diff options
| author | Russell King - ARM Linux <linux@arm.linux.org.uk> | 2011-07-21 18:14:08 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2011-07-26 12:03:29 +0200 |
| commit | 760596c6b986e6345a28392cf40ee344bfd209a6 (patch) | |
| tree | 4c08d2b8a0c28c4eb6ac558d672be5bb5e4eae05 /drivers/dma | |
| parent | DMA: PL08x: avoid recalculating cctl at each prepare (diff) | |
| download | linux-760596c6b986e6345a28392cf40ee344bfd209a6.tar.xz linux-760596c6b986e6345a28392cf40ee344bfd209a6.zip | |
DMA: PL08x: cleanup selection of burst size
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/amba-pl08x.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index a84db8b39ba1..9aa2bd4452d3 100644 --- a/drivers/dma/amba-pl08x.c +++ b/drivers/dma/amba-pl08x.c @@ -1048,50 +1048,42 @@ pl08x_dma_tx_status(struct dma_chan *chan, /* PrimeCell DMA extension */ struct burst_table { - int burstwords; + u32 burstwords; u32 reg; }; static const struct burst_table burst_sizes[] = { { .burstwords = 256, - .reg = (PL080_BSIZE_256 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_256 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_256, }, { .burstwords = 128, - .reg = (PL080_BSIZE_128 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_128 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_128, }, { .burstwords = 64, - .reg = (PL080_BSIZE_64 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_64 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_64, }, { .burstwords = 32, - .reg = (PL080_BSIZE_32 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_32 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_32, }, { .burstwords = 16, - .reg = (PL080_BSIZE_16 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_16 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_16, }, { .burstwords = 8, - .reg = (PL080_BSIZE_8 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_8 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_8, }, { .burstwords = 4, - .reg = (PL080_BSIZE_4 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_4 << PL080_CONTROL_DB_SIZE_SHIFT), + .reg = PL080_BSIZE_4, }, { - .burstwords = 1, - .reg = (PL080_BSIZE_1 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_1 << PL080_CONTROL_DB_SIZE_SHIFT), + .burstwords = 0, + .reg = PL080_BSIZE_1, }, }; @@ -1135,15 +1127,25 @@ static u32 pl08x_width(enum dma_slave_buswidth width) return ~0; } +static u32 pl08x_burst(u32 maxburst) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(burst_sizes); i++) + if (burst_sizes[i].burstwords <= maxburst) + break; + + return burst_sizes[i].reg; +} + static int dma_set_runtime_config(struct dma_chan *chan, struct dma_slave_config *config) { struct pl08x_dma_chan *plchan = to_pl08x_chan(chan); struct pl08x_driver_data *pl08x = plchan->host; enum dma_slave_buswidth addr_width; - u32 width, maxburst; + u32 width, burst, maxburst; u32 cctl = 0; - int i; if (!plchan->slave) return -EINVAL; @@ -1173,20 +1175,16 @@ static int dma_set_runtime_config(struct dma_chan *chan, cctl |= width << PL080_CONTROL_DWIDTH_SHIFT; /* - * Now decide on a maxburst: * If this channel will only request single transfers, set this * down to ONE element. Also select one element if no maxburst * is specified. */ - if (plchan->cd->single || maxburst == 0) { - cctl |= (PL080_BSIZE_1 << PL080_CONTROL_SB_SIZE_SHIFT) | - (PL080_BSIZE_1 << PL080_CONTROL_DB_SIZE_SHIFT); - } else { - for (i = 0; i < ARRAY_SIZE(burst_sizes); i++) - if (burst_sizes[i].burstwords <= maxburst) - break; - cctl |= burst_sizes[i].reg; - } + if (plchan->cd->single) + maxburst = 1; + + burst = pl08x_burst(maxburst); + cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT; + cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT; if (plchan->runtime_direction == DMA_FROM_DEVICE) { plchan->src_addr = config->src_addr; |