period_len       2093 drivers/dma/amba-pl08x.c 		size_t period_len, enum dma_transfer_direction direction,
period_len       2104 drivers/dma/amba-pl08x.c 		__func__, period_len, buf_len,
period_len       2114 drivers/dma/amba-pl08x.c 	for (tmp = 0; tmp < buf_len; tmp += period_len) {
period_len       2116 drivers/dma/amba-pl08x.c 				      buf_addr + tmp, period_len);
period_len       1207 drivers/dma/at_hdmac.c 		size_t period_len)
period_len       1209 drivers/dma/at_hdmac.c 	if (period_len > (ATC_BTSIZE_MAX << reg_width))
period_len       1211 drivers/dma/at_hdmac.c 	if (unlikely(period_len & ((1 << reg_width) - 1)))
period_len       1228 drivers/dma/at_hdmac.c 		unsigned int reg_width, size_t period_len,
period_len       1240 drivers/dma/at_hdmac.c 		| period_len >> reg_width;
period_len       1244 drivers/dma/at_hdmac.c 		desc->lli.saddr = buf_addr + (period_len * period_index);
period_len       1252 drivers/dma/at_hdmac.c 		desc->len = period_len;
period_len       1257 drivers/dma/at_hdmac.c 		desc->lli.daddr = buf_addr + (period_len * period_index);
period_len       1264 drivers/dma/at_hdmac.c 		desc->len = period_len;
period_len       1285 drivers/dma/at_hdmac.c 		size_t period_len, enum dma_transfer_direction direction,
period_len       1295 drivers/dma/at_hdmac.c 	unsigned int		periods = buf_len / period_len;
period_len       1301 drivers/dma/at_hdmac.c 			periods, buf_len, period_len);
period_len       1303 drivers/dma/at_hdmac.c 	if (unlikely(!atslave || !buf_len || !period_len)) {
period_len       1323 drivers/dma/at_hdmac.c 	if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
period_len       1335 drivers/dma/at_hdmac.c 					     reg_width, period_len, direction))
period_len        735 drivers/dma/at_xdmac.c 			 size_t buf_len, size_t period_len,
period_len        741 drivers/dma/at_xdmac.c 	unsigned int		periods = buf_len / period_len;
period_len        746 drivers/dma/at_xdmac.c 		__func__, &buf_addr, buf_len, period_len,
period_len        781 drivers/dma/at_xdmac.c 			desc->lld.mbr_da = buf_addr + i * period_len;
period_len        783 drivers/dma/at_xdmac.c 			desc->lld.mbr_sa = buf_addr + i * period_len;
period_len        790 drivers/dma/at_xdmac.c 			| period_len >> at_xdmac_get_dwidth(desc->lld.mbr_cfg);
period_len        227 drivers/dma/bcm2835-dma.c 	size_t period_len,
period_len        237 drivers/dma/bcm2835-dma.c 	if (!period_len)
period_len        249 drivers/dma/bcm2835-dma.c 	if (*total_len + control_block->length < period_len) {
period_len        256 drivers/dma/bcm2835-dma.c 	control_block->length = period_len - *total_len;
period_len        306 drivers/dma/bcm2835-dma.c 	size_t period_len, gfp_t gfp)
period_len        350 drivers/dma/bcm2835-dma.c 				len, period_len, &total_len,
period_len        696 drivers/dma/bcm2835-dma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        723 drivers/dma/bcm2835-dma.c 		period_len = buf_len;
period_len        729 drivers/dma/bcm2835-dma.c 	if (buf_len % period_len)
period_len        732 drivers/dma/bcm2835-dma.c 			      __func__, buf_len, period_len);
period_len        758 drivers/dma/bcm2835-dma.c 		 DIV_ROUND_UP(buf_len, period_len) *
period_len        760 drivers/dma/bcm2835-dma.c 		 bcm2835_dma_frames_for_length(period_len, max_len);
period_len        770 drivers/dma/bcm2835-dma.c 					period_len, GFP_NOWAIT);
period_len        485 drivers/dma/dma-axi-dmac.c 	unsigned int num_periods, unsigned int period_len,
