staging: iio move scan_elements into ring buffer

tested with sca3000, adis16400

Signed-off-by: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/adis16209_ring.c

@@ -115,11 +115,11 @@ static void adis16209_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16209_state *st
 		= container_of(work_s, struct adis16209_state,
 			       work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -127,19 +127,19 @@ static void adis16209_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16209_read_ring_data(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i] = be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
-					    (u8 *)data,
-					    st->last_timestamp);
+	ring->access.store_to(ring,
+			      (u8 *)data,
+			      st->last_timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -159,19 +159,6 @@ int adis16209_configure_ring(struct iio_dev *indio_dev)
 	struct adis16209_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16209_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_rot.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_aux_adc.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16209_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -182,11 +169,23 @@ int adis16209_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16209_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_rot.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp.number);
+	iio_scan_mask_set(ring, iio_scan_el_aux_adc.number);
+	iio_scan_mask_set(ring, iio_scan_el_incli_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_incli_y.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16209_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/accel/adis16240_ring.c

@@ -107,11 +107,11 @@ static void adis16240_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16240_state *st
 		= container_of(work_s, struct adis16240_state,
 				work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -119,17 +119,17 @@ static void adis16240_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16240_read_ring_data(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i] = be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
+	ring->access.store_to(ring,
 			(u8 *)data,
 			st->last_timestamp);
 
@@ -151,17 +151,6 @@ int adis16240_configure_ring(struct iio_dev *indio_dev)
 	struct adis16240_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16240_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_aux_adc.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16240_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -172,11 +161,21 @@ int adis16240_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16240_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp.number);
+	iio_scan_mask_set(ring, iio_scan_el_aux_adc.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16240_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/accel/lis3l02dq_ring.c

@@ -150,38 +150,40 @@ ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
 	int ret, len = 0, i = 0;
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct iio_ring_buffer *ring = dev_info->ring;
+	struct attribute_group *scan_el_attrs = ring->scan_el_attrs;
 	s16 *data;
 
-	while (dev_info->scan_el_attrs->attrs[i]) {
+	while (scan_el_attrs->attrs[i]) {
 		el = to_iio_scan_el((struct device_attribute *)
-				    (dev_info->scan_el_attrs->attrs[i]));
+				    (scan_el_attrs->attrs[i]));
 		/* label is in fact the address */
 		if (el->label == this_attr->address)
 			break;
 		i++;
 	}
-	if (!dev_info->scan_el_attrs->attrs[i]) {
+	if (!scan_el_attrs->attrs[i]) {
 		ret = -EINVAL;
 		goto error_ret;
 	}
 	/* If this element is in the scan mask */
-	ret = iio_scan_mask_query(dev_info, el->number);
+	ret = iio_scan_mask_query(ring, el->number);
 	if (ret < 0)
 		goto error_ret;
 	if (ret) {
-		data = kmalloc(dev_info->ring->access.get_bytes_per_datum(dev_info->ring),
+		data = kmalloc(ring->access.get_bytes_per_datum(ring),
 			       GFP_KERNEL);
 		if (data == NULL)
 			return -ENOMEM;
-		ret = dev_info->ring->access.read_last(dev_info->ring,
-						      (u8 *)data);
+		ret = ring->access.read_last(ring,
+					(u8 *)data);
 		if (ret)
 			goto error_free_data;
 	} else {
 		ret = -EINVAL;
 		goto error_ret;
 	}
-	len = iio_scan_mask_count_to_right(dev_info, el->number);
+	len = iio_scan_mask_count_to_right(ring, el->number);
 	if (len < 0) {
 		ret = len;
 		goto error_free_data;
@@ -211,11 +213,12 @@ static const u8 read_all_tx_array[] = {
  **/
 static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
 {
+	struct iio_ring_buffer *ring = st->help.indio_dev->ring;
 	struct spi_transfer *xfers;
 	struct spi_message msg;
 	int ret, i, j = 0;
 
