[PATCH 1/3] DMA: PL330: Infer transfer direction from transfer request instead of platform data
Boojin Kim
boojin.kim at samsung.com
Tue Aug 23 21:21:18 EDT 2011
Thomas Abraham wrote:
> Sent: Tuesday, August 23, 2011 7:00 AM
> To: linux-arm-kernel at lists.infradead.org
> Cc: linux-samsung-soc at vger.kernel.org; kgene.kim at samsung.com;
> vinod.koul at intel.com; Jassi Brar; Boojin Kim
> Subject: [PATCH 1/3] DMA: PL330: Infer transfer direction from
> transfer request instead of platform data
>
> The transfer direction for a channel can be inferred from the transfer
> request and the need for specifying transfer direction in platfrom
> data
> can be eliminated. So the structure definition 'struct dma_pl330_peri'
> is no longer required.
>
> With the 'struct dma_pl330_peri' removed, the dma controller transfer
> capabilities cannot be inferred any longer. Hence, the dma controller
> capabilities is specified using platforme data.
>
> Cc: Jassi Brar <jassisinghbrar at gmail.com>
> Cc: Boojin Kim <boojin.kim at samsung.com>
> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
> ---
> drivers/dma/pl330.c | 56 ++++++++------------------------------
> ------
> include/linux/amba/pl330.h | 14 +++--------
> 2 files changed, 14 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 3a0baac..6592b9a 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -507,7 +507,7 @@ pluck_desc(struct dma_pl330_dmac *pdmac)
> static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan
> *pch)
> {
> struct dma_pl330_dmac *pdmac = pch->dmac;
> - struct dma_pl330_peri *peri = pch->chan.private;
> + u8 *peri_id = pch->chan.private;
> struct dma_pl330_desc *desc;
>
> /* Pluck one desc from the pool of DMAC */
> @@ -531,14 +531,7 @@ static struct dma_pl330_desc
> *pl330_get_desc(struct dma_pl330_chan *pch)
> desc->pchan = pch;
> desc->txd.cookie = 0;
> async_tx_ack(&desc->txd);
> -
> - if (peri) {
> - desc->req.rqtype = peri->rqtype;
> - desc->req.peri = pch->chan.chan_id;
> - } else {
> - desc->req.rqtype = MEMTOMEM;
> - desc->req.peri = 0;
> - }
> + desc->req.peri = (peri_id) ? pch->chan.chan_id : 0;
>
> dma_async_tx_descriptor_init(&desc->txd, &pch->chan);
>
> @@ -625,12 +618,14 @@ static struct dma_async_tx_descriptor
> *pl330_prep_dma_cyclic(
> case DMA_TO_DEVICE:
> desc->rqcfg.src_inc = 1;
> desc->rqcfg.dst_inc = 0;
> + desc->req.rqtype = MEMTODEV;
> src = dma_addr;
> dst = pch->fifo_addr;
> break;
> case DMA_FROM_DEVICE:
> desc->rqcfg.src_inc = 0;
> desc->rqcfg.dst_inc = 1;
> + desc->req.rqtype = DEVTOMEM;
> src = pch->fifo_addr;
> dst = dma_addr;
> break;
> @@ -657,16 +652,12 @@ pl330_prep_dma_memcpy(struct dma_chan *chan,
> dma_addr_t dst,
> {
> struct dma_pl330_desc *desc;
> struct dma_pl330_chan *pch = to_pchan(chan);
> - struct dma_pl330_peri *peri = chan->private;
> struct pl330_info *pi;
> int burst;
>
> if (unlikely(!pch || !len))
> return NULL;
>
> - if (peri && peri->rqtype != MEMTOMEM)
> - return NULL;
> -
> pi = &pch->dmac->pif;
>
> desc = __pl330_prep_dma_memcpy(pch, dst, src, len);
> @@ -675,6 +666,7 @@ pl330_prep_dma_memcpy(struct dma_chan *chan,
> dma_addr_t dst,
>
> desc->rqcfg.src_inc = 1;
> desc->rqcfg.dst_inc = 1;
> + desc->req.rqtype = MEMTOMEM;
>
> /* Select max possible burst size */
> burst = pi->pcfg.data_bus_width / 8;