period_len        493 drivers/dma/dma-axi-dmac.c 	num_segments = DIV_ROUND_UP(period_len, chan->max_length);
period_len        494 drivers/dma/dma-axi-dmac.c 	segment_size = DIV_ROUND_UP(period_len, num_segments);
period_len        499 drivers/dma/dma-axi-dmac.c 		len = period_len;
period_len        569 drivers/dma/dma-axi-dmac.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        583 drivers/dma/dma-axi-dmac.c 	if (period_len == 0 || buf_len % period_len)
period_len        586 drivers/dma/dma-axi-dmac.c 	num_periods = buf_len / period_len;
period_len        587 drivers/dma/dma-axi-dmac.c 	num_segments = DIV_ROUND_UP(period_len, chan->max_length);
period_len        594 drivers/dma/dma-axi-dmac.c 		period_len, desc->sg);
period_len        400 drivers/dma/dma-jz4780.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        408 drivers/dma/dma-jz4780.c 	if (buf_len % period_len)
period_len        411 drivers/dma/dma-jz4780.c 	periods = buf_len / period_len;
period_len        419 drivers/dma/dma-jz4780.c 					      period_len, direction);
period_len        425 drivers/dma/dma-jz4780.c 		buf_addr += period_len;
period_len       1116 drivers/dma/ep93xx_dma.c 			   size_t buf_len, size_t period_len,
period_len       1135 drivers/dma/ep93xx_dma.c 	if (period_len > DMA_MAX_CHAN_BYTES) {
period_len       1137 drivers/dma/ep93xx_dma.c 			 period_len);
period_len       1145 drivers/dma/ep93xx_dma.c 	for (offset = 0; offset < buf_len; offset += period_len) {
period_len       1160 drivers/dma/ep93xx_dma.c 		desc->size = period_len;
period_len        444 drivers/dma/fsl-edma-common.c 		size_t period_len, enum dma_transfer_direction direction,
period_len        460 drivers/dma/fsl-edma-common.c 	sg_len = buf_len / period_len;
period_len        480 drivers/dma/fsl-edma-common.c 	iter = period_len / nbytes;
period_len        504 drivers/dma/fsl-edma-common.c 		dma_buf_next += period_len;
period_len        236 drivers/dma/fsl-edma-common.h 		size_t period_len, enum dma_transfer_direction direction,
period_len        368 drivers/dma/img-mdc-dma.c 	size_t period_len, enum dma_transfer_direction dir,
period_len        377 drivers/dma/img-mdc-dma.c 	if (!buf_len && !period_len)
period_len        392 drivers/dma/img-mdc-dma.c 	mdesc->list_period_len = DIV_ROUND_UP(period_len,
period_len        396 drivers/dma/img-mdc-dma.c 		size_t remainder = min(period_len, buf_len);
period_len        868 drivers/dma/imx-dma.c 		size_t period_len, enum dma_transfer_direction direction,
period_len        875 drivers/dma/imx-dma.c 	unsigned int periods = buf_len / period_len;
period_len        878 drivers/dma/imx-dma.c 			__func__, imxdmac->channel, buf_len, period_len);
period_len        899 drivers/dma/imx-dma.c 		sg_dma_len(&imxdmac->sg_list[i]) = period_len;
period_len        900 drivers/dma/imx-dma.c 		dma_addr += period_len;
period_len        323 drivers/dma/imx-sdma.c 	unsigned int		period_len;
period_len        806 drivers/dma/imx-sdma.c 		bd->mode.count = desc->period_len;
period_len       1526 drivers/dma/imx-sdma.c 		size_t period_len, enum dma_transfer_direction direction,
period_len       1531 drivers/dma/imx-sdma.c 	int num_periods = buf_len / period_len;
period_len       1544 drivers/dma/imx-sdma.c 	desc->period_len = period_len;
period_len       1548 drivers/dma/imx-sdma.c 	if (period_len > SDMA_BD_MAX_CNT) {
period_len       1550 drivers/dma/imx-sdma.c 				channel, period_len, SDMA_BD_MAX_CNT);
