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SubjectRe: [PATCH v2 2/2] dmaengine: omap-dma: Support for slave devices with data port window
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On 11/25/2016 08:12 AM, Vinod Koul wrote:
> On Thu, Nov 17, 2016 at 02:50:17PM +0200, Peter Ujfalusi wrote:
>> @@ -921,11 +931,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
>>
>> d->ccr = c->ccr | CCR_SYNC_FRAME;
>> if (dir == DMA_DEV_TO_MEM) {
>> - d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
>> d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
>> +
>> + d->ccr |= CCR_DST_AMODE_POSTINC;
>> + if (port_window) {
>> + d->ccr |= CCR_SRC_AMODE_DBLIDX;
>> + d->ei = 1;
>> + /*
>> + * One frame covers the port_window and by configure
>> + * the source frame index to be -1 * (port_window - 1)
>> + * we instruct the sDMA that after a frame is processed
>> + * it should move back to the start of the window.
>> + */
>> + d->fi = -(port_window - 1);
>> +
>> + if (port_window >= 64)
>> + d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
>> + else if (port_window >= 32)
>> + d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
>> + else if (port_window >= 16)
>> + d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
>
> this and other would look better with a switch..

I'm not sure if it will be any better:

switch (port_window) {
case 0 ... 15:
break;
case 16 ... 31:
d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
break;
case 32 ... 63:
d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
break;
default:
d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
break;
}


--
Péter

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