ENGR00293101 hwmon: mma8451: add sys interface to set sensor scale mode.

mma8451 sensor driver on i.MX6Q/DL SabreSD/AUTO doesn't provide the
interface to set sensor scale. The new sys interface name is "scalemode".
The mode is defined as:
MODE_2G : 0, MODE_4G : 1, MODE_8G : 2

Signed-off-by: Luwei Zhou <b45643@freescale.com>

diff --git a/drivers/hwmon/mxc_mma8451.c b/drivers/hwmon/mxc_mma8451.c
index ddac67dd41a490197576bb8575425327d1cc2574..f4407bc5beba9d1708c210a5d196ba6bf80a97ff 100644 (file)
--- a/drivers/hwmon/mxc_mma8451.c
+++ b/drivers/hwmon/mxc_mma8451.c
@@ -179,14 +179,14 @@ static int mma8451_change_mode(struct i2c_client *client, int mode)
        result = i2c_smbus_write_byte_data(client, MMA8451_CTRL_REG1, 0);
        if (result < 0)
                goto out;
+       mma_status.active = MMA_STANDBY;
 
-       mma_status.mode = mode;
        result = i2c_smbus_write_byte_data(client, MMA8451_XYZ_DATA_CFG,
-                                          mma_status.mode);
+                                          mode);
        if (result < 0)
                goto out;
-       mma_status.active = MMA_STANDBY;
        mdelay(MODE_CHANGE_DELAY_MS);
+       mma_status.mode = mode;
 
        return 0;
 out:
@@ -331,14 +331,74 @@ static ssize_t mma8451_position_store(struct device *dev,
        return count;
 }
 
+static ssize_t mma8451_scalemode_show(struct device *dev,
+                                       struct device_attribute *attr,
+                                       char *buf)
+{
+       int mode = 0;
+       mutex_lock(&mma8451_lock);
+       mode = (int)mma_status.mode;
+       mutex_unlock(&mma8451_lock);
+
+       return sprintf(buf, "%d\n", mode);
+}
+
+static ssize_t mma8451_scalemode_store(struct device *dev,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t count)
+{
+       unsigned long  mode;
+       int ret, active_save;
+       struct i2c_client *client = mma8451_i2c_client;
+
+       ret = strict_strtoul(buf, 10, &mode);
+       if (ret) {
+               dev_err(dev, "string transform error\n");
+               goto out;
+       }
+
+       if (mode > MODE_8G) {
+               dev_warn(dev, "not supported mode\n");
+               ret = count;
+               goto out;
+       }
+
+       mutex_lock(&mma8451_lock);
+       if (mode == mma_status.mode) {
+               ret = count;
+               goto out_unlock;
+       }
+
+       active_save = mma_status.active;
+       ret = mma8451_change_mode(client, mode);
+       if (ret)
+               goto out_unlock;
+
+       if (active_save == MMA_ACTIVED) {
+               ret = i2c_smbus_write_byte_data(client, MMA8451_CTRL_REG1, 1);
+
+               if (ret)
+                       goto out_unlock;
+               mma_status.active = active_save;
+       }
+
+out_unlock:
+       mutex_unlock(&mma8451_lock);
+out:
+       return ret;
+}
+
 static DEVICE_ATTR(enable, S_IWUSR | S_IRUGO,
-                  mma8451_enable_show, mma8451_enable_store);
+                       mma8451_enable_show, mma8451_enable_store);
 static DEVICE_ATTR(position, S_IWUSR | S_IRUGO,
-                  mma8451_position_show, mma8451_position_store);
+                       mma8451_position_show, mma8451_position_store);
+static DEVICE_ATTR(scalemode, S_IWUSR | S_IRUGO,
+                       mma8451_scalemode_show, mma8451_scalemode_store);
 
 static struct attribute *mma8451_attributes[] = {
        &dev_attr_enable.attr,
        &dev_attr_position.attr,
+       &dev_attr_scalemode.attr,
        NULL
 };