hwmon: (ntc_thermistor) Support B57330V2103 from EPCOS

This patch adds support for the ntc thermistor B57330V2103 from EPCOS.
Signed-off-by: Johannes Pointner <johannes.pointner@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt

@@ -3,6 +3,7 @@ NTC Thermistor hwmon sensors
 
 Requires node properties:
 - "compatible" value : one of
+	"epcos,b57330v2103"
 	"murata,ncp15wb473"
 	"murata,ncp18wb473"
 	"murata,ncp21wb473"

Documentation/hwmon/ntc_thermistor

@@ -6,6 +6,11 @@ Supported thermistors from Murata:
   Prefixes: 'ncp15wb473', 'ncp18wb473', 'ncp21wb473', 'ncp03wb473', 'ncp15wl333'
   Datasheet: Publicly available at Murata
 
+Supported thermistors from EPCOS:
+* EPCOS NTC Thermistors B57330V2103
+  Prefixes: b57330v2103
+  Datasheet: Publicly available at EPCOS
+
 Other NTC thermistors can be supported simply by adding compensation
 tables; e.g., NCP15WL333 support is added by the table ncpXXwl333.
 

drivers/hwmon/Kconfig

@@ -1073,7 +1073,7 @@ config SENSORS_NTC_THERMISTOR
 
 	  Currently, this driver supports
 	  NCP15WB473, NCP18WB473, NCP21WB473, NCP03WB473, and NCP15WL333
-	  from Murata.
+	  from Murata and B57330V2103 from EPCOS.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called ntc-thermistor.

drivers/hwmon/ntc_thermistor.c

@@ -51,6 +51,7 @@ static const struct platform_device_id ntc_thermistor_id[] = {
 	{ "ncp21wb473", TYPE_NCPXXWB473 },
 	{ "ncp03wb473", TYPE_NCPXXWB473 },
 	{ "ncp15wl333", TYPE_NCPXXWL333 },
+	{ "b57330v2103", TYPE_B57330V2103},
 	{ },
 };
 
@@ -133,6 +134,47 @@ static const struct ntc_compensation ncpXXwl333[] = {
 	{ .temp_c	= 125, .ohm	= 707 },
 };
 
+/*
+ * The following compensation table is from the specification of EPCOS NTC
+ * Thermistors Datasheet
+ */
+static const struct ntc_compensation b57330v2103[] = {
+	{ .temp_c	= -40, .ohm	= 190030 },
+	{ .temp_c	= -35, .ohm	= 145360 },
+	{ .temp_c	= -30, .ohm	= 112060 },
+	{ .temp_c	= -25, .ohm	= 87041 },
+	{ .temp_c	= -20, .ohm	= 68104 },
+	{ .temp_c	= -15, .ohm	= 53665 },
+	{ .temp_c	= -10, .ohm	= 42576 },
+	{ .temp_c	= -5, .ohm	= 34001 },
+	{ .temp_c	= 0, .ohm	= 27326 },
+	{ .temp_c	= 5, .ohm	= 22096 },
+	{ .temp_c	= 10, .ohm	= 17973 },
+	{ .temp_c	= 15, .ohm	= 14703 },
+	{ .temp_c	= 20, .ohm	= 12090 },
+	{ .temp_c	= 25, .ohm	= 10000 },
+	{ .temp_c	= 30, .ohm	= 8311 },
+	{ .temp_c	= 35, .ohm	= 6941 },
+	{ .temp_c	= 40, .ohm	= 5825 },
+	{ .temp_c	= 45, .ohm	= 4911 },
+	{ .temp_c	= 50, .ohm	= 4158 },
+	{ .temp_c	= 55, .ohm	= 3536 },
+	{ .temp_c	= 60, .ohm	= 3019 },
+	{ .temp_c	= 65, .ohm	= 2588 },
+	{ .temp_c	= 70, .ohm	= 2227 },
+	{ .temp_c	= 75, .ohm	= 1924 },
+	{ .temp_c	= 80, .ohm	= 1668 },
+	{ .temp_c	= 85, .ohm	= 1451 },
+	{ .temp_c	= 90, .ohm	= 1266 },
+	{ .temp_c	= 95, .ohm	= 1108 },
+	{ .temp_c	= 100, .ohm	= 973 },
+	{ .temp_c	= 105, .ohm	= 857 },
+	{ .temp_c	= 110, .ohm	= 757 },
+	{ .temp_c	= 115, .ohm	= 671 },
+	{ .temp_c	= 120, .ohm	= 596 },
+	{ .temp_c	= 125, .ohm	= 531 },
+};
+
 struct ntc_data {
 	struct device *hwmon_dev;
 	struct ntc_thermistor_platform_data *pdata;
@@ -173,6 +215,8 @@ static const struct of_device_id ntc_match[] = {
 		.data = &ntc_thermistor_id[3] },
 	{ .compatible = "murata,ncp15wl333",
 		.data = &ntc_thermistor_id[4] },
+	{ .compatible = "epcos,b57330v2103",
+		.data = &ntc_thermistor_id[5]},
 
 	/* Usage of vendor name "ntc" is deprecated */
 	{ .compatible = "ntc,ncp15wb473",
@@ -490,6 +534,10 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
 		data->comp = ncpXXwl333;
 		data->n_comp = ARRAY_SIZE(ncpXXwl333);
 		break;
+	case TYPE_B57330V2103:
+		data->comp = b57330v2103;
+		data->n_comp = ARRAY_SIZE(b57330v2103);
+		break;
 	default:
 		dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
 				pdev_id->driver_data, pdev_id->name);
@@ -546,7 +594,7 @@ static struct platform_driver ntc_thermistor_driver = {
 
 module_platform_driver(ntc_thermistor_driver);
 
-MODULE_DESCRIPTION("NTC Thermistor Driver from Murata");
+MODULE_DESCRIPTION("NTC Thermistor Driver");
 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:ntc-thermistor");

include/linux/platform_data/ntc_thermistor.h

@@ -26,6 +26,7 @@ struct iio_channel;
 enum ntc_thermistor_type {
 	TYPE_NCPXXWB473,
 	TYPE_NCPXXWL333,
+	TYPE_B57330V2103,
 };
 
 struct ntc_thermistor_platform_data {