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dmaengine: ti: k3-udma: Move the TR counter calculation to helper function

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Move the TR counter parameter configuration code out from the prep_memcpy
callback to a helper function to allow a generic re-usable code for other
TR based transfers.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200214091441.27535-4-peter.ujfalusi@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Peter Ujfalusi 2020-02-14 11:14:38 +02:00 committed by Vinod Koul
parent 16cd3c6701
commit a97934071f
1 changed files with 51 additions and 23 deletions
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68
drivers/dma/ti/k3-udma.c
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@ -2029,6 +2029,51 @@ static struct udma_desc *udma_alloc_tr_desc(struct udma_chan *uc,
return d;
}
/**
* udma_get_tr_counters - calculate TR counters for a given length
* @len: Length of the trasnfer
* @align_to: Preferred alignment
* @tr0_cnt0: First TR icnt0
* @tr0_cnt1: First TR icnt1
* @tr1_cnt0: Second (if used) TR icnt0
*
* For len < SZ_64K only one TR is enough, tr1_cnt0 is not updated
* For len >= SZ_64K two TRs are used in a simple way:
* First TR: SZ_64K-alignment blocks (tr0_cnt0, tr0_cnt1)
* Second TR: the remaining length (tr1_cnt0)
*
* Returns the number of TRs the length needs (1 or 2)
* -EINVAL if the length can not be supported
*/
static int udma_get_tr_counters(size_t len, unsigned long align_to,
u16 *tr0_cnt0, u16 *tr0_cnt1, u16 *tr1_cnt0)
{
if (len < SZ_64K) {
*tr0_cnt0 = len;
*tr0_cnt1 = 1;
return 1;
}
if (align_to > 3)
align_to = 3;
realign:
*tr0_cnt0 = SZ_64K - BIT(align_to);
if (len / *tr0_cnt0 >= SZ_64K) {
if (align_to) {
align_to--;
goto realign;
}
return -EINVAL;
}
*tr0_cnt1 = len / *tr0_cnt0;
*tr1_cnt0 = len % *tr0_cnt0;
return 2;
}
static struct udma_desc *
udma_prep_slave_sg_tr(struct udma_chan *uc, struct scatterlist *sgl,
unsigned int sglen, enum dma_transfer_direction dir,
@ -2581,31 +2626,14 @@ udma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
return NULL;
}
if (len < SZ_64K) {
num_tr = 1;
tr0_cnt0 = len;
tr0_cnt1 = 1;
} else {
unsigned long align_to = __ffs(src | dest);
if (align_to > 3)
align_to = 3;
/*
* Keep simple: tr0: SZ_64K-alignment blocks,
* tr1: the remaining
*/
num_tr = 2;
tr0_cnt0 = (SZ_64K - BIT(align_to));
if (len / tr0_cnt0 >= SZ_64K) {
num_tr = udma_get_tr_counters(len, __ffs(src | dest), &tr0_cnt0,
&tr0_cnt1, &tr1_cnt0);
if (num_tr < 0) {
dev_err(uc->ud->dev, "size %zu is not supported\n",
len);
return NULL;
}
tr0_cnt1 = len / tr0_cnt0;
tr1_cnt0 = len % tr0_cnt0;
}
d = udma_alloc_tr_desc(uc, tr_size, num_tr, DMA_MEM_TO_MEM);
if (!d)
return NULL;