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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>
This commit is contained in:
Clemens Gruber 2016-11-09 22:22:34 +01:00 committed by Guenter Roeck
parent b502a926d2
commit f4dc811c16
1 changed files with 36 additions and 12 deletions
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48
drivers/hwmon/mcp3021.c
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@ -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,