5 files changed, 44 insertions, 10 deletions

diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c
index d4bc114572d..ac254fba551 100644
--- a/drivers/hwmon/pmbus/lm25066.c
+++ b/drivers/hwmon/pmbus/lm25066.c
@@ -161,6 +161,17 @@ static int lm25066_write_word_data(struct i2c_client *client, int page, int reg,
 	return ret;
 }
 
+static int lm25066_write_byte(struct i2c_client *client, int page, u8 value)
+{
+	if (page > 1)
+		return -EINVAL;
+
+	if (page == 0)
+		return pmbus_write_byte(client, 0, value);
+
+	return 0;
+}
+
 static int lm25066_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
@@ -204,6 +215,7 @@ static int lm25066_probe(struct i2c_client *client,
 
 	info->read_word_data = lm25066_read_word_data;
 	info->write_word_data = lm25066_write_word_data;
+	info->write_byte = lm25066_write_byte;
 
 	switch (id->driver_data) {
 	case lm25066:
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index 0808d986d75..a6ae20ffef6 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -325,6 +325,7 @@ struct pmbus_driver_info {
 	int (*read_word_data)(struct i2c_client *client, int page, int reg);
 	int (*write_word_data)(struct i2c_client *client, int page, int reg,
 			       u16 word);
+	int (*write_byte)(struct i2c_client *client, int page, u8 value);
 	/*
 	 * The identify function determines supported PMBus functionality.
 	 * This function is only necessary if a chip driver supports multiple
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 5c1b6cf3170..397fc59b568 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -182,6 +182,24 @@ int pmbus_write_byte(struct i2c_client *client, int page, u8 value)
 }
 EXPORT_SYMBOL_GPL(pmbus_write_byte);
 
+/*
+ * _pmbus_write_byte() is similar to pmbus_write_byte(), but checks if
+ * a device specific mapping funcion exists and calls it if necessary.
+ */
+static int _pmbus_write_byte(struct i2c_client *client, int page, u8 value)
+{
+	struct pmbus_data *data = i2c_get_clientdata(client);
+	const struct pmbus_driver_info *info = data->info;
+	int status;
+
+	if (info->write_byte) {
+		status = info->write_byte(client, page, value);
+		if (status != -ENODATA)
+			return status;
+	}
+	return pmbus_write_byte(client, page, value);
+}
+
 int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word)
 {
 	int rv;
@@ -281,7 +299,7 @@ static int _pmbus_read_byte_data(struct i2c_client *client, int page, int reg)
 
 static void pmbus_clear_fault_page(struct i2c_client *client, int page)
 {
-	pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
+	_pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
 }
 
 void pmbus_clear_faults(struct i2c_client *client)
@@ -960,6 +978,8 @@ static void pmbus_find_max_attr(struct i2c_client *client,
 struct pmbus_limit_attr {
 	u16 reg;		/* Limit register */
 	bool update;		/* True if register needs updates */
+	bool low;		/* True if low limit; for limits with compare
+				   functions only */
 	const char *attr;	/* Attribute name */
 	const char *alarm;	/* Alarm attribute name */
 	u32 sbit;		/* Alarm attribute status bit */
@@ -1011,7 +1031,8 @@ static bool pmbus_add_limit_attrs(struct i2c_client *client,
 				if (attr->compare) {
 					pmbus_add_boolean_cmp(data, name,
 						l->alarm, index,
-						cbase, cindex,
+						l->low ? cindex : cbase,
+						l->low ? cbase : cindex,
 						attr->sbase + page, l->sbit);
 				} else {
 					pmbus_add_boolean_reg(data, name,
@@ -1348,11 +1369,13 @@ static const struct pmbus_sensor_attr power_attributes[] = {
 static const struct pmbus_limit_attr temp_limit_attrs[] = {
 	{
 		.reg = PMBUS_UT_WARN_LIMIT,
+		.low = true,
 		.attr = "min",
 		.alarm = "min_alarm",
 		.sbit = PB_TEMP_UT_WARNING,
 	}, {
 		.reg = PMBUS_UT_FAULT_LIMIT,
+		.low = true,
 		.attr = "lcrit",
 		.alarm = "lcrit_alarm",
 		.sbit = PB_TEMP_UT_FAULT,
@@ -1381,11 +1404,13 @@ static const struct pmbus_limit_attr temp_limit_attrs[] = {
 static const struct pmbus_limit_attr temp_limit_attrs23[] = {
 	{
 		.reg = PMBUS_UT_WARN_LIMIT,
+		.low = true,
 		.attr = "min",
 		.alarm = "min_alarm",
 		.sbit = PB_TEMP_UT_WARNING,
 	}, {
 		.reg = PMBUS_UT_FAULT_LIMIT,
+		.low = true,
 		.attr = "lcrit",
 		.alarm = "lcrit_alarm",
 		.sbit = PB_TEMP_UT_FAULT,
diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index ace1c731973..d0ddb60155c 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -141,13 +141,11 @@ static int ucd9000_probe(struct i2c_client *client,
 	block_buffer[ret] = '\0';
 	dev_info(&client->dev, "Device ID %s\n", block_buffer);
 
-	mid = NULL;
-	for (i = 0; i < ARRAY_SIZE(ucd9000_id); i++) {
-		mid = &ucd9000_id[i];
+	for (mid = ucd9000_id; mid->name[0]; mid++) {
 		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
 			break;
 	}
-	if (!mid || !strlen(mid->name)) {
+	if (!mid->name[0]) {
 		dev_err(&client->dev, "Unsupported device\n");
 		return -ENODEV;
 	}
diff --git a/drivers/hwmon/pmbus/ucd9200.c b/drivers/hwmon/pmbus/ucd9200.c
index ffcc1cf3609..c65e9da707c 100644
--- a/drivers/hwmon/pmbus/ucd9200.c
+++ b/drivers/hwmon/pmbus/ucd9200.c
@@ -68,13 +68,11 @@ static int ucd9200_probe(struct i2c_client *client,
 	block_buffer[ret] = '\0';
 	dev_info(&client->dev, "Device ID %s\n", block_buffer);
 
-	mid = NULL;
-	for (i = 0; i < ARRAY_SIZE(ucd9200_id); i++) {
-		mid = &ucd9200_id[i];
+	for (mid = ucd9200_id; mid->name[0]; mid++) {
 		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
 			break;
 	}
-	if (!mid || !strlen(mid->name)) {
+	if (!mid->name[0]) {
 		dev_err(&client->dev, "Unsupported device\n");
 		return -ENODEV;
 	}