iio: accell: mma8452: Reduce sleep time when data not ready

Modified the sleep method when data is not ready to allow for sampling > 50sps to work.

Signed-off-by: Richard Tresidder <rtresidd@electromag.com.au>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 7a2da7f9d4dcf33ee6ee28aaf30c9d61e2a455da..7e3d82cff3d5f2537608c0a21d9bf277767e7bd8 100644 (file)
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -106,6 +106,7 @@ struct mma8452_data {
        u8 ctrl_reg1;
        u8 data_cfg;
        const struct mma_chip_info *chip_info;
+       int sleep_val;
 };
 
  /**
@@ -193,7 +194,11 @@ static int mma8452_drdy(struct mma8452_data *data)
                if ((ret & MMA8452_STATUS_DRDY) == MMA8452_STATUS_DRDY)
                        return 0;
 
-               msleep(20);
+               if (data->sleep_val <= 20)
+                       usleep_range(data->sleep_val * 250,
+                                    data->sleep_val * 500);
+               else
+                       msleep(20);
        }
 
        dev_err(&data->client->dev, "data not ready\n");
@@ -544,6 +549,18 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
        return -EINVAL;
 }
 
+static int mma8452_calculate_sleep(struct mma8452_data *data)
+{
+       int ret, i = mma8452_get_odr_index(data);
+
+       if (mma8452_samp_freq[i][0] > 0)
+               ret = 1000 / mma8452_samp_freq[i][0];
+       else
+               ret = 1000;
+
+       return ret == 0 ? 1 : ret;
+}
+
 static int mma8452_standby(struct mma8452_data *data)
 {
        return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
@@ -700,6 +717,8 @@ static int mma8452_write_raw(struct iio_dev *indio_dev,
                data->ctrl_reg1 &= ~MMA8452_CTRL_DR_MASK;
                data->ctrl_reg1 |= i << MMA8452_CTRL_DR_SHIFT;
 
+               data->sleep_val = mma8452_calculate_sleep(data);
+
                ret = mma8452_change_config(data, MMA8452_CTRL_REG1,
                                            data->ctrl_reg1);
                break;
@@ -1593,6 +1612,9 @@ static int mma8452_probe(struct i2c_client *client,
 
        data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
                          (MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
+
+       data->sleep_val = mma8452_calculate_sleep(data);
+
        ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
                                        data->ctrl_reg1);
        if (ret < 0)