hwmon: (lm90) Read limit registers only once

Read limit registers only once at startup or after errors to improve
driver performance.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 2a330bd..322a73d 100644 (file)
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -508,6 +508,102 @@ static void lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
        data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
 }
 
+static int lm90_update_limits(struct device *dev)
+{
+       struct lm90_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
+       int val;
+
+       val = lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT);
+       if (val < 0)
+               return val;
+       data->temp8[LOCAL_CRIT] = val;
+
+       val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
+       if (val < 0)
+               return val;
+       data->temp8[REMOTE_CRIT] = val;
+
+       val = lm90_read_reg(client, LM90_REG_R_TCRIT_HYST);
+       if (val < 0)
+               return val;
+       data->temp_hyst = val;
+
+       lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
+       if (val < 0)
+               return val;
+       data->temp11[REMOTE_LOW] = val << 8;
+
+       if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
+               val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL);
+               if (val < 0)
+                       return val;
+               data->temp11[REMOTE_LOW] |= val;
+       }
+
+       val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
+       if (val < 0)
+               return val;
+       data->temp11[REMOTE_HIGH] = val << 8;
+
+       if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
+               val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL);
+               if (val < 0)
+                       return val;
+               data->temp11[REMOTE_HIGH] |= val;
+       }
+
+       if (data->flags & LM90_HAVE_OFFSET) {
+               val = lm90_read16(client, LM90_REG_R_REMOTE_OFFSH,
+                                 LM90_REG_R_REMOTE_OFFSL);
+               if (val < 0)
+                       return val;
+               data->temp11[REMOTE_OFFSET] = val;
+       }
+
+       if (data->flags & LM90_HAVE_EMERGENCY) {
+               val = lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG);
+               if (val < 0)
+                       return val;
+               data->temp8[LOCAL_EMERG] = val;
+
+               val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
+               if (val < 0)
+                       return val;
+               data->temp8[REMOTE_EMERG] = val;
+       }
+
+       if (data->kind == max6696) {
+               val = lm90_select_remote_channel(client, data, 1);
+               if (val < 0)
+                       return val;
+
+               val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
+               if (val < 0)
+                       return val;
+               data->temp8[REMOTE2_CRIT] = val;
+
+               val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
+               if (val < 0)
+                       return val;
+               data->temp8[REMOTE2_EMERG] = val;
+
+               val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
+               if (val < 0)
+                       return val;
+               data->temp11[REMOTE2_LOW] = val << 8;
+
+               val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
+               if (val < 0)
+                       return val;
+               data->temp11[REMOTE2_HIGH] = val << 8;
+
+               lm90_select_remote_channel(client, data, 0);
+       }
+
+       return 0;
+}
+
 static struct lm90_data *lm90_update_device(struct device *dev)
 {
        struct lm90_data *data = dev_get_drvdata(dev);
@@ -517,10 +613,19 @@ static struct lm90_data *lm90_update_device(struct device *dev)
 
        mutex_lock(&data->update_lock);
 
+       if (!data->valid) {
+               val = lm90_update_limits(dev);
+               if (val < 0)
+                       goto error;
+       }
+
        next_update = data->last_updated +
                      msecs_to_jiffies(data->update_interval);
        if (time_after(jiffies, next_update) || !data->valid) {
                dev_dbg(&client->dev, "Updating lm90 data.\n");
+
+               data->valid = 0;
+
                val = lm90_read_reg(client, LM90_REG_R_LOCAL_LOW);
                if (val < 0)
                        goto error;
@@ -531,20 +636,6 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                        goto error;
                data->temp8[LOCAL_HIGH] = val;
 
-               val = lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT);
-               if (val < 0)
-                       goto error;
-               data->temp8[LOCAL_CRIT] = val;
-
-               val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
-               if (val < 0)
-                       goto error;
-               data->temp8[REMOTE_CRIT] = val;
-               val = lm90_read_reg(client, LM90_REG_R_TCRIT_HYST);
-               if (val < 0)
-                       goto error;
-               data->temp_hyst = val;
-
                if (data->reg_local_ext) {
                        val = lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
                                          data->reg_local_ext);
@@ -563,44 +654,6 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                        goto error;
                data->temp11[REMOTE_TEMP] = val;
 
-               lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
-               if (val < 0)
-                       goto error;
-               data->temp11[REMOTE_LOW] = val << 8;
-               if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
-                       val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL);
-                       if (val < 0)
-                               goto error;
-                       data->temp11[REMOTE_LOW] |= val;
-               }
-               val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
-               if (val < 0)
-                       goto error;
-               data->temp11[REMOTE_HIGH] = val << 8;
-               if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
-                       val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL);
-                       if (val < 0)
-                               goto error;
-                       data->temp11[REMOTE_HIGH] |= val;
-               }
-
-               if (data->flags & LM90_HAVE_OFFSET) {
-                       val = lm90_read16(client, LM90_REG_R_REMOTE_OFFSH,
-                                         LM90_REG_R_REMOTE_OFFSL);
-                       if (val < 0)
-                               goto error;
-                       data->temp11[REMOTE_OFFSET] = val;
-               }
-               if (data->flags & LM90_HAVE_EMERGENCY) {
-                       val = lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG);
-                       if (val < 0)
-                               goto error;
-                       data->temp8[LOCAL_EMERG] = val;
-                       val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
-                       if (val < 0)
-                               goto error;
-                       data->temp8[REMOTE_EMERG] = val;
-               }
                val = lm90_read_reg(client, LM90_REG_R_STATUS);
                if (val < 0)
                        goto error;
@@ -611,32 +664,12 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                        if (val < 0)
                                goto error;
 
-                       val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
-                       if (val < 0)
-                               goto error;
-                       data->temp8[REMOTE2_CRIT] = val;
-
-                       val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
-                       if (val < 0)
-                               goto error;
-                       data->temp8[REMOTE2_EMERG] = val;
-
                        val = lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
                                          LM90_REG_R_REMOTE_TEMPL);
                        if (val < 0)
                                goto error;
                        data->temp11[REMOTE2_TEMP] = val;
 
-                       val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
-                       if (val < 0)
-                               goto error;
-                       data->temp11[REMOTE2_LOW] = val << 8;
-
-                       val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
-                       if (val < 0)
-                               goto error;
-                       data->temp11[REMOTE2_HIGH] = val << 8;
-
                        lm90_select_remote_channel(client, data, 0);
 
                        val = lm90_read_reg(client, MAX6696_REG_R_STATUS2);