period_len       1560 drivers/dma/imx-sdma.c 		bd->mode.count = period_len;
period_len       1574 drivers/dma/imx-sdma.c 				i, period_len, (u64)dma_addr,
period_len       1580 drivers/dma/imx-sdma.c 		dma_addr += period_len;
period_len       1581 drivers/dma/imx-sdma.c 		buf += period_len;
period_len       1668 drivers/dma/imx-sdma.c 				desc->period_len - desc->chn_real_count;
period_len        590 drivers/dma/k3dma.c 		       size_t buf_len, size_t period_len,
period_len        604 drivers/dma/k3dma.c 	       buf_len, period_len, (int)dir);
period_len        621 drivers/dma/k3dma.c 	if (period_len < modulo)
period_len        622 drivers/dma/k3dma.c 		modulo = period_len;
period_len        635 drivers/dma/k3dma.c 		if (since >= period_len) {
period_len        638 drivers/dma/k3dma.c 			since -= period_len;
period_len        607 drivers/dma/mmp_pdma.c 			 dma_addr_t buf_addr, size_t len, size_t period_len,
period_len        615 drivers/dma/mmp_pdma.c 	if (!dchan || !len || !period_len)
period_len        619 drivers/dma/mmp_pdma.c 	if (len % period_len != 0)
period_len        622 drivers/dma/mmp_pdma.c 	if (period_len > PDMA_MAX_DESC_BYTES)
period_len        653 drivers/dma/mmp_pdma.c 				  (DCMD_LENGTH & period_len));
period_len        666 drivers/dma/mmp_pdma.c 		len -= period_len;
period_len        669 drivers/dma/mmp_pdma.c 			dma_src += period_len;
period_len        671 drivers/dma/mmp_pdma.c 			dma_dst += period_len;
period_len        123 drivers/dma/mmp_tdma.c 	size_t				period_len;
period_len        424 drivers/dma/mmp_tdma.c 		size_t period_len, enum dma_transfer_direction direction,
period_len        429 drivers/dma/mmp_tdma.c 	int num_periods = buf_len / period_len;
period_len        435 drivers/dma/mmp_tdma.c 	if (period_len > TDMA_MAX_XFER_BYTES) {
period_len        438 drivers/dma/mmp_tdma.c 				period_len, TDMA_MAX_XFER_BYTES);
period_len        467 drivers/dma/mmp_tdma.c 		desc->byte_cnt = period_len;
period_len        468 drivers/dma/mmp_tdma.c 		dma_addr += period_len;
period_len        469 drivers/dma/mmp_tdma.c 		buf += period_len;
period_len        478 drivers/dma/mmp_tdma.c 	tdmac->period_len = period_len;
period_len        595 drivers/dma/mxs-dma.c 		size_t period_len, enum dma_transfer_direction direction,
period_len        600 drivers/dma/mxs-dma.c 	u32 num_periods = buf_len / period_len;
period_len        617 drivers/dma/mxs-dma.c 	if (period_len > MAX_XFER_BYTES) {
period_len        620 drivers/dma/mxs-dma.c 				period_len, MAX_XFER_BYTES);
period_len        633 drivers/dma/mxs-dma.c 		ccw->xfer_bytes = period_len;
period_len        644 drivers/dma/mxs-dma.c 		dma_addr += period_len;
period_len        645 drivers/dma/mxs-dma.c 		buf += period_len;
period_len        942 drivers/dma/owl-dma.c 				     size_t period_len,
period_len        952 drivers/dma/owl-dma.c 	unsigned int periods = buf_len / period_len;
period_len        970 drivers/dma/owl-dma.c 			src = buf_addr + (period_len * i);
period_len        974 drivers/dma/owl-dma.c 			dst = buf_addr + (period_len * i);
period_len        977 drivers/dma/owl-dma.c 		ret = owl_dma_cfg_lli(vchan, lli, src, dst, period_len,
period_len       2666 drivers/dma/pl330.c 		size_t period_len, enum dma_transfer_direction direction,
period_len       2676 drivers/dma/pl330.c 	if (len % period_len != 0)
period_len       2690 drivers/dma/pl330.c 	for (i = 0; i < len / period_len; i++) {
period_len       2734 drivers/dma/pl330.c 		desc->bytes_requested = period_len;