-	xfers = kzalloc((st->help.indio_dev->scan_count) * 2
+	xfers = kzalloc((ring->scan_count) * 2
 			* sizeof(*xfers), GFP_KERNEL);
 	if (!xfers)
 		return -ENOMEM;
@@ -223,7 +226,7 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
 	mutex_lock(&st->buf_lock);
 
 	for (i = 0; i < ARRAY_SIZE(read_all_tx_array)/4; i++) {
-		if (st->help.indio_dev->scan_mask & (1 << i)) {
+		if (ring->scan_mask & (1 << i)) {
 			/* lower byte */
 			xfers[j].tx_buf = st->tx + 2*j;
 			st->tx[2*j] = read_all_tx_array[i*4];
@@ -251,7 +254,7 @@ static int lis3l02dq_read_all(struct lis3l02dq_state *st, u8 *rx_array)
 	 * values in alternate bytes
 	 */
 	spi_message_init(&msg);
-	for (j = 0; j < st->help.indio_dev->scan_count * 2; j++)
+	for (j = 0; j < ring->scan_count * 2; j++)
 		spi_message_add_tail(&xfers[j], &msg);
 
 	ret = spi_sync(st->us, &msg);
@@ -279,13 +282,13 @@ static int lis3l02dq_get_ring_element(struct iio_sw_ring_helper_state *h,
 	u8 *rx_array ;
 	s16 *data = (s16 *)buf;
 
-	rx_array = kzalloc(4 * (h->indio_dev->scan_count), GFP_KERNEL);
+	rx_array = kzalloc(4 * (h->indio_dev->ring->scan_count), GFP_KERNEL);
 	if (rx_array == NULL)
 		return -ENOMEM;
 	ret = lis3l02dq_read_all(lis3l02dq_h_to_s(h), rx_array);
 	if (ret < 0)
 		return ret;
-	for (i = 0; i < h->indio_dev->scan_count; i++)
+	for (i = 0; i < h->indio_dev->ring->scan_count; i++)
 		data[i] = combine_8_to_16(rx_array[i*4+1],
 					rx_array[i*4+3]);
 	kfree(rx_array);
@@ -481,14 +484,7 @@ int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 	struct iio_sw_ring_helper_state *h = iio_dev_get_devdata(indio_dev);
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&h->work_trigger_to_ring, lis3l02dq_trigger_bh_to_ring);
-	/* Set default scan mode */
 	h->get_ring_element = &lis3l02dq_get_ring_element;
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &lis3l02dq_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring)
@@ -498,11 +494,18 @@ int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &lis3l02dq_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &lis3l02dq_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;;

drivers/staging/iio/accel/sca3000_ring.c

@@ -264,12 +264,12 @@ static inline void sca3000_rb_free(struct iio_ring_buffer *r)
 
 int sca3000_configure_ring(struct iio_dev *indio_dev)
 {
-	indio_dev->scan_el_attrs = &sca3000_scan_el_group;
 	indio_dev->ring = sca3000_rb_allocate(indio_dev);
 	if (indio_dev->ring == NULL)
 		return -ENOMEM;
 	indio_dev->modes |= INDIO_RING_HARDWARE_BUFFER;
 
+	indio_dev->ring->scan_el_attrs = &sca3000_scan_el_group;
 	indio_dev->ring->access.rip_lots = &sca3000_rip_hw_rb;
 	indio_dev->ring->access.get_length = &sca3000_ring_get_length;
 	indio_dev->ring->access.get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum;

drivers/staging/iio/adc/max1363_core.c

@@ -1631,7 +1631,6 @@ static int __devinit max1363_probe(struct i2c_client *client,
 	st->indio_dev->attrs = st->chip_info->dev_attrs;
 
