From 0c01b644f77a3df892a48a59901997469aeab0a7 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 28 Oct 2010 20:31:44 +0200 Subject: [PATCH] hwmon: (lm90) Add support for update_interval sysfs attribute Signed-off-by: Guenter Roeck Signed-off-by: Jean Delvare --- drivers/hwmon/lm90.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 92 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 1913f8a5d733..f9e76c757de8 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -151,6 +151,9 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680, #define MAX6659_REG_R_LOCAL_EMERG 0x17 #define MAX6659_REG_W_LOCAL_EMERG 0x17 +#define LM90_DEF_CONVRATE_RVAL 6 /* Def conversion rate register value */ +#define LM90_MAX_CONVRATE_MS 16000 /* Maximum conversion rate in ms */ + /* * Device flags */ @@ -197,6 +200,7 @@ struct lm90_params { u32 flags; /* Capabilities */ u16 alert_alarms; /* Which alarm bits trigger ALERT# */ /* Upper 8 bits for max6695/96 */ + u8 max_convrate; /* Maximum conversion rate register value */ }; static const struct lm90_params lm90_params[] = { @@ -204,48 +208,59 @@ static const struct lm90_params lm90_params[] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_BROKEN_ALERT, .alert_alarms = 0x7c, + .max_convrate = 10, }, [adt7461] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_BROKEN_ALERT, .alert_alarms = 0x7c, + .max_convrate = 10, }, [lm86] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT, .alert_alarms = 0x7b, + .max_convrate = 9, }, [lm90] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT, .alert_alarms = 0x7b, + .max_convrate = 9, }, [lm99] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT, .alert_alarms = 0x7b, + .max_convrate = 9, }, [max6646] = { .flags = LM90_HAVE_LOCAL_EXT, .alert_alarms = 0x7c, + .max_convrate = 6, }, [max6657] = { .flags = LM90_HAVE_LOCAL_EXT, .alert_alarms = 0x7c, + .max_convrate = 8, }, [max6659] = { .flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY, .alert_alarms = 0x7c, + .max_convrate = 8, }, [max6680] = { .flags = LM90_HAVE_OFFSET, .alert_alarms = 0x7c, + .max_convrate = 7, }, [max6696] = { .flags = LM90_HAVE_LOCAL_EXT | LM90_HAVE_EMERGENCY | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3, .alert_alarms = 0x187c, + .max_convrate = 6, }, [w83l771] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT, .alert_alarms = 0x7c, + .max_convrate = 8, }, }; @@ -261,9 +276,13 @@ struct lm90_data { int kind; u32 flags; + int update_interval; /* in milliseconds */ + u8 config_orig; /* Original configuration register value */ + u8 convrate_orig; /* Original conversion rate register value */ u16 alert_alarms; /* Which alarm bits trigger ALERT# */ /* Upper 8 bits for max6695/96 */ + u8 max_convrate; /* Maximum conversion rate */ /* registers values */ s8 temp8[8]; /* 0: local low limit @@ -385,15 +404,41 @@ static inline void lm90_select_remote_channel(struct i2c_client *client, } } +/* + * Set conversion rate. + * client->update_lock must be held when calling this function (unless we are + * in detection or initialization steps). + */ +static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data, + unsigned int interval) +{ + int i; + unsigned int update_interval; + + /* Shift calculations to avoid rounding errors */ + interval <<= 6; + + /* find the nearest update rate */ + for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6; + i < data->max_convrate; i++, update_interval >>= 1) + if (interval >= update_interval * 3 / 4) + break; + + i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i); + data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64); +} + static struct lm90_data *lm90_update_device(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct lm90_data *data = i2c_get_clientdata(client); + unsigned long next_update; mutex_lock(&data->update_lock); - if (time_after(jiffies, data->last_updated + HZ / 2 + HZ / 10) - || !data->valid) { + next_update = data->last_updated + + msecs_to_jiffies(data->update_interval) + 1; + if (time_after(jiffies, next_update) || !data->valid) { u8 h, l; u8 alarms; @@ -828,6 +873,34 @@ static ssize_t show_alarm(struct device *dev, struct device_attribute return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1); } +static ssize_t show_update_interval(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lm90_data *data = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", data->update_interval); +} + +static ssize_t set_update_interval(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct lm90_data *data = i2c_get_clientdata(client); + unsigned long val; + int err; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + + mutex_lock(&data->update_lock); + lm90_set_convrate(client, data, val); + mutex_unlock(&data->update_lock); + + return count; +} + static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp11, NULL, 0, 4); static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp11, NULL, 0, 0); static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8, @@ -859,6 +932,9 @@ static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6); /* Raw alarm file for compatibility */ static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); +static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval, + set_update_interval); + static struct attribute *lm90_attributes[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp2_input.dev_attr.attr, @@ -879,6 +955,7 @@ static struct attribute *lm90_attributes[] = { &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, &dev_attr_alarms.attr, + &dev_attr_update_interval.attr, NULL }; @@ -1198,14 +1275,19 @@ static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data) static void lm90_init_client(struct i2c_client *client) { - u8 config; + u8 config, convrate; struct lm90_data *data = i2c_get_clientdata(client); + if (lm90_read_reg(client, LM90_REG_R_CONVRATE, &convrate) < 0) { + dev_warn(&client->dev, "Failed to read convrate register!\n"); + convrate = LM90_DEF_CONVRATE_RVAL; + } + data->convrate_orig = convrate; + /* * Start the conversions. */ - i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, - 5); /* 2 Hz */ + lm90_set_convrate(client, data, 500); /* 500ms; 2Hz conversion rate */ if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) { dev_warn(&client->dev, "Initialization failed!\n"); return; @@ -1266,6 +1348,9 @@ static int lm90_probe(struct i2c_client *new_client, /* Set chip capabilities */ data->flags = lm90_params[data->kind].flags; + /* Set maximum conversion rate */ + data->max_convrate = lm90_params[data->kind].max_convrate; + /* Initialize the LM90 chip */ lm90_init_client(new_client); @@ -1327,6 +1412,8 @@ static int lm90_remove(struct i2c_client *client) lm90_remove_files(client, data); /* Restore initial configuration */ + i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, + data->convrate_orig); i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, data->config_orig); -- 2.11.0