Commit af959b7b authored by Sean Nyekjaer's avatar Sean Nyekjaer Committed by Jonathan Cameron
Browse files

iio: accel: fxls8962af: fix errata bug E3 - I2C burst reads 



When flushing the hw fifo there is a bug in the I2C that prevents burst
reads of more than one sample pair.

Signed-off-by: default avatarSean Nyekjaer <sean@geanix.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 79e3a5bd

drivers/iio/accel/fxls8962af-core.c

+30 −3
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 


#include <linux/bits.h>

#include <linux/bitfield.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/of_irq.h>

#include <linux/pm_runtime.h>
@@ -623,16 +624,42 @@ static const struct iio_buffer_setup_ops fxls8962af_buffer_ops = { 
	.postdisable = fxls8962af_buffer_postdisable,

};



static int fxls8962af_i2c_raw_read_errata3(struct fxls8962af_data *data,

					   u16 *buffer, int samples,

					   int sample_length)

{

	int i, ret;



	for (i = 0; i < samples; i++) {

		ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB,

				      &buffer[i * 3], sample_length);

		if (ret)

			return ret;

	}



	return ret;

}



static int fxls8962af_fifo_transfer(struct fxls8962af_data *data,

				    u16 *buffer, int samples)

{

	struct device *dev = regmap_get_device(data->regmap);

	int sample_length = 3 * sizeof(*buffer);

	int ret;

	int total_length = samples * sample_length;

	int ret;



	if (i2c_verify_client(dev))

		/*

		 * Due to errata bug:

		 * E3: FIFO burst read operation error using I2C interface

		 * We have to avoid burst reads on I2C..

		 */

		ret = fxls8962af_i2c_raw_read_errata3(data, buffer, samples,

						      sample_length);

	else

		ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer,

				      total_length);



	if (ret)

		dev_err(dev, "Error transferring data from fifo: %d\n", ret);