 	/* Todo: this shouldn't be here. */
-	st->indio_dev->scan_el_attrs = st->chip_info->scan_attrs;
 	st->indio_dev->dev_data = (void *)(st);
 	st->indio_dev->driver_module = THIS_MODULE;
 	st->indio_dev->modes = INDIO_DIRECT_MODE;

drivers/staging/iio/adc/max1363_ring.c

@@ -30,6 +30,7 @@
 /* Todo: test this */
 int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
 {
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 	unsigned long numvals;
 	int count = 0, ret;
 	u8 *ring_data;
@@ -44,8 +45,7 @@ int max1363_single_channel_from_ring(long mask, struct max1363_state *st)
 		ret = -ENOMEM;
 		goto error_ret;
 	}
-	ret = st->indio_dev->ring->access.read_last(st->indio_dev->ring,
-						ring_data);
+	ret = ring->access.read_last(ring, ring_data);
 	if (ret)
 		goto error_free_ring_data;
 	/* Need a count of channels prior to this one */
@@ -77,6 +77,7 @@ error_ret:
 static int max1363_ring_preenable(struct iio_dev *indio_dev)
 {
 	struct max1363_state *st = indio_dev->dev_data;
+	struct iio_ring_buffer *ring = indio_dev->ring;
 	size_t d_size;
 	unsigned long numvals;
 
@@ -84,7 +85,7 @@ static int max1363_ring_preenable(struct iio_dev *indio_dev)
 	 * Need to figure out the current mode based upon the requested
 	 * scan mask in iio_dev
 	 */
-	st->current_mode = max1363_match_mode(st->indio_dev->scan_mask,
+	st->current_mode = max1363_match_mode(ring->scan_mask,
 					st->chip_info);
 	if (!st->current_mode)
 		return -EINVAL;
@@ -92,14 +93,14 @@ static int max1363_ring_preenable(struct iio_dev *indio_dev)
 	max1363_set_scan_mode(st);
 
 	numvals = hweight_long(st->current_mode->modemask);
-	if (indio_dev->ring->access.set_bytes_per_datum) {
+	if (ring->access.set_bytes_per_datum) {
 		if (st->chip_info->bits != 8)
 			d_size = numvals*2 + sizeof(s64);
 		else
 			d_size = numvals + sizeof(s64);
 		if (d_size % 8)
 			d_size += 8 - (d_size % 8);
-		indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring, d_size);
+		ring->access.set_bytes_per_datum(ring, d_size);
 	}
 
 	return 0;
@@ -135,7 +136,7 @@ static void max1363_poll_bh_to_ring(struct work_struct *work_s)
 	struct max1363_state *st = container_of(work_s, struct max1363_state,
 						  poll_work);
 	struct iio_dev *indio_dev = st->indio_dev;
-	struct iio_sw_ring_buffer *ring = iio_to_sw_ring(indio_dev->ring);
+	struct iio_sw_ring_buffer *sw_ring = iio_to_sw_ring(indio_dev->ring);
 	s64 time_ns;
 	__u8 *rxbuf;
 	int b_sent;
@@ -175,7 +176,7 @@ static void max1363_poll_bh_to_ring(struct work_struct *work_s)
 
 	memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
 
-	indio_dev->ring->access.store_to(&ring->buf, rxbuf, time_ns);
+	indio_dev->ring->access.store_to(&sw_ring->buf, rxbuf, time_ns);
 done:
 	kfree(rxbuf);
 	atomic_dec(&st->protect_ring);
@@ -193,12 +194,13 @@ int max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 		goto error_ret;
 	}
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&st->indio_dev->ring->access);
+	iio_ring_sw_register_funcs(&indio_dev->ring->access);
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &max1363_poll_func_th);
 	if (ret)
 		goto error_deallocate_sw_rb;
 
 	/* Ring buffer functions - here trigger setup related */
+	indio_dev->ring->scan_el_attrs = st->chip_info->scan_attrs;
 	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
 	indio_dev->ring->preenable = &max1363_ring_preenable;
 	indio_dev->ring->predisable = &iio_triggered_ring_predisable;

drivers/staging/iio/gyro/adis16260_ring.c

@@ -110,11 +110,11 @@ static void adis16260_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16260_state *st
 		= container_of(work_s, struct adis16260_state,
 				work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -122,17 +122,17 @@ static void adis16260_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16260_read_ring_data(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i] = be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
+	ring->access.store_to(ring,
 			(u8 *)data,
 			st->last_timestamp);
 
