[PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
Nicolas Ferre
nicolas.ferre at atmel.com
Wed Sep 17 05:10:50 PDT 2014
On 15/09/2014 16:50, Ludovic Desroches :
> New atmel DMA controller known as XDMAC, introduced with SAMA5D4
> devices.
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> ---
> drivers/dma/Kconfig | 7 +
> drivers/dma/Makefile | 1 +
> drivers/dma/at_xdmac.c | 1210 ++++++++++++++++++++++++++++++++++++++++
> drivers/dma/at_xdmac.h | 307 ++++++++++
> include/dt-bindings/dma/at91.h | 25 +
> 5 files changed, 1550 insertions(+)
> create mode 100644 drivers/dma/at_xdmac.c
> create mode 100644 drivers/dma/at_xdmac.h
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 9b1ea0e..d04e79a 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -107,6 +107,13 @@ config AT_HDMAC
> help
> Support the Atmel AHB DMA controller.
>
> +config AT_XDMAC
> + tristate "Atmel XDMA support"
> + depends on ARCH_AT91
> + select DMA_ENGINE
> + help
> + Support the Atmel XDMA controller.
> +
> config FSL_DMA
> tristate "Freescale Elo series DMA support"
> depends on FSL_SOC
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index c6adb92..f32bfe1 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/
> obj-$(CONFIG_MV_XOR) += mv_xor.o
> obj-$(CONFIG_DW_DMAC_CORE) += dw/
> obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
> +obj-$(CONFIG_AT_XDMAC) += at_xdmac.o
> obj-$(CONFIG_MX3_IPU) += ipu/
> obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
> obj-$(CONFIG_SH_DMAE_BASE) += sh/
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> new file mode 100644
> index 0000000..9c7af22
> --- /dev/null
> +++ b/drivers/dma/at_xdmac.c
> @@ -0,0 +1,1210 @@
> +/*
> + * Driver for the Atmel Extensible DMA Controller (aka XDMAC on AT91 systems)
> + *
> + * Copyright (C) 2014 Atmel Corporation
> + *
> + * Author: Ludovic Desroches <ludovic.desroches at atmel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <dt-bindings/dma/at91.h>
> +#include <linux/clk.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/of_dma.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +
> +#include "dmaengine.h"
> +#include "at_xdmac.h"
> +
> +static unsigned int init_nr_desc_per_channel = 64;
> +module_param(init_nr_desc_per_channel, uint, 0644);
> +MODULE_PARM_DESC(init_nr_desc_per_channel,
> + "initial descriptors per channel (default: 64)");
> +
> +
> +static bool at_xdmac_chan_is_enabled(struct at_xdmac_chan *atchan)
> +{
> + return at_xdmac_chan_read(atchan, AT_XDMAC_GS) & atchan->mask;
> +}
> +
> +static void at_xdmac_off(struct at_xdmac *atxdmac)
> +{
> + at_xdmac_write(atxdmac, AT_XDMAC_GD, -1L);
> +
> + /* Wait that all chans are disabled. */
> + while (at_xdmac_read(atxdmac, AT_XDMAC_GS))
> + cpu_relax();
> + at_xdmac_write(atxdmac, AT_XDMAC_GID, -1L);
> +}
> +
> +/* Call with lock hold. */
> +static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
> + struct at_xdmac_desc *first)
> +{
> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
> + u32 reg;
> +
> + dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, first);
> +
> + if (at_xdmac_chan_is_enabled(atchan))
> + return;
> +
> + /* Set transfer as active to not try to start it again. */
> + first->active_xfer = true;
> +
> + /* Tell xdmac where to get the first descriptor. */
> + reg = AT_XDMAC_CNDA_NDA(first->tx_dma_desc.phys)
> + | AT_XDMAC_CNDA_NDAIF(atchan->memif);
> + at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, reg);
> +
> + /*
> + * When doing memory to memory transfer we need to use the next
> + * descriptor view 2 since some fields of the configuration register
> + * depend on transfer size and src/dest addresses.
> + */
> + if (atchan->cfg & AT_XDMAC_CC_TYPE_PER_TRAN) {
> + reg = AT_XDMAC_CNDC_NDVIEW_NDV1;
> + at_xdmac_chan_write(atchan, AT_XDMAC_CC, atchan->cfg);
> + } else
Style: we need {} even in the alternative.
> + reg = AT_XDMAC_CNDC_NDVIEW_NDV2;
> +
> + reg |= AT_XDMAC_CNDC_NDDUP
> + | AT_XDMAC_CNDC_NDSUP
> + | AT_XDMAC_CNDC_NDE;
> + at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, reg);
> +
> + dev_vdbg(chan2dev(&atchan->chan),
> + "%s: XDMAC_CC=0x%08x XDMAC_CNDA=0x%08x, XDMAC_CNDC=0x%08x, "
> + "XDMAC_CSA=0x%08x, XDMAC_CDA=0x%08x, XDMAC_CUBC=0x%08x\n",
> + __func__, at_xdmac_chan_read(atchan, AT_XDMAC_CC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
> +
> + /*
> + * There is no end of list when doing cyclic dma, we need to get
> + * an interrupt after each periods.
> + */
> + if (at_xdmac_chan_is_cyclic(atchan))
> + at_xdmac_chan_write(atchan, AT_XDMAC_CIE, AT_XDMAC_CIE_BIE);
> + else
> + at_xdmac_chan_write(atchan, AT_XDMAC_CIE, AT_XDMAC_CIE_LIE);
> + at_xdmac_write(atxdmac, AT_XDMAC_GIE, atchan->mask);
> + dev_vdbg(chan2dev(&atchan->chan),
> + "%s: enable channel (0x%08x)\n", __func__, atchan->mask);
After having read the remark from Arnd and as we discussed together, a
write memory barrier seems needed here.
