iio: accel: stk8ba50: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[ Upstream commit 334883894bc1e145a1e0f5de1b0d1b6a1133f0e6 ]

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of this function.

Fixes: db6a19b8251f ("iio: accel: Add trigger support for STK8BA50")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-8-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c
index 3ead378..e8087d7 100644 (file)
--- a/drivers/iio/accel/stk8ba50.c
+++ b/drivers/iio/accel/stk8ba50.c
@@ -91,12 +91,11 @@ struct stk8ba50_data {
        u8 sample_rate_idx;
        struct iio_trigger *dready_trig;
        bool dready_trigger_on;
-       /*
-        * 3 x 16-bit channels (10-bit data, 6-bit padding) +
-        * 1 x 16 padding +
-        * 4 x 16 64-bit timestamp
-        */
-       s16 buffer[8];
+       /* Ensure timestamp is naturally aligned */
+       struct {
+               s16 chans[3];
+               s64 timetamp __aligned(8);
+       } scan;
 };
 
 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {                     \
@@ -324,7 +323,7 @@ static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
                ret = i2c_smbus_read_i2c_block_data(data->client,
                                                    STK8BA50_REG_XOUT,
                                                    STK8BA50_ALL_CHANNEL_SIZE,
-                                                   (u8 *)data->buffer);
+                                                   (u8 *)data->scan.chans);
                if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
                        dev_err(&data->client->dev, "register read failed\n");
                        goto err;
@@ -337,10 +336,10 @@ static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
                        if (ret < 0)
                                goto err;
 
-                       data->buffer[i++] = ret;
+                       data->scan.chans[i++] = ret;
                }
        }
-       iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+       iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
                                           pf->timestamp);
 err:
        mutex_unlock(&data->lock);