@@ -154,16 +154,6 @@ int adis16260_configure_ring(struct iio_dev *indio_dev)
 	struct adis16260_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16260_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_aux_adc.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_angl.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16260_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -174,11 +164,20 @@ int adis16260_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16260_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro.number);
+	iio_scan_mask_set(ring, iio_scan_el_aux_adc.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp.number);
+	iio_scan_mask_set(ring, iio_scan_el_angl.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16260_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/iio.h

@@ -90,12 +90,7 @@ void iio_remove_event_from_list(struct iio_event_handler_list *el,
  * @ring:		[DRIVER] any ring buffer present
  * @mlock:		[INTERN] lock used to prevent simultaneous device state
  *			changes
- * @scan_el_attrs:	[DRIVER] control of scan elements if that scan mode
- *			control method is used
- * @scan_count:	[INTERN] the number of elements in the current scan mode
- * @scan_mask:		[INTERN] bitmask used in masking scan mode elements
  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
- * @scan_timestamp:	[INTERN] does the scan mode include a timestamp
  * @trig:		[INTERN] current device trigger (ring buffer modes)
  * @pollfunc:		[DRIVER] function run on trigger being recieved
  **/
@@ -118,104 +113,11 @@ struct iio_dev {
 	struct iio_ring_buffer		*ring;
 	struct mutex			mlock;
 
-	struct attribute_group		*scan_el_attrs;
-	int				scan_count;
-
-	u32				scan_mask;
 	u32				*available_scan_masks;
-	bool				scan_timestamp;
 	struct iio_trigger		*trig;
 	struct iio_poll_func		*pollfunc;
 };
 
-/*
- * These are mainly provided to allow for a change of implementation if a device
- * has a large number of scan elements
- */
-#define IIO_MAX_SCAN_LENGTH 31
-
-/* note 0 used as error indicator as it doesn't make sense. */
-static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
-{
-	while (*av_masks) {
-		if (!(~*av_masks & mask))
-			return *av_masks;
-		av_masks++;
-	}
-	return 0;
-}
-
-static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
-{
-	u32 mask;
-
-	if (bit > IIO_MAX_SCAN_LENGTH)
-		return -EINVAL;
-
-	if (!dev_info->scan_mask)
-		return 0;
-
-	if (dev_info->available_scan_masks)
-		mask = iio_scan_mask_match(dev_info->available_scan_masks,
-					dev_info->scan_mask);
-	else
-		mask = dev_info->scan_mask;
-
-	if (!mask)
-		return -EINVAL;
-
-	return !!(mask & (1 << bit));
-};
-
-static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
-{
-	u32 mask;
-	u32 trialmask = dev_info->scan_mask | (1 << bit);
-
-	if (bit > IIO_MAX_SCAN_LENGTH)
-		return -EINVAL;
-	if (dev_info->available_scan_masks) {
-		mask = iio_scan_mask_match(dev_info->available_scan_masks,
-					trialmask);
-		if (!mask)
-			return -EINVAL;
-	}
-	dev_info->scan_mask = trialmask;
-	dev_info->scan_count++;
-
-	return 0;
-};
-
-static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
-{
-	if (bit > IIO_MAX_SCAN_LENGTH)
-		return -EINVAL;
-	dev_info->scan_mask &= ~(1 << bit);
-	dev_info->scan_count--;
-	return 0;
-};
-
-/**
- * iio_scan_mask_count_to_right() - how many scan elements occur before here
- * @dev_info: the iio_device whose scan mode we are querying
- * @bit: which number scan element is this
- **/
-static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
-						int bit)
-{
-	int count = 0;
-	int mask = (1 << bit);
-	if (bit > IIO_MAX_SCAN_LENGTH)
-		return -EINVAL;
-	while (mask) {
-		mask >>= 1;
-		if (mask & dev_info->scan_mask)
-			count++;
-	}
-
-	return count;
-}
-
 /**
  * iio_device_register() - register a device with the IIO subsystem
  * @dev_info:		Device structure filled by the device driver

