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Commit 2e5219c7 authored by Lukasz Majewski's avatar Lukasz Majewski Committed by Guenter Roeck
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hwmon: (pwm-fan) Read PWM FAN configuration from device tree 



This patch provides code for reading PWM FAN configuration data via
device tree. The pwm-fan can work with full speed when configuration
is not provided. However, errors are propagated when wrong DT bindings
are found.
Additionally the struct pwm_fan_ctx has been extended.

Signed-off-by: default avatarLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent cb85ca33

drivers/hwmon/pwm-fan.c

+49 −1
Original line number Diff line number Diff line
@@ -30,7 +30,10 @@ 
struct pwm_fan_ctx {

	struct mutex lock;

	struct pwm_device *pwm;

	unsigned char pwm_value;

	unsigned int pwm_value;

	unsigned int pwm_fan_state;

	unsigned int pwm_fan_max_state;

	unsigned int *pwm_fan_cooling_levels;

};



static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
@@ -100,6 +103,46 @@ static struct attribute *pwm_fan_attrs[] = { 


ATTRIBUTE_GROUPS(pwm_fan);



int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)

{

	struct device_node *np = dev->of_node;

	int num, i, ret;



	if (!of_find_property(np, "cooling-levels", NULL))

		return 0;



	ret = of_property_count_u32_elems(np, "cooling-levels");

	if (ret <= 0) {

		dev_err(dev, "Wrong data!\n");

		return ret ? : -EINVAL;

	}



	num = ret;

	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),

						   GFP_KERNEL);

	if (!ctx->pwm_fan_cooling_levels)

		return -ENOMEM;



	ret = of_property_read_u32_array(np, "cooling-levels",

					 ctx->pwm_fan_cooling_levels, num);

	if (ret) {

		dev_err(dev, "Property 'cooling-levels' cannot be read!\n");

		return ret;

	}



	for (i = 0; i < num; i++) {

		if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {

			dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,

				ctx->pwm_fan_cooling_levels[i], MAX_PWM);

			return -EINVAL;

		}

	}



	ctx->pwm_fan_max_state = num - 1;



	return 0;

}



static int pwm_fan_probe(struct platform_device *pdev)

{

	struct device *hwmon;
@@ -145,6 +188,11 @@ static int pwm_fan_probe(struct platform_device *pdev) 
		pwm_disable(ctx->pwm);

		return PTR_ERR(hwmon);

	}



	ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);

	if (ret)

		return ret;



	return 0;

}