staging:iio: rationalization of different buffer implementation hooks.

1) move a generic helper function out of ring_sw. It applies to other buffers as well.
2) Get rid of a lot of left over function definitions.
3) Move all the access functions into static structures.
4) Introduce and use a static structure for the setup functions, preenable etc.

Some driver conversions thanks to Michael Hennerich (pulled out of patches
that would otherwise sit after this).

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/adis16201_ring.c

@@ -68,7 +68,7 @@ static irqreturn_t adis16201_trigger_handler(int irq, void *p)
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = ring->access.get_bytes_per_datum(ring);
+	size_t datasize = ring->access->get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize, GFP_KERNEL);
 	if (data == NULL) {
@@ -86,7 +86,7 @@ static irqreturn_t adis16201_trigger_handler(int irq, void *p)
 	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	ring->access.store_to(ring, (u8 *)data, pf->timestamp);
+	ring->access->store_to(ring, (u8 *)data, pf->timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -101,6 +101,12 @@ void adis16201_unconfigure_ring(struct iio_dev *indio_dev)
 	iio_sw_rb_free(indio_dev->ring);
 }
 
+static const struct iio_ring_setup_ops adis16201_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int adis16201_configure_ring(struct iio_dev *indio_dev)
 {
 	int ret = 0;
@@ -113,12 +119,10 @@ int adis16201_configure_ring(struct iio_dev *indio_dev)
 	}
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &iio_triggered_ring_postenable;
-	ring->predisable = &iio_triggered_ring_predisable;
+	ring->access = &ring_sw_access_funcs;
+	ring->setup_ops = &adis16201_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/adis16203_ring.c

@@ -73,7 +73,7 @@ static irqreturn_t adis16203_trigger_handler(int irq, void *p)
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = ring->access.get_bytes_per_datum(ring);
+	size_t datasize = ring->access->get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize, GFP_KERNEL);
 	if (data == NULL) {
@@ -91,7 +91,7 @@ static irqreturn_t adis16203_trigger_handler(int irq, void *p)
 	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	ring->access.store_to(ring,
+	ring->access->store_to(ring,
 			      (u8 *)data,
 			      pf->timestamp);
 
@@ -108,6 +108,12 @@ void adis16203_unconfigure_ring(struct iio_dev *indio_dev)
 	iio_sw_rb_free(indio_dev->ring);
 }
 
+static const struct iio_ring_setup_ops adis16203_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int adis16203_configure_ring(struct iio_dev *indio_dev)
 {
 	int ret = 0;
@@ -120,12 +126,10 @@ int adis16203_configure_ring(struct iio_dev *indio_dev)
 	}
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&ring->access);
 	ring->bpe = 2;
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &iio_triggered_ring_postenable;
-	ring->predisable = &iio_triggered_ring_predisable;
+	ring->access = &ring_sw_access_funcs;
+	ring->setup_ops = &adis16203_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/adis16204_ring.c

@@ -70,7 +70,7 @@ static irqreturn_t adis16204_trigger_handler(int irq, void *p)
 	struct iio_ring_buffer *ring = indio_dev->ring;
 	int i = 0;
 	s16 *data;
-	size_t datasize = ring->access.get_bytes_per_datum(ring);
+	size_t datasize = ring->access->get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize, GFP_KERNEL);
 	if (data == NULL) {
@@ -88,7 +88,7 @@ static irqreturn_t adis16204_trigger_handler(int irq, void *p)
 	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	ring->access.store_to(ring, (u8 *)data, pf->timestamp);
+	ring->access->store_to(ring, (u8 *)data, pf->timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -103,6 +103,12 @@ void adis16204_unconfigure_ring(struct iio_dev *indio_dev)
 	iio_sw_rb_free(indio_dev->ring);
 }
 
+static const struct iio_ring_setup_ops adis16204_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int adis16204_configure_ring(struct iio_dev *indio_dev)
 {
 	int ret = 0;
@@ -115,12 +121,10 @@ int adis16204_configure_ring(struct iio_dev *indio_dev)
 	}
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&ring->access);
+	ring->access = &ring_sw_access_funcs;
 	ring->bpe = 2;
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &iio_triggered_ring_postenable;
-	ring->predisable = &iio_triggered_ring_predisable;
+	ring->setup_ops = &adis16204_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/adis16209_ring.c

@@ -71,7 +71,7 @@ static irqreturn_t adis16209_trigger_handler(int irq, void *p)
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = ring->access.get_bytes_per_datum(ring);
+	size_t datasize = ring->access->get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize , GFP_KERNEL);
 	if (data == NULL) {
@@ -88,7 +88,7 @@ static irqreturn_t adis16209_trigger_handler(int irq, void *p)
 	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	ring->access.store_to(ring, (u8 *)data, pf->timestamp);
+	ring->access->store_to(ring, (u8 *)data, pf->timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -103,6 +103,12 @@ void adis16209_unconfigure_ring(struct iio_dev *indio_dev)
 	iio_sw_rb_free(indio_dev->ring);
 }
 
