hwmon: (pmbus) Support reading and writing of word registers in device specific code

Some PMBus devices use non-standard registers for some of the sensors and/or
limits. To support such devices, add code to support reading and writing of word
size registers in device specific code.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>

2 files changed, 50 insertions, 6 deletions

diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index cc5b6a23260..d631caeda10 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -286,6 +286,9 @@ struct pmbus_driver_info {
          * necessary.
          */
         int (*read_byte_data)(struct i2c_client *client, int page, int reg);
+        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);
         /*
          * The identify function determines supported PMBus functionality.
          * This function is only necessary if a chip driver supports multiple
@@ -299,6 +302,7 @@ struct pmbus_driver_info {
 
 int pmbus_set_page(struct i2c_client *client, u8 page);
 int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg);
+int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word);
 int pmbus_read_byte_data(struct i2c_client *client, u8 page, u8 reg);
 void pmbus_clear_faults(struct i2c_client *client);
 bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 8ff7ebf5338..29143bf886b 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -175,8 +175,7 @@ static int pmbus_write_byte(struct i2c_client *client, u8 page, u8 value)
         return i2c_smbus_write_byte(client, value);
 }
 
-static int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg,
-                                 u16 word)
+int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word)
 {
         int rv;
 
@@ -186,6 +185,28 @@ static int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg,
 
         return i2c_smbus_write_word_data(client, reg, word);
 }
+EXPORT_SYMBOL_GPL(pmbus_write_word_data);
+
+/*
+ * _pmbus_write_word_data() is similar to pmbus_write_word_data(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_write_word_data(struct i2c_client *client, int page, int reg,
+                                  u16 word)
+{
+        struct pmbus_data *data = i2c_get_clientdata(client);
+        const struct pmbus_driver_info *info = data->info;
+        int status;
+
+        if (info->write_word_data) {
+                status = info->write_word_data(client, page, reg, word);
+                if (status != -ENODATA)
+                        return status;
+        }
+        if (reg >= PMBUS_VIRT_BASE)
+                return -EINVAL;
+        return pmbus_write_word_data(client, page, reg, word);
+}
 
 int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg)
 {
@@ -199,6 +220,24 @@ int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg)
 }
 EXPORT_SYMBOL_GPL(pmbus_read_word_data);
 
+/*
+ * _pmbus_read_word_data() is similar to pmbus_read_word_data(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_read_word_data(struct i2c_client *client, int page, int reg)
+{
+        struct pmbus_data *data = i2c_get_clientdata(client);
+        const struct pmbus_driver_info *info = data->info;
+        int status;
+
+        if (info->read_word_data) {
+                status = info->read_word_data(client, page, reg);
+                if (status != -ENODATA)
+                        return status;
+        }
+        return pmbus_read_word_data(client, page, reg);
+}
+
 int pmbus_read_byte_data(struct i2c_client *client, u8 page, u8 reg)
 {
         int rv;
@@ -275,7 +314,7 @@ EXPORT_SYMBOL_GPL(pmbus_get_driver_info);
 
 /*
  * _pmbus_read_byte_data() is similar to pmbus_read_byte_data(), but checks if
- * a device specific mapping funcion exists and calls it if necessary.
+ * a device specific mapping function exists and calls it if necessary.
  */
 static int _pmbus_read_byte_data(struct i2c_client *client, int page, int reg)
 {
@@ -350,8 +389,9 @@ static struct pmbus_data *pmbus_update_device(struct device *dev)
 
                         if (!data->valid || sensor->update)
                                 sensor->data
-                                    = pmbus_read_word_data(client, sensor->page,
-                                                           sensor->reg);
+                                    = _pmbus_read_word_data(client,
+                                                            sensor->page,
+                                                            sensor->reg);
                 }
                 pmbus_clear_faults(client);
                 data->last_updated = jiffies;
@@ -722,7 +762,7 @@ static ssize_t pmbus_set_sensor(struct device *dev,
 
         mutex_lock(&data->update_lock);
         regval = pmbus_data2reg(data, sensor->class, val);
-        ret = pmbus_write_word_data(client, sensor->page, sensor->reg, regval);
+        ret = _pmbus_write_word_data(client, sensor->page, sensor->reg, regval);
         if (ret < 0)
                 rv = ret;
         else