brcm2708: update linux 4.4 patches to latest version

As usual these patches were extracted and rebased from the raspberry pi repo:
https://github.com/raspberrypi/linux/tree/rpi-4.4.y

Also adds support for Raspberry Pi Compute Module 3 (untested).

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 378 insertions, 0 deletions

diff --git a/target/linux/brcm2708/patches-4.4/0396-dmaengine-bcm2835-move-controlblock-chain-generation.patch b/target/linux/brcm2708/patches-4.4/0396-dmaengine-bcm2835-move-controlblock-chain-generation.patch
new file mode 100644
index 0000000000..1507d6be47
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0396-dmaengine-bcm2835-move-controlblock-chain-generation.patch
@@ -0,0 +1,378 @@
+From a41b5c7005c6880ac91b9e08062c6b6813df758e Mon Sep 17 00:00:00 2001
+From: Martin Sperl <kernel@martin.sperl.org>
+Date: Wed, 16 Mar 2016 12:24:59 -0700
+Subject: [PATCH] dmaengine: bcm2835: move controlblock chain generation into
+ separate method
+
+In preparation of adding slave_sg functionality this patch moves the
+generation/allocation of bcm2835_desc and the building of
+the corresponding DMA-control-block chain from bcm2835_dma_prep_dma_cyclic
+into the newly created method bcm2835_dma_create_cb_chain.
+
+Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
+Reviewed-by: Eric Anholt <eric@anholt.net>
+Signed-off-by: Eric Anholt <eric@anholt.net>
+Signed-off-by: Vinod Koul <vinod.koul@intel.com>
+---
+ drivers/dma/bcm2835-dma.c | 294 +++++++++++++++++++++++++++++++---------------
+ 1 file changed, 198 insertions(+), 96 deletions(-)
+
+--- a/drivers/dma/bcm2835-dma.c
++++ b/drivers/dma/bcm2835-dma.c
+@@ -88,12 +88,12 @@ struct bcm2835_desc {
+ 	struct virt_dma_desc vd;
+ 	enum dma_transfer_direction dir;
+ 
+-	struct bcm2835_cb_entry *cb_list;
+-
+ 	unsigned int frames;
+ 	size_t size;
+ 
+ 	bool cyclic;
++
++	struct bcm2835_cb_entry cb_list[];
+ };
+ 
+ #define BCM2835_DMA_CS		0x00
+@@ -169,6 +169,13 @@ struct bcm2835_desc {
+ #define BCM2835_DMA_CHAN(n)	((n) << 8) /* Base address */
+ #define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n))
+ 
++/* how many frames of max_len size do we need to transfer len bytes */
++static inline size_t bcm2835_dma_frames_for_length(size_t len,
++						   size_t max_len)
++{
++	return DIV_ROUND_UP(len, max_len);
++}
++
+ static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d)
+ {
+ 	return container_of(d, struct bcm2835_dmadev, ddev);
+@@ -185,19 +192,161 @@ static inline struct bcm2835_desc *to_bc
+ 	return container_of(t, struct bcm2835_desc, vd.tx);
+ }
+ 
+-static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
++static void bcm2835_dma_free_cb_chain(struct bcm2835_desc *desc)
+ {
+-	struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd);
+-	int i;
++	size_t i;
+ 
+ 	for (i = 0; i < desc->frames; i++)
+ 		dma_pool_free(desc->c->cb_pool, desc->cb_list[i].cb,
+ 			      desc->cb_list[i].paddr);
+ 
+-	kfree(desc->cb_list);
+ 	kfree(desc);
+ }
+ 
++static void bcm2835_dma_desc_free(struct virt_dma_desc *vd)
++{
++	bcm2835_dma_free_cb_chain(
++		container_of(vd, struct bcm2835_desc, vd));
++}
++
++static void bcm2835_dma_create_cb_set_length(
++	struct bcm2835_chan *chan,
++	struct bcm2835_dma_cb *control_block,
++	size_t len,
++	size_t period_len,
++	size_t *total_len,
++	u32 finalextrainfo)
++{
++	/* set the length */
++	control_block->length = len;
++
++	/* finished if we have no period_length */
++	if (!period_len)
++		return;
++
++	/*
++	 * period_len means: that we need to generate
++	 * transfers that are terminating at every
++	 * multiple of period_len - this is typically
++	 * used to set the interrupt flag in info
++	 * which is required during cyclic transfers
++	 */
++
++	/* have we filled in period_length yet? */
++	if (*total_len + control_block->length < period_len)
++		return;
++
++	/* calculate the length that remains to reach period_length */
++	control_block->length = period_len - *total_len;
++
++	/* reset total_length for next period */
++	*total_len = 0;
++
++	/* add extrainfo bits in info */
++	control_block->info |= finalextrainfo;