> + at_xdmac_write(atxdmac, AT_XDMAC_GE, atchan->mask);
> +
> + dev_vdbg(chan2dev(&atchan->chan),
> + "%s: XDMAC_CC=0x%08x XDMAC_CNDA=0x%08x, XDMAC_CNDC=0x%08x, "
> + "XDMAC_CSA=0x%08x, XDMAC_CDA=0x%08x, XDMAC_CUBC=0x%08x\n",
> + __func__, at_xdmac_chan_read(atchan, AT_XDMAC_CC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
> +
> +}
> +
> +static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx)
> +{
> + struct at_xdmac_desc *desc = txd_to_at_desc(tx);
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(tx->chan);
> + dma_cookie_t cookie;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> + cookie = dma_cookie_assign(tx);
> +
> + dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n",
> + __func__, atchan, desc);
> + list_add_tail(&desc->xfer_node, &atchan->xfers_list);
> + if (list_is_singular(&atchan->xfers_list))
> + at_xdmac_start_xfer(atchan, desc);
> +
> + spin_unlock_irqrestore(&atchan->lock, flags);
> + return cookie;
> +}
> +
> +static struct at_xdmac_desc *at_xdmac_alloc_desc(struct dma_chan *chan,
> + gfp_t gfp_flags)
> +{
> + struct at_xdmac_desc *desc;
> + struct at_xdmac *atxdmac = to_at_xdmac(chan->device);
> + dma_addr_t phys;
> +
> + desc = dma_pool_alloc(atxdmac->at_xdmac_desc_pool, gfp_flags, &phys);
> + if (desc) {
> + memset(desc, 0, sizeof(*desc));
> + INIT_LIST_HEAD(&desc->descs_list);
> + dma_async_tx_descriptor_init(&desc->tx_dma_desc, chan);
> + desc->tx_dma_desc.tx_submit = at_xdmac_tx_submit;
> + desc->tx_dma_desc.phys = phys;
> + }
> +
> + return desc;
> +}
> +
> +/* Call must be protected by lock. */
> +static struct at_xdmac_desc *at_xdmac_get_desc(struct at_xdmac_chan *atchan)
> +{
> + struct at_xdmac_desc *desc;
> +
> + if (list_empty(&atchan->free_descs_list)) {
> + desc = at_xdmac_alloc_desc(&atchan->chan, GFP_NOWAIT);
> + } else {
> + desc = list_first_entry(&atchan->free_descs_list,
> + struct at_xdmac_desc, desc_node);
> + list_del(&desc->desc_node);
> + }
> +
> + return desc;
> +}
> +
> +static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *of_dma)
> +{
> + struct at_xdmac *atxdmac = of_dma->of_dma_data;
> + struct at_xdmac_chan *atchan;
> + struct dma_chan *chan;
> + struct device *dev = atxdmac->dma.dev;
> + dma_cap_mask_t mask;
> +
> + if (dma_spec->args_count != 2) {
> + dev_err(dev, "dma phandler args: bad number of args\n");
> + return NULL;
> + }
> +
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_SLAVE, mask);
> + chan = dma_get_any_slave_channel(&atxdmac->dma);
> + if (!chan) {
> + dev_err(dev, "can't get a dma channel\n");
> + return NULL;
> + }
> +
> + atchan = to_at_xdmac_chan(chan);
> + atchan->memif = AT91_XDMAC_DT_GET_MEM_IF(dma_spec->args[0]);
> + atchan->perif = AT91_XDMAC_DT_GET_PER_IF(dma_spec->args[0]);
> + atchan->perid = AT91_XDMAC_DT_GET_PERID(dma_spec->args[1]);
> + dev_info(dev, "chan dt cfg: memif=%u perif=%u perid=%u\n",
> + atchan->memif, atchan->perif, atchan->perid);
> +
> + return chan;
> +}
> +
> +static int at_xdmac_set_slave_config(struct dma_chan *chan,
> + struct dma_slave_config *sconfig)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> +
> + atchan->cfg = AT91_XDMAC_DT_PERID(atchan->perid)
> + | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
> + | AT_XDMAC_CC_MBSIZE_SIXTEEN
> + | AT_XDMAC_CC_TYPE_PER_TRAN;
> +
> + if (sconfig->direction == DMA_DEV_TO_MEM) {
> + atchan->cfg |= AT_XDMAC_CC_DAM_INCREMENTED_AM
> + | AT_XDMAC_CC_SAM_FIXED_AM
> + | AT_XDMAC_CC_DIF(atchan->memif)
> + | AT_XDMAC_CC_SIF(atchan->perif)
> + | AT_XDMAC_CC_DSYNC_PER2MEM;
> + atchan->dwidth = ffs(sconfig->src_addr_width) - 1;
> + atchan->cfg |= AT_XDMAC_CC_DWIDTH(atchan->dwidth);
> + atchan->cfg |= at_xdmac_csize(sconfig->src_maxburst);
> + } else if (sconfig->direction == DMA_MEM_TO_DEV) {
> + atchan->cfg |= AT_XDMAC_CC_DAM_FIXED_AM
> + | AT_XDMAC_CC_SAM_INCREMENTED_AM
> + | AT_XDMAC_CC_DIF(atchan->perif)
> + | AT_XDMAC_CC_SIF(atchan->memif)
> + | AT_XDMAC_CC_DSYNC_MEM2PER;
> + atchan->dwidth = ffs(sconfig->dst_addr_width) - 1;
> + atchan->cfg |= AT_XDMAC_CC_DWIDTH(atchan->dwidth);
> + atchan->cfg |= at_xdmac_csize(sconfig->dst_maxburst);
> + } else
Style: {} missing.
> + return -EINVAL;
> +
> + /*
> + * Src address and dest addr are needed to configure the link list
> + * descriptor so keep the slave configuration.
