staging:iio: Add support for multiple buffers

Route all buffer writes through the demux.
Addition or removal of a buffer results in tear down and
setup of all the buffers for a given device.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Tested-by: srinivas pandruvada <srinivas.pandruvada@intel.com>

drivers/iio/accel/hid-sensor-accel-3d.c

@@ -197,21 +197,8 @@ static const struct iio_info accel_3d_info = {
 /* Function to push data to buffer */
 static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
 {
-	struct iio_buffer *buffer = indio_dev->buffer;
-	int datum_sz;
-
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
-	if (!buffer) {
-		dev_err(&indio_dev->dev, "Buffer == NULL\n");
-		return;
-	}
-	datum_sz = buffer->access->get_bytes_per_datum(buffer);
-	if (len > datum_sz) {
-		dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
-				datum_sz);
-		return;
-	}
-	iio_push_to_buffer(buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 }
 
 /* Callback handler to send event after all samples are received and captured */

drivers/iio/adc/ad7266.c

@@ -91,7 +91,6 @@ static irqreturn_t ad7266_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
-	struct iio_buffer *buffer = indio_dev->buffer;
 	struct ad7266_state *st = iio_priv(indio_dev);
 	int ret;
 
@@ -99,7 +98,7 @@ static irqreturn_t ad7266_trigger_handler(int irq, void *p)
 	if (ret == 0) {
 		if (indio_dev->scan_timestamp)
 			((s64 *)st->data)[1] = pf->timestamp;
-		iio_push_to_buffer(buffer, (u8 *)st->data);
+		iio_push_to_buffers(indio_dev, (u8 *)st->data);
 	}
 
 	iio_trigger_notify_done(indio_dev->trig);

drivers/iio/adc/ad7476.c

@@ -76,7 +76,7 @@ static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
 	if (indio_dev->scan_timestamp)
 		((s64 *)st->data)[1] = time_ns;
 
-	iio_push_to_buffer(indio_dev->buffer, st->data);
+	iio_push_to_buffers(indio_dev, st->data);
 done:
 	iio_trigger_notify_done(indio_dev->trig);
 

drivers/iio/adc/ad7887.c

@@ -134,7 +134,7 @@ static irqreturn_t ad7887_trigger_handler(int irq, void *p)
 		memcpy(st->data + indio_dev->scan_bytes - sizeof(s64),
 		       &time_ns, sizeof(time_ns));
 
-	iio_push_to_buffer(indio_dev->buffer, st->data);
+	iio_push_to_buffers(indio_dev, st->data);
 done:
 	iio_trigger_notify_done(indio_dev->trig);
 

drivers/iio/adc/ad_sigma_delta.c

@@ -391,7 +391,7 @@ static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
 		break;
 	}
 
-	iio_push_to_buffer(indio_dev->buffer, (uint8_t *)data);
+	iio_push_to_buffers(indio_dev, (uint8_t *)data);
 
 	iio_trigger_notify_done(indio_dev->trig);
 	sigma_delta->irq_dis = false;

drivers/iio/adc/at91_adc.c

@@ -65,7 +65,6 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *idev = pf->indio_dev;
 	struct at91_adc_state *st = iio_priv(idev);
-	struct iio_buffer *buffer = idev->buffer;
 	int i, j = 0;
 
 	for (i = 0; i < idev->masklength; i++) {
@@ -81,7 +80,7 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 		*timestamp = pf->timestamp;
 	}
 
-	iio_push_to_buffer(buffer, st->buffer);
+	iio_push_to_buffers(indio_dev, (u8 *)st->buffer);
 
 	iio_trigger_notify_done(idev->trig);
 

drivers/iio/gyro/hid-sensor-gyro-3d.c

@@ -197,21 +197,8 @@ static const struct iio_info gyro_3d_info = {
 /* Function to push data to buffer */
 static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
 {
-	struct iio_buffer *buffer = indio_dev->buffer;
-	int datum_sz;
-
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
-	if (!buffer) {
-		dev_err(&indio_dev->dev, "Buffer == NULL\n");
-		return;
-	}
-	datum_sz = buffer->access->get_bytes_per_datum(buffer);
-	if (len > datum_sz) {
-		dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
-				datum_sz);
-		return;
-	}
-	iio_push_to_buffer(buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 }
 
