hwmon: lm95245: implement remote over-temperature shutdown alarm limit

In addition to the critical temperature alarm limit this chip features
a second alarm limit called remote over-temperature shutdown ROS with
a separate pin configurable as trigger output. Implement this feature
and add platform data to allow configuring respective pin as output.

2 files changed, 49 insertions, 1 deletions

diff --git a/drivers/hwmon/lm95245.c b/drivers/hwmon/lm95245.c
index 93862375407d..33c8e35a67be 100644
--- a/drivers/hwmon/lm95245.c
+++ b/drivers/hwmon/lm95245.c
@@ -34,6 +34,8 @@
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
 
+#include <linux/lm95245.h>
+
 #define DEVNAME "lm95245"
 
 static const unsigned short normal_i2c[] = {
@@ -93,6 +95,7 @@ static const unsigned short normal_i2c[] = {
 #define RATE_CR1000	0x02
 #define RATE_CR2500	0x03
 
+#define STATUS1_ROS		0x10
 #define STATUS1_DIODE_FAULT	0x04
 #define STATUS1_RTCRIT		0x02
 #define STATUS1_LOC		0x01
@@ -107,6 +110,7 @@ static const u8 lm95245_reg_address[] = {
 	LM95245_REG_R_REMOTE_TEMPL_S,
 	LM95245_REG_R_REMOTE_TEMPH_U,
 	LM95245_REG_R_REMOTE_TEMPL_U,
+	LM95245_REG_RW_REMOTE_OS_LIMIT,
 	LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
 	LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
 	LM95245_REG_RW_COMMON_HYSTERESIS,
@@ -118,7 +122,8 @@ static const u8 lm95245_reg_address[] = {
 enum {
 	INDEX_LOCAL_TEMP = 0,
 	INDEX_REMOTE_TEMP = 2,
-	INDEX_LOCAL_OS_TCRIT_LIMIT = 6,
+	INDEX_REMOTE_OS_LIMIT = 6,
+	INDEX_LOCAL_OS_TCRIT_LIMIT,
 	INDEX_REMOTE_TCRIT_LIMIT,
 	INDEX_COMMON_HYSTERESIS,
 	INDEX_STATUS1,
@@ -402,10 +407,14 @@ static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
 		STATUS1_LOC);
 
 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, INDEX_REMOTE_TEMP);
+static SENSOR_DEVICE_ATTR(temp2_os, S_IWUSR | S_IRUGO, show_limit,
+		set_limit, INDEX_REMOTE_OS_LIMIT);
 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
 		set_limit, INDEX_REMOTE_TCRIT_LIMIT);
 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
 		set_crit_hyst, INDEX_COMMON_HYSTERESIS);
+static SENSOR_DEVICE_ATTR(temp2_os_alarm, S_IRUGO, show_alarm, NULL,
+		STATUS1_ROS);
 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
 		STATUS1_RTCRIT);
 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
@@ -422,8 +431,10 @@ static struct attribute *lm95245_attributes[] = {
 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_os.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp2_os_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp2_type.dev_attr.attr,
 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
@@ -472,6 +483,13 @@ static void lm95245_init_client(struct i2c_client *client)
 		i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
 			data->config1);
 	}
+
+	/* Configure over-temperature shutdown (OS) output pin */
+	if (client->dev.platform_data && ((struct lm95245_platform_data*)(client->dev.platform_data))->enable_os_pin) {
+		data->config2 |= CFG2_OS_A0;
+		i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
+			data->config2);
+	}
 }
 
 static int lm95245_probe(struct i2c_client *new_client,
diff --git a/include/linux/lm95245.h b/include/linux/lm95245.h
new file mode 100644
index 000000000000..b9290c7708b2
--- /dev/null
+++ b/include/linux/lm95245.h
@@ -0,0 +1,30 @@
+/*
+ * include/linux/lm95245.h
+ *
+ * LM95245, temperature monitoring device from National Semiconductors
+ *
+ * Copyright (c) 2013, Toradex, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef _LINUX_LM95245_H
+#define _LINUX_LM95245_H
+
+struct lm95245_platform_data {
+	bool enable_os_pin;
+};
+
+#endif /* _LINUX_LM95245_H */