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author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2020-02-14 12:14:38 +0300 |
---|---|---|
committer | Vinod Koul <vkoul@kernel.org> | 2020-02-19 10:39:11 +0300 |
commit | a97934071fc3b0a5e52c89e06da68bcac0481de3 (patch) | |
tree | e4037030772da71bbfbbffe0f867e7e89421fac3 | |
parent | 16cd3c670183d788f5a0dfe41415d3386ba92ed9 (diff) | |
download | linux-a97934071fc3b0a5e52c89e06da68bcac0481de3.tar.xz |
dmaengine: ti: k3-udma: Move the TR counter calculation to helper function
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>
-rw-r--r-- | drivers/dma/ti/k3-udma.c | 74 |
1 files changed, 51 insertions, 23 deletions
diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c index cb9259e104b4..9b00013d6f63 100644 --- a/drivers/dma/ti/k3-udma.c +++ b/drivers/dma/ti/k3-udma.c @@ -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, @@ -2581,29 +2626,12 @@ 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) { - dev_err(uc->ud->dev, "size %zu is not supported\n", - len); - return NULL; - } - - tr0_cnt1 = len / tr0_cnt0; - tr1_cnt0 = len % tr0_cnt0; + 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; } d = udma_alloc_tr_desc(uc, tr_size, num_tr, DMA_MEM_TO_MEM); |