+static const struct iio_ring_setup_ops adis16209_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int adis16209_configure_ring(struct iio_dev *indio_dev)
 {
 	int ret = 0;
@@ -115,12 +121,10 @@ int adis16209_configure_ring(struct iio_dev *indio_dev)
 	}
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&ring->access);
+	ring->access = &ring_sw_access_funcs;
 	ring->bpe = 2;
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &iio_triggered_ring_postenable;
-	ring->predisable = &iio_triggered_ring_predisable;
+	ring->setup_ops = &adis16209_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/adis16240_ring.c

@@ -68,7 +68,7 @@ static irqreturn_t adis16240_trigger_handler(int irq, void *p)
 
 	int i = 0;
 	s16 *data;
-	size_t datasize = ring->access.get_bytes_per_datum(ring);
+	size_t datasize = ring->access->get_bytes_per_datum(ring);
 
 	data = kmalloc(datasize, GFP_KERNEL);
 	if (data == NULL) {
@@ -85,7 +85,7 @@ static irqreturn_t adis16240_trigger_handler(int irq, void *p)
 	if (ring->scan_timestamp)
 		*((s64 *)(data + ((i + 3)/4)*4)) = pf->timestamp;
 
-	ring->access.store_to(ring, (u8 *)data, pf->timestamp);
+	ring->access->store_to(ring, (u8 *)data, pf->timestamp);
 
 	iio_trigger_notify_done(st->indio_dev->trig);
 	kfree(data);
@@ -100,6 +100,12 @@ void adis16240_unconfigure_ring(struct iio_dev *indio_dev)
 	iio_sw_rb_free(indio_dev->ring);
 }
 
+static const struct iio_ring_setup_ops adis16240_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int adis16240_configure_ring(struct iio_dev *indio_dev)
 {
 	int ret = 0;
@@ -112,12 +118,10 @@ int adis16240_configure_ring(struct iio_dev *indio_dev)
 	}
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&ring->access);
+	ring->access = &ring_sw_access_funcs;
 	ring->bpe = 2;
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &iio_triggered_ring_postenable;
-	ring->predisable = &iio_triggered_ring_predisable;
+	ring->setup_ops = &adis16240_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/lis3l02dq.h

@@ -196,12 +196,12 @@ void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev);
 #ifdef CONFIG_LIS3L02DQ_BUF_RING_SW
 #define lis3l02dq_free_buf iio_sw_rb_free
 #define lis3l02dq_alloc_buf iio_sw_rb_allocate
-#define lis3l02dq_register_buf_funcs iio_ring_sw_register_funcs
+#define lis3l02dq_access_funcs ring_sw_access_funcs
 #endif
 #ifdef CONFIG_LIS3L02DQ_BUF_KFIFO
 #define lis3l02dq_free_buf iio_kfifo_free
 #define lis3l02dq_alloc_buf iio_kfifo_allocate
-#define lis3l02dq_register_buf_funcs iio_kfifo_register_funcs
+#define lis3l02dq_access_funcs kfifo_access_funcs
 #endif
 irqreturn_t lis3l02dq_data_rdy_trig_poll(int irq, void *private);
 #define lis3l02dq_th lis3l02dq_data_rdy_trig_poll

drivers/staging/iio/accel/lis3l02dq_ring.c

@@ -54,12 +54,12 @@ ssize_t lis3l02dq_read_accel_from_ring(struct iio_ring_buffer *ring,
 	if (!iio_scan_mask_query(ring, index))
 		return -EINVAL;
 
-	data = kmalloc(ring->access.get_bytes_per_datum(ring),
+	data = kmalloc(ring->access->get_bytes_per_datum(ring),
 		       GFP_KERNEL);
 	if (data == NULL)
 		return -ENOMEM;
 
-	ret = ring->access.read_last(ring, (u8 *)data);
+	ret = ring->access->read_last(ring, (u8 *)data);
 	if (ret)
 		goto error_free_data;
 	*val = data[iio_scan_mask_count_to_right(ring, index)];
@@ -400,6 +400,11 @@ static int lis3l02dq_ring_predisable(struct iio_dev *indio_dev)
 	return ret;
 }
 
+static const struct iio_ring_setup_ops lis3l02dq_ring_setup_ops = {
+	.preenable = &iio_sw_ring_preenable,
+	.postenable = &lis3l02dq_ring_postenable,
+	.predisable = &lis3l02dq_ring_predisable,
+};
 
 int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 {
@@ -415,13 +420,11 @@ int lis3l02dq_configure_ring(struct iio_dev *indio_dev)
 
 	indio_dev->ring = ring;
 	/* Effectively select the ring buffer implementation */
-	lis3l02dq_register_buf_funcs(&ring->access);
+	indio_dev->ring->access = &lis3l02dq_access_funcs;
 	ring->bpe = 2;
 
 	ring->scan_timestamp = true;
-	ring->preenable = &iio_sw_ring_preenable;
-	ring->postenable = &lis3l02dq_ring_postenable;
-	ring->predisable = &lis3l02dq_ring_predisable;
+	ring->setup_ops = &lis3l02dq_ring_setup_ops;
 	ring->owner = THIS_MODULE;
 
