[PATCH 2/2] hwmon: (lm75) Support active-high alert polarity

[Markus Stockhausen <markus.stockhausen@gmx.de>]

LM75 devices supported by this driver support configurable active-high
alert polarity. This is already documented in the devicetree description.
Add support for it to the driver.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
---
 drivers/hwmon/lm75.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 8b74cc314196..9542f04e215e 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -123,7 +123,9 @@ struct lm75_data {
 
 static const u8 lm75_sample_set_masks[] = { 0 << 5, 1 << 5, 2 << 5, 3 << 5 };
 
-#define LM75_SAMPLE_CLEAR_MASK	(3 << 5)
+#define LM75_ALERT_POLARITY_HIGH_8_BIT	(BIT(2))
+#define LM75_ALERT_POLARITY_HIGH_16_BIT	(BIT(2) << 8)
+#define LM75_SAMPLE_CLEAR_MASK		(3 << 5)
 
 /* The structure below stores the configuration values of the supported devices.
  * In case of being supported multiple configurations, the default one must
@@ -728,6 +730,7 @@ static int lm75_generic_probe(struct device *dev, const char *name,
 	struct device *hwmon_dev;
 	struct lm75_data *data;
 	int status, err;
+	u16 set_mask;
 
 	data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
 	if (!data)
@@ -762,8 +765,15 @@ static int lm75_generic_probe(struct device *dev, const char *name,
 		return err;
 	data->orig_conf = status;
 
-	err = lm75_write_config(data, data->params->set_mask,
-				data->params->clr_mask);
+	set_mask = data->params->set_mask;
+	if (of_property_read_bool(dev->of_node, "ti,alert-polarity-active-high")) {
+		if (!data->params->config_reg_16bits)
+			set_mask |= LM75_ALERT_POLARITY_HIGH_8_BIT;
+		else
+			set_mask |= LM75_ALERT_POLARITY_HIGH_16_BIT;
+	}
+
+	err = lm75_write_config(data, set_mask, data->params->clr_mask);
 	if (err)
 		return err;
 
-- 
2.54.0