From 2f22d5dff6f95d777c4cb217b99bfdf1fe306128 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 6 Jan 2009 14:41:33 -0800 Subject: adt7470: observe the number of temperature sensors to shorten update time The adt7470 driver currently assumes that 1s is the proper time to wait to read all temperature sensors. However, the correct time is 200ms * number_of_sensors. This patch sets the default time to provide for 10 sensors and then lowers it based on the number of sensor inputs that have nozero values. Signed-off-by: Darrick J. Wong Cc: Jean Delvare Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/hwmon/adt7470.c | 56 ++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 48 insertions(+), 8 deletions(-) diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c index b7a442a80bd..ab8d5ebc9f7 100644 --- a/drivers/hwmon/adt7470.c +++ b/drivers/hwmon/adt7470.c @@ -129,8 +129,8 @@ I2C_CLIENT_INSMOD_1(adt7470); /* How often do we reread sensor limit values? (In jiffies) */ #define LIMIT_REFRESH_INTERVAL (60 * HZ) -/* sleep 1s while gathering temperature data */ -#define TEMP_COLLECTION_TIME 1000 +/* Wait at least 200ms per sensor for 10 sensors */ +#define TEMP_COLLECTION_TIME 2000 /* datasheet says to divide this number by the fan reading to get fan rpm */ #define FAN_PERIOD_TO_RPM(x) ((90000 * 60) / (x)) @@ -147,6 +147,8 @@ struct adt7470_data { unsigned long sensors_last_updated; /* In jiffies */ unsigned long limits_last_updated; /* In jiffies */ + int num_temp_sensors; /* -1 = probe */ + s8 temp[ADT7470_TEMP_COUNT]; s8 temp_min[ADT7470_TEMP_COUNT]; s8 temp_max[ADT7470_TEMP_COUNT]; @@ -256,12 +258,10 @@ static struct adt7470_data *adt7470_update_device(struct device *dev) cfg |= 0x80; i2c_smbus_write_byte_data(client, ADT7470_REG_CFG, cfg); - /* - * Delay is 200ms * number of tmp05 sensors. Too bad - * there's no way to figure out how many are connected. - * For now, assume 1s will work. - */ - msleep(TEMP_COLLECTION_TIME); + /* Delay is 200ms * number of temp sensors. */ + msleep((data->num_temp_sensors >= 0 ? + data->num_temp_sensors * 200 : + TEMP_COLLECTION_TIME)); /* done reading temperature sensors */ cfg = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG); @@ -276,6 +276,12 @@ static struct adt7470_data *adt7470_update_device(struct device *dev) data->temp[i] = i2c_smbus_read_byte_data(client, ADT7470_TEMP_REG(i)); + /* Figure out the number of temp sensors */ + if (data->num_temp_sensors < 0) + for (i = 0; i < ADT7470_TEMP_COUNT; i++) + if (data->temp[i]) + data->num_temp_sensors = i + 1; + for (i = 0; i < ADT7470_FAN_COUNT; i++) data->fan[i] = adt7470_read_word_data(client, ADT7470_REG_FAN(i)); @@ -359,6 +365,35 @@ out: return data; } +static ssize_t show_num_temp_sensors(struct device *dev, + struct device_attribute *devattr, + char *buf) +{ + struct adt7470_data *data = adt7470_update_device(dev); + return sprintf(buf, "%d\n", data->num_temp_sensors); +} + +static ssize_t set_num_temp_sensors(struct device *dev, + struct device_attribute *devattr, + const char *buf, + size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct adt7470_data *data = i2c_get_clientdata(client); + long temp; + + if (strict_strtol(buf, 10, &temp)) + return -EINVAL; + + temp = SENSORS_LIMIT(temp, -1, 10); + + mutex_lock(&data->lock); + data->num_temp_sensors = temp; + mutex_unlock(&data->lock); + + return count; +} + static ssize_t show_temp_min(struct device *dev, struct device_attribute *devattr, char *buf) @@ -825,6 +860,8 @@ static ssize_t show_alarm(struct device *dev, } static DEVICE_ATTR(alarm_mask, S_IRUGO, show_alarm_mask, NULL); +static DEVICE_ATTR(num_temp_sensors, S_IWUSR | S_IRUGO, show_num_temp_sensors, + set_num_temp_sensors); static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max, 0); @@ -997,6 +1034,7 @@ static SENSOR_DEVICE_ATTR(pwm4_auto_channels_temp, S_IWUSR | S_IRUGO, static struct attribute *adt7470_attr[] = { &dev_attr_alarm_mask.attr, + &dev_attr_num_temp_sensors.attr, &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp2_max.dev_attr.attr, &sensor_dev_attr_temp3_max.dev_attr.attr, @@ -1129,6 +1167,8 @@ static int adt7470_probe(struct i2c_client *client, goto exit; } + data->num_temp_sensors = -1; + i2c_set_clientdata(client, data); mutex_init(&data->lock); -- cgit v1.2.3