> @@ -703,25 +695,14 @@ pl330_prep_slave_sg(struct dma_chan *chan,
> struct scatterlist *sgl,
> {
> struct dma_pl330_desc *first, *desc = NULL;
> struct dma_pl330_chan *pch = to_pchan(chan);
> - struct dma_pl330_peri *peri = chan->private;
> struct scatterlist *sg;
> unsigned long flags;
> int i;
> dma_addr_t addr;
>
> - if (unlikely(!pch || !sgl || !sg_len || !peri))
> + if (unlikely(!pch || !sgl || !sg_len))
> return NULL;
>
> - /* Make sure the direction is consistent */
> - if ((direction == DMA_TO_DEVICE &&
> - peri->rqtype != MEMTODEV) ||
> - (direction == DMA_FROM_DEVICE &&
> - peri->rqtype != DEVTOMEM)) {
> - dev_err(pch->dmac->pif.dev, "%s:%d Invalid Direction\n",
> - __func__, __LINE__);
> - return NULL;
> - }
> -
> addr = pch->fifo_addr;
>
> first = NULL;
> @@ -761,11 +742,13 @@ pl330_prep_slave_sg(struct dma_chan *chan,
> struct scatterlist *sgl,
> if (direction == DMA_TO_DEVICE) {
> desc->rqcfg.src_inc = 1;
> desc->rqcfg.dst_inc = 0;
> + desc->req.rqtype = MEMTODEV;
> fill_px(&desc->px,
> addr, sg_dma_address(sg), sg_dma_len(sg));
> } else {
> desc->rqcfg.src_inc = 0;
> desc->rqcfg.dst_inc = 1;
> + desc->req.rqtype = DEVTOMEM;
> fill_px(&desc->px,
> sg_dma_address(sg), addr, sg_dma_len(sg));
> }
> @@ -872,27 +855,7 @@ pl330_probe(struct amba_device *adev, const
> struct amba_id *id)
>
> for (i = 0; i < num_chan; i++) {
> pch = &pdmac->peripherals[i];
> - if (pdat) {
> - struct dma_pl330_peri *peri = &pdat->peri[i];
> -
> - switch (peri->rqtype) {
> - case MEMTOMEM:
> - dma_cap_set(DMA_MEMCPY, pd->cap_mask);
> - break;
> - case MEMTODEV:
> - case DEVTOMEM:
> - dma_cap_set(DMA_SLAVE, pd->cap_mask);
> - dma_cap_set(DMA_CYCLIC, pd->cap_mask);
> - break;
If remove capabilities setting, dmaengine() doesn't search the channel that
client requests with specific capability.
So, I think dma_request_channel() would fail.
> - default:
> - dev_err(&adev->dev, "DEVTODEV Not
> Supported\n");
> - continue;
> - }
> - pch->chan.private = peri;
> - } else {
> - dma_cap_set(DMA_MEMCPY, pd->cap_mask);
> - pch->chan.private = NULL;
> - }
> + pch->chan.private = (pdat) ? &pdat->peri_id[i] : NULL;
>
> INIT_LIST_HEAD(&pch->work_list);
> spin_lock_init(&pch->lock);
> @@ -907,6 +870,7 @@ pl330_probe(struct amba_device *adev, const struct
> amba_id *id)
> }
>
> pd->dev = &adev->dev;
> + pd->cap_mask = pdat->cap_mask;
>
> pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
> pd->device_free_chan_resources = pl330_free_chan_resources;
> diff --git a/include/linux/amba/pl330.h b/include/linux/amba/pl330.h
> index d12f077..0b87300 100644
> --- a/include/linux/amba/pl330.h
> +++ b/include/linux/amba/pl330.h
> @@ -13,15 +13,7 @@
> #define __AMBA_PL330_H_
>
> #include <asm/hardware/pl330.h>
> -
> -struct dma_pl330_peri {
> - /*
> - * Peri_Req i/f of the DMAC that is
> - * peripheral could be reached from.
> - */
> - u8 peri_id; /* specific dma id */
> - enum pl330_reqtype rqtype;
> -};
> +#include <linux/dmaengine.h>
>
> struct dma_pl330_platdata {
> /*
> @@ -33,7 +25,9 @@ struct dma_pl330_platdata {
> */
> u8 nr_valid_peri;
> /* Array of valid peripherals */
> - struct dma_pl330_peri *peri;
> + u8 *peri_id;
> + /* Operational capabilities */
> + dma_cap_mask_t cap_mask;
> /* Bytes to allocate for MC buffer */
> unsigned mcbuf_sz;
> };
> --
> 1.6.6.rc2
>
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