 	/* Set default scan mode */

drivers/staging/iio/accel/sca3000_ring.c

@@ -367,17 +367,20 @@ static inline void sca3000_rb_free(struct iio_ring_buffer *r)
 		iio_put_ring_buffer(r);
 }
 
+static const struct iio_ring_access_funcs sca3000_ring_access_funcs = {
+	.read_first_n = &sca3000_read_first_n_hw_rb,
+	.get_length = &sca3000_ring_get_length,
+	.get_bytes_per_datum = &sca3000_ring_get_bytes_per_datum,
+};
+
 int sca3000_configure_ring(struct iio_dev *indio_dev)
 {
 	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->access.read_first_n = &sca3000_read_first_n_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;
+	indio_dev->ring->access = &sca3000_ring_access_funcs;
 
 	iio_scan_mask_set(indio_dev->ring, 0);
 	iio_scan_mask_set(indio_dev->ring, 1);
@@ -432,10 +435,14 @@ static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
 	return __sca3000_hw_ring_state_set(indio_dev, 0);
 }
 
+static const struct iio_ring_setup_ops sca3000_ring_setup_ops = {
+	.preenable = &sca3000_hw_ring_preenable,
+	.postdisable = &sca3000_hw_ring_postdisable,
+};
+
 void sca3000_register_ring_funcs(struct iio_dev *indio_dev)
 {
-	indio_dev->ring->preenable = &sca3000_hw_ring_preenable;
-	indio_dev->ring->postdisable = &sca3000_hw_ring_postdisable;
+	indio_dev->ring->setup_ops = &sca3000_ring_setup_ops;
 }
 
 /**

drivers/staging/iio/adc/ad7298_ring.c

@@ -32,13 +32,13 @@ int ad7298_scan_from_ring(struct ad7298_state *st, long ch)
 		goto error_ret;
 	}
 
-	ring_data = kmalloc(ring->access.get_bytes_per_datum(ring),
+	ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
 			    GFP_KERNEL);
 	if (ring_data == NULL) {
 		ret = -ENOMEM;
 		goto error_ret;
 	}
-	ret = ring->access.read_last(ring, (u8 *) ring_data);
+	ret = ring->access->read_last(ring, (u8 *) ring_data);
 	if (ret)
 		goto error_free_ring_data;
 
@@ -74,8 +74,8 @@ static int ad7298_ring_preenable(struct iio_dev *indio_dev)
 			d_size += sizeof(s64) - (d_size % sizeof(s64));
 	}
 
-	if (ring->access.set_bytes_per_datum)
-		ring->access.set_bytes_per_datum(ring, d_size);
+	if (ring->access->set_bytes_per_datum)
+		ring->access->set_bytes_per_datum(ring, d_size);
 
 	st->d_size = d_size;
 
@@ -140,12 +140,18 @@ static irqreturn_t ad7298_trigger_handler(int irq, void *p)
 	for (i = 0; i < ring->scan_count; i++)
 		buf[i] = be16_to_cpu(st->rx_buf[i]);
 
-	indio_dev->ring->access.store_to(ring, (u8 *)buf, time_ns);
+	indio_dev->ring->access->store_to(ring, (u8 *)buf, time_ns);
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
 }
 
+static const struct iio_ring_setup_ops ad7298_ring_setup_ops = {
+	.preenable = &ad7298_ring_preenable,
+	.postenable = &iio_triggered_ring_postenable,
+	.predisable = &iio_triggered_ring_predisable,
+};
+
 int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 {
 	int ret;
@@ -156,7 +162,7 @@ int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 		goto error_ret;
 	}
 	/* Effectively select the ring buffer implementation */
-	iio_ring_sw_register_funcs(&indio_dev->ring->access);
+	indio_dev->ring->access = &ring_sw_access_funcs;
 
 	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
 	if (indio_dev->pollfunc == NULL) {
@@ -173,10 +179,7 @@ int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 		goto error_free_poll_func;
 	}
 	/* Ring buffer functions - here trigger setup related */
-	indio_dev->ring->preenable = &ad7298_ring_preenable;
-	indio_dev->ring->postenable = &iio_triggered_ring_postenable;
-	indio_dev->ring->predisable = &iio_triggered_ring_predisable;
-
+	indio_dev->ring->setup_ops = &ad7298_ring_setup_ops;
 	indio_dev->ring->scan_timestamp = true;
 
 	/* Flag that polled ring buffering is possible */