drivers/staging/iio/imu/adis16300_ring.c

@@ -134,11 +134,11 @@ static void adis16300_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16300_state *st
 		= container_of(work_s, struct adis16300_state,
 			       work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -146,19 +146,19 @@ static void adis16300_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16300_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i] = be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
-					    (u8 *)data,
-					    st->last_timestamp);
+	ring->access.store_to(ring,
+			(u8 *)data,
+			st->last_timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -178,20 +178,6 @@ int adis16300_configure_ring(struct iio_dev *indio_dev)
 	struct adis16300_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16300_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_incli_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_incli_y.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16300_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -202,11 +188,24 @@ int adis16300_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16300_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp.number);
+	iio_scan_mask_set(ring, iio_scan_el_adc_0.number);
+	iio_scan_mask_set(ring, iio_scan_el_incli_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_incli_y.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16300_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/imu/adis16350_ring.c

@@ -134,11 +134,11 @@ static void adis16350_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16350_state *st
 		= container_of(work_s, struct adis16350_state,
 			       work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -146,19 +146,19 @@ static void adis16350_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16350_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i] = be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
-					    (u8 *)data,
-					    st->last_timestamp);
+	ring->access.store_to(ring,
+			(u8 *)data,
+			st->last_timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -178,22 +178,6 @@ int adis16350_configure_ring(struct iio_dev *indio_dev)
 	struct adis16350_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16350_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16350_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -204,11 +188,26 @@ int adis16350_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16350_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_adc_0.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16350_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/imu/adis16400_ring.c

@@ -143,11 +143,11 @@ static void adis16400_trigger_bh_to_ring(struct work_struct *work_s)
 	struct adis16400_state *st
 		= container_of(work_s, struct adis16400_state,
 			       work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -155,19 +155,19 @@ static void adis16400_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		if (adis16400_spi_read_burst(&st->indio_dev->dev, st->rx) >= 0)
-			for (; i < st->indio_dev->scan_count; i++)
+			for (; i < ring->scan_count; i++)
 				data[i]	= be16_to_cpup(
 					(__be16 *)&(st->rx[i*2]));
 
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = st->last_timestamp;
 
-	st->indio_dev->ring->access.store_to(st->indio_dev->ring,
-					    (u8 *)data,
-					    st->last_timestamp);
+	ring->access.store_to(ring,
+			(u8 *) data,
+			st->last_timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -187,23 +187,6 @@ int adis16400_configure_ring(struct iio_dev *indio_dev)
 	struct adis16400_state *st = indio_dev->dev_data;
 	struct iio_ring_buffer *ring;
 	INIT_WORK(&st->work_trigger_to_ring, adis16400_trigger_bh_to_ring);
-	/* Set default scan mode */
-
-	iio_scan_mask_set(indio_dev, iio_scan_el_supply.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_gyro_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_accel_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_magn_x.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_magn_y.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_magn_z.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_temp.number);
-	iio_scan_mask_set(indio_dev, iio_scan_el_adc_0.number);
-	indio_dev->scan_timestamp = true;
-
-	indio_dev->scan_el_attrs = &adis16400_scan_el_group;
 
 	ring = iio_sw_rb_allocate(indio_dev);
 	if (!ring) {
@@ -214,11 +197,27 @@ int adis16400_configure_ring(struct iio_dev *indio_dev)
 	/* Effectively select the ring buffer implementation */
 	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
+	ring->scan_el_attrs = &adis16400_scan_el_group;
+	ring->scan_timestamp = true;
 	ring->preenable = &iio_sw_ring_preenable;
 	ring->postenable = &iio_triggered_ring_postenable;
 	ring->predisable = &iio_triggered_ring_predisable;
 	ring->owner = THIS_MODULE;
 
+	/* Set default scan mode */
+	iio_scan_mask_set(ring, iio_scan_el_supply.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_gyro_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_accel_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_magn_x.number);
+	iio_scan_mask_set(ring, iio_scan_el_magn_y.number);
+	iio_scan_mask_set(ring, iio_scan_el_magn_z.number);
+	iio_scan_mask_set(ring, iio_scan_el_temp.number);
+	iio_scan_mask_set(ring, iio_scan_el_adc_0.number);
+
 	ret = iio_alloc_pollfunc(indio_dev, NULL, &adis16400_poll_func_th);
 	if (ret)
 		goto error_iio_sw_rb_free;

drivers/staging/iio/industrialio-core.c

@@ -507,24 +507,12 @@ static int iio_device_register_sysfs(struct iio_dev *dev_info)
 		goto error_ret;
 	}
 
