Commit b5fcb8a4 authored by Paul Barker's avatar Paul Barker Committed by Guenter Roeck
Browse files

hwmon: pwm-fan: Refactor pwm_fan_probe 



Use platform_irq_count to determine the number of fan tachometer inputs
configured in the device tree. At this stage we support either 0 or 1
inputs.

Once we have this information we only need to read the
pulses-per-revolution value if a fan tachometer is actually configured
via an IRQ value.

Also add a debug print of the IRQ number and the pulses-per-revolution
value to aid in investigating issues.

Signed-off-by: default avatarPaul Barker <pbarker@konsulko.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201126174408.755-2-pbarker@konsulko.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 02c155cb

drivers/hwmon/pwm-fan.c

+33 −17
Original line number Diff line number Diff line
@@ -286,7 +286,7 @@ static int pwm_fan_probe(struct platform_device *pdev) 
	struct device *hwmon;

	int ret;

	struct pwm_state state = { };

	u32 ppr = 2;

	int tach_count;



	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);

	if (!ctx)
@@ -300,10 +300,6 @@ static int pwm_fan_probe(struct platform_device *pdev) 


	platform_set_drvdata(pdev, ctx);



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

	if (ctx->irq == -EPROBE_DEFER)

		return ctx->irq;



	ctx->reg_en = devm_regulator_get_optional(dev, "fan");

	if (IS_ERR(ctx->reg_en)) {

		if (PTR_ERR(ctx->reg_en) != -ENODEV)
@@ -339,20 +335,40 @@ static int pwm_fan_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);

	ctx->pulses_per_revolution = ppr;

	if (!ctx->pulses_per_revolution) {

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

		return -EINVAL;

	}

	tach_count = platform_irq_count(pdev);

	if (tach_count < 0)

		return dev_err_probe(dev, tach_count,

				     "Could not get number of fan tachometer inputs\n");



	if (tach_count > 0) {

		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);

			if (ret) {

			dev_err(dev, "Failed to request interrupt: %d\n", ret);

				dev_err(dev,

					"Failed to request interrupt: %d\n",

					ret);

				return ret;

			}

		}



		of_property_read_u32(dev->of_node,

				     "pulses-per-revolution",

				     &ppr);

		ctx->pulses_per_revolution = ppr;

		if (!ctx->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);



		ctx->sample_start = ktime_get();

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

	}