> + */
> + memcpy(&atchan->dma_sconfig, sconfig, sizeof(struct dma_slave_config));
> +
> + dev_dbg(chan2dev(chan), "%s: atchan->cfg=0x%08x\n", __func__, atchan->cfg);
> +
> + return 0;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> + unsigned int sg_len, enum dma_transfer_direction direction,
> + unsigned long flags, void *context)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct dma_slave_config *sconfig = &atchan->dma_sconfig;
> + struct at_xdmac_desc *first = NULL, *prev = NULL;
> + struct scatterlist *sg;
> + int i;
> +
> + if (!sgl)
> + return NULL;
> +
> + if (!is_slave_direction(direction)) {
> + dev_err(chan2dev(chan), "invalid DMA direction\n");
> + return NULL;
> + }
> +
> + dev_dbg(chan2dev(chan), "%s: sg_len=%d, dir=%s, flags=0x%lx\n",
> + __func__, sg_len,
> + direction == DMA_MEM_TO_DEV ? "to device" : "from device",
> + flags);
> +
> + /* Protect dma_sconfig field that can be modified by set_slave_conf. */
> + spin_lock(&atchan->lock);
> +
> + /* Prepare descriptors. */
> + for_each_sg(sgl, sg, sg_len, i) {
> + struct at_xdmac_desc *desc = NULL;
> + u32 len, mem;
> +
> + len = sg_dma_len(sg);
> + mem = sg_dma_address(sg);
> + if (unlikely(!len)) {
> + dev_err(chan2dev(chan), "sg data length is zero\n");
> + spin_unlock(&atchan->lock);
> + return NULL;
> + }
> + dev_dbg(chan2dev(chan), "%s: * sg%d len=%u, mem=0x%08x\n",
> + __func__, i, len, mem);
> +
> + desc = at_xdmac_get_desc(atchan);
> + if (!desc) {
> + dev_err(chan2dev(chan), "can't get descriptor\n");
> + if (first)
> + list_splice_init(&first->descs_list, &atchan->free_descs_list);
> + spin_unlock(&atchan->lock);
> + return NULL;
> + }
> +
> + /* Linked list descriptor setup. */
> + if (direction == DMA_DEV_TO_MEM) {
> + desc->lld.mbr_sa = sconfig->src_addr;
> + desc->lld.mbr_da = mem;
> + } else {
> + desc->lld.mbr_sa = mem;
> + desc->lld.mbr_da = sconfig->dst_addr;
> + }
> + desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV1 /* next descriptor view */
> + | AT_XDMAC_MBR_UBC_NDEN /* next descriptor dst parameter update */
> + | AT_XDMAC_MBR_UBC_NSEN /* next descriptor src parameter update */
> + | (i == sg_len - 1 ? 0 : AT_XDMAC_MBR_UBC_NDE) /* descriptor fetch */
> + | len / (1 << atchan->dwidth); /* microblock length */
> + dev_dbg(chan2dev(chan),
> + "%s: lld: mbr_sa=0x%08x, mbr_da=0x%08x, mbr_ubc=0x%08x\n",
> + __func__, desc->lld.mbr_sa, desc->lld.mbr_da, desc->lld.mbr_ubc);
> +
> + /* Chain lld. */
> + if (prev) {
> + prev->lld.mbr_nda = desc->tx_dma_desc.phys;
> + dev_dbg(chan2dev(chan),
> + "%s: chain lld: prev=0x%p, mbr_nda=0x%08x\n",
> + __func__, prev, prev->lld.mbr_nda);
> + }
> +
> + prev = desc;
> + if (!first)
> + first = desc;
> +
> + dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
> + __func__, desc, first);
> + list_add_tail(&desc->desc_node, &first->descs_list);
> + }
> +
> + spin_unlock(&atchan->lock);
> +
> + first->tx_dma_desc.cookie = -EBUSY;
> + first->tx_dma_desc.flags = flags;
> + first->xfer_size = sg_len;
> +
> + return &first->tx_dma_desc;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +at_xdmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
> + size_t buf_len, size_t period_len,
> + enum dma_transfer_direction direction,
> + unsigned long flags)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct dma_slave_config *sconfig = &atchan->dma_sconfig;
> + struct at_xdmac_desc *first = NULL, *prev = NULL;
> + unsigned int periods = buf_len / period_len;
> + unsigned long lock_flags;
> + int i;
> +
> + dev_dbg(chan2dev(chan), "%s: buf_addr=0x%08x, buf_len=%d, period_len=%d, "
> + "dir=%s, flags=0x%lx\n",
> + __func__, buf_addr, buf_len, period_len,
> + direction == DMA_MEM_TO_DEV ? "mem2per" : "per2mem", flags);
> +
> + if (!is_slave_direction(direction)) {
> + dev_err(chan2dev(chan), "invalid DMA direction\n");
> + return NULL;
> + }
> +
> + if (test_and_set_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status)) {
> + dev_err(chan2dev(chan), "channel currently used\n");
> + return NULL;
> + }
> +
> + for (i = 0; i < periods; i++) {
> + struct at_xdmac_desc *desc = NULL;
> +
> + spin_lock_irqsave(&atchan->lock, lock_flags);
> + desc = at_xdmac_get_desc(atchan);
> + spin_unlock_irqrestore(&atchan->lock, lock_flags);
> + if (!desc) {
> + dev_err(chan2dev(chan), "can't get descriptor\n");
> + if (first)
> + list_splice_init(&first->descs_list, &atchan->free_descs_list);
> + return NULL;
> + }
> + dev_dbg(chan2dev(chan),
> + "%s: desc=0x%p, tx_dma_desc.phys=0x%08x\n",
> + __func__, desc, desc->tx_dma_desc.phys);
> +
> + if (direction == DMA_DEV_TO_MEM) {
> + desc->lld.mbr_sa = sconfig->src_addr;
> + desc->lld.mbr_da = buf_addr + i * period_len;
> + } else {
> + desc->lld.mbr_sa = buf_addr + i * period_len;
> + desc->lld.mbr_da = sconfig->dst_addr;
> + };
> + desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV1
> + | AT_XDMAC_MBR_UBC_NDEN
> + | AT_XDMAC_MBR_UBC_NSEN
> + | AT_XDMAC_MBR_UBC_NDE
> + | period_len / (1 << atchan->dwidth);
> +
> + dev_dbg(chan2dev(chan),
> + "%s: lld: mbr_sa=0x%08x, mbr_da=0x%08x, mbr_ubc=0x%08x\n",
> + __func__, desc->lld.mbr_sa, desc->lld.mbr_da, desc->lld.mbr_ubc);
> +
> + /* Chain lld. */
> + if (prev) {
> + prev->lld.mbr_nda = desc->tx_dma_desc.phys;
> + dev_dbg(chan2dev(chan),
> + "%s: chain lld: prev=0x%p, mbr_nda=0x%08x\n",
> + __func__, prev, prev->lld.mbr_nda);
> + }
> +
> + prev = desc;
> + if (!first)
> + first = desc;
> +
> + dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
> + __func__, desc, first);
> + list_add_tail(&desc->desc_node, &first->descs_list);
> + }
> +
> + prev->lld.mbr_nda = first->tx_dma_desc.phys;
> + dev_dbg(chan2dev(chan),
> + "%s: chain lld: prev=0x%p, mbr_nda=0x%08x\n",
> + __func__, prev, prev->lld.mbr_nda);
> + first->tx_dma_desc.cookie = -EBUSY;
> + first->tx_dma_desc.flags = flags;
> + first->xfer_size = buf_len;
> +
> + return &first->tx_dma_desc;
> +}
> +
> +static struct dma_async_tx_descriptor *
> +at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
> + size_t len, unsigned long flags)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct at_xdmac_desc *first = NULL, *prev = NULL;
> + size_t remaining_size = len, xfer_size = 0, ublen;
> + dma_addr_t src_addr = src, dst_addr = dest;
> + u32 dwidth;
> + /*
> + * WARNING: The channel configuration is set here since there is no
> + * dmaengine_slave_config call in this case. Moreover we don't know the
> + * direction, it involves we can't dynamically set the source and dest
> + * interface so we have to use the same one. Only interface 0 allows EBI
> + * access. Hopefully we can access DDR through both ports (at least on
> + * SAMA5D4x), so we can use the same interface for source and dest,
> + * that solves the fact we don't know the direction.