period_len       2735 drivers/dma/pl330.c 		fill_px(&desc->px, dst, src, period_len);
period_len       2742 drivers/dma/pl330.c 		dma_addr += period_len;
period_len       1022 drivers/dma/pxa_dma.c 		     dma_addr_t buf_addr, size_t len, size_t period_len,
period_len       1032 drivers/dma/pxa_dma.c 	if (!dchan || !len || !period_len)
period_len       1040 drivers/dma/pxa_dma.c 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
period_len       1041 drivers/dma/pxa_dma.c 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
period_len       1045 drivers/dma/pxa_dma.c 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
period_len       1048 drivers/dma/pxa_dma.c 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
period_len       1050 drivers/dma/pxa_dma.c 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
period_len       1051 drivers/dma/pxa_dma.c 	nb_desc *= DIV_ROUND_UP(len, period_len);
period_len       1065 drivers/dma/pxa_dma.c 		dma += period_len;
period_len       1066 drivers/dma/pxa_dma.c 		len -= period_len;
period_len       1191 drivers/dma/sh/rcar-dmac.c 			  size_t buf_len, size_t period_len,
period_len       1201 drivers/dma/sh/rcar-dmac.c 	if (rchan->mid_rid < 0 || buf_len < period_len) {
period_len       1204 drivers/dma/sh/rcar-dmac.c 			__func__, buf_len, period_len, rchan->mid_rid);
period_len       1211 drivers/dma/sh/rcar-dmac.c 	sg_len = buf_len / period_len;
period_len       1230 drivers/dma/sh/rcar-dmac.c 		dma_addr_t src = buf_addr + (period_len * i);
period_len       1232 drivers/dma/sh/rcar-dmac.c 		sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len,
period_len       1235 drivers/dma/sh/rcar-dmac.c 		sg_dma_len(&sgl[i]) = period_len;
period_len        693 drivers/dma/sh/shdma-base.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        700 drivers/dma/sh/shdma-base.c 	unsigned int sg_len = buf_len / period_len;
period_len        718 drivers/dma/sh/shdma-base.c 	if (slave_id < 0 || (buf_len < period_len)) {
period_len        721 drivers/dma/sh/shdma-base.c 			__func__, buf_len, period_len, slave_id);
period_len        738 drivers/dma/sh/shdma-base.c 		dma_addr_t src = buf_addr + (period_len * i);
period_len        740 drivers/dma/sh/shdma-base.c 		sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len,
period_len        743 drivers/dma/sh/shdma-base.c 		sg_dma_len(&sgl[i]) = period_len;
period_len        758 drivers/dma/sirf-dma.c 	size_t buf_len, size_t period_len,
period_len        776 drivers/dma/sirf-dma.c 	if (buf_len !=  2 * period_len)
period_len        448 drivers/dma/st_fdma.c 		size_t period_len, enum dma_transfer_direction direction,
period_len        459 drivers/dma/st_fdma.c 	if (!period_len)
period_len        468 drivers/dma/st_fdma.c 	if (len % period_len != 0) {
period_len        473 drivers/dma/st_fdma.c 	sg_len = len / period_len;
period_len        494 drivers/dma/st_fdma.c 			hw_node->saddr = buf_addr + (i * period_len);
period_len        496 drivers/dma/st_fdma.c 			hw_node->daddr = buf_addr + (i * period_len);
period_len        498 drivers/dma/st_fdma.c 		hw_node->nbytes = period_len;
period_len        499 drivers/dma/st_fdma.c 		hw_node->generic.length = period_len;
period_len       2510 drivers/dma/ste_dma40.c 		     size_t buf_len, size_t period_len,
period_len       2513 drivers/dma/ste_dma40.c 	unsigned int periods = buf_len / period_len;
period_len       2524 drivers/dma/ste_dma40.c 		sg_dma_len(&sg[i]) = period_len;
