[PATCH V1 1/1] iio: accel: sca3300: Extend the trigger buffer from 16 to 32 bytes

[LI Qingwu]

After added inclination angle channels, the trigger buffer size is
insufficient. Extend the buffer size from 16 to 32 bytes, and change
the trigger buffer from the struct to a u8 array to adapt the sensor
with/without inclination angles output.
New trigger buffer data:
  - SCA3300: 3 accel channels, temp, and timestamp.
  - SCL3300: 3 accel channels, temp, 3 incli channels, and timestamp.
Readjustment the scan index to make it consistent with the buffer data.

Signed-off-by: LI Qingwu <Qing-wu.Li@xxxxxxxxxxxxxxxxxxxxxxx>
---
 drivers/iio/accel/sca3300.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index 3c4827bfef53..820dfb635bf1 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -47,12 +47,20 @@
 #define SCL3300_REG_ANG_CTRL 0x0C
 #define SCL3300_ANG_ENABLE   0x1F
 
+/*
+ * Buffer size max case:
+ * Three accel channels, two bytes per channel.
+ * Temperature channel, two bytes.
+ * Three incli channels, two bytes per channel.
+ * Timestamp channel, eight bytes.
+ */
+#define SCA3300_MAX_BUFFER_SIZE (ALIGN(2 * 7, sizeof(s64)) + sizeof(s64))
+
 enum sca3300_scan_indexes {
 	SCA3300_ACC_X = 0,
 	SCA3300_ACC_Y,
 	SCA3300_ACC_Z,
 	SCA3300_TEMP,
-	SCA3300_TIMESTAMP,
 	SCA3300_INCLI_X,
 	SCA3300_INCLI_Y,
 	SCA3300_INCLI_Z,
@@ -140,10 +148,10 @@ static const struct iio_chan_spec scl3300_channels[] = {
 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y),
 	SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z),
 	SCA3300_TEMP_CHANNEL(SCA3300_TEMP, 0x05),
-	IIO_CHAN_SOFT_TIMESTAMP(4),
 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_X, 0x09, X),
 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Y, 0x0A, Y),
 	SCA3300_INCLI_CHANNEL(SCA3300_INCLI_Z, 0x0B, Z),
+	IIO_CHAN_SOFT_TIMESTAMP(7),
 };
 
 static const unsigned long sca3300_scan_masks[] = {
@@ -184,7 +192,9 @@ struct sca3300_chip_info {
  * @spi: SPI device structure
  * @lock: Data buffer lock
  * @chip: Sensor chip specific information
- * @scan: Triggered buffer. Four channel 16-bit data + 64-bit timestamp
+ * @buffer: Triggered buffer:
+ *          -SCA3300: 4 channel 16-bit data + 64-bit timestamp
+ *          -SCL3300: 7 channel 16-bit data + 64-bit timestamp
  * @txbuf: Transmit buffer
  * @rxbuf: Receive buffer
  */
@@ -192,10 +202,7 @@ struct sca3300_data {
 	struct spi_device *spi;
 	struct mutex lock;
 	const struct sca3300_chip_info *chip;
-	struct {
-		s16 channels[4];
-		s64 ts __aligned(sizeof(s64));
-	} scan;
+	u8 buffer[SCA3300_MAX_BUFFER_SIZE] __aligned(sizeof(s64));
 	u8 txbuf[4] __aligned(IIO_DMA_MINALIGN);
 	u8 rxbuf[4];
 };
@@ -484,21 +491,21 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sca3300_data *data = iio_priv(indio_dev);
 	int bit, ret, val, i = 0;
+	s16 *channels = (s16 *)data->buffer;
 
 	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
-		ret = sca3300_read_reg(data, sca3300_channels[bit].address,
-				       &val);
+		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);
 		if (ret) {
 			dev_err_ratelimited(&data->spi->dev,
 				"failed to read register, error: %d\n", ret);
 			/* handled, but bailing out due to errors */
 			goto out;
 		}
-		data->scan.channels[i++] = val;
+		channels[i++] = val;
 	}
 
-	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
 					   iio_get_time_ns(indio_dev));
 out:
 	iio_trigger_notify_done(indio_dev->trig);
-- 
2.25.1