On Thu, May 14, 2015 at 07:53:23PM +0200, Robert Jarzmik wrote:
> +#define DCSR(n) (0x0000 + ((n) << 2))
> +#define DALGN(n) 0x00a0
> +#define DINT 0x00f0
> +#define DDADR(n) (0x0200 + ((n) << 4))
> +#define DSADR(n) (0x0204 + ((n) << 4))
> +#define DTADR(n) (0x0208 + ((n) << 4))
> +#define DCMD(n) (0x020c + ((n) << 4))
> +
> +#define DCSR_RUN BIT(31) /* Run Bit (read / write) */
> +#define DCSR_NODESC BIT(30) /* No-Descriptor Fetch (read / write) */
> +#define DCSR_STOPIRQEN BIT(29) /* Stop Interrupt Enable (read / write)
> */
> +#define DCSR_REQPEND BIT(8) /* Request Pending (read-only) */
> +#define DCSR_STOPSTATE BIT(3) /* Stop State (read-only) */
> +#define DCSR_ENDINTR BIT(2) /* End Interrupt (read / write) */
> +#define DCSR_STARTINTR BIT(1) /* Start Interrupt (read / write) */
> +#define DCSR_BUSERR BIT(0) /* Bus Error Interrupt (read / write) */
> +
> +#define DCSR_EORIRQEN BIT(28) /* End of Receive Interrupt Enable
> (R/W) */
> +#define DCSR_EORJMPEN BIT(27) /* Jump to next descriptor on EOR */
> +#define DCSR_EORSTOPEN BIT(26) /* STOP on an EOR */
> +#define DCSR_SETCMPST BIT(25) /* Set Descriptor Compare Status */
> +#define DCSR_CLRCMPST BIT(24) /* Clear Descriptor Compare Status */
> +#define DCSR_CMPST BIT(10) /* The Descriptor Compare Status */
> +#define DCSR_EORINTR BIT(9) /* The end of Receive */
would help if these are PXA_xxx
> +
> +/*
> + * Requestor lines are mapped as :
> + * - lines 0 to 63 : DRCMR(line) = 0x100 + line * 4
> + * - lines 64 to +oo : DRCMR(line) = 0x1000 + line * 4
> + */
> +#define DRCMR(n) ((((n) < 64) ? 0x0100 : 0x1100) + (((n) & 0x3f) << 2))
This is hard to read, why not make this a function?
> +static int pxad_alloc_chan_resources(struct dma_chan *dchan)
> +{
> + struct pxad_chan *chan = to_pxad_chan(dchan);
> + struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
> +
> + if (chan->desc_pool)
> + return 1;
> +
> + chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
> + pdev->slave.dev,
> + sizeof(struct pxad_desc_hw),
> + __alignof__(struct pxad_desc_hw),
why __alignof__ and why not simple say sizeof(struct pxad_desc_hw) to align
the pool for this struct. Also you have given the descriptor size here for
pool size, which sounds odd and ideally you would like to request a large
pool for channel for allocating multiple desc
> +static struct pxad_desc_sw *
> +pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
> +{
> + struct pxad_desc_sw *sw_desc;
> + dma_addr_t dma;
> + int i;
> +
> + sw_desc = kzalloc(sizeof(*sw_desc) +
> + nb_hw_desc * sizeof(struct pxad_desc_hw *),
> + GFP_ATOMIC);
GFP_NOWAIT
> + if (!sw_desc)
> + return NULL;
> + sw_desc->desc_pool = chan->desc_pool;
> +
> + for (i = 0; i < nb_hw_desc; i++) {
> + sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
> + GFP_ATOMIC, &dma);
GFP_NOWAIT
--
~Vinod
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