-	if (dev_info->scan_el_attrs) {
-		ret = sysfs_create_group(&dev_info->dev.kobj,
-					 dev_info->scan_el_attrs);
-		if (ret)
-			dev_err(&dev_info->dev,
-				"Failed to add sysfs scan els\n");
-	}
-
 error_ret:
 	return ret;
 }
 
 static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
 {
-	if (dev_info->scan_el_attrs)
-		sysfs_remove_group(&dev_info->dev.kobj,
-				   dev_info->scan_el_attrs);
-
 	sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 }
 

drivers/staging/iio/industrialio-ring.c

@@ -279,6 +279,16 @@ int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
 	if (ret)
 		goto error_free_ring_buffer_event_chrdev;
 
+	if (ring->scan_el_attrs) {
+		ret = sysfs_create_group(&ring->dev.kobj,
+					 ring->scan_el_attrs);
+		if (ret) {
+			dev_err(&ring->dev,
+				"Failed to add sysfs scan elements\n");
+			goto error_free_ring_buffer_event_chrdev;
+		}
+	}
+
 	return ret;
 error_free_ring_buffer_event_chrdev:
 	__iio_free_ring_buffer_event_chrdev(ring);
@@ -291,6 +301,10 @@ EXPORT_SYMBOL(iio_ring_buffer_register);
 
 void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
 {
+	if (ring->scan_el_attrs)
+		sysfs_remove_group(&ring->dev.kobj,
+				   ring->scan_el_attrs);
+
 	__iio_free_ring_buffer_access_chrdev(ring);
 	__iio_free_ring_buffer_event_chrdev(ring);
 	device_del(&ring->dev);
@@ -465,10 +479,10 @@ ssize_t iio_scan_el_show(struct device *dev,
 			 char *buf)
 {
 	int ret;
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
 	struct iio_scan_el *this_el = to_iio_scan_el(attr);
 
-	ret = iio_scan_mask_query(indio_dev, this_el->number);
+	ret = iio_scan_mask_query(ring, this_el->number);
 	if (ret < 0)
 		return ret;
 	return sprintf(buf, "%d\n", ret);
@@ -482,7 +496,8 @@ ssize_t iio_scan_el_store(struct device *dev,
 {
 	int ret = 0;
 	bool state;
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+	struct iio_dev *indio_dev = ring->indio_dev;
 	struct iio_scan_el *this_el = to_iio_scan_el(attr);
 
 	state = !(buf[0] == '0');
@@ -491,19 +506,17 @@ ssize_t iio_scan_el_store(struct device *dev,
 		ret = -EBUSY;
 		goto error_ret;
 	}
-	ret = iio_scan_mask_query(indio_dev, this_el->number);
+	ret = iio_scan_mask_query(ring, this_el->number);
 	if (ret < 0)
 		goto error_ret;
 	if (!state && ret) {
-		ret = iio_scan_mask_clear(indio_dev, this_el->number);
+		ret = iio_scan_mask_clear(ring, this_el->number);
 		if (ret)
 			goto error_ret;
-		indio_dev->scan_count--;
 	} else if (state && !ret) {
-		ret = iio_scan_mask_set(indio_dev, this_el->number);
+		ret = iio_scan_mask_set(ring, this_el->number);
 		if (ret)
 			goto error_ret;
-		indio_dev->scan_count++;
 	}
 	if (this_el->set_state)
 		ret = this_el->set_state(this_el, indio_dev, state);
@@ -519,8 +532,8 @@ ssize_t iio_scan_el_ts_show(struct device *dev,
 			    struct device_attribute *attr,
 			    char *buf)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	return sprintf(buf, "%d\n", indio_dev->scan_timestamp);
+	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", ring->scan_timestamp);
 }
 EXPORT_SYMBOL(iio_scan_el_ts_show);
 