> + */
> + u32 chan_cc = AT_XDMAC_CC_DAM_INCREMENTED_AM
> + | AT_XDMAC_CC_SAM_INCREMENTED_AM
> + | AT_XDMAC_CC_DIF(0)
> + | AT_XDMAC_CC_SIF(0)
> + | AT_XDMAC_CC_MBSIZE_SIXTEEN
> + | AT_XDMAC_CC_TYPE_MEM_TRAN;
> +
> + dev_dbg(chan2dev(chan), "%s: src=0x%08x, dest=0x%08x, len=%d, flags=0x%lx\n",
> + __func__, src, dest, len, flags);
> +
> + if (unlikely(!len))
> + return NULL;
> +
> + /* Check address alignment to select the greater data width we can use.
Style: "/*" alone on the line ;-)
> + * Some XDMAC implementations don't provide dword transfer, in this
> + * case selecting dword has the same behavior as selecting word transfers.
> + */
> + if (!((src_addr | dst_addr) & 7)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_DWORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);
> + } else if (!((src_addr | dst_addr) & 3)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_WORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);
> + } else if (!((src_addr | dst_addr) & 1)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_HALFWORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);
> + } else {
> + dwidth = AT_XDMAC_CC_DWIDTH_BYTE;
> + dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);
> + }
> +
> + atchan->cfg = chan_cc | AT_XDMAC_CC_DWIDTH(dwidth);
> +
> + /* Prepare descriptors. */
> + while (remaining_size) {
> + struct at_xdmac_desc *desc = NULL;
> +
> + dev_dbg(chan2dev(chan), "%s: remaining_size=%u\n", __func__, remaining_size);
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> + desc = at_xdmac_get_desc(atchan);
> + spin_unlock_irqrestore(&atchan->lock, flags);
> + if (!desc) {
> + dev_err(chan2dev(chan), "can't get descriptor\n");
> + if (first)
> + list_splice_init(&first->descs_list, &atchan->free_descs_list);
> + return NULL;
> + }
> +
> + /* Update src and dest addresses. */
> + src_addr += xfer_size;
> + dst_addr += xfer_size;
> +
> + if (remaining_size >= AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)
> + xfer_size = AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth;
> + else
> + xfer_size = remaining_size;
> +
> + dev_dbg(chan2dev(chan), "%s: xfer_size=%u\n", __func__, xfer_size);
> +
> + /* Check remaining length and change data width if needed. */
> + if (!((src_addr | dst_addr | xfer_size) & 7)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_DWORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);
> + } else if (!((src_addr | dst_addr | xfer_size) & 3)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_WORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);
> + } else if (!((src_addr | dst_addr | xfer_size) & 1)) {
> + dwidth = AT_XDMAC_CC_DWIDTH_HALFWORD;
> + dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);
> + } else if ((src_addr | dst_addr | xfer_size) & 1) {
> + dwidth = AT_XDMAC_CC_DWIDTH_BYTE;
> + dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);
> + }
> + chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
> +
> + ublen = xfer_size >> dwidth;
> + remaining_size -= xfer_size;
> +
> + desc->lld.mbr_sa = src_addr;
> + desc->lld.mbr_da = dst_addr;
> + desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV2
> + | AT_XDMAC_MBR_UBC_NDEN
> + | AT_XDMAC_MBR_UBC_NSEN
> + | (remaining_size ? 0 : AT_XDMAC_MBR_UBC_NDE)
> + | ublen;
> + desc->lld.mbr_cfg = chan_cc;
> +
> + dev_dbg(chan2dev(chan),
> + "%s: lld: mbr_sa=0x%08x, mbr_da=0x%08x, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n",
> + __func__, desc->lld.mbr_sa, desc->lld.mbr_da, desc->lld.mbr_ubc, desc->lld.mbr_cfg);
> +
> + /* Chain lld. */
> + if (prev) {
> + prev->lld.mbr_nda = desc->tx_dma_desc.phys;
> + dev_dbg(chan2dev(chan),
> + "%s: chain lld: prev=0x%p, mbr_nda=0x%08x\n",
> + __func__, prev, prev->lld.mbr_nda);
> + }
> +
> + prev = desc;
> + if (!first)
> + first = desc;
> +
> + dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
> + __func__, desc, first);
> + list_add_tail(&desc->desc_node, &first->descs_list);
> + }
> +
> + first->tx_dma_desc.cookie = -EBUSY;
> + first->tx_dma_desc.flags = flags;
> + first->xfer_size = len;
> +
> + return &first->tx_dma_desc;
> +}
> +
> +static enum dma_status
> +at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
> + struct dma_tx_state *txstate)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
> + struct at_xdmac_desc *desc, *_desc;
> + unsigned long flags;
> + enum dma_status ret;
> + int residue;
> + u32 cur_nda;
> +
> + ret = dma_cookie_status(chan, cookie, txstate);
> + if (ret == DMA_COMPLETE)
> + return ret;
> +
> + if (!txstate)
> + return ret;
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> +
> + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
> +
> + /*
> + * If the transfer has not been started yet, don't need to compute the
> + * residue, it's the transfer length.
> + */
> + if (!desc->active_xfer) {
> + dma_set_residue(txstate, desc->xfer_size);
> + return ret;
> + }
> +
> + residue = desc->xfer_size;
> + /* Flush FIFO. */
> + at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask);
> + while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS));
> + cpu_relax();
> +
> + cur_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc;
> + /*
> + * Remove size of all microblocks already transferred and the current
> + * one. Then add the remaining size to transfer of the current
> + * microblock.
