Code for reading PWM FAN configuration data via device tree.

Signed-off-by: Lukasz Majewski <l.majew...@samsung.com>
---
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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