hwmon: (mcp3021) add devicetree support

Support setting the reference voltage from the device tree.

Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/mcp3021.c b/drivers/hwmon/mcp3021.c
index 7225d24e52aeb3d19b54140e920a32cdf811445d..1929734c3b1d9e52a5c870093acc80fcc44101c0 100644 (file)
--- a/drivers/hwmon/mcp3021.c
+++ b/drivers/hwmon/mcp3021.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
  * Author: Mingkai Hu <Mingkai.hu@freescale.com>
  * 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
  * voltage unit is mV. Through the sysfs interface, lm-sensors tool
@@ -22,11 +23,13 @@
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
-/* Vdd info */
-#define MCP3021_VDD_MAX                5500
-#define MCP3021_VDD_MIN                2700
-#define MCP3021_VDD_REF                3300
+/* Vdd / reference voltage in millivolt */
+#define MCP3021_VDD_REF_MAX    5500
+#define MCP3021_VDD_REF_MIN    2700
+#define MCP3021_VDD_REF_DEFAULT        3300
 
 /* output format */
 #define MCP3021_SAR_SHIFT      2
@@ -47,7 +50,7 @@ enum chips {
  */
 struct mcp3021_data {
        struct device *hwmon_dev;
-       u32 vdd;        /* device power supply */
+       u32 vdd;        /* supply and reference voltage in millivolt */
        u16 sar_shift;
        u16 sar_mask;
        u8 output_res;
@@ -106,6 +109,7 @@ static int mcp3021_probe(struct i2c_client *client,
 {
        int err;
        struct mcp3021_data *data = NULL;
+       struct device_node *np = client->dev.of_node;
 
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
                return -ENODEV;
@@ -117,6 +121,21 @@ static int mcp3021_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, data);
 
+       if (np) {
+               if (!of_property_read_u32(np, "reference-voltage-microvolt",
+                                         &data->vdd))
+                       data->vdd /= 1000;
+               else
+                       data->vdd = MCP3021_VDD_REF_DEFAULT;
+       } else {
+               u32 *pdata = dev_get_platdata(&client->dev);
+
+               if (pdata)
+                       data->vdd = *pdata;
+               else
+                       data->vdd = MCP3021_VDD_REF_DEFAULT;
+       }
+
        switch (id->driver_data) {
        case mcp3021:
                data->sar_shift = MCP3021_SAR_SHIFT;
@@ -131,13 +150,8 @@ static int mcp3021_probe(struct i2c_client *client,
                break;
        }
 
-       if (dev_get_platdata(&client->dev)) {
-               data->vdd = *(u32 *)dev_get_platdata(&client->dev);
-               if (data->vdd > MCP3021_VDD_MAX || data->vdd < MCP3021_VDD_MIN)
-                       return -EINVAL;
-       } else {
-               data->vdd = MCP3021_VDD_REF;
-       }
+       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)
@@ -173,9 +187,19 @@ static const struct i2c_device_id mcp3021_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, mcp3021_id);
 
+#ifdef CONFIG_OF
+static const struct of_device_id of_mcp3021_match[] = {
+       { .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
+       { .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
+       { }
+};
+MODULE_DEVICE_TABLE(of, of_mcp3021_match);
+#endif
+
 static struct i2c_driver mcp3021_driver = {
        .driver = {
                .name = "mcp3021",
+               .of_match_table = of_match_ptr(of_mcp3021_match),
        },
        .probe = mcp3021_probe,
        .remove = mcp3021_remove,