++}
++
++/**
++ * bcm2835_dma_create_cb_chain - create a control block and fills data in
++ *
++ * @chan:           the @dma_chan for which we run this
++ * @direction:      the direction in which we transfer
++ * @cyclic:         it is a cyclic transfer
++ * @info:           the default info bits to apply per controlblock
++ * @frames:         number of controlblocks to allocate
++ * @src:            the src address to assign (if the S_INC bit is set
++ *                  in @info, then it gets incremented)
++ * @dst:            the dst address to assign (if the D_INC bit is set
++ *                  in @info, then it gets incremented)
++ * @buf_len:        the full buffer length (may also be 0)
++ * @period_len:     the period length when to apply @finalextrainfo
++ *                  in addition to the last transfer
++ *                  this will also break some control-blocks early
++ * @finalextrainfo: additional bits in last controlblock
++ *                  (or when period_len is reached in case of cyclic)
++ * @gfp:            the GFP flag to use for allocation
++ */
++static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
++	struct dma_chan *chan, enum dma_transfer_direction direction,
++	bool cyclic, u32 info, u32 finalextrainfo, size_t frames,
++	dma_addr_t src, dma_addr_t dst, size_t buf_len,
++	size_t period_len, gfp_t gfp)
++{
++	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
++	size_t len = buf_len, total_len;
++	size_t frame;
++	struct bcm2835_desc *d;
++	struct bcm2835_cb_entry *cb_entry;
++	struct bcm2835_dma_cb *control_block;
++
++	/* allocate and setup the descriptor. */
++	d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
++		    gfp);
++	if (!d)
++		return NULL;
++
++	d->c = c;
++	d->dir = direction;
++	d->cyclic = cyclic;
++
++	/*
++	 * Iterate over all frames, create a control block
++	 * for each frame and link them together.
++	 */
++	for (frame = 0, total_len = 0; frame < frames; d->frames++, frame++) {
++		cb_entry = &d->cb_list[frame];
++		cb_entry->cb = dma_pool_alloc(c->cb_pool, gfp,
++					      &cb_entry->paddr);
++		if (!cb_entry->cb)
++			goto error_cb;
++
++		/* fill in the control block */
++		control_block = cb_entry->cb;
++		control_block->info = info;
++		control_block->src = src;
++		control_block->dst = dst;
++		control_block->stride = 0;
++		control_block->next = 0;
++		/* set up length in control_block if requested */
++		if (buf_len) {
++			/* calculate length honoring period_length */
++			bcm2835_dma_create_cb_set_length(
++				c, control_block,
++				len, period_len, &total_len,
++				cyclic ? finalextrainfo : 0);
++
++			/* calculate new remaining length */
++			len -= control_block->length;
++		}
++
++		/* link this the last controlblock */
++		if (frame)
++			d->cb_list[frame - 1].cb->next = cb_entry->paddr;
++
++		/* update src and dst and length */
++		if (src && (info & BCM2835_DMA_S_INC))
++			src += control_block->length;
++		if (dst && (info & BCM2835_DMA_D_INC))
++			dst += control_block->length;
++
++		/* Length of total transfer */
++		d->size += control_block->length;
++	}
++
++	/* the last frame requires extra flags */
++	d->cb_list[d->frames - 1].cb->info |= finalextrainfo;
++
++	/* detect a size missmatch */
++	if (buf_len && (d->size != buf_len))
++		goto error_cb;
++
++	return d;
++error_cb:
++	bcm2835_dma_free_cb_chain(d);
++
++	return NULL;
++}
++
+ static int bcm2835_dma_abort(void __iomem *chan_base)
+ {
+ 	unsigned long cs;
+@@ -391,12 +540,11 @@ static struct dma_async_tx_descriptor *b
+ 	unsigned long flags)
+ {
+ 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
+-	enum dma_slave_buswidth dev_width;
+ 	struct bcm2835_desc *d;
+-	dma_addr_t dev_addr;
+-	unsigned int es, sync_type;
+-	unsigned int frame;
+-	int i;
++	dma_addr_t src, dst;
++	u32 info = BCM2835_DMA_WAIT_RESP;
++	u32 extra = BCM2835_DMA_INT_EN;
++	size_t frames;
+ 
+ 	/* Grab configuration */
+ 	if (!is_slave_direction(direction)) {
+@@ -404,104 +552,58 @@ static struct dma_async_tx_descriptor *b
+ 		return NULL;
+ 	}
+ 
+-	if (direction == DMA_DEV_TO_MEM) {
+-		dev_addr = c->cfg.src_addr;
