Commit 01695410 authored by Paul Barker's avatar Paul Barker Committed by Guenter Roeck
Browse files

hwmon: (pwm-fan) Store tach data separately 



The data for the (optional) fan tachometer input is moved to a separate
structure which is only allocated if an input is actually configured.

After this change the pulse IRQ handler takes a pointer to the
tachometer data structure instead of the whole device context.

Signed-off-by: default avatarPaul Barker <pbarker@konsulko.com>
Link: https://lore.kernel.org/r/20201212195008.6036-2-pbarker@konsulko.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 8bfc731e

drivers/hwmon/pwm-fan.c

+32 −20
Original line number Diff line number Diff line
@@ -21,15 +21,19 @@ 


#define MAX_PWM 255



struct pwm_fan_tach {

	int irq;

	atomic_t pulses;

	unsigned int rpm;

	u8 pulses_per_revolution;

};



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;

	struct pwm_fan_tach *tach;

	ktime_t sample_start;

	struct timer_list rpm_timer;
@@ -65,9 +69,9 @@ static const struct hwmon_channel_info pwm_fan_channel_fan = { 
/* 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;

	struct pwm_fan_tach *tach = dev_id;



	atomic_inc(&ctx->pulses);

	atomic_inc(&tach->pulses);



	return IRQ_HANDLED;

}
@@ -75,14 +79,15 @@ static irqreturn_t pulse_handler(int irq, void *dev_id) 
static void sample_timer(struct timer_list *t)

{

	struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);

	struct pwm_fan_tach *tach = ctx->tach;

	unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);

	int pulses;



	if (delta) {

		pulses = atomic_read(&ctx->pulses);

		atomic_sub(pulses, &ctx->pulses);

		ctx->rpm = (unsigned int)(pulses * 1000 * 60) /

			(ctx->pulses_per_revolution * delta);

		pulses = atomic_read(&tach->pulses);

		atomic_sub(pulses, &tach->pulses);

		tach->rpm = (unsigned int)(pulses * 1000 * 60) /

			(tach->pulses_per_revolution * delta);



		ctx->sample_start = ktime_get();

	}
@@ -152,7 +157,7 @@ static int pwm_fan_read(struct device *dev, enum hwmon_sensor_types type, 
		return 0;



	case hwmon_fan:

		*val = ctx->rpm;

		*val = ctx->tach->rpm;

		return 0;



	default:
@@ -372,14 +377,21 @@ static int pwm_fan_probe(struct platform_device *pdev) 
	channels[0] = &pwm_fan_channel_pwm;



	if (tach_count > 0) {

		struct pwm_fan_tach *tach;

		u32 ppr = 2;



		ctx->irq = platform_get_irq(pdev, 0);

		if (ctx->irq == -EPROBE_DEFER)

			return ctx->irq;

		if (ctx->irq > 0) {

			ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,

					       pdev->name, ctx);

		tach = devm_kzalloc(dev, sizeof(struct pwm_fan_tach),

					 GFP_KERNEL);

		if (!tach)

			return -ENOMEM;

		ctx->tach = tach;



		tach->irq = platform_get_irq(pdev, 0);

		if (tach->irq == -EPROBE_DEFER)

			return tach->irq;

		if (tach->irq > 0) {

			ret = devm_request_irq(dev, tach->irq, pulse_handler, 0,

					       pdev->name, tach);

			if (ret) {

				dev_err(dev,

					"Failed to request interrupt: %d\n",
@@ -391,14 +403,14 @@ static int pwm_fan_probe(struct platform_device *pdev) 
		of_property_read_u32(dev->of_node,

				     "pulses-per-revolution",

				     &ppr);

		ctx->pulses_per_revolution = ppr;

		if (!ctx->pulses_per_revolution) {

		tach->pulses_per_revolution = ppr;

		if (!tach->pulses_per_revolution) {

			dev_err(dev, "pulses-per-revolution can't be zero.\n");

			return -EINVAL;

		}



		dev_dbg(dev, "tach: irq=%d, pulses_per_revolution=%d\n",

			ctx->irq, ctx->pulses_per_revolution);

			tach->irq, tach->pulses_per_revolution);



		ctx->sample_start = ktime_get();

		mod_timer(&ctx->rpm_timer, jiffies + HZ);