@@ -530,7 +543,8 @@ ssize_t iio_scan_el_ts_store(struct device *dev,
 			     size_t len)
 {
 	int ret = 0;
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+	struct iio_dev *indio_dev = ring->indio_dev;
 	bool state;
 	state = !(buf[0] == '0');
 	mutex_lock(&indio_dev->mlock);
@@ -538,7 +552,7 @@ ssize_t iio_scan_el_ts_store(struct device *dev,
 		ret = -EBUSY;
 		goto error_ret;
 	}
-	indio_dev->scan_timestamp = state;
+	ring->scan_timestamp = state;
 error_ret:
 	mutex_unlock(&indio_dev->mlock);
 

drivers/staging/iio/ring_generic.h

@@ -102,6 +102,11 @@ struct iio_ring_access_funcs {
  * @bytes_per_datum	[DEVICE] size of individual datum including timestamp
  * @bpe:		[DEVICE] size of individual channel value
  * @loopcount:		[INTERN] number of times the ring has looped
+ * @scan_el_attrs:	[DRIVER] control of scan elements if that scan mode
+ *			control method is used
+ * @scan_count:	[INTERN] the number of elements in the current scan mode
+ * @scan_mask:		[INTERN] bitmask used in masking scan mode elements
+ * @scan_timestamp:	[INTERN] does the scan mode include a timestamp
  * @access_handler:	[INTERN] chrdev access handling
  * @ev_int:		[INTERN] chrdev interface for the event chrdev
  * @shared_ev_pointer:	[INTERN] the shared event pointer to allow escalation of
@@ -124,6 +129,10 @@ struct iio_ring_buffer {
 	int				bytes_per_datum;
 	int				bpe;
 	int				loopcount;
+	struct attribute_group		*scan_el_attrs;
+	int				scan_count;
+	u32				scan_mask;
+	bool				scan_timestamp;
 	struct iio_handler		access_handler;
 	struct iio_event_interface	ev_int;
 	struct iio_shared_ev_pointer	shared_ev_pointer;
@@ -258,6 +267,97 @@ ssize_t iio_scan_el_ts_show(struct device *dev, struct device_attribute *attr,
 				   iio_scan_el_ts_store),	\
 	}
 
+/*
+ * These are mainly provided to allow for a change of implementation if a device
+ * has a large number of scan elements
+ */
+#define IIO_MAX_SCAN_LENGTH 31
+
+/* note 0 used as error indicator as it doesn't make sense. */
+static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
+{
+	while (*av_masks) {
+		if (!(~*av_masks & mask))
+			return *av_masks;
+		av_masks++;
+	}
+	return 0;
+}
+
+static inline int iio_scan_mask_query(struct iio_ring_buffer *ring, int bit)
+{
+	struct iio_dev *dev_info = ring->indio_dev;
+	u32 mask;
+
+	if (bit > IIO_MAX_SCAN_LENGTH)
+		return -EINVAL;
+
+	if (!ring->scan_mask)
+		return 0;
+
+	if (dev_info->available_scan_masks)
+		mask = iio_scan_mask_match(dev_info->available_scan_masks,
+					ring->scan_mask);
+	else
+		mask = ring->scan_mask;
+
+	if (!mask)
+		return -EINVAL;
+
+	return !!(mask & (1 << bit));
+};
+
+static inline int iio_scan_mask_set(struct iio_ring_buffer *ring, int bit)
+{
+	struct iio_dev *dev_info = ring->indio_dev;
+	u32 mask;
+	u32 trialmask = ring->scan_mask | (1 << bit);
+
+	if (bit > IIO_MAX_SCAN_LENGTH)
+		return -EINVAL;
+	if (dev_info->available_scan_masks) {
+		mask = iio_scan_mask_match(dev_info->available_scan_masks,
+					trialmask);
+		if (!mask)
+			return -EINVAL;
+	}
+	ring->scan_mask = trialmask;
+	ring->scan_count++;
+
+	return 0;
+};
+
+static inline int iio_scan_mask_clear(struct iio_ring_buffer *ring, int bit)
+{
+	if (bit > IIO_MAX_SCAN_LENGTH)
+		return -EINVAL;
+	ring->scan_mask &= ~(1 << bit);
+	ring->scan_count--;
+	return 0;
+};
+
+/**
+ * iio_scan_mask_count_to_right() - how many scan elements occur before here
+ * @dev_info: the iio_device whose scan mode we are querying
+ * @bit: which number scan element is this
+ **/
+static inline int iio_scan_mask_count_to_right(struct iio_ring_buffer *ring,
+						int bit)
+{
+	int count = 0;
+	int mask = (1 << bit);
+	if (bit > IIO_MAX_SCAN_LENGTH)
+		return -EINVAL;
+	while (mask) {
+		mask >>= 1;
+		if (mask & ring->scan_mask)
+			count++;
+	}
+
+	return count;
+}
+
+
 static inline void iio_put_ring_buffer(struct iio_ring_buffer *ring)
 {
 	put_device(&ring->dev);

drivers/staging/iio/ring_sw.c

@@ -435,23 +435,24 @@ EXPORT_SYMBOL(iio_sw_rb_free);
 
 int iio_sw_ring_preenable(struct iio_dev *indio_dev)
 {
+	struct iio_ring_buffer *ring = indio_dev->ring;
 	size_t size;
 	dev_dbg(&indio_dev->dev, "%s\n", __func__);
 	/* Check if there are any scan elements enabled, if not fail*/
-	if (!(indio_dev->scan_count || indio_dev->scan_timestamp))
+	if (!(ring->scan_count || ring->scan_timestamp))
 		return -EINVAL;
-	if (indio_dev->scan_timestamp)
-		if (indio_dev->scan_count)
+	if (ring->scan_timestamp)
+		if (ring->scan_count)
 			/* Timestamp (aligned to s64) and data */
-			size = (((indio_dev->scan_count * indio_dev->ring->bpe)
+			size = (((ring->scan_count * ring->bpe)
 					+ sizeof(s64) - 1)
 				& ~(sizeof(s64) - 1))
 				+ sizeof(s64);
 		else /* Timestamp only  */
 			size = sizeof(s64);
 	else /* Data only */
-		size = indio_dev->scan_count * indio_dev->ring->bpe;
-	indio_dev->ring->access.set_bytes_per_datum(indio_dev->ring, size);
+		size = ring->scan_count * ring->bpe;
+	ring->access.set_bytes_per_datum(ring, size);
 
 	return 0;
 }
@@ -462,9 +463,9 @@ void iio_sw_trigger_bh_to_ring(struct work_struct *work_s)
 	struct iio_sw_ring_helper_state *st
 		= container_of(work_s, struct iio_sw_ring_helper_state,
 			work_trigger_to_ring);
+	struct iio_ring_buffer *ring = st->indio_dev->ring;
 	int len = 0;
-	size_t datasize = st->indio_dev
-		->ring->access.get_bytes_per_datum(st->indio_dev->ring);
+	size_t datasize = ring->access.get_bytes_per_datum(ring);
 	char *data = kmalloc(datasize, GFP_KERNEL);
 
 	if (data == NULL) {
@@ -473,16 +474,16 @@ void iio_sw_trigger_bh_to_ring(struct work_struct *work_s)
 		return;
 	}
 
-	if (st->indio_dev->scan_count)
+	if (ring->scan_count)
 		len = st->get_ring_element(st, data);
 
 	  /* Guaranteed to be aligned with 8 byte boundary */
-	if (st->indio_dev->scan_timestamp)
+	if (ring->scan_timestamp)
 		*(s64 *)(((phys_addr_t)data + len
 				+ sizeof(s64) - 1) & ~(sizeof(s64) - 1))
 			= st->last_timestamp;
-	  st->indio_dev->ring->access.store_to(st->indio_dev->ring,
-					(u8 *)data,
+	ring->access.store_to(ring,
+			(u8 *)data,
 			st->last_timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);