 /* Callback handler to send event after all samples are received and captured */

drivers/iio/industrialio-core.c

@@ -856,6 +856,7 @@ struct iio_dev *iio_device_alloc(int sizeof_priv)
 			return NULL;
 		}
 		dev_set_name(&dev->dev, "iio:device%d", dev->id);
+		INIT_LIST_HEAD(&dev->buffer_list);
 	}
 
 	return dev;

drivers/iio/light/adjd_s311.c

@@ -164,7 +164,6 @@ static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct adjd_s311_data *data = iio_priv(indio_dev);
-	struct iio_buffer *buffer = indio_dev->buffer;
 	s64 time_ns = iio_get_time_ns();
 	int len = 0;
 	int i, j = 0;
@@ -187,7 +186,7 @@ static irqreturn_t adjd_s311_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*(s64 *)((u8 *)data->buffer + ALIGN(len, sizeof(s64)))
 			= time_ns;
-	iio_push_to_buffer(buffer, (u8 *)data->buffer);
+	iio_push_to_buffers(indio_dev, (u8 *)data->buffer);
 
 done:
 	iio_trigger_notify_done(indio_dev->trig);

drivers/iio/light/hid-sensor-als.c

@@ -176,21 +176,8 @@ static const struct iio_info als_info = {
 /* Function to push data to buffer */
 static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
 {
-	struct iio_buffer *buffer = indio_dev->buffer;
-	int datum_sz;
-
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
-	if (!buffer) {
-		dev_err(&indio_dev->dev, "Buffer == NULL\n");
-		return;
-	}
-	datum_sz = buffer->access->get_bytes_per_datum(buffer);
-	if (len > datum_sz) {
-		dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
-				datum_sz);
-		return;
-	}
-	iio_push_to_buffer(buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 }
 
 /* Callback handler to send event after all samples are received and captured */

drivers/iio/magnetometer/hid-sensor-magn-3d.c

@@ -198,21 +198,8 @@ static const struct iio_info magn_3d_info = {
 /* Function to push data to buffer */
 static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
 {
-	struct iio_buffer *buffer = indio_dev->buffer;
-	int datum_sz;
-
 	dev_dbg(&indio_dev->dev, "hid_sensor_push_data\n");
-	if (!buffer) {
-		dev_err(&indio_dev->dev, "Buffer == NULL\n");
-		return;
-	}
-	datum_sz = buffer->access->get_bytes_per_datum(buffer);
-	if (len > datum_sz) {
-		dev_err(&indio_dev->dev, "Datum size mismatch %d:%d\n", len,
-				datum_sz);
-		return;
-	}
-	iio_push_to_buffer(buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 }
 
 /* Callback handler to send event after all samples are received and captured */

drivers/staging/iio/accel/adis16201_ring.c

@@ -82,7 +82,7 @@ static irqreturn_t adis16201_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/accel/adis16203_ring.c

@@ -81,7 +81,7 @@ static irqreturn_t adis16203_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/accel/adis16204_ring.c

@@ -78,7 +78,7 @@ static irqreturn_t adis16204_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/accel/adis16209_ring.c

@@ -78,7 +78,7 @@ static irqreturn_t adis16209_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/accel/adis16240_ring.c

@@ -76,7 +76,7 @@ static irqreturn_t adis16240_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/accel/lis3l02dq_ring.c

@@ -154,7 +154,7 @@ static irqreturn_t lis3l02dq_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*(s64 *)((u8 *)data + ALIGN(len, sizeof(s64)))
 			= pf->timestamp;
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/adc/ad7298_ring.c

