diff options
| author | Daniel Golle <daniel@makrotopia.org> | 2016-08-01 12:07:18 +0200 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2016-09-08 21:34:16 -0700 |
| commit | 30fe976fe7a8de2d29c152cdcae207231503d564 (patch) | |
| tree | 7048046f0d1fe1872fc82f0ae3fee4abd2bbee39 /drivers/hwmon | |
| parent | 4f120397fc3f0717d1ffac76d6338e87e13e0e9f (diff) | |
| download | lwn-30fe976fe7a8de2d29c152cdcae207231503d564.tar.gz lwn-30fe976fe7a8de2d29c152cdcae207231503d564.zip | |
hwmon: (ltc4151) Make shunt-resistor configurable
Allow to specify the resistance of the attached shunt via DT by
adding the shunt-resistor property. Fall-back to the previous
default (1 mOhm) if unset.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
[groeck: Fixed 'line over 80 columns' checkpatch warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/ltc4151.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/drivers/hwmon/ltc4151.c b/drivers/hwmon/ltc4151.c index c86a18402496..8445c9fd946b 100644 --- a/drivers/hwmon/ltc4151.c +++ b/drivers/hwmon/ltc4151.c @@ -30,6 +30,7 @@ #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of.h> #include <linux/init.h> #include <linux/err.h> #include <linux/slab.h> @@ -52,6 +53,7 @@ struct ltc4151_data { struct mutex update_lock; bool valid; unsigned long last_updated; /* in jiffies */ + unsigned int shunt; /* in micro ohms */ /* Registers */ u8 regs[6]; @@ -111,9 +113,9 @@ static int ltc4151_get_value(struct ltc4151_data *data, u8 reg) case LTC4151_SENSE_H: /* * 20uV resolution. Convert to current as measured with - * an 1 mOhm sense resistor, in mA. + * a given sense resistor, in mA. */ - val = val * 20; + val = val * 20 * 1000 / data->shunt; break; case LTC4151_VIN_H: /* 25 mV per increment */ @@ -176,6 +178,7 @@ static int ltc4151_probe(struct i2c_client *client, struct device *dev = &client->dev; struct ltc4151_data *data; struct device *hwmon_dev; + u32 shunt; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -ENODEV; @@ -184,6 +187,15 @@ static int ltc4151_probe(struct i2c_client *client, if (!data) return -ENOMEM; + if (of_property_read_u32(client->dev.of_node, + "shunt-resistor-micro-ohms", &shunt)) + shunt = 1000; /* 1 mOhm if not set via DT */ + + if (shunt == 0) + return -EINVAL; + + data->shunt = shunt; + data->client = client; mutex_init(&data->update_lock); @@ -199,10 +211,16 @@ static const struct i2c_device_id ltc4151_id[] = { }; MODULE_DEVICE_TABLE(i2c, ltc4151_id); +static const struct of_device_id ltc4151_match[] = { + { .compatible = "lltc,ltc4151" }, + {}, +}; + /* This is the driver that will be inserted */ static struct i2c_driver ltc4151_driver = { .driver = { .name = "ltc4151", + .of_match_table = of_match_ptr(ltc4151_match), }, .probe = ltc4151_probe, .id_table = ltc4151_id, |