Signed-off-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
---
v3 changes:
- Removed unnecessary constant.
- Improved update interval calculation to avoid rounding error.
drivers/hwmon/lm90.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 93 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 1913f8a..afb7a1e 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 +404,42 @@ 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 <<= 2;
+
+ /* find the nearest update rate */
+ for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 2;
+ 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);
+ /* round the reported interval */
+ data->update_interval = (update_interval + 2) >> 2;
+}
+
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 +874,34 @@ 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 +933,9 @@ 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 +956,7 @@ 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 +1276,19 @@ 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 +1349,9 @@ 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 +1413,8 @@ 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);
--
1.7.3.1
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