_timer_sync(&ctx->rpm_timer); > + > if (ctx->pwm_value) > pwm_disable(ctx->pwm); > > -- > 2.7.4 >
On 11.04.19 18:57, Guenter Roeck wrote: > On Thu, Apr 11, 2019 at 03:30:11PM +0200, Stefan Wahren wrote: >> >> -ATTRIBUTE_GROUPS(pwm_fan); >> +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, >> + int n) >> +{ >> + struct device *dev = container_of(kobj, struct device, kobj); >> + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); >> + struct device_attribute *devattr; >> + >> + /* Hide fan_input in case no interrupt is available */ >> + devattr = container_of(a, struct device_attribute, attr); > Field day for static analyzers - devattr is no longer used. > No need to resend. I'll let the series rest for a couple of days > and then apply to hwmon-next (after removing devattr) unless there are > additional comments. > Thank you Stefan
On 11.04.19 15:30, Stefan Wahren wrote: > This adds RPM support to the pwm-fan driver in order to use with > fancontrol/pwmconfig. This feature is intended for fans with a tachometer > output signal, which generate a defined number of pulses per revolution. Wouldn't it be better to have a CONFIG_* flag for keeping the kernel image size smaller when this feature isn't needed ? --mtx
Hi Enrico, On 12.04.19 15:15, Enrico Weigelt, metux IT consult wrote: > On 11.04.19 15:30, Stefan Wahren wrote: >> This adds RPM support to the pwm-fan driver in order to use with >> fancontrol/pwmconfig. This feature is intended for fans with a tachometer >> output signal, which generate a defined number of pulses per revolution. > Wouldn't it be better to have a CONFIG_* flag for keeping the kernel > image size smaller when this feature isn't needed ? i compared the kernel module size in linux-next for ARM without and with this patch: without patch: 12088 bytes with patch: 14292 bytes I don't think it is worth the trouble. Stefan > > > --mtx >
On 4/12/19 6:35 AM, Stefan Wahren wrote: > Hi Enrico, > > On 12.04.19 15:15, Enrico Weigelt, metux IT consult wrote: >> On 11.04.19 15:30, Stefan Wahren wrote: >>> This adds RPM support to the pwm-fan driver in order to use with >>> fancontrol/pwmconfig. This feature is intended for fans with a tachometer >>> output signal, which generate a defined number of pulses per revolution. >> Wouldn't it be better to have a CONFIG_* flag for keeping the kernel >> image size smaller when this feature isn't needed ? > > i compared the kernel module size in linux-next for ARM without and with > this patch: > without patch: 12088 bytes > with patch: 14292 bytes > > I don't think it is worth the trouble. > Agreed. This would end up being a mess, with lots of configuration options in various drivers. Please don't start it. Guenter
On 4/12/19 4:50 AM, Robin Murphy wrote: > On 12/04/2019 12:07, Stefan Wahren wrote: >> On 11.04.19 18:57, Guenter Roeck wrote: >>> On Thu, Apr 11, 2019 at 03:30:11PM +0200, Stefan Wahren wrote: >>>> >>>> -ATTRIBUTE_GROUPS(pwm_fan); >>>> +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, >>>> + int n) >>>> +{ >>>> + struct device *dev = container_of(kobj, struct device, kobj); >>>> + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); >>>> + struct device_attribute *devattr; >>>> + >>>> + /* Hide fan_input in case no interrupt is available */ >>>> + devattr = container_of(a, struct device_attribute, attr); >>> Field day for static analyzers - devattr is no longer used. >>> No need to resend. I'll let the series rest for a couple of days >>> and then apply to hwmon-next (after removing devattr) unless there are >>> additional comments. >>> >> Thank you > > FWIW you can have a > > Reviewed-by: Robin Murphy <robin.murphy@arm.com> > > for the whole series. The only minor comment that springs to mind > isn't actually specific to this patch, so is probably best made as > the follow-up below. > > Robin. > Any