hwmon: (lm90) Move 16-bit value read to a separate function

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@linux-fr.org>
Acked-by: Martyn Welch <martyn.welch@gefanuc.com>

1 files changed, 43 insertions, 29 deletions

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index c24fe36ac787..73a1c622fb7a 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1,7 +1,7 @@
 /*
  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
- * Copyright (C) 2003-2006  Jean Delvare <khali@linux-fr.org>
+ * Copyright (C) 2003-2008  Jean Delvare <khali@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
@@ -736,6 +736,38 @@ static int lm90_remove(struct i2c_client *client)
         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);
@@ -744,7 +776,7 @@ static struct lm90_data *lm90_update_device(struct device *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]);
@@ -754,39 +786,21 @@ static struct lm90_data *lm90_update_device(struct device *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;
-
-                if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
+                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, &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);