+-		dev_width = c->cfg.src_addr_width;
+-		sync_type = BCM2835_DMA_S_DREQ;
+-	} else {
+-		dev_addr = c->cfg.dst_addr;
+-		dev_width = c->cfg.dst_addr_width;
+-		sync_type = BCM2835_DMA_D_DREQ;
+-	}
+-
+-	/* Bus width translates to the element size (ES) */
+-	switch (dev_width) {
+-	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+-		es = BCM2835_DMA_DATA_TYPE_S32;
+-		break;
+-	default:
++	if (!buf_len) {
++		dev_err(chan->device->dev,
++			"%s: bad buffer length (= 0)\n", __func__);
+ 		return NULL;
+ 	}
+ 
+-	/* Now allocate and setup the descriptor. */
+-	d = kzalloc(sizeof(*d), GFP_NOWAIT);
+-	if (!d)
+-		return NULL;
+-
+-	d->c = c;
+-	d->dir = direction;
+-	d->frames = buf_len / period_len;
+-	d->cyclic = true;
++	/*
++	 * warn if buf_len is not a multiple of period_len - this may leed
++	 * to unexpected latencies for interrupts and thus audiable clicks
++	 */
++	if (buf_len % period_len)
++		dev_warn_once(chan->device->dev,
++			      "%s: buffer_length (%zd) is not a multiple of period_len (%zd)\n",
++			      __func__, buf_len, period_len);
++
++	/* Setup DREQ channel */
++	if (c->dreq != 0)
++		info |= BCM2835_DMA_PER_MAP(c->dreq);
+ 
+-	d->cb_list = kcalloc(d->frames, sizeof(*d->cb_list), GFP_KERNEL);
+-	if (!d->cb_list) {
+-		kfree(d);
+-		return NULL;
++	if (direction == DMA_DEV_TO_MEM) {
++		if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
++			return NULL;
++		src = c->cfg.src_addr;
++		dst = buf_addr;
++		info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC;
++	} else {
++		if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
++			return NULL;
++		dst = c->cfg.dst_addr;
++		src = buf_addr;
++		info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC;
+ 	}
+-	/* Allocate memory for control blocks */
+-	for (i = 0; i < d->frames; i++) {
+-		struct bcm2835_cb_entry *cb_entry = &d->cb_list[i];
+ 
+-		cb_entry->cb = dma_pool_zalloc(c->cb_pool, GFP_ATOMIC,
+-					       &cb_entry->paddr);
+-		if (!cb_entry->cb)
+-			goto error_cb;
+-	}
++	/* calculate number of frames */
++	frames = DIV_ROUND_UP(buf_len, period_len);
+ 
+ 	/*
+-	 * Iterate over all frames, create a control block
+-	 * for each frame and link them together.
++	 * allocate the CB chain
++	 * note that we need to use GFP_NOWAIT, as the ALSA i2s dmaengine
++	 * implementation calls prep_dma_cyclic with interrupts disabled.
+ 	 */
+-	for (frame = 0; frame < d->frames; frame++) {
+-		struct bcm2835_dma_cb *control_block = d->cb_list[frame].cb;
+-
+-		/* Setup adresses */
+-		if (d->dir == DMA_DEV_TO_MEM) {
+-			control_block->info = BCM2835_DMA_D_INC;
+-			control_block->src = dev_addr;
+-			control_block->dst = buf_addr + frame * period_len;
+-		} else {
+-			control_block->info = BCM2835_DMA_S_INC;
+-			control_block->src = buf_addr + frame * period_len;
+-			control_block->dst = dev_addr;
+-		}
+-
+-		/* Enable interrupt */
+-		control_block->info |= BCM2835_DMA_INT_EN;
+-
+-		/* Setup synchronization */
+-		if (sync_type != 0)
+-			control_block->info |= sync_type;
+-
+-		/* Setup DREQ channel */
+-		if (c->dreq != 0)
+-			control_block->info |=
+-				BCM2835_DMA_PER_MAP(c->dreq);
+-
+-		/* Length of a frame */
+-		control_block->length = period_len;
+-		d->size += control_block->length;
++	d = bcm2835_dma_create_cb_chain(chan, direction, true,
++					info, extra,
++					frames, src, dst, buf_len,
++					period_len, GFP_NOWAIT);
++	if (!d)
++		return NULL;
+ 
+-		/*
+-		 * Next block is the next frame.
+-		 * This DMA engine driver currently only supports cyclic DMA.
+-		 * Therefore, wrap around at number of frames.
+-		 */
+-		control_block->next = d->cb_list[((frame + 1) % d->frames)].paddr;
+-	}
++	/* wrap around into a loop */
++	d->cb_list[d->frames - 1].cb->next = d->cb_list[0].paddr;
+ 
+ 	return vchan_tx_prep(&c->vc, &d->vd, flags);
+-error_cb:
+-	i--;
+-	for (; i >= 0; i--) {
+-		struct bcm2835_cb_entry *cb_entry = &d->cb_list[i];
+-
+-		dma_pool_free(c->cb_pool, cb_entry->cb, cb_entry->paddr);
+-	}
+-
+-	kfree(d->cb_list);
+-	kfree(d);
+-	return NULL;
+ }
+ 
+ static int bcm2835_dma_slave_config(struct dma_chan *chan,