> + */
> + list_for_each_entry_safe(desc, _desc, &desc->descs_list, desc_node) {
> + residue -= (desc->lld.mbr_ubc & 0xffffff) << atchan->dwidth;
> + if ((desc->lld.mbr_nda & 0xfffffffc) == cur_nda)
> + break;
> + }
> + residue += at_xdmac_chan_read(atchan, AT_XDMAC_CUBC) << atchan->dwidth;
> +
> + spin_unlock_irqrestore(&atchan->lock, flags);
> +
> + dma_set_residue(txstate, residue);
> +
> + dev_dbg(chan2dev(chan),
> + "%s: desc=0x%p, tx_dma_desc.phys=0x%08x, tx_status=%d, cookie=%d, residue=%d\n",
> + __func__, desc, desc->tx_dma_desc.phys, ret, cookie, residue);
> +
> + return ret;
> +}
> +
> +static void at_xdmac_remove_xfer(struct at_xdmac_chan *atchan,
> + struct at_xdmac_desc *desc)
> +{
> + dev_dbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
> +
> + /*
> + * Remove the transfer from the transfer list then move the transfer
> + * descriptors into the free descriptors list.
> + */
> + list_del(&desc->xfer_node);
> + list_splice_init(&desc->descs_list, &atchan->free_descs_list);
> +}
> +
> +static void at_xdmac_advance_work(struct at_xdmac_chan *atchan)
> +{
> + struct at_xdmac_desc *desc;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> +
> + /*
> + * If channel is enabled, do nothing, advance_work will be triggered
> + * after the interruption.
> + */
> + if (!at_xdmac_chan_is_enabled(atchan) && !list_empty(&atchan->xfers_list)) {
> + desc = list_first_entry(&atchan->xfers_list,
> + struct at_xdmac_desc,
> + xfer_node);
> + dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
> + if (!desc->active_xfer)
> + at_xdmac_start_xfer(atchan, desc);
> + }
> +
> + spin_unlock_irqrestore(&atchan->lock, flags);
> +}
> +
> +static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
> +{
> + struct at_xdmac_desc *desc;
> + struct dma_async_tx_descriptor *txd;
> +
> + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
> + txd = &desc->tx_dma_desc;
> +
> + if (txd->callback && (txd->flags & DMA_PREP_INTERRUPT))
> + txd->callback(txd->callback_param);
> +}
> +
> +static void at_xdmac_tasklet(unsigned long data)
> +{
> + struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
> + struct at_xdmac_desc *desc;
> + u32 error_mask;
> +
> + dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08lx\n",
> + __func__, atchan->status);
> +
> + error_mask = AT_XDMAC_CIS_RBEIS
> + | AT_XDMAC_CIS_WBEIS
> + | AT_XDMAC_CIS_ROIS;
> +
> + if (at_xdmac_chan_is_cyclic(atchan)) {
> + at_xdmac_handle_cyclic(atchan);
> + } else if ((atchan->status & AT_XDMAC_CIS_LIS)
> + || (atchan->status & error_mask)) {
> + struct dma_async_tx_descriptor *txd;
> +
> + if (atchan->status & AT_XDMAC_CIS_RBEIS)
> + dev_err(chan2dev(&atchan->chan), "read bus error!!!");
> + else if (atchan->status & AT_XDMAC_CIS_WBEIS)
> + dev_err(chan2dev(&atchan->chan), "write bus error!!!");
> + else if (atchan->status & AT_XDMAC_CIS_ROIS)
> + dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
> +
> + desc = list_first_entry(&atchan->xfers_list,
> + struct at_xdmac_desc,
> + xfer_node);
> + dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
> + BUG_ON(!desc->active_xfer);
> +
> + txd = &desc->tx_dma_desc;
> +
> + at_xdmac_remove_xfer(atchan, desc);
> +
> + if (!at_xdmac_chan_is_cyclic(atchan)) {
> + dma_cookie_complete(txd);
> + if (txd->callback && (txd->flags & DMA_PREP_INTERRUPT))
> + txd->callback(txd->callback_param);
> + }
> +
> + dma_run_dependencies(txd);
> +
> + at_xdmac_advance_work(atchan);
> + }
> +}
> +
> +static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
> +{
> + struct at_xdmac *atxdmac = (struct at_xdmac *)dev_id;
> + struct at_xdmac_chan *atchan;
> + u32 imr, status, pending;
> + u32 chan_imr, chan_status;
> + int i, ret = IRQ_NONE;
> +
> + do {
> + imr = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
> + status = at_xdmac_read(atxdmac, AT_XDMAC_GIS);
> + pending = status & imr;
> +
> + dev_vdbg(atxdmac->dma.dev,
> + "%s: status=0x%08x, imr=0x%08x, pending=0x%08x\n",
> + __func__, status, imr, pending);
> +
> + if (!pending)
> + break;
> +
> + /* We have to find which channel has generated the interrupt. */
> + for (i = 0; i < atxdmac->dma.chancnt; i++) {
> + if (!((1 << i) & pending))
> + continue;
> +
> + atchan = &atxdmac->chan[i];
> + chan_imr = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
> + chan_status = at_xdmac_chan_read(atchan, AT_XDMAC_CIS);
> + atchan->status = chan_status & chan_imr;
> + dev_vdbg(atxdmac->dma.dev,
> + "%s: chan%d: imr=0x%x, status=0x%x\n",
> + __func__, i, chan_imr, chan_status);
> + dev_vdbg(chan2dev(&atchan->chan),
> + "%s: XDMAC_CC=0x%08x XDMAC_CNDA=0x%08x, "
> + "XDMAC_CNDC=0x%08x, XDMAC_CSA=0x%08x, "
> + "XDMAC_CDA=0x%08x, XDMAC_CUBC=0x%08x\n",
> + __func__,
> + at_xdmac_chan_read(atchan, AT_XDMAC_CC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
> + at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
> +
> + if (atchan->status & (AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS))
> + at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
> +
> + tasklet_schedule(&atchan->tasklet);
> + ret = IRQ_HANDLED;
> + }
> +
> + } while (pending);
> +
> + return ret;
> +}
> +
> +static void at_xdmac_issue_pending(struct dma_chan *chan)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> +
> + dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
> +
> + if (!at_xdmac_chan_is_cyclic(atchan))
> + at_xdmac_advance_work(atchan);
> +
> + return;
> +}
> +
> +static int at_xdmac_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
> + unsigned long arg)
> +{
> + struct at_xdmac_desc *desc, *_desc;
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
> + unsigned long flags;
> + int ret = 0;
> +
> + dev_dbg(chan2dev(chan), "%s: cmd=%d\n", __func__, cmd);
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> +
> + switch (cmd) {
> + case DMA_PAUSE:
> + at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask);
> + set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
> + break;
> +
> + case DMA_RESUME:
> + if (!at_xdmac_chan_is_paused(atchan))
> + break;
> +
> + at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask);
> + clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
> + break;
> +
> + case DMA_TERMINATE_ALL:
> + at_xdmac_write(atxdmac, AT_XDMAC_GIE, atchan->mask);
This is not needed, is it?
