[PATCH v2 7/8] hwmon: thermal: Read PWM FAN configuration from device tree

[Lukasz Majewski]

Code for reading PWM FAN configuration data via device tree.

Signed-off-by: Lukasz Majewski <l.majewski@xxxxxxxxxxx>
---
Changes for v2:
- Rename pwm_fan_max_states to pwm_fan_cooling_levels
- Moving pwm_fan_of_get_cooling_data() call after setting end enabling PWM FAN
- pwm_fan_of_get_cooling_data() now can fail - preserving old behaviour
- Remove unnecessary dev_err() call
---
 drivers/hwmon/pwm-fan.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 870e100..8e68308 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -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 +103,47 @@ 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;
+	struct property *pp;
+	int len, num, i;
+
+	pp = of_find_property(np, "cooling-levels", &len);
+	if (!pp) {
+		dev_err(dev, "Property: 'cooling-levels' not found\n");
+		return -EINVAL;
+	}
+
+	if (len == 0) {
+		dev_err(dev, "Length wrong value!\n");
+		return -EINVAL;
+	}
+
+	ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, len, GFP_KERNEL);
+	if (!ctx->pwm_fan_cooling_levels)
+		return -ENOMEM;
+
+	num = len / sizeof(u32);
+	if (of_property_read_u32_array(np, pp->name,
+				       ctx->pwm_fan_cooling_levels, num)) {
+		dev_err(dev, "Property: %s cannot be read!\n", pp->name);
+		return -EINVAL;
+	}
+
+	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 +189,8 @@ static int pwm_fan_probe(struct platform_device *pdev)
 		pwm_disable(ctx->pwm);
 		return PTR_ERR(hwmon);
 	}
+
+	pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
 	return 0;
 }
 
-- 
2.0.0.rc2

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