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 <[email protected]> --- 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