chance you can send the patch below as separate patch ? I track patches using patchwork, and attachments don't show up there. Thanks, Guenter > ----->8----- > From: Robin Murphy <robin.murphy@arm.com> > Subject: [PATCH] hwmon: pwm-fan: Report probe errors consistently > > Printing the error code for a failure provides a head-start for > debugging, since it's often sufficient to pinpoint the origin of the > failure. We already do this for some probe-failure messages, so let's > make the rest of them consistent. > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > drivers/hwmon/pwm-fan.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index 8c4c5eefd4ca..556db4bef743 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -330,7 +330,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > > ret = pwm_apply_state(ctx->pwm, &state); > if (ret) { > - dev_err(&pdev->dev, "Failed to configure PWM\n"); > + dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret); > goto err_reg_disable; > } > > @@ -348,7 +348,8 @@ static int pwm_fan_probe(struct platform_device *pdev) > ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, > pdev->name, ctx); > if (ret) { > - dev_err(&pdev->dev, "Can't get interrupt working.\n"); > + dev_err(&pdev->dev, > + "Failed to request interrupt: %d\n", ret); > goto err_pwm_disable; > } > ctx->sample_start = ktime_get(); > @@ -358,8 +359,9 @@ static int pwm_fan_probe(struct platform_device *pdev) > hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", > ctx, pwm_fan_groups); > if (IS_ERR(hwmon)) { > - dev_err(&pdev->dev, "Failed to register hwmon device\n"); > ret = PTR_ERR(hwmon); > + dev_err(&pdev->dev, > + "Failed to register hwmon device: %d\n", ret); > goto err_del_timer; > } > > @@ -373,9 +375,10 @@ static int pwm_fan_probe(struct platform_device *pdev) > "pwm-fan", ctx, > &pwm_fan_cooling_ops); > if (IS_ERR(cdev)) { > - dev_err(&pdev->dev, > - "Failed to register pwm-fan as cooling device"); > ret = PTR_ERR(cdev); > + dev_err(&pdev->dev, > + "Failed to register pwm-fan as cooling device: %d\n", > + ret); > goto err_del_timer; > } > ctx->cdev = cdev; >
On 12/04/2019 14:50, Guenter Roeck wrote: > On 4/12/19 4:50 AM, Robin Murphy wrote: >> On 12/04/2019 12:07, Stefan Wahren wrote: >>> On 11.04.19 18:57, Guenter Roeck wrote: >>>> On Thu, Apr 11, 2019 at 03:30:11PM +0200, Stefan Wahren wrote: >>>>> -ATTRIBUTE_GROUPS(pwm_fan); >>>>> +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct >>>>> attribute *a, >>>>> + int n) >>>>> +{ >>>>> + struct device *dev = container_of(kobj, struct device, kobj); >>>>> + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); >>>>> + struct device_attribute *devattr; >>>>> + >>>>> + /* Hide fan_input in case no interrupt is available */ >>>>> + devattr = container_of(a, struct device_attribute, attr); >>>> Field day for static analyzers - devattr is no longer used. >>>> No need to resend. I'll let the series rest for a couple of days >>>> and then apply to hwmon-next (after removing devattr) unless there are >>>> additional comments. >>>> >>> Thank you >> >> FWIW you can have a >> >> Reviewed-by: Robin Murphy <robin.murphy@arm.com> >> >> for the whole series. The only minor comment that springs to mind >> isn't actually specific to this patch, so is probably best made as >> the follow-up below. >> >> Robin. >> > > Any chance you can send the patch below as separate patch ? I track patches > using patchwork, and attachments don't show up there. Sure, can do - would you like an explicit R-b on #1 and #2 here for patchwork to pick up as well? Robin. > > Thanks, > Guenter > >> ----->8----- >> From: Robin Murphy <robin.murphy@arm.com> >> Subject: [PATCH] hwmon: pwm-fan: Report probe errors consistently >> >> Printing the error code for a failure provides a head-start for >> debugging, since it's often