From: Stefan Wahren <stefan.wahren@i2se.com>
To: Kamil Debski <kamil@wypas.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Cc: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
Stefan Wahren <stefan.wahren@i2se.com>
Subject: [PATCH RFC 3/3] hwmon: pwm-fan: Add RPM support via external interrupt
Date: Wed, 30 Jan 2019 16:07:07 +0100 [thread overview]
Message-ID: <1548860827-29796-4-git-send-email-stefan.wahren@i2se.com> (raw)
In-Reply-To: <1548860827-29796-1-git-send-email-stefan.wahren@i2se.com>
This adds RPM support to the pwm-fan driver in order to use with
fancontrol/pwmconfig. This feature is intended for 2 pulse-per-revolution
fans which provides a tachometer output signal.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
drivers/hwmon/pwm-fan.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 9e0591e..731fdc6 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>
@@ -26,13 +27,22 @@
#include <linux/regulator/consumer.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
+#include <linux/timer.h>
#define MAX_PWM 255
+#define SAMPLE_TIME 1 /* seconds */
+#define PULSE_PER_REVOLUTION 2
struct pwm_fan_ctx {
struct mutex lock;
struct pwm_device *pwm;
struct regulator *reg_en;
+
+ int irq;
+ unsigned int pulses;
+ unsigned int rpm;
+ struct timer_list sample_timer;
+
unsigned int pwm_value;
unsigned int pwm_fan_state;
unsigned int pwm_fan_max_state;
@@ -40,6 +50,27 @@ struct pwm_fan_ctx {
struct thermal_cooling_device *cdev;
};
+static irqreturn_t pulse_handler(int irq, void *dev_id)
+{
+ struct pwm_fan_ctx *ctx = dev_id;
+
+ if (ctx->pulses < INT_MAX / 2)
+ ctx->pulses++;
+
+ return IRQ_HANDLED;
+}
+
+static void sample_timer(struct timer_list *t)
+{
+ struct pwm_fan_ctx *ctx = from_timer(ctx, t, sample_timer);
+ unsigned int pulses;
+
+ pulses = ctx->pulses;
+ ctx->pulses -= pulses;
+ ctx->rpm = pulses * 60 / SAMPLE_TIME / PULSE_PER_REVOLUTION;
+ mod_timer(&ctx->sample_timer, jiffies + (HZ * SAMPLE_TIME));
+}
+
static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
unsigned long period;
@@ -100,11 +131,20 @@ 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,
};
@@ -263,6 +303,19 @@ static int pwm_fan_probe(struct platform_device *pdev)
}
}
+ timer_setup(&ctx->sample_timer, sample_timer, 0);
+
+ ctx->irq = platform_get_irq(pdev, 0);
+ 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");
+ return ret;
+ }
+ mod_timer(&ctx->sample_timer, jiffies + (HZ * SAMPLE_TIME));
+ }
+
hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
ctx, pwm_fan_groups);
if (IS_ERR(hwmon)) {
@@ -304,6 +357,8 @@ 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->sample_timer);
+
if (ctx->pwm_value)
pwm_disable(ctx->pwm);
--
2.7.4
next prev parent reply other threads:[~2019-01-30 15:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-30 15:07 [PATCH RFC 0/3] hwmon: pwm-fan: Add RPM support Stefan Wahren
2019-01-30 15:07 ` [PATCH RFC 1/3] dt-bindings: hwmon: Add tachometer interrupt to pwm-fan Stefan Wahren
2019-01-30 17:28 ` Guenter Roeck
2019-01-30 20:23 ` Stefan Wahren
2019-01-30 20:35 ` Guenter Roeck
2019-01-31 8:02 ` Stefan Wahren
2019-01-31 17:19 ` Guenter Roeck
2019-01-30 15:07 ` [PATCH RFC 2/3] Documentation: pwm-fan: Add description for RPM support Stefan Wahren
2019-01-30 15:07 ` Stefan Wahren [this message]
2019-01-31 17:40 ` [PATCH RFC 3/3] hwmon: pwm-fan: Add RPM support via external interrupt Guenter Roeck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1548860827-29796-4-git-send-email-stefan.wahren@i2se.com \
--to=stefan.wahren@i2se.com \
--cc=b.zolnierkie@samsung.com \
--cc=devicetree@vger.kernel.org \
--cc=jdelvare@suse.com \
--cc=kamil@wypas.org \
--cc=linux-hwmon@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=mark.rutland@arm.com \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).