hwmon: (ntc_thermistor) Switch to generic firmware props

This switches to retrieveing the configuration of the NTC
from generic firmware properties so that we get neutral from
device tree: now ACPI or, more importantly, software nodes
can be used to spawn NTC devices provided they have the
required properties.

This was inspired by the similar changes made to the IIO
drivers.

This was tested on the Ux500 HREF with the NTC devices
probing from device tree just as fine after this as before.

Cc: Peter Rosin <peda@axentia.se>
Cc: Chris Lesiak <chris.lesiak@licor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211206020423.62402-2-linus.walleij@linaro.orgSigned-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/ntc_thermistor.c

@@ -9,10 +9,10 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/math64.h>
+#include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/err.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/fixp-arith.h>
 #include <linux/iio/consumer.h>
 #include <linux/hwmon.h>
@@ -595,12 +595,11 @@ static const struct hwmon_chip_info ntc_chip_info = {
 	.info = ntc_info,
 };
 
-static int ntc_thermistor_parse_dt(struct device *dev,
-				   struct ntc_data *data)
+static int ntc_thermistor_parse_props(struct device *dev,
+				      struct ntc_data *data)
 {
 	struct iio_channel *chan;
 	enum iio_chan_type type;
-	struct device_node *np = dev->of_node;
 	int ret;
 
 	chan = devm_iio_channel_get(dev, NULL);
@@ -614,14 +613,19 @@ static int ntc_thermistor_parse_dt(struct device *dev,
 	if (type != IIO_VOLTAGE)
 		return -EINVAL;
 
-	if (of_property_read_u32(np, "pullup-uv", &data->pullup_uv))
-		return -ENODEV;
-	if (of_property_read_u32(np, "pullup-ohm", &data->pullup_ohm))
-		return -ENODEV;
-	if (of_property_read_u32(np, "pulldown-ohm", &data->pulldown_ohm))
-		return -ENODEV;
+	ret = device_property_read_u32(dev, "pullup-uv", &data->pullup_uv);
+	if (ret)
+		return dev_err_probe(dev,  ret, "pullup-uv not specified\n");
+
+	ret = device_property_read_u32(dev, "pullup-ohm", &data->pullup_ohm);
+	if (ret)
+		return dev_err_probe(dev,  ret, "pullup-ohm not specified\n");
+
+	ret = device_property_read_u32(dev, "pulldown-ohm", &data->pulldown_ohm);
+	if (ret)
+		return dev_err_probe(dev,  ret, "pulldown-ohm not specified\n");
 
-	if (of_find_property(np, "connected-positive", NULL))
+	if (device_property_read_bool(dev, "connected-positive"))
 		data->connect = NTC_CONNECTED_POSITIVE;
 	else /* status change should be possible if not always on. */
 		data->connect = NTC_CONNECTED_GROUND;
@@ -634,8 +638,6 @@ static int ntc_thermistor_parse_dt(struct device *dev,
 static int ntc_thermistor_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	const struct of_device_id *of_id =
-			of_match_device(of_match_ptr(ntc_match), dev);
 	const struct platform_device_id *pdev_id;
 	struct device *hwmon_dev;
 	struct ntc_data *data;
@@ -645,7 +647,7 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
-	ret = ntc_thermistor_parse_dt(dev, data);
+	ret = ntc_thermistor_parse_props(dev, data);
 	if (ret)
 		return ret;
 
@@ -660,7 +662,7 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
+	pdev_id = device_get_match_data(dev);
 
 	if (pdev_id->driver_data >= ARRAY_SIZE(ntc_type)) {
 		dev_err(dev, "Unknown device type: %lu(%s)\n",
@@ -688,7 +690,7 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
 static struct platform_driver ntc_thermistor_driver = {
 	.driver = {
 		.name = "ntc-thermistor",
-		.of_match_table = of_match_ptr(ntc_match),
+		.of_match_table = ntc_match,
 	},
 	.probe = ntc_thermistor_probe,
 	.id_table = ntc_thermistor_id,