> + at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
> + while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
> + cpu_relax();
> +
> + /* Cancel all pending transfers. */
> + list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node)
> + at_xdmac_remove_xfer(atchan, desc);
> +
> + clear_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
> + break;
> +
> + case DMA_SLAVE_CONFIG:
> + ret = at_xdmac_set_slave_config(chan,
> + (struct dma_slave_config *)arg);
> + break;
> +
> + default:
> + dev_err(chan2dev(chan),
> + "unmanaged or unknown dma control cmd: %d\n", cmd);
> + ret = -ENXIO;
> + }
> +
> + spin_unlock_irqrestore(&atchan->lock, flags);
> +
> + return ret;
> +}
> +
> +static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct at_xdmac_desc *desc;
> + unsigned long flags;
> + int i;
> +
> + spin_lock_irqsave(&atchan->lock, flags);
> +
> + if (at_xdmac_chan_is_enabled(atchan)) {
> + dev_err(chan2dev(chan),
> + "can't allocate channel resources (channel enabled)\n");
> + i = -EIO;
> + goto spin_unlock;
> + }
> +
> + if (!list_empty(&atchan->free_descs_list)) {
> + dev_err(chan2dev(chan),
> + "can't allocate channel resources (channel not free from a previous use)\n");
> + i = -EIO;
> + goto spin_unlock;
> + }
> +
> + for (i = 0; i < init_nr_desc_per_channel; i++) {
> + desc = at_xdmac_alloc_desc(chan, GFP_ATOMIC);
> + if (!desc) {
> + dev_warn(chan2dev(chan),
> + "only %d descriptors have been allocated\n", i);
> + break;
> + }
> + list_add_tail(&desc->desc_node, &atchan->free_descs_list);
> + }
> +
> + dma_cookie_init(chan);
> +
> + dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
> +
> +spin_unlock:
> + spin_unlock_irqrestore(&atchan->lock, flags);
> + return i;
> +}
> +
> +static void at_xdmac_free_chan_resources(struct dma_chan *chan)
> +{
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> + struct at_xdmac *atxdmac = to_at_xdmac(chan->device);
> + struct at_xdmac_desc *desc, *_desc;
> +
> + list_for_each_entry_safe(desc, _desc, &atchan->free_descs_list, desc_node) {
> + dev_dbg(chan2dev(chan), "%s: freeing descriptor %p\n", __func__, desc);
> + list_del(&desc->desc_node);
> + dma_pool_free(atxdmac->at_xdmac_desc_pool, desc, desc->tx_dma_desc.phys);
> + }
> +
> + return;
> +}
> +
> +#define AT_XDMAC_DMA_BUSWIDTHS\
> + (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
> + BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
> + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
> + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
> + BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
> +
> +static int at_xdmac_device_slave_caps(struct dma_chan *dchan,
> + struct dma_slave_caps *caps)
> +{
> +
> + caps->src_addr_widths = AT_XDMAC_DMA_BUSWIDTHS;
> + caps->dstn_addr_widths = AT_XDMAC_DMA_BUSWIDTHS;
> + caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
> + caps->cmd_pause = true;
> + caps->cmd_terminate = true;
> + caps->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int atmel_xdmac_prepare(struct device *dev)
For this funtion, maybe CONFIG_PM is the directive that you should use.
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
> + struct dma_chan *chan, *_chan;
> +
> + list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> +
> + /* Wait for transfer completion, except in cyclic case. */
> + if (at_xdmac_chan_is_enabled(atchan) && !at_xdmac_chan_is_cyclic(atchan))
> + return -EAGAIN;
> + }
> + return 0;
> +}
> +
> +static int atmel_xdmac_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
> + struct dma_chan *chan, *_chan;
> +
> + list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
> + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
> +
> + if (at_xdmac_chan_is_cyclic(atchan)) {
> + if (!at_xdmac_chan_is_paused(atchan))
> + at_xdmac_control(chan, DMA_PAUSE, 0);
> + atchan->save_cim = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
> + atchan->save_cnda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA);
> + atchan->save_cndc = at_xdmac_chan_read(atchan, AT_XDMAC_CNDC);
> + }
> + }
> + atxdmac->save_gim = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
> +
> + at_xdmac_off(atxdmac);
> + clk_disable_unprepare(atxdmac->clk);
> + return 0;
> +}
> +
> +static int atmel_xdmac_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
> + struct at_xdmac_chan *atchan;
> + struct dma_chan *chan, *_chan;
> + int i;
> +
> + clk_prepare_enable(atxdmac->clk);
> +
> + /* Clear pending interrupts. */
> + for (i = 0; i < atxdmac->dma.chancnt; i++) {
> + atchan = &atxdmac->chan[i];
> + while (at_xdmac_chan_read(atchan, AT_XDMAC_CIS))
> + cpu_relax();
> + }
> +
> + at_xdmac_write(atxdmac, AT_XDMAC_GIE, atxdmac->save_gim);
> + at_xdmac_write(atxdmac, AT_XDMAC_GE, atxdmac->save_gs);
> + list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
> + atchan = to_at_xdmac_chan(chan);
> + at_xdmac_chan_write(atchan, AT_XDMAC_CC, atchan->cfg);
> + if (at_xdmac_chan_is_cyclic(atchan)) {
> + at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, atchan->save_cnda);
> + at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, atchan->save_cndc);
> + at_xdmac_chan_write(atchan, AT_XDMAC_CIE, atchan->save_cim);
As realized together, a write memory barried seems needed here.