sufficient to pinpoint the origin of the >> failure. We already do this for some probe-failure messages, so let's >> make the rest of them consistent. >> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> drivers/hwmon/pwm-fan.c | 13 ++++++++----- >> 1 file changed, 8 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c >> index 8c4c5eefd4ca..556db4bef743 100644 >> --- a/drivers/hwmon/pwm-fan.c >> +++ b/drivers/hwmon/pwm-fan.c >> @@ -330,7 +330,7 @@ static int pwm_fan_probe(struct platform_device >> *pdev) >> >> ret = pwm_apply_state(ctx->pwm, &state); >> if (ret) { >> - dev_err(&pdev->dev, "Failed to configure PWM\n"); >> + dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret); >> goto err_reg_disable; >> } >> >> @@ -348,7 +348,8 @@ static int pwm_fan_probe(struct platform_device >> *pdev) >> ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, >> pdev->name, ctx); >> if (ret) { >> - dev_err(&pdev->dev, "Can't get interrupt working.\n"); >> + dev_err(&pdev->dev, >> + "Failed to request interrupt: %d\n", ret); >> goto err_pwm_disable; >> } >> ctx->sample_start = ktime_get(); >> @@ -358,8 +359,9 @@ static int pwm_fan_probe(struct platform_device >> *pdev) >> hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, >> "pwmfan", >> ctx, pwm_fan_groups); >> if (IS_ERR(hwmon)) { >> - dev_err(&pdev->dev, "Failed to register hwmon device\n"); >> ret = PTR_ERR(hwmon); >> + dev_err(&pdev->dev, >> + "Failed to register hwmon device: %d\n", ret); >> goto err_del_timer; >> } >> >> @@ -373,9 +375,10 @@ static int pwm_fan_probe(struct platform_device >> *pdev) >> "pwm-fan", ctx, >> &pwm_fan_cooling_ops); >> if (IS_ERR(cdev)) { >> - dev_err(&pdev->dev, >> - "Failed to register pwm-fan as cooling device"); >> ret = PTR_ERR(cdev); >> + dev_err(&pdev->dev, >> + "Failed to register pwm-fan as cooling device: %d\n", >> + ret); >> goto err_del_timer; >> } >> ctx->cdev = cdev; >> >
On 4/12/19 6:54 AM, Robin Murphy wrote: > On 12/04/2019 14:50, Guenter Roeck wrote: >> On 4/12/19 4:50 AM, Robin Murphy wrote: >>> On 12/04/2019 12:07, Stefan Wahren wrote: >>>> On 11.04.19 18:57, Guenter Roeck wrote: >>>>> On Thu, Apr 11, 2019 at 03:30:11PM +0200, Stefan Wahren wrote: >>>>>> -ATTRIBUTE_GROUPS(pwm_fan); >>>>>> +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, >>>>>> + int n) >>>>>> +{ >>>>>> + struct device *dev = container_of(kobj, struct device, kobj); >>>>>> + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); >>>>>> + struct device_attribute *devattr; >>>>>> + >>>>>> + /* Hide fan_input in case no interrupt is available */ >>>>>> + devattr = container_of(a, struct device_attribute, attr); >>>>> Field day for static analyzers - devattr is no longer used. >>>>> No need to resend. I'll let the series rest for a couple of days >>>>> and then apply to hwmon-next (after removing devattr) unless there are >>>>> additional comments. >>>>> >>>> Thank you >>> >>> FWIW you can have a >>> >>> Reviewed-by: Robin Murphy <robin.murphy@arm.com> >>> >>> for the whole series. The only minor comment that springs to mind >>> isn't actually specific to this patch, so is probably best made as >>> the follow-up below. >>> >>> Robin. >>> >> >> Any chance you can send the patch below as separate patch ? I track patches >> using patchwork, and attachments don't show up there. > > Sure, can do - would you like an explicit R-b on #1 and #2 here for patchwork to pick up as well? > That would simplify my life a bit, but I can add that part myself to the patches. I primarily like to have the patches in patchwork to make sure they don't get lost and that I can pick them up again later if needed. Thanks, Guenter > Robin. > >> >> Thanks, >> Guenter >> >>> ----->8----- >>> From: Robin Murphy <robin.murphy@arm.com> >>> Subject: [PATCH] hwmon: pwm-fan: Report probe errors consistently >>> >>> Printing