iio: proximity: rfd77402: Use kernel helper for result polling

Replace the manually written polling loop with read_poll_timeout(),
the kernel's standard helper for waiting on hardware status.This
makes the code easier to read.

Move the polling logic into a dedicated helper function, as it will
be reused by future updates.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Shrikant Raskar <raskar.shree97@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/proximity/rfd77402.c b/drivers/iio/proximity/rfd77402.c
index 6cae805632a285b956fb375ae2f66e8a6d1072af..3d564366327013779d7e0d01549e24b0075876ba 100644 (file)
--- a/drivers/iio/proximity/rfd77402.c
+++ b/drivers/iio/proximity/rfd77402.c
@@ -12,6 +12,7 @@
 
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 
 #include <linux/iio/iio.h>
@@ -110,10 +111,31 @@ static int rfd77402_set_state(struct i2c_client *client, u8 state, u16 check)
        return 0;
 }
 
-static int rfd77402_measure(struct i2c_client *client)
+static int rfd77402_wait_for_result(struct rfd77402_data *data)
 {
+       struct i2c_client *client = data->client;
+       int val, ret;
+
+       /*
+        * As per RFD77402 datasheet section '3.1.1 Single Measure', the
+        * suggested timeout value for single measure is 100ms.
+        */
+       ret = read_poll_timeout(i2c_smbus_read_byte_data, val,
+                                (val < 0) || (val & RFD77402_ICSR_RESULT),
+                                10 * USEC_PER_MSEC,
+                                10 * 10 * USEC_PER_MSEC,
+                                false,
+                                client, RFD77402_ICSR);
+       if (val < 0)
+               return val;
+
+       return ret;
+}
+
+static int rfd77402_measure(struct rfd77402_data *data)
+{
+       struct i2c_client *client = data->client;
        int ret;
-       int tries = 10;
 
        ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_ON,
                                 RFD77402_STATUS_MCPU_ON);
@@ -126,23 +148,9 @@ static int rfd77402_measure(struct i2c_client *client)
        if (ret < 0)
                goto err;
 
-       while (tries-- > 0) {
-               ret = i2c_smbus_read_byte_data(client, RFD77402_ICSR);
-               if (ret < 0)
-                       goto err;
-               if (ret & RFD77402_ICSR_RESULT)
-                       break;
-               /*
-                * As per RFD77402 datasheet section '3.1.1 Single Measure',
-                * the suggested timeout value for single measure is 100ms.
-                */
-               msleep(10);
-       }
-
-       if (tries < 0) {
-               ret = -ETIMEDOUT;
+       ret = rfd77402_wait_for_result(data);
+       if (ret < 0)
                goto err;
-       }
 
        ret = i2c_smbus_read_word_data(client, RFD77402_RESULT_R);
        if (ret < 0)
@@ -172,7 +180,7 @@ static int rfd77402_read_raw(struct iio_dev *indio_dev,
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                mutex_lock(&data->lock);
-               ret = rfd77402_measure(data->client);
+               ret = rfd77402_measure(data);
                mutex_unlock(&data->lock);
                if (ret < 0)
                        return ret;