From 87c33daadbfea6034830d5494ecaa7521de0cdd3 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 27 May 2010 19:58:46 +0200 Subject: [PATCH] hwmon: (adm1031) Allow setting update rate Based on earlier work by Ira W. Snyder. The adm1031 chip is capable of using a runtime configurable sampling rate, using the fan filter register. Add support for reading and setting the update rate via sysfs. Signed-off-by: Jean Delvare Acked-by: Ira W. Snyder --- drivers/hwmon/adm1031.c | 68 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 66 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/adm1031.c b/drivers/hwmon/adm1031.c index 1644b92e7cc4..15c1a9616af3 100644 --- a/drivers/hwmon/adm1031.c +++ b/drivers/hwmon/adm1031.c @@ -36,6 +36,7 @@ #define ADM1031_REG_FAN_DIV(nr) (0x20 + (nr)) #define ADM1031_REG_PWM (0x22) #define ADM1031_REG_FAN_MIN(nr) (0x10 + (nr)) +#define ADM1031_REG_FAN_FILTER (0x23) #define ADM1031_REG_TEMP_OFFSET(nr) (0x0d + (nr)) #define ADM1031_REG_TEMP_MAX(nr) (0x14 + 4 * (nr)) @@ -61,6 +62,9 @@ #define ADM1031_CONF2_TACH2_ENABLE 0x08 #define ADM1031_CONF2_TEMP_ENABLE(chan) (0x10 << (chan)) +#define ADM1031_UPDATE_RATE_MASK 0x1c +#define ADM1031_UPDATE_RATE_SHIFT 2 + /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END }; @@ -75,6 +79,7 @@ struct adm1031_data { int chip_type; char valid; /* !=0 if following fields are valid */ unsigned long last_updated; /* In jiffies */ + unsigned int update_rate; /* In milliseconds */ /* The chan_select_table contains the possible configurations for * auto fan control. */ @@ -738,6 +743,57 @@ static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 12); static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 13); static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 14); +/* Update Rate */ +static const unsigned int update_rates[] = { + 16000, 8000, 4000, 2000, 1000, 500, 250, 125, +}; + +static ssize_t show_update_rate(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct adm1031_data *data = i2c_get_clientdata(client); + + return sprintf(buf, "%u\n", data->update_rate); +} + +static ssize_t set_update_rate(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct adm1031_data *data = i2c_get_clientdata(client); + unsigned long val; + int i, err; + u8 reg; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + + /* find the nearest update rate from the table */ + for (i = 0; i < ARRAY_SIZE(update_rates) - 1; i++) { + if (val >= update_rates[i]) + break; + } + /* if not found, we point to the last entry (lowest update rate) */ + + /* set the new update rate while preserving other settings */ + reg = adm1031_read_value(client, ADM1031_REG_FAN_FILTER); + reg &= ~ADM1031_UPDATE_RATE_MASK; + reg |= i << ADM1031_UPDATE_RATE_SHIFT; + adm1031_write_value(client, ADM1031_REG_FAN_FILTER, reg); + + mutex_lock(&data->update_lock); + data->update_rate = update_rates[i]; + mutex_unlock(&data->update_lock); + + return count; +} + +static DEVICE_ATTR(update_rate, S_IRUGO | S_IWUSR, show_update_rate, + set_update_rate); + static struct attribute *adm1031_attributes[] = { &sensor_dev_attr_fan1_input.dev_attr.attr, &sensor_dev_attr_fan1_div.dev_attr.attr, @@ -774,6 +830,7 @@ static struct attribute *adm1031_attributes[] = { &sensor_dev_attr_auto_fan1_min_pwm.dev_attr.attr, + &dev_attr_update_rate.attr, &dev_attr_alarms.attr, NULL @@ -900,6 +957,7 @@ static void adm1031_init_client(struct i2c_client *client) { unsigned int read_val; unsigned int mask; + int i; struct adm1031_data *data = i2c_get_clientdata(client); mask = (ADM1031_CONF2_PWM1_ENABLE | ADM1031_CONF2_TACH1_ENABLE); @@ -919,18 +977,24 @@ static void adm1031_init_client(struct i2c_client *client) ADM1031_CONF1_MONITOR_ENABLE); } + /* Read the chip's update rate */ + mask = ADM1031_UPDATE_RATE_MASK; + read_val = adm1031_read_value(client, ADM1031_REG_FAN_FILTER); + i = (read_val & mask) >> ADM1031_UPDATE_RATE_SHIFT; + data->update_rate = update_rates[i]; } static struct adm1031_data *adm1031_update_device(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct adm1031_data *data = i2c_get_clientdata(client); + unsigned long next_update; int chan; mutex_lock(&data->update_lock); - if (time_after(jiffies, data->last_updated + HZ + HZ / 2) - || !data->valid) { + next_update = data->last_updated + msecs_to_jiffies(data->update_rate); + if (time_after(jiffies, next_update) || !data->valid) { dev_dbg(&client->dev, "Starting adm1031 update\n"); for (chan = 0;