+static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
+ dma_addr_t psrc,
+ dma_addr_t pdst,
+ size_t len)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_desc *desc;
+ size_t xfer_count;
+
+ u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
+ u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
+ ATC_SRC_ADDR_MODE_FIXED |
+ ATC_DST_ADDR_MODE_INCR |
+ ATC_FC_MEM2MEM;
+
+ xfer_count = len >> 2;
+ if (xfer_count > ATC_BTSIZE_MAX) {
+ dev_err(chan2dev(chan), "%s: buffer is too big\n",
+ __func__);
+ return NULL;
+ }
+
+ desc = atc_desc_get(atchan);
+ if (!desc) {
+ dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
+ __func__);
+ return NULL;
+ }
+
+ desc->lli.saddr = psrc;
+ desc->lli.daddr = pdst;
+ desc->lli.ctrla = ctrla | xfer_count;
+ desc->lli.ctrlb = ctrlb;
+
+ desc->txd.cookie = 0;
+ desc->len = len;
+
+ return desc;
+}
+
+/**
+ * atc_prep_dma_memset - prepare a memcpy operation
+ * @chan: the channel to prepare operation on
+ * @dest: operation virtual destination address
+ * @value: value to set memory buffer to
+ * @len: operation length
+ * @flags: tx descriptor status flags
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
+ size_t len, unsigned long flags)
+{
+ struct at_dma *atdma = to_at_dma(chan->device);
+ struct at_desc *desc;
+ void __iomem *vaddr;
+ dma_addr_t paddr;
+
+ dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__,
+ &dest, value, len, flags);
+
+ if (unlikely(!len)) {
+ dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
+ return NULL;
+ }
+
+ if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
+ dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n",
+ __func__);
+ return NULL;
+ }
+
+ vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+ if (!vaddr) {
+ dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
+ __func__);
+ return NULL;
+ }
+ *(u32*)vaddr = value;
+
+ desc = atc_create_memset_desc(chan, paddr, dest, len);
+ if (!desc) {
+ dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
+ __func__);
+ goto err_free_buffer;
+ }
+
+ desc->memset_paddr = paddr;
+ desc->memset_vaddr = vaddr;
+ desc->memset_buffer = true;
+
+ desc->txd.cookie = -EBUSY;
+ desc->total_len = len;
+
+ /* set end-of-link on the descriptor */
+ set_desc_eol(desc);
+
+ desc->txd.flags = flags;
+
+ return &desc->txd;
+
+err_free_buffer:
+ dma_pool_free(atdma->memset_pool, vaddr, paddr);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+atc_prep_dma_memset_sg(struct dma_chan *chan,
+ struct scatterlist *sgl,
+ unsigned int sg_len, int value,
+ unsigned long flags)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma *atdma = to_at_dma(chan->device);
+ struct at_desc *desc = NULL, *first = NULL, *prev = NULL;
+ struct scatterlist *sg;
+ void __iomem *vaddr;
+ dma_addr_t paddr;
+ size_t total_len = 0;
+ int i;
+
+ dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
+ value, sg_len, flags);
+
+ if (unlikely(!sgl || !sg_len)) {
+ dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
+ __func__);
+ return NULL;
+ }
+
+ vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+ if (!vaddr) {
+ dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
+ __func__);
+ return NULL;
+ }
+ *(u32*)vaddr = value;
+
+ for_each_sg(sgl, sg, sg_len, i) {
+ dma_addr_t dest = sg_dma_address(sg);
+ size_t len = sg_dma_len(sg);
+
+ dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n",
+ __func__, &dest, len);
+
+ if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
+ dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
+ __func__);
+ goto err_put_desc;
+ }
+
+ desc = atc_create_memset_desc(chan, paddr, dest, len);
+ if (!desc)
+ goto err_put_desc;
+
+ atc_desc_chain(&first, &prev, desc);
+
+ total_len += len;
+ }
+
+ /*
+ * Only set the buffer pointers on the last descriptor to
+ * avoid free'ing while we have our transfer still going
+ */
+ desc->memset_paddr = paddr;
+ desc->memset_vaddr = vaddr;
+ desc->memset_buffer = true;
+
+ first->txd.cookie = -EBUSY;
+ first->total_len = total_len;
+
+ /* set end-of-link on the descriptor */
+ set_desc_eol(desc);
+
+ first->txd.flags = flags;
+
+ return &first->txd;
+
+err_put_desc:
+ atc_desc_put(atchan, first);
+ return NULL;
+}