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.
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(-)
--
2.7.4
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 <[email protected]>
---
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);
+ 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
This adds a short description for the new RPM support of the pwm-fan
driver.
Signed-off-by: Stefan Wahren <[email protected]>
---
Documentation/hwmon/pwm-fan | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/hwmon/pwm-fan b/Documentation/hwmon/pwm-fan
index 18529d2..82fe967 100644
--- a/Documentation/hwmon/pwm-fan
+++ b/Documentation/hwmon/pwm-fan
@@ -15,3 +15,6 @@ The driver implements a simple interface for driving a fan connected to
a PWM output. It uses the generic PWM interface, thus it can be used with
a range of SoCs. The driver exposes the fan to the user space through
the hwmon's sysfs interface.
+
+The fan rotation speed returned via the optional 'fan1_input' is extrapolated
+from the sampled interrupts from the tachometer signal within 1 second.
--
2.7.4
This adds the tachometer interrupt to the pwm-fan binding, which is
necessary for RPM support.
Signed-off-by: Stefan Wahren <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
index 49ca5d8..6ced829b 100644
--- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
+++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
@@ -7,7 +7,16 @@ Required properties:
which correspond to thermal cooling states
Optional properties:
-- fan-supply : phandle to the regulator that provides power to the fan
+- fan-supply : phandle to the regulator that provides power to the fan
+- interrupts : This contains a single interrupt specifier which
+ describes the tachometer output of the fan as an
+ interrupt source. The output signal must generate a
+ defined number of interrupts per fan revolution, which
+ require that it must be self resetting edge interrupts.
+ See interrupt-controller/interrupts.txt for the format.
+- pulses-per-revolution : define the tachometer pulses per fan revolution as
+ an integer (default is 2 interrupts per revolution).
+ The value must be greater than zero.
Example:
fan0: pwm-fan {
@@ -38,3 +47,13 @@ Example:
};
};
};
+
+Example 2:
+ fan0: pwm-fan {
+ compatible = "pwm-fan";
+ pwms = <&pwm 0 40000 0>;
+ fan-supply = <®_fan>;
+ interrupt-parent = <&gpio5>;
+ interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
+ pulses-per-revolution = <2>;
+ };
--
2.7.4
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 <[email protected]>
> ---
> 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 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 <[email protected]>
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.
----->8-----
From: Robin Murphy <[email protected]>
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 <[email protected]>
---
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 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
--
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
[email protected] -- +49-151-27565287
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 <[email protected]>
>
> 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 <[email protected]>
> 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 <[email protected]>
> ---
> 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 <[email protected]>
>>
>> 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 <[email protected]>
>> 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 <[email protected]>
>> ---
>> 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 <[email protected]>
>>>
>>> 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 <[email protected]>
>>> 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 <[email protected]>
>>> ---
>>> 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(-)
>