Merge tag 'hwmon-for-linus-v4.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Select CONFIG_BITREVERSE for sht15 driver to avoid build failure if
   it is not configured.

 - Force wait for conversion time for the first valid data in tmp102
   driver to avoid reporting erroneous data to the thermal subsystem.

* tag 'hwmon-for-linus-v4.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (sht15) Select CONFIG_BITREVERSE
  hwmon: (tmp102) Force wait for conversion time for the first valid data

2 files changed, 16 insertions, 1 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8f59f057cdf4..80a73bfc1a65 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1217,6 +1217,7 @@ config SENSORS_PWM_FAN
 config SENSORS_SHT15
         tristate "Sensiron humidity and temperature sensors. SHT15 and compat."
         depends on GPIOLIB || COMPILE_TEST
+        select BITREVERSE
         help
           If you say yes here you get support for the Sensiron SHT10, SHT11,
           SHT15, SHT71, SHT75 humidity and temperature sensors.
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index 65482624ea2c..5289aa0980a8 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -58,6 +58,7 @@ struct tmp102 {
         u16 config_orig;
         unsigned long last_update;
         int temp[3];
+        bool first_time;
 };
 
 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
@@ -93,6 +94,7 @@ static struct tmp102 *tmp102_update_device(struct device *dev)
                                 tmp102->temp[i] = tmp102_reg_to_mC(status);
                 }
                 tmp102->last_update = jiffies;
+                tmp102->first_time = false;
         }
         mutex_unlock(&tmp102->lock);
         return tmp102;
@@ -102,6 +104,12 @@ static int tmp102_read_temp(void *dev, int *temp)
 {
         struct tmp102 *tmp102 = tmp102_update_device(dev);
 
+        /* Is it too early even to return a conversion? */
+        if (tmp102->first_time) {
+                dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
+                return -EAGAIN;
+        }
+
         *temp = tmp102->temp[0];
 
         return 0;
@@ -114,6 +122,10 @@ static ssize_t tmp102_show_temp(struct device *dev,
         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
         struct tmp102 *tmp102 = tmp102_update_device(dev);
 
+        /* Is it too early even to return a read? */
+        if (tmp102->first_time)
+                return -EAGAIN;
+
         return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
 }
 
@@ -207,7 +219,9 @@ static int tmp102_probe(struct i2c_client *client,
                 status = -ENODEV;
                 goto fail_restore_config;
         }
-        tmp102->last_update = jiffies - HZ;
+        tmp102->last_update = jiffies;
+        /* Mark that we are not ready with data until conversion is complete */
+        tmp102->first_time = true;
         mutex_init(&tmp102->lock);
 
         hwmon_dev = hwmon_device_register_with_groups(dev, client->name,