[PATCH v5 1/3] iio: proximity: vcnl3020: add DMA safe buffer

From: Ivan Mikhaylov
Date: Thu Jul 22 2021 - 11:34:46 EST


Add DMA safe buffer for bulk transfers.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@xxxxxxxxx>
---
drivers/iio/proximity/vcnl3020.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/proximity/vcnl3020.c b/drivers/iio/proximity/vcnl3020.c
index 43817f6b3086..c90f9c6e9e97 100644
--- a/drivers/iio/proximity/vcnl3020.c
+++ b/drivers/iio/proximity/vcnl3020.c
@@ -57,12 +57,14 @@ static const int vcnl3020_prox_sampling_frequency[][2] = {
* @dev: vcnl3020 device.
* @rev: revision id.
* @lock: lock for protecting access to device hardware registers.
+ * @buf: DMA safe __be16 buffer.
*/
struct vcnl3020_data {
struct regmap *regmap;
struct device *dev;
u8 rev;
struct mutex lock;
+ __be16 buf ____cacheline_aligned;
};

/**
@@ -144,7 +146,6 @@ static int vcnl3020_measure_proximity(struct vcnl3020_data *data, int *val)
{
int rc;
unsigned int reg;
- __be16 res;

mutex_lock(&data->lock);

@@ -163,12 +164,12 @@ static int vcnl3020_measure_proximity(struct vcnl3020_data *data, int *val)
}

/* high & low result bytes read */
- rc = regmap_bulk_read(data->regmap, VCNL_PS_RESULT_HI, &res,
- sizeof(res));
+ rc = regmap_bulk_read(data->regmap, VCNL_PS_RESULT_HI, &data->buf,
+ sizeof(data->buf));
if (rc)
goto err_unlock;

- *val = be16_to_cpu(res);
+ *val = be16_to_cpu(data->buf);

err_unlock:
mutex_unlock(&data->lock);
--
2.31.1