period_len       2525 drivers/dma/ste_dma40.c 		dma_addr += period_len;
period_len        895 drivers/dma/stm32-dma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        904 drivers/dma/stm32-dma.c 	if (!buf_len || !period_len) {
period_len        914 drivers/dma/stm32-dma.c 	if (buf_len % period_len) {
period_len        930 drivers/dma/stm32-dma.c 	ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len);
period_len        934 drivers/dma/stm32-dma.c 	nb_data_items = period_len / buswidth;
period_len        941 drivers/dma/stm32-dma.c 	if (buf_len == period_len)
period_len        949 drivers/dma/stm32-dma.c 	num_periods = buf_len / period_len;
period_len        956 drivers/dma/stm32-dma.c 		desc->sg_req[i].len = period_len;
period_len        965 drivers/dma/stm32-dma.c 		buf_addr += period_len;
period_len        822 drivers/dma/stm32-mdma.c 			   size_t buf_len, size_t period_len,
period_len        845 drivers/dma/stm32-mdma.c 	if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
period_len        850 drivers/dma/stm32-mdma.c 	if (buf_len % period_len) {
period_len        855 drivers/dma/stm32-mdma.c 	count = buf_len / period_len;
period_len        865 drivers/dma/stm32-mdma.c 						&ctbr, src_addr, period_len);
period_len        871 drivers/dma/stm32-mdma.c 						&ctbr, dst_addr, period_len);
period_len        887 drivers/dma/stm32-mdma.c 			src_addr = buf_addr + i * period_len;
period_len        891 drivers/dma/stm32-mdma.c 			dst_addr = buf_addr + i * period_len;
period_len        895 drivers/dma/stm32-mdma.c 					dst_addr, period_len, ctcr, ctbr,
period_len        662 drivers/dma/sun4i-dma.c 			  size_t period_len, enum dma_transfer_direction dir,
period_len        739 drivers/dma/sun4i-dma.c 	nr_periods = DIV_ROUND_UP(len / period_len, 2);
period_len        742 drivers/dma/sun4i-dma.c 		offset = i * period_len * 2;
period_len        743 drivers/dma/sun4i-dma.c 		plength = min((len - offset), (period_len * 2));
period_len        765 drivers/dma/sun6i-dma.c 					size_t period_len,
period_len        776 drivers/dma/sun6i-dma.c 	unsigned int i, periods = buf_len / period_len;
period_len        796 drivers/dma/sun6i-dma.c 		v_lli->len = period_len;
period_len        800 drivers/dma/sun6i-dma.c 			v_lli->src = buf_addr + period_len * i;
period_len        807 drivers/dma/sun6i-dma.c 			v_lli->dst = buf_addr + period_len * i;
period_len       1125 drivers/dma/tegra20-apb-dma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len       1138 drivers/dma/tegra20-apb-dma.c 	if (!buf_len || !period_len) {
period_len       1163 drivers/dma/tegra20-apb-dma.c 	if (buf_len % period_len) {
period_len       1168 drivers/dma/tegra20-apb-dma.c 	len = period_len;
period_len        123 drivers/dma/tegra210-adma.c 	size_t				period_len;
period_len        404 drivers/dma/tegra210-adma.c 	return desc->buf_len - (periods_remaining * desc->period_len);
period_len        603 drivers/dma/tegra210-adma.c 	ch_regs->tc = desc->period_len & ADMA_CH_TC_COUNT_MASK;
period_len        610 drivers/dma/tegra210-adma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        616 drivers/dma/tegra210-adma.c 	if (!buf_len || !period_len || period_len > ADMA_CH_TC_COUNT_MASK) {
period_len        621 drivers/dma/tegra210-adma.c 	if (buf_len % period_len) {
period_len        636 drivers/dma/tegra210-adma.c 	desc->period_len = period_len;
period_len        637 drivers/dma/tegra210-adma.c 	desc->num_periods = buf_len / period_len;
