[PATCH v2] hwmon: Consider LM64 temperature offset

From: Dirk Eibach
Date: Wed Feb 09 2011 - 04:51:48 EST


LM64 has 16 degrees Celsius temperature offset on all
remote sensor registers.
This was not considered When LM64 support was added to lm63.c.

Signed-off-by: Dirk Eibach <eibach@xxxxxxxx>
---
Changes since v1:
- avoid calculating offset repeatedly
- gave reasonable names to 8bit temperature accessors
- removed redundant chip id detection
- added comment why temp2_crit cannot be set

drivers/hwmon/lm63.c | 56 +++++++++++++++++++++++++++++++++++++++----------
1 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/drivers/hwmon/lm63.c b/drivers/hwmon/lm63.c
index 776aeb3..2d0cf6d 100644
--- a/drivers/hwmon/lm63.c
+++ b/drivers/hwmon/lm63.c
@@ -98,6 +98,9 @@ static const unsigned short normal_i2c[] = { 0x18, 0x4c, 0x4e, I2C_CLIENT_END };
* value, it uses signed 8-bit values with LSB = 1 degree Celsius.
* For remote temperature, low and high limits, it uses signed 11-bit values
* with LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
+ * For LM64 the actual remote diode temperature is 16 degree Celsius higher
+ * than the register reading. Remote temperature setpoints have to be
+ * adapted accordingly.
*/

#define FAN_FROM_REG(reg) ((reg) == 0xFFFC || (reg) == 0 ? 0 : \
@@ -165,6 +168,8 @@ struct lm63_data {
struct mutex update_lock;
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
+ int kind;
+ int temp2_offset;

/* registers values */
u8 config, config_fan;
@@ -247,16 +252,34 @@ static ssize_t show_pwm1_enable(struct device *dev, struct device_attribute *dum
return sprintf(buf, "%d\n", data->config_fan & 0x20 ? 1 : 2);
}

-static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
- char *buf)
+/*
+ * There are 8bit registers for both local(temp1) and remote(temp2) sensor.
+ * For remote sensor registers temp2_offset has to be considered,
+ * for local sensor it must not.
+ * So we need separate 8bit accessors for local and remote sensor.
+ */
+static ssize_t show_local_temp8(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct lm63_data *data = lm63_update_device(dev);
return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[attr->index]));
}

-static ssize_t set_temp8(struct device *dev, struct device_attribute *dummy,
- const char *buf, size_t count)
+static ssize_t show_remote_temp8(struct device *dev,
+ struct device_attribute *devattr,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ struct lm63_data *data = lm63_update_device(dev);
+ return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[attr->index])
+ + data->temp2_offset);
+}
+
+static ssize_t set_local_temp8(struct device *dev,
+ struct device_attribute *dummy,
+ const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lm63_data *data = i2c_get_clientdata(client);
@@ -274,7 +297,8 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
struct lm63_data *data = lm63_update_device(dev);
- return sprintf(buf, "%d\n", TEMP11_FROM_REG(data->temp11[attr->index]));
+ return sprintf(buf, "%d\n", TEMP11_FROM_REG(data->temp11[attr->index])
+ + data->temp2_offset);
}

static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
@@ -294,7 +318,7 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
int nr = attr->index;

mutex_lock(&data->update_lock);
- data->temp11[nr] = TEMP11_TO_REG(val);
+ data->temp11[nr] = TEMP11_TO_REG(val - data->temp2_offset);
i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
data->temp11[nr] >> 8);
i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
@@ -310,6 +334,7 @@ static ssize_t show_temp2_crit_hyst(struct device *dev, struct device_attribute
{
struct lm63_data *data = lm63_update_device(dev);
return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[2])
+ + data->temp2_offset
- TEMP8_FROM_REG(data->temp2_crit_hyst));
}

@@ -324,7 +349,7 @@ static ssize_t set_temp2_crit_hyst(struct device *dev, struct device_attribute *
long hyst;

mutex_lock(&data->update_lock);
- hyst = TEMP8_FROM_REG(data->temp8[2]) - val;
+ hyst = TEMP8_FROM_REG(data->temp8[2]) + data->temp2_offset - val;
i2c_smbus_write_byte_data(client, LM63_REG_REMOTE_TCRIT_HYST,
HYST_TO_REG(hyst));
mutex_unlock(&data->update_lock);
@@ -355,16 +380,18 @@ static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan,
static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm1, set_pwm1);
static DEVICE_ATTR(pwm1_enable, S_IRUGO, show_pwm1_enable, NULL);

-static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp8, NULL, 0);
-static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
- set_temp8, 1);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_local_temp8, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_local_temp8,
+ set_local_temp8, 1);

static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
set_temp11, 1);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
set_temp11, 2);
-static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp8, NULL, 2);
+/* temp2_crit can only be set once which should be job of the bootloader */
+static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_remote_temp8,
+ NULL, 2);
static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp2_crit_hyst,
set_temp2_crit_hyst);

@@ -479,7 +506,12 @@ static int lm63_probe(struct i2c_client *new_client,
data->valid = 0;
mutex_init(&data->update_lock);

- /* Initialize the LM63 chip */
+ /* Set the device type */
+ data->kind = id->driver_data;
+ if (data->kind == lm64)
+ data->temp2_offset = 16000;
+
+ /* Initialize chip */
lm63_init_client(new_client);

/* Register sysfs hooks */
--
1.5.6.5

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