the error code for a failure provides a head-start for >>> debugging, since it's often sufficient to pinpoint the origin of the >>> failure. We already do this for some probe-failure messages, so let's >>> make the rest of them consistent. >>> >>> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >>> --- >>> drivers/hwmon/pwm-fan.c | 13 ++++++++----- >>> 1 file changed, 8 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c >>> index 8c4c5eefd4ca..556db4bef743 100644 >>> --- a/drivers/hwmon/pwm-fan.c >>> +++ b/drivers/hwmon/pwm-fan.c >>> @@ -330,7 +330,7 @@ static int pwm_fan_probe(struct platform_device *pdev) >>> >>> ret = pwm_apply_state(ctx->pwm, &state); >>> if (ret) { >>> - dev_err(&pdev->dev, "Failed to configure PWM\n"); >>> + dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret); >>> goto err_reg_disable; >>> } >>> >>> @@ -348,7 +348,8 @@ static int pwm_fan_probe(struct platform_device *pdev) >>> ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, >>> pdev->name, ctx); >>> if (ret) { >>> - dev_err(&pdev->dev, "Can't get interrupt working.\n"); >>> + dev_err(&pdev->dev, >>> + "Failed to request interrupt: %d\n", ret); >>> goto err_pwm_disable; >>> } >>> ctx->sample_start = ktime_get(); >>> @@ -358,8 +359,9 @@ static int pwm_fan_probe(struct platform_device *pdev) >>> hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", >>> ctx, pwm_fan_groups); >>> if (IS_ERR(hwmon)) { >>> - dev_err(&pdev->dev, "Failed to register hwmon device\n"); >>> ret = PTR_ERR(hwmon); >>> + dev_err(&pdev->dev, >>> + "Failed to register hwmon device: %d\n", ret); >>> goto err_del_timer; >>> } >>> >>> @@ -373,9 +375,10 @@ static int pwm_fan_probe(struct platform_device *pdev) >>> "pwm-fan", ctx, >>> &pwm_fan_cooling_ops); >>> if (IS_ERR(cdev)) { >>> - dev_err(&pdev->dev, >>> - "Failed to register pwm-fan as cooling device"); >>> ret = PTR_ERR(cdev); >>> + dev_err(&pdev->dev, >>> + "Failed to register pwm-fan as cooling device: %d\n", >>> + ret); >>> goto err_del_timer; >>> } >>> ctx->cdev = cdev; >>> >> >
On 4/11/19 6:30 AM, Stefan Wahren wrote: > Contrary to the gpio-fan the pwm-fan driver isn't easy to setup > with pwmconfig/fancontrol because of the missing hwmon sysfs entry > for actual revolutions per minute. This series adds this feature. > Series applied to hwmon-next. Thanks, Guenter > Changes in V5: > - address Guenter's and Robin's comments: > - use of_property_read_u32 to get pulses-per-revolution > - call platform_get_irq ealier to avoid glitches on the regulator > - simplify pwm_fan_attrs_visible > > Changes in V4: > - remove copy & paste artifact in dt-binding example > - switch to u64 for rpm calculation > - drop overflow handling and init atomic > - handle 0 not as valid irq > - reduce range of pulses_per_revolution > - handle probe defer of platform_get_irq > - delete timer properly in bail-out path > > Changes in V3: > - rename property interrupt-ratio to pulses-per-revolution > to avoid confusion with interrupt binding > - handle error case pulses-per-revolution = 0 > - bail out properly in case we are unable to request the irq > > Changes in V2: > - address Guenter's comments: > - improve description of interrupts > - use atomic_t to avoid races of the pulse counter > - measure sample time to make rpm more reliable under load > - make sysfs entry fan1_input conditional > - add dt-property to define interrupts per fan revolution > - example for fan with RPM support > > Stefan Wahren (3): > dt-bindings: hwmon: Add tachometer interrupt to pwm-fan > Documentation: pwm-fan: Add description for RPM support > hwmon: pwm-fan: Add RPM support via external interrupt > > .../devicetree/bindings/hwmon/pwm-fan.txt | 21 +++- > Documentation/hwmon/pwm-fan | 3 + > drivers/hwmon/pwm-fan.c | 107 ++++++++++++++++++++- > 3 files changed, 126 insertions(+), 5 deletions(-) >