> + at_xdmac_write(atxdmac, AT_XDMAC_GE, atchan->mask);
> + }
> + }
> + return 0;
> +}
> +#else
> +# define atmel_xdmac_prepare NULL
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static int at_xdmac_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + struct at_xdmac *atxdmac;
> + int irq, size, nr_channels, i, ret;
> + void __iomem *base;
> + u32 reg;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -EINVAL;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return irq;
> +
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + /*
> + * Read number of xdmac channels, read helper function can't be used
> + * since atxdmac is not yet allocated and we need to know the number
> + * of channels to do the allocation.
> + */
> + reg = readl_relaxed(base + AT_XDMAC_GTYPE);
> + nr_channels = AT_XDMAC_NB_CH(reg);
> + if (nr_channels > AT_XDMAC_MAX_CHAN) {
> + dev_err(&pdev->dev, "invalid number of channels (%u)\n",
> + nr_channels);
> + return -EINVAL;
> + }
> +
> + size = sizeof(*atxdmac);
> + size += nr_channels * sizeof(struct at_xdmac_chan);
> + atxdmac = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
> + if (!atxdmac) {
> + dev_err(&pdev->dev, "can't allocate at_xdmac structure\n");
> + return -ENOMEM;
> + }
> +
> + atxdmac->regs = base;
> + atxdmac->irq = irq;
> +
> + atxdmac->clk = devm_clk_get(&pdev->dev, "dma_clk");
> + if (IS_ERR(atxdmac->clk)) {
> + dev_err(&pdev->dev, "can't get dma_clk\n");
> + return PTR_ERR(atxdmac->clk);
> + }
> +
> + /* Do not use dev res to prevent races with tasklet */
> + ret = request_irq(atxdmac->irq, at_xdmac_interrupt, 0, "at_xdmac", atxdmac);
> + if (ret) {
> + dev_err(&pdev->dev, "can't request irq\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(atxdmac->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "can't prepare or enable clock\n");
> + goto err_free_irq;
> + }
> +
> + atxdmac->at_xdmac_desc_pool =
> + dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
> + sizeof(struct at_xdmac_desc), 4, 0);
> + if (!atxdmac->at_xdmac_desc_pool) {
> + dev_err(&pdev->dev, "no memory for descriptors dma pool\n");
> + ret = -ENOMEM;
> + goto err_clk_disable;
> + }
> +
> + dma_cap_set(DMA_CYCLIC, atxdmac->dma.cap_mask);
> + dma_cap_set(DMA_MEMCPY, atxdmac->dma.cap_mask);
> + dma_cap_set(DMA_SLAVE, atxdmac->dma.cap_mask);
> + atxdmac->dma.dev = &pdev->dev;
> + atxdmac->dma.device_alloc_chan_resources = at_xdmac_alloc_chan_resources;
> + atxdmac->dma.device_free_chan_resources = at_xdmac_free_chan_resources;
> + atxdmac->dma.device_tx_status = at_xdmac_tx_status;
> + atxdmac->dma.device_issue_pending = at_xdmac_issue_pending;
> + atxdmac->dma.device_prep_dma_cyclic = at_xdmac_prep_dma_cyclic;
> + atxdmac->dma.device_prep_dma_memcpy = at_xdmac_prep_dma_memcpy;
> + atxdmac->dma.device_prep_slave_sg = at_xdmac_prep_slave_sg;
> + atxdmac->dma.device_control = at_xdmac_control;
> + atxdmac->dma.chancnt = nr_channels;
> + atxdmac->dma.device_slave_caps = at_xdmac_device_slave_caps;
> +
> + /* Disable all chans and interrupts. */
> + at_xdmac_off(atxdmac);
> +
> + /* Init channels. */
> + INIT_LIST_HEAD(&atxdmac->dma.channels);
> + for (i = 0; i < nr_channels; i++) {
> + struct at_xdmac_chan *atchan = &atxdmac->chan[i];
> +
> + atchan->chan.device = &atxdmac->dma;
> + list_add_tail(&atchan->chan.device_node,
> + &atxdmac->dma.channels);
> +
> + atchan->ch_regs = at_xdmac_chan_reg_base(atxdmac, i);
> + atchan->mask = 1 << i;
> +
> + spin_lock_init(&atchan->lock);
> + INIT_LIST_HEAD(&atchan->xfers_list);
> + INIT_LIST_HEAD(&atchan->free_descs_list);
> + tasklet_init(&atchan->tasklet, at_xdmac_tasklet,
> + (unsigned long)atchan);
> +
> + /* Clear pending interrupts. */
> + while (at_xdmac_chan_read(atchan, AT_XDMAC_CIS))
> + cpu_relax();
> + }
> + platform_set_drvdata(pdev, atxdmac);
> +
> + ret = dma_async_device_register(&atxdmac->dma);
> + if (ret) {
> + dev_err(&pdev->dev, "fail to register DMA engine device\n");
> + goto err_clk_disable;
> + }
> +
> + ret = of_dma_controller_register(pdev->dev.of_node,
> + at_xdmac_xlate, atxdmac);
> + if (ret) {
> + dev_err(&pdev->dev, "could not register of dma controller\n");
> + goto err_dma_unregister;
> + }
> +
> + dev_info(&pdev->dev, "%d channels, mapped at 0x%p\n",
> + nr_channels, atxdmac->regs);
> +
> + return 0;
> +
> +err_dma_unregister:
> + dma_async_device_unregister(&atxdmac->dma);
> +err_clk_disable:
> + clk_disable_unprepare(atxdmac->clk);
> +err_free_irq:
> + free_irq(atxdmac->irq, atxdmac->dma.dev);
> + return ret;
> +}
> +
> +static int at_xdmac_remove(struct platform_device *pdev)
> +{
> + struct at_xdmac *atxdmac = (struct at_xdmac *)platform_get_drvdata(pdev);
> + int i;
> +
> + at_xdmac_off(atxdmac);
> + of_dma_controller_free(pdev->dev.of_node);
> + dma_async_device_unregister(&atxdmac->dma);
> + clk_disable_unprepare(atxdmac->clk);
> +
> + synchronize_irq(atxdmac->irq);
> +
> + free_irq(atxdmac->irq, atxdmac->dma.dev);
> +
> + for (i = 0; i < atxdmac->dma.chancnt; i++) {
> + struct at_xdmac_chan *atchan = &atxdmac->chan[i];
> +
> + tasklet_kill(&atchan->tasklet);
> + at_xdmac_free_chan_resources(&atchan->chan);
> + }
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops atmel_xdmac_dev_pm_ops = {
> + .prepare = atmel_xdmac_prepare,