period_len       1267 drivers/dma/ti/edma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len       1279 drivers/dma/ti/edma.c 	if (unlikely(!echan || !buf_len || !period_len))
period_len       1302 drivers/dma/ti/edma.c 	if (unlikely(buf_len % period_len)) {
period_len       1307 drivers/dma/ti/edma.c 	nslots = (buf_len / period_len) + 1;
period_len       1324 drivers/dma/ti/edma.c 		if (burst == period_len) {
period_len       1325 drivers/dma/ti/edma.c 			period_len = buf_len;
period_len       1344 drivers/dma/ti/edma.c 		__func__, echan->ch_num, nslots, period_len, buf_len);
period_len       1366 drivers/dma/ti/edma.c 				       dst_addr, burst, dev_width, period_len,
period_len       1374 drivers/dma/ti/edma.c 			dst_addr += period_len;
period_len       1376 drivers/dma/ti/edma.c 			src_addr += period_len;
period_len       1069 drivers/dma/ti/omap-dma.c 	size_t period_len, enum dma_transfer_direction dir, unsigned long flags)
period_len       1117 drivers/dma/ti/omap-dma.c 	d->sg[0].en = period_len / es_bytes[es];
period_len       1118 drivers/dma/ti/omap-dma.c 	d->sg[0].fn = buf_len / period_len;
period_len        538 drivers/dma/xilinx/xilinx_dma.c 				     size_t period_len)
period_len        541 drivers/dma/xilinx/xilinx_dma.c 		hw->buf_addr = lower_32_bits(buf_addr + sg_used + period_len);
period_len        543 drivers/dma/xilinx/xilinx_dma.c 						 period_len);
period_len        545 drivers/dma/xilinx/xilinx_dma.c 		hw->buf_addr = buf_addr + sg_used + period_len;
period_len       1876 drivers/dma/xilinx/xilinx_dma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len       1887 drivers/dma/xilinx/xilinx_dma.c 	if (!period_len)
period_len       1890 drivers/dma/xilinx/xilinx_dma.c 	num_periods = buf_len / period_len;
period_len       1910 drivers/dma/xilinx/xilinx_dma.c 		while (sg_used < period_len) {
period_len       1922 drivers/dma/xilinx/xilinx_dma.c 			copy = xilinx_dma_calc_copysize(chan, period_len,
period_len       1926 drivers/dma/xilinx/xilinx_dma.c 					  period_len * i);
period_len        605 drivers/dma/zx_dma.c 		size_t period_len, enum dma_transfer_direction dir,
period_len        611 drivers/dma/zx_dma.c 	int num_periods = buf_len / period_len;
period_len        614 drivers/dma/zx_dma.c 	if (period_len > DMA_MAX_SIZE) {
period_len        635 drivers/dma/zx_dma.c 		zx_dma_fill_desc(ds, dst, src, period_len, num++,
period_len        637 drivers/dma/zx_dma.c 		dma_addr += period_len;
period_len        638 drivers/dma/zx_dma.c 		buf += period_len;
period_len        606 drivers/staging/ralink-gdma/ralink-gdma.c 	size_t period_len, enum dma_transfer_direction direction,
period_len        613 drivers/staging/ralink-gdma/ralink-gdma.c 	if (buf_len % period_len)
period_len        616 drivers/staging/ralink-gdma/ralink-gdma.c 	if (period_len > GDMA_REG_CTRL0_TX_MASK) {
period_len        618 drivers/staging/ralink-gdma/ralink-gdma.c 			period_len);
period_len        622 drivers/staging/ralink-gdma/ralink-gdma.c 	num_periods = buf_len / period_len;
period_len        640 drivers/staging/ralink-gdma/ralink-gdma.c 		desc->sg[i].len = period_len;
period_len        641 drivers/staging/ralink-gdma/ralink-gdma.c 		buf_addr += period_len;
period_len        785 include/linux/dmaengine.h 		size_t period_len, enum dma_transfer_direction direction,
period_len        865 include/linux/dmaengine.h 		size_t period_len, enum dma_transfer_direction dir,
period_len        872 include/linux/dmaengine.h 						period_len, dir, flags);