@@ -93,7 +93,7 @@ static irqreturn_t ad7298_trigger_handler(int irq, void *p)
 						 indio_dev->masklength); i++)
 		buf[i] = be16_to_cpu(st->rx_buf[i]);
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)buf);
+	iio_push_to_buffers(indio_dev, (u8 *)buf);
 
 done:
 	iio_trigger_notify_done(indio_dev->trig);

drivers/staging/iio/adc/ad7606_ring.c

@@ -83,7 +83,7 @@ static void ad7606_poll_bh_to_ring(struct work_struct *work_s)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(buf + indio_dev->scan_bytes - sizeof(s64))) = time_ns;
 
-	iio_push_to_buffer(indio_dev->buffer, buf);
+	iio_push_to_buffers(indio_dev, buf);
 done:
 	gpio_set_value(st->pdata->gpio_convst, 0);
 	iio_trigger_notify_done(indio_dev->trig);

drivers/staging/iio/adc/ad799x_ring.c

@@ -77,7 +77,7 @@ static irqreturn_t ad799x_trigger_handler(int irq, void *p)
 		memcpy(rxbuf + indio_dev->scan_bytes - sizeof(s64),
 			&time_ns, sizeof(time_ns));
 
-	iio_push_to_buffer(indio_dev->buffer, rxbuf);
+	iio_push_to_buffers(indio_dev, rxbuf);
 done:
 	kfree(rxbuf);
 out:

drivers/staging/iio/adc/max1363_ring.c

@@ -80,7 +80,7 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
 
 	if (indio_dev->scan_timestamp)
 		memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
-	iio_push_to_buffer(indio_dev->buffer, rxbuf);
+	iio_push_to_buffers(indio_dev, rxbuf);
 
 done_free:
 	kfree(rxbuf);

drivers/staging/iio/adc/mxs-lradc.c

@@ -237,7 +237,6 @@ static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *iio = pf->indio_dev;
 	struct mxs_lradc *lradc = iio_priv(iio);
-	struct iio_buffer *buffer = iio->buffer;
 	const uint32_t chan_value = LRADC_CH_ACCUMULATE |
 		((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
 	int i, j = 0;
@@ -256,7 +255,7 @@ static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
 		*timestamp = pf->timestamp;
 	}
 
-	iio_push_to_buffer(buffer, (u8 *)lradc->buffer);
+	iio_push_to_buffers(iio, (u8 *)lradc->buffer);
 
 	iio_trigger_notify_done(iio->trig);
 

drivers/staging/iio/gyro/adis16260_ring.c

@@ -81,7 +81,7 @@ static irqreturn_t adis16260_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 done:

drivers/staging/iio/iio_simple_dummy_buffer.c

@@ -46,7 +46,6 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
-	struct iio_buffer *buffer = indio_dev->buffer;
 	int len = 0;
 	u16 *data;
 
@@ -76,7 +75,7 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
 		     i < bitmap_weight(indio_dev->active_scan_mask,
 				       indio_dev->masklength);
 		     i++, j++) {
-			j = find_next_bit(buffer->scan_mask,
+			j = find_next_bit(indio_dev->active_scan_mask,
 					  indio_dev->masklength, j);
 			/* random access read from the 'device' */
 			data[i] = fakedata[j];
@@ -87,7 +86,7 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		*(s64 *)((u8 *)data + ALIGN(len, sizeof(s64)))
 			= iio_get_time_ns();
-	iio_push_to_buffer(buffer, (u8 *)data);
+	iio_push_to_buffers(indio_dev, (u8 *)data);
 
 	kfree(data);
 

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

@@ -647,7 +647,6 @@ static void ad5933_work(struct work_struct *work)
 	struct ad5933_state *st = container_of(work,
 		struct ad5933_state, work.work);
 	struct iio_dev *indio_dev = i2c_get_clientdata(st->client);
-	struct iio_buffer *ring = indio_dev->buffer;
 	signed short buf[2];
 	unsigned char status;
 
