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authorMike Looijmans <mike.looijmans@topic.nl>2016-08-22 08:47:51 +0200
committerGuenter Roeck <linux@roeck-us.net>2016-09-08 21:34:17 -0700
commita6cdeefeca47b834109bb13941c699be92c4ff97 (patch)
tree821718a50fee14e934d2b85c963fe4ccaa35b65f /drivers/hwmon
parent88de8e1d43e2a1c591e9fd261d0443826c7bebee (diff)
downloadlinux-a6cdeefeca47b834109bb13941c699be92c4ff97.tar.bz2
hwmon: (max6650) Add devicetree support
Parse devicetree parameters for voltage and prescaler setting. This allows using multiple max6550 devices with varying settings, and also makes it possible to instantiate and configure the device using devicetree. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/max6650.c47
1 files changed, 36 insertions, 11 deletions
diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 162a520f4bd6..c87517aee83a 100644
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -39,6 +39,7 @@
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
+#include <linux/of_device.h>
/*
* Insmod parameters
@@ -48,7 +49,7 @@
static int fan_voltage;
/* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */
static int prescaler;
-/* clock: The clock frequency of the chip the driver should assume */
+/* clock: The clock frequency of the chip (max6651 can be clocked externally) */
static int clock = 254000;
module_param(fan_voltage, int, S_IRUGO);
@@ -133,6 +134,19 @@ static const u8 tach_reg[] = {
MAX6650_REG_TACH3,
};
+static const struct of_device_id max6650_dt_match[] = {
+ {
+ .compatible = "maxim,max6650",
+ .data = (void *)1
+ },
+ {
+ .compatible = "maxim,max6651",
+ .data = (void *)4
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, max6650_dt_match);
+
static struct max6650_data *max6650_update_device(struct device *dev)
{
struct max6650_data *data = dev_get_drvdata(dev);
@@ -566,6 +580,17 @@ static int max6650_init_client(struct max6650_data *data,
struct device *dev = &client->dev;
int config;
int err = -EIO;
+ u32 voltage;
+ u32 prescale;
+
+ if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
+ &voltage))
+ voltage = fan_voltage;
+ else
+ voltage /= 1000000; /* Microvolts to volts */
+ if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
+ &prescale))
+ prescale = prescaler;
config = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
@@ -574,7 +599,7 @@ static int max6650_init_client(struct max6650_data *data,
return err;
}
- switch (fan_voltage) {
+ switch (voltage) {
case 0:
break;
case 5:
@@ -584,14 +609,10 @@ static int max6650_init_client(struct max6650_data *data,
config |= MAX6650_CFG_V12;
break;
default:
- dev_err(dev, "illegal value for fan_voltage (%d)\n",
- fan_voltage);
+ dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
}
- dev_info(dev, "Fan voltage is set to %dV.\n",
- (config & MAX6650_CFG_V12) ? 12 : 5);
-
- switch (prescaler) {
+ switch (prescale) {
case 0:
break;
case 1:
@@ -614,10 +635,11 @@ static int max6650_init_client(struct max6650_data *data,
| MAX6650_CFG_PRESCALER_16;
break;
default:
- dev_err(dev, "illegal value for prescaler (%d)\n", prescaler);
+ dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
}
- dev_info(dev, "Prescaler is set to %d.\n",
+ dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
+ (config & MAX6650_CFG_V12) ? 12 : 5,
1 << (config & MAX6650_CFG_PRESCALER_MASK));
/*
@@ -651,6 +673,8 @@ static int max6650_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
+ const struct of_device_id *of_id =
+ of_match_device(of_match_ptr(max6650_dt_match), dev);
struct max6650_data *data;
struct device *hwmon_dev;
int err;
@@ -661,7 +685,7 @@ static int max6650_probe(struct i2c_client *client,
data->client = client;
mutex_init(&data->update_lock);
- data->nr_fans = id->driver_data;
+ data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
/*
* Initialize the max6650 chip
@@ -691,6 +715,7 @@ MODULE_DEVICE_TABLE(i2c, max6650_id);
static struct i2c_driver max6650_driver = {
.driver = {
.name = "max6650",
+ .of_match_table = of_match_ptr(max6650_dt_match),
},
.probe = max6650_probe,
.id_table = max6650_id,