> + SET_LATE_SYSTEM_SLEEP_PM_OPS(atmel_xdmac_suspend, atmel_xdmac_resume)
> +};
> +
> +static const struct of_device_id atmel_xdmac_dt_ids[] = {
> + {
> + .compatible = "atmel,sama5d4-dma",
> + }, {
> + /* sentinel */
> + }
> +};
> +MODULE_DEVICE_TABLE(of, atmel_xdmac_dt_ids);
> +
> +static struct platform_driver at_xdmac_driver = {
> + .probe = at_xdmac_probe,
> + .remove = at_xdmac_remove,
> + .driver = {
> + .name = "at_xdmac",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(atmel_xdmac_dt_ids),
> + .pm = &atmel_xdmac_dev_pm_ops,
> + }
> +};
> +
> +static int __init at_xdmac_init(void)
> +{
> + return platform_driver_probe(&at_xdmac_driver, at_xdmac_probe);
> +}
> +subsys_initcall(at_xdmac_init);
> +
> +MODULE_DESCRIPTION("Atmel Extended DMA Controller driver");
> +MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches at atmel.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/dma/at_xdmac.h b/drivers/dma/at_xdmac.h
> new file mode 100644
> index 0000000..5f4d898
> --- /dev/null
> +++ b/drivers/dma/at_xdmac.h
> @@ -0,0 +1,307 @@
> +/*
> + * Copyright (C) 2014 Atmel Corporation
> + *
> + * Author: Ludovic Desroches <ludovic.desroches at atmel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef __AT_XDMAC_H__
> +#define __AT_XDMAC_H__
> +
> +#include <linux/clk.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/of_dma.h>
> +#include <linux/platform_device.h>
> +
> +#include "dmaengine.h"
> +
> +/* Global registers */
> +#define AT_XDMAC_GTYPE 0x00 /* Global Type Register */
> +#define AT_XDMAC_NB_CH(i) (((i) & 0x1F) + 1) /* Number of Channels Minus One */
> +#define AT_XDMAC_FIFO_SZ(i) (((i) >> 5) & 0x7FF) /* Number of Bytes */
> +#define AT_XDMAC_NB_REQ(i) ((((i) >> 16) & 0x3F) + 1) /* Number of Peripheral Requests Minus One */
> +#define AT_XDMAC_GCFG 0x04 /* Global Configuration Register */
> +#define AT_XDMAC_GWAC 0x08 /* Global Weighted Arbiter Configuration Register */
> +#define AT_XDMAC_GIE 0x0C /* Global Interrupt Enable Register */
> +#define AT_XDMAC_GID 0x10 /* Global Interrupt Disable Register */
> +#define AT_XDMAC_GIM 0x14 /* Global Interrupt Mask Register */
> +#define AT_XDMAC_GIS 0x18 /* Global Interrupt Status Register */
> +#define AT_XDMAC_GE 0x1C /* Global Channel Enable Register */
> +#define AT_XDMAC_GD 0x20 /* Global Channel Disable Register */
> +#define AT_XDMAC_GS 0x24 /* Global Channel Status Register */
> +#define AT_XDMAC_GRS 0x28 /* Global Channel Read Suspend Register */
> +#define AT_XDMAC_GWS 0x2C /* Global Write Suspend Register */
> +#define AT_XDMAC_GRWS 0x30 /* Global Channel Read Write Suspend Register */
> +#define AT_XDMAC_GRWR 0x34 /* Global Channel Read Write Resume Register */
> +#define AT_XDMAC_GSWR 0x38 /* Global Channel Software Request Register */
> +#define AT_XDMAC_GSWS 0x3C /* Global channel Software Request Status Register */
> +#define AT_XDMAC_GSWF 0x40 /* Global Channel Software Flush Request Register */
> +#define AT_XDMAC_VERSION 0xFFC /* XDMAC Version Register */
> +
> +/* Channel relative registers offsets */
> +#define AT_XDMAC_CIE 0x00 /* Channel Interrupt Enable Register */
> +#define AT_XDMAC_CIE_BIE BIT(0) /* End of Block Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_LIE BIT(1) /* End of Linked List Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_DIE BIT(2) /* End of Disable Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_FIE BIT(3) /* End of Flush Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_RBEIE BIT(4) /* Read Bus Error Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_WBEIE BIT(5) /* Write Bus Error Interrupt Enable Bit */
> +#define AT_XDMAC_CIE_ROIE BIT(6) /* Request Overflow Interrupt Enable Bit */
> +#define AT_XDMAC_CID 0x04 /* Channel Interrupt Disable Register */
> +#define AT_XDMAC_CID_BID BIT(0) /* End of Block Interrupt Disable Bit */
> +#define AT_XDMAC_CID_LID BIT(1) /* End of Linked List Interrupt Disable Bit */
> +#define AT_XDMAC_CID_DID BIT(2) /* End of Disable Interrupt Disable Bit */
> +#define AT_XDMAC_CID_FID BIT(3) /* End of Flush Interrupt Disable Bit */
> +#define AT_XDMAC_CID_RBEID BIT(4) /* Read Bus Error Interrupt Disable Bit */
> +#define AT_XDMAC_CID_WBEID BIT(5) /* Write Bus Error Interrupt Disable Bit */
> +#define AT_XDMAC_CID_ROID BIT(6) /* Request Overflow Interrupt Disable Bit */
> +#define AT_XDMAC_CIM 0x08 /* Channel Interrupt Mask Register */
> +#define AT_XDMAC_CIM_BIM BIT(0) /* End of Block Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_LIM BIT(1) /* End of Linked List Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_DIM BIT(2) /* End of Disable Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_FIM BIT(3) /* End of Flush Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_RBEIM BIT(4) /* Read Bus Error Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_WBEIM BIT(5) /* Write Bus Error Interrupt Mask Bit */
> +#define AT_XDMAC_CIM_ROIM BIT(6) /* Request Overflow Interrupt Mask Bit */
> +#define AT_XDMAC_CIS 0x0C /* Channel Interrupt Status Register */
> +#define AT_XDMAC_CIS_BIS BIT(0) /* End of Block Interrupt Status Bit */
> +#define AT_XDMAC_CIS_LIS BIT(1) /* End of Linked List Interrupt Status Bit */
> +#define AT_XDMAC_CIS_DIS BIT(2) /