The maximum block size is a configurable parameter for the chip. So, driver will try to get it from the encoded component parameters. Otherwise it will come from the platform data.
Signed-off-by: Andy Shevchenko <[email protected]> --- arch/arm/mach-spear13xx/spear13xx.c | 1 + arch/avr32/mach-at32ap/at32ap700x.c | 1 + drivers/dma/dw_dmac.c | 34 ++++++++++++++++++---------------- drivers/dma/dw_dmac_regs.h | 3 +++ include/linux/dw_dmac.h | 2 ++ 5 files changed, 25 insertions(+), 16 deletions(-) diff --git a/arch/arm/mach-spear13xx/spear13xx.c b/arch/arm/mach-spear13xx/spear13xx.c index cf936b1..c64d812 100644 --- a/arch/arm/mach-spear13xx/spear13xx.c +++ b/arch/arm/mach-spear13xx/spear13xx.c @@ -78,6 +78,7 @@ struct dw_dma_platform_data dmac_plat_data = { .nr_channels = 8, .chan_allocation_order = CHAN_ALLOCATION_DESCENDING, .chan_priority = CHAN_PRIORITY_DESCENDING, + .block_size = 4095U, }; void __init spear13xx_l2x0_init(void) diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c index 0445c4f..2c4aefe 100644 --- a/arch/avr32/mach-at32ap/at32ap700x.c +++ b/arch/avr32/mach-at32ap/at32ap700x.c @@ -605,6 +605,7 @@ static void __init genclk_init_parent(struct clk *clk) static struct dw_dma_platform_data dw_dmac0_data = { .nr_channels = 3, + .block_size = 4095U, }; static struct resource dw_dmac0_resource[] = { diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 2a3b730..ab718ee 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -58,16 +58,6 @@ }) /* - * This is configuration-dependent and usually a funny size like 4095. - * - * Note that this is a transfer count, i.e. if we transfer 32-bit - * words, we can do 16380 bytes per descriptor. - * - * This parameter is also system-specific. - */ -#define DWC_MAX_COUNT 4095U - -/* * Number of descriptors to allocate for each channel. This should be * made configurable somehow; preferably, the clients (at least the * ones using slave transfers) should be able to give us a hint. @@ -669,7 +659,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, for (offset = 0; offset < len; offset += xfer_count << src_width) { xfer_count = min_t(size_t, (len - offset) >> src_width, - DWC_MAX_COUNT); + dwc->block_size); desc = dwc_desc_get(dwc); if (!desc) @@ -770,8 +760,8 @@ slave_sg_todev_fill_desc: desc->lli.sar = mem; desc->lli.dar = reg; desc->lli.ctllo = ctllo | DWC_CTLL_SRC_WIDTH(mem_width); - if ((len >> mem_width) > DWC_MAX_COUNT) { - dlen = DWC_MAX_COUNT << mem_width; + if ((len >> mem_width) > dwc->block_size) { + dlen = dwc->block_size << mem_width; mem += dlen; len -= dlen; } else { @@ -830,8 +820,8 @@ slave_sg_fromdev_fill_desc: desc->lli.sar = reg; desc->lli.dar = mem; desc->lli.ctllo = ctllo | DWC_CTLL_DST_WIDTH(mem_width); - if ((len >> reg_width) > DWC_MAX_COUNT) { - dlen = DWC_MAX_COUNT << reg_width; + if ((len >> reg_width) > dwc->block_size) { + dlen = dwc->block_size << reg_width; mem += dlen; len -= dlen; } else { @@ -1214,7 +1204,7 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan, periods = buf_len / period_len; /* Check for too big/unaligned periods and unaligned DMA buffer. */ - if (period_len > (DWC_MAX_COUNT << reg_width)) + if (period_len > (dwc->block_size << reg_width)) goto out_err; if (unlikely(period_len & ((1 << reg_width) - 1))) goto out_err; @@ -1380,6 +1370,7 @@ static int __devinit dw_probe(struct platform_device *pdev) bool autocfg; unsigned int dw_params; unsigned int nr_channels; + unsigned int max_blk_size; int irq; int err; int i; @@ -1420,6 +1411,9 @@ static int __devinit dw_probe(struct platform_device *pdev) dw->regs = regs; + /* get hardware configuration parameters */ + max_blk_size = dma_readl(dw, MAX_BLK_SIZE); + /* Calculate all channel mask before DMA setup */ dw->all_chan_mask = (1 << nr_channels) - 1; @@ -1465,6 +1459,14 @@ static int __devinit dw_probe(struct platform_device *pdev) INIT_LIST_HEAD(&dwc->free_list); channel_clear_bit(dw, CH_EN, dwc->mask); + + /* hardware configuration */ + if (autocfg) { + dwc->block_size = + (4 << ((max_blk_size >> 4 * i) & 0xf)) - 1; + } else { + dwc->block_size = pdata->block_size; + } } /* Clear all interrupts on all channels. */ diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h index 0f96965..233f5e5 100644 --- a/drivers/dma/dw_dmac_regs.h +++ b/drivers/dma/dw_dmac_regs.h @@ -186,6 +186,9 @@ struct dw_dma_chan { unsigned int descs_allocated; + /* hardware configuration */ + unsigned short block_size; + /* configuration passed via DMA_SLAVE_CONFIG */ struct dma_slave_config dma_sconfig; }; diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h index 2412e02..3315ef9 100644 --- a/include/linux/dw_dmac.h +++ b/include/linux/dw_dmac.h @@ -19,6 +19,7 @@ * @nr_channels: Number of channels supported by hardware (max 8) * @is_private: The device channels should be marked as private and not for * by the general purpose DMA channel allocator. + * @block_size: Maximum block size supported by the controller */ struct dw_dma_platform_data { unsigned int nr_channels; @@ -29,6 +30,7 @@ struct dw_dma_platform_data { #define CHAN_PRIORITY_ASCENDING 0 /* chan0 highest */ #define CHAN_PRIORITY_DESCENDING 1 /* chan7 highest */ unsigned char chan_priority; + unsigned short block_size; }; /* bursts size */ -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
