hwmon: (mcp3021) improve driver support for newer hwmon interface

This driver is currently broken, it does not show the in0_input sysfs
file and also returns the following message on startup:

hwmon_device_register() is deprecated. Please convert the driver to
use hwmon_device_register_with_info().

This patch converts the driver and also cleans up the 'read' function.

Signed-off-by: Marc Ferland <ferlandm@amotus.ca>
Link: https://lore.kernel.org/r/20220712193504.1374656-1-ferlandm@amotus.ca
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/mcp3021.c b/drivers/hwmon/mcp3021.c
index ce27807..e093b19 100644 (file)
--- a/drivers/hwmon/mcp3021.c
+++ b/drivers/hwmon/mcp3021.c
@@ -7,7 +7,7 @@
  * Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
  * DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
  *
- * This driver export the value of analog input voltage to sysfs, the
+ * This driver exports the value of analog input voltage to sysfs, the
  * voltage unit is mV. Through the sysfs interface, lm-sensors tool
  * can also display the input voltage.
  */
@@ -45,19 +45,29 @@ enum chips {
  * Client data (each client gets its own)
  */
 struct mcp3021_data {
-       struct device *hwmon_dev;
+       struct i2c_client *client;
        u32 vdd;        /* supply and reference voltage in millivolt */
        u16 sar_shift;
        u16 sar_mask;
        u8 output_res;
 };
 
-static int mcp3021_read16(struct i2c_client *client)
+static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
 {
-       struct mcp3021_data *data = i2c_get_clientdata(client);
-       int ret;
-       u16 reg;
+       return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
+}
+
+static int mcp3021_read(struct device *dev, enum hwmon_sensor_types type,
+                       u32 attr, int channel, long *val)
+{
+       struct mcp3021_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
        __be16 buf;
+       u16 reg;
+       int ret;
+
+       if (type != hwmon_in)
+               return -EOPNOTSUPP;
 
        ret = i2c_master_recv(client, (char *)&buf, 2);
        if (ret < 0)
@@ -74,39 +84,46 @@ static int mcp3021_read16(struct i2c_client *client)
         */
        reg = (reg >> data->sar_shift) & data->sar_mask;
 
-       return reg;
-}
+       *val = volts_from_reg(data, reg);
 
-static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
-{
-       return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
+       return 0;
 }
 
-static ssize_t in0_input_show(struct device *dev,
-                             struct device_attribute *attr, char *buf)
+static umode_t mcp3021_is_visible(const void *_data,
+                                 enum hwmon_sensor_types type,
+                                 u32 attr, int channel)
 {
-       struct i2c_client *client = to_i2c_client(dev);
-       struct mcp3021_data *data = i2c_get_clientdata(client);
-       int reg, in_input;
+       if (type != hwmon_in)
+               return 0;
 
-       reg = mcp3021_read16(client);
-       if (reg < 0)
-               return reg;
+       if (attr != hwmon_in_input)
+               return 0;
 
-       in_input = volts_from_reg(data, reg);
-
-       return sprintf(buf, "%d\n", in_input);
+       return 0444;
 }
 
-static DEVICE_ATTR_RO(in0_input);
+static const struct hwmon_channel_info *mcp3021_info[] = {
+       HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
+       NULL
+};
+
+static const struct hwmon_ops mcp3021_hwmon_ops = {
+       .is_visible = mcp3021_is_visible,
+       .read = mcp3021_read,
+};
+
+static const struct hwmon_chip_info mcp3021_chip_info = {
+       .ops = &mcp3021_hwmon_ops,
+       .info = mcp3021_info,
+};
 
 static const struct i2c_device_id mcp3021_id[];
 
 static int mcp3021_probe(struct i2c_client *client)
 {
-       int err;
        struct mcp3021_data *data = NULL;
        struct device_node *np = client->dev.of_node;
+       struct device *hwmon_dev;
 
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
                return -ENODEV;
@@ -147,34 +164,17 @@ static int mcp3021_probe(struct i2c_client *client)
                break;
        }
 
+       data->client = client;
+
        if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN)
                return -EINVAL;
 
-       err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr);
-       if (err)
-               return err;
-
-       data->hwmon_dev = hwmon_device_register(&client->dev);
-       if (IS_ERR(data->hwmon_dev)) {
-               err = PTR_ERR(data->hwmon_dev);
-               goto exit_remove;
-       }
-
-       return 0;
-
-exit_remove:
-       sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
-       return err;
-}
-
-static int mcp3021_remove(struct i2c_client *client)
-{
-       struct mcp3021_data *data = i2c_get_clientdata(client);
-
-       hwmon_device_unregister(data->hwmon_dev);
-       sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
-
-       return 0;
+       hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
+                                                        client->name,
+                                                        data,
+                                                        &mcp3021_chip_info,
+                                                        NULL);
+       return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
 static const struct i2c_device_id mcp3021_id[] = {
@@ -199,7 +199,6 @@ static struct i2c_driver mcp3021_driver = {
                .of_match_table = of_match_ptr(of_mcp3021_match),
        },
        .probe_new = mcp3021_probe,
-       .remove = mcp3021_remove,
        .id_table = mcp3021_id,
 };