[PATCH 8/9] hwmon: thermal: Provide 'default-pulse-width' property to setup FAN on boot

[Lukasz Majewski]

Up till now the PWM fan was enabled by default in the pwm-fan driver.
Now, by defining 'default-pulse-width' device tree property, it is possible
to configure the fan RPM on boot. By specifying value of 0, one can disable it.

Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx>
---
 drivers/hwmon/pwm-fan.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 97b77e9..c1cf48b 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -34,6 +34,7 @@ struct pwm_fan_ctx {
 	unsigned int pwm_value;
 	unsigned int pwm_fan_state;
 	unsigned int pwm_fan_max_state;
+	unsigned int pwm_fan_default_width;
 	unsigned int *pwm_fan_cooling_states;
 };
 
@@ -172,8 +173,21 @@ static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
 int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
 {
 	struct device_node *np = dev->of_node;
+	int len, num, i, ret;
 	struct property *pp;
-	int len, num, i;
+
+	ret = of_property_read_u32(np, "default-pulse-width",
+				   &ctx->pwm_fan_default_width);
+	if (ret) {
+		dev_err(dev, "Property: 'default-pulse-width' not found\n");
+		return -EINVAL;
+	}
+
+	if (ctx->pwm_fan_default_width > MAX_PWM) {
+		dev_err(dev, "'default-pulse-width %d larger than %d\n",
+			ctx->pwm_fan_default_width, MAX_PWM);
+		return -EINVAL;
+	}
 
 	pp = of_find_property(np, "cooling-pwm-values", &len);
 	if (!pp) {
@@ -217,7 +231,6 @@ static int pwm_fan_probe(struct platform_device *pdev)
 	struct thermal_cooling_device *cdev;
 	struct pwm_fan_ctx *ctx;
 	struct device *hwmon;
-	int duty_cycle;
 	int ret;
 
 	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
@@ -237,22 +250,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	/* Set duty cycle to maximum allowed */
-	duty_cycle = ctx->pwm->period - 1;
-	ctx->pwm_value = MAX_PWM;
-
-	ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to configure PWM\n");
-		return ret;
-	}
-
-	/* Enbale PWM output */
-	ret = pwm_enable(ctx->pwm);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to enable PWM\n");
-		return ret;
-	}
+	__set_pwm(ctx, ctx->pwm_fan_default_width);
 
 	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
 						       ctx, pwm_fan_groups);
-- 
2.0.0.rc2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/