@@ -677,8 +676,7 @@ static void ad5933_work(struct work_struct *work)
 		} else {
 			buf[0] = be16_to_cpu(buf[0]);
 		}
-		/* save datum to the ring */
-		iio_push_to_buffer(ring, (u8 *)buf);
+		iio_push_to_buffers(indio_dev, (u8 *)buf);
 	} else {
 		/* no data available - try again later */
 		schedule_delayed_work(&st->work, st->poll_time_jiffies);

drivers/staging/iio/imu/adis16400_ring.c

@@ -114,7 +114,6 @@ static irqreturn_t adis16400_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct adis16400_state *st = iio_priv(indio_dev);
-	struct iio_buffer *ring = indio_dev->buffer;
 	int i = 0, j, ret = 0;
 	s16 *data;
 
@@ -148,9 +147,9 @@ static irqreturn_t adis16400_trigger_handler(int irq, void *p)
 		}
 	}
 	/* Guaranteed to be aligned with 8 byte boundary */
-	if (ring->scan_timestamp)
+	if (indio_dev->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
-	iio_push_to_buffer(ring, (u8 *) data);
+	iio_push_to_buffers(indio_dev, (u8 *) data);
 
 done:
 	kfree(data);

drivers/staging/iio/meter/ade7758_ring.c

@@ -73,7 +73,7 @@ static irqreturn_t ade7758_trigger_handler(int irq, void *p)
 	if (indio_dev->scan_timestamp)
 		dat64[1] = pf->timestamp;
 
-	iio_push_to_buffer(indio_dev->buffer, (u8 *)dat64);
+	iio_push_to_buffers(indio_dev, (u8 *)dat64);
 
 	iio_trigger_notify_done(indio_dev->trig);
 

include/linux/iio/buffer.h

@@ -66,7 +66,8 @@ struct iio_buffer_access_funcs {
  * @stufftoread:	[INTERN] flag to indicate new data.
  * @demux_list:		[INTERN] list of operations required to demux the scan.
  * @demux_bounce:	[INTERN] buffer for doing gather from incoming scan.
- **/
+ * @buffer_list:	[INTERN] entry in the devices list of current buffers.
+ */
 struct iio_buffer {
 	int					length;
 	int					bytes_per_datum;
@@ -81,8 +82,21 @@ struct iio_buffer {
 	const struct attribute_group *attrs;
 	struct list_head			demux_list;
 	unsigned char				*demux_bounce;
+	struct list_head			buffer_list;
 };
 
+/**
+ * iio_update_buffers() - add or remove buffer from active list
+ * @indio_dev:		device to add buffer to
+ * @insert_buffer:	buffer to insert
+ * @remove_buffer:	buffer_to_remove
+ *
+ * Note this will tear down the all buffering and build it up again
+ */
+int iio_update_buffers(struct iio_dev *indio_dev,
+		       struct iio_buffer *insert_buffer,
+		       struct iio_buffer *remove_buffer);
+
 /**
  * iio_buffer_init() - Initialize the buffer structure
  * @buffer:		buffer to be initialized
@@ -115,11 +129,11 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
 		      struct iio_buffer *buffer, int bit);
 
 /**
- * iio_push_to_buffer() - push to a registered buffer.
- * @buffer:		IIO buffer structure for device
- * @data:		the data to push to the buffer
+ * iio_push_to_buffers() - push to a registered buffer.
+ * @indio_dev:		iio_dev structure for device.
+ * @data:		Full scan.
  */
-int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data);
+int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data);
 
 int iio_update_demux(struct iio_dev *indio_dev);
 

include/linux/iio/iio.h

@@ -410,6 +410,7 @@ struct iio_buffer_setup_ops {
  *			and owner
  * @event_interface:	[INTERN] event chrdevs associated with interrupt lines
  * @buffer:		[DRIVER] any buffer present
+ * @buffer_list:	[INTERN] list of all buffers currently attached
  * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
  * @mlock:		[INTERN] lock used to prevent simultaneous device state
  *			changes
@@ -448,6 +449,7 @@ struct iio_dev {
 	struct iio_event_interface	*event_interface;
 
 	struct iio_buffer		*buffer;
+	struct list_head		buffer_list;
 	int				scan_bytes;
 	struct mutex			mlock;