Move the code which aggregates two 8-bit register values into a 16-bit
value to a separate function. We'll need to do it a second time soon and
I don't want to duplicate the code.
Signed-off-by: Jean Delvare <khali at linux-fr.org>
---
drivers/hwmon/lm90.c | 70 ++++++++++++++++++++++++++++++--------------------
1 file changed, 42 insertions(+), 28 deletions(-)
--- linux-2.6.26-rc4.orig/drivers/hwmon/lm90.c 2008-05-27 14:14:56.000000000 +0200
+++ linux-2.6.26-rc4/drivers/hwmon/lm90.c 2008-05-27 21:50:38.000000000 +0200
@@ -1,7 +1,7 @@
/*
* lm90.c - Part of lm_sensors, Linux kernel modules for hardware
* monitoring
- * Copyright (C) 2003-2006 Jean Delvare <khali at linux-fr.org>
+ * Copyright (C) 2003-2008 Jean Delvare <khali at linux-fr.org>
*
* Based on the lm83 driver. The LM90 is a sensor chip made by National
* Semiconductor. It reports up to two temperatures (its own plus up to
@@ -729,6 +729,38 @@ static int lm90_detach_client(struct i2c
return 0;
}
+static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
+{
+ int err;
+ u8 oldh, newh, l;
+
+ /*
+ * There is a trick here. We have to read two registers to have the
+ * sensor temperature, but we have to beware a conversion could occur
+ * inbetween the readings. The datasheet says we should either use
+ * the one-shot conversion register, which we don't want to do
+ * (disables hardware monitoring) or monitor the busy bit, which is
+ * impossible (we can't read the values and monitor that bit at the
+ * exact same time). So the solution used here is to read the high
+ * byte once, then the low byte, then the high byte again. If the new
+ * high byte matches the old one, then we have a valid reading. Else
+ * we have to read the low byte again, and now we believe we have a
+ * correct reading.
+ */
+ if ((err = lm90_read_reg(client, regh, &oldh))
+ || (err = lm90_read_reg(client, regl, &l))
+ || (err = lm90_read_reg(client, regh, &newh)))
+ return err;
+ if (oldh != newh) {
+ err = lm90_read_reg(client, regl, &l);
+ if (err)
+ return err;
+ }
+ *value = (newh << 8) | l;
+
+ return 0;
+}
+
static struct lm90_data *lm90_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
@@ -737,7 +769,7 @@ static struct lm90_data *lm90_update_dev
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
- u8 oldh, newh, l;
+ u8 h, l;
dev_dbg(&client->dev, "Updating lm90 data.\n");
lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
@@ -747,39 +779,21 @@ static struct lm90_data *lm90_update_dev
lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
- /*
- * There is a trick here. We have to read two registers to
- * have the remote sensor temperature, but we have to beware
- * a conversion could occur inbetween the readings. The
- * datasheet says we should either use the one-shot
- * conversion register, which we don't want to do (disables
- * hardware monitoring) or monitor the busy bit, which is
- * impossible (we can't read the values and monitor that bit
- * at the exact same time). So the solution used here is to
- * read the high byte once, then the low byte, then the high
- * byte again. If the new high byte matches the old one,
- * then we have a valid reading. Else we have to read the low
- * byte again, and now we believe we have a correct reading.
- */
- if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
- && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
- && lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
- && (newh == oldh
- || lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
- data->temp11[0] = (newh << 8) | l;
+ lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
+ LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);
- if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
+ if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
- data->temp11[1] = (newh << 8) | l;
- if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
+ data->temp11[1] = (h << 8) | l;
+ if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
- data->temp11[2] = (newh << 8) | l;
+ data->temp11[2] = (h << 8) | l;
if (data->kind != max6657) {
if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
- &newh) == 0
+ &h) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
&l) == 0)
- data->temp11[3] = (newh << 8) | l;
+ data->temp11[3] = (h << 8) | l;
}
lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
--
Jean Delvare
