iio: core: Simplify the registration of kfifo buffers

Among all the users of the kfifo buffers, no one uses the
INDIO_BUFFER_HARDWARE mode. So let's take this as a general rule and
simplify a little bit the internals - overall the documentation - by
eliminating unused specific cases. Use the INDIO_BUFFER_SOFTWARE mode by
default with kfifo buffers, which will basically mimic what all the "non
direct" modes do.

Cc: Benson Leung <[e-mail]>
Cc: Guenter Roeck <[e-mail]>
Cc: Jyoti Bhayana <[e-mail]>
Cc: Jean-Baptiste Maneyrol <[e-mail]>
Cc: Lorenzo Bianconi <[e-mail]>
Cc: Michael Hennerich <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/accel/adxl367.c

···
 		return ret;
 
 	ret = devm_iio_kfifo_buffer_setup_ext(st->dev, indio_dev,
-					      INDIO_BUFFER_SOFTWARE,
 					      &adxl367_buffer_ops,
 					      adxl367_fifo_attributes);
 	if (ret)

drivers/iio/accel/fxls8962af-core.c

···
 			return ret;
 
 		ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
-						  INDIO_BUFFER_SOFTWARE,
 						  &fxls8962af_buffer_ops);
 		if (ret)
 			return ret;

drivers/iio/accel/sca3000.c

···
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	ret = devm_iio_kfifo_buffer_setup(&spi->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &sca3000_ring_setup_ops);
 	if (ret)
 		return ret;

drivers/iio/accel/ssp_accel_sensor.c

···
 	indio_dev->available_scan_masks = ssp_accel_scan_mask;
 
 	ret = devm_iio_kfifo_buffer_setup(&pdev->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &ssp_accel_buffer_ops);
 	if (ret)
 		return ret;

drivers/iio/adc/ina2xx-adc.c

···
 	indio_dev->name = id->name;
 
 	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &ina2xx_setup_ops);
 	if (ret)
 		return ret;

drivers/iio/adc/ti_am335x_adc.c

···
 {
 	int ret;
 
-	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
-					  setup_ops);
+	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev, setup_ops);
 	if (ret)
 		return ret;
 

drivers/iio/buffer/kfifo_buf.c

···
  * devm_iio_kfifo_buffer_setup_ext - Allocate a kfifo buffer & attach it to an IIO device
  * @dev: Device object to which to attach the life-time of this kfifo buffer
  * @indio_dev: The device the buffer should be attached to
- * @mode_flags: The mode flags for this buffer (INDIO_BUFFER_SOFTWARE and/or
- *		INDIO_BUFFER_TRIGGERED).
  * @setup_ops: The setup_ops required to configure the HW part of the buffer (optional)
  * @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer
  *
···
  */
 int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
 				    struct iio_dev *indio_dev,
-				    int mode_flags,
 				    const struct iio_buffer_setup_ops *setup_ops,
 				    const struct attribute **buffer_attrs)
 {
 	struct iio_buffer *buffer;
 
-	if (!mode_flags)
-		return -EINVAL;
-
 	buffer = devm_iio_kfifo_allocate(dev);
 	if (!buffer)
 		return -ENOMEM;
 
-	mode_flags &= kfifo_access_funcs.modes;
-
-	indio_dev->modes |= mode_flags;
+	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
 	indio_dev->setup_ops = setup_ops;
 
 	buffer->attrs = buffer_attrs;

drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c

···
 			 * We can not use trigger here, as events are generated
 			 * as soon as sample_frequency is set.
 			 */
-			ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev,
-							      INDIO_BUFFER_SOFTWARE, NULL,
+			ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev, NULL,
 							      cros_ec_sensor_fifo_attributes);
 			if (ret)
 				return ret;

drivers/iio/common/scmi_sensors/scmi_iio.c

···
 
 		err = devm_iio_kfifo_buffer_setup(&scmi_iio_dev->dev,
 						  scmi_iio_dev,
-						  INDIO_BUFFER_SOFTWARE,
 						  &scmi_iio_buffer_ops);
 		if (err < 0) {
 			dev_err(dev,

drivers/iio/gyro/ssp_gyro_sensor.c

···
 	indio_dev->available_scan_masks = ssp_gyro_scan_mask;
 
 	ret = devm_iio_kfifo_buffer_setup(&pdev->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &ssp_gyro_buffer_ops);
 	if (ret)
 		return ret;

drivers/iio/health/max30100.c

···
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &max30100_buffer_setup_ops);
 	if (ret)
 		return ret;

drivers/iio/health/max30102.c

···
 	}
 
 	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &max30102_buffer_setup_ops);
 	if (ret)
 		return ret;

drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c

···
 	indio_dev->available_scan_masks = inv_icm42600_accel_scan_masks;
 
 	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &inv_icm42600_buffer_ops);
 	if (ret)
 		return ERR_PTR(ret);

drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c

···
 	indio_dev->setup_ops = &inv_icm42600_buffer_ops;
 
 	ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &inv_icm42600_buffer_ops);
 	if (ret)
 		return ERR_PTR(ret);

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

···
 			continue;
 
 		ret = devm_iio_kfifo_buffer_setup(hw->dev, hw->iio_devs[i],
-						  INDIO_BUFFER_SOFTWARE,
 						  &st_lsm6dsx_buffer_ops);
 		if (ret)
 			return ret;

drivers/iio/light/apds9960.c

···
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &apds9960_buffer_setup_ops);
 	if (ret)
 		return ret;

drivers/staging/iio/impedance-analyzer/ad5933.c

···
 	indio_dev->num_channels = ARRAY_SIZE(ad5933_channels);
 
 	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
-					  INDIO_BUFFER_SOFTWARE,
 					  &ad5933_ring_setup_ops);
 	if (ret)
 		return ret;

include/linux/iio/kfifo_buf.h

···
 
 int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
 				    struct iio_dev *indio_dev,
-				    int mode_flags,
 				    const struct iio_buffer_setup_ops *setup_ops,
 				    const struct attribute **buffer_attrs);
 
-#define devm_iio_kfifo_buffer_setup(dev, indio_dev, mode_flags, setup_ops)	\
-	devm_iio_kfifo_buffer_setup_ext((dev), (indio_dev), (mode_flags), (setup_ops), NULL)
+#define devm_iio_kfifo_buffer_setup(dev, indio_dev, setup_ops)	\
+	devm_iio_kfifo_buffer_setup_ext((dev), (indio_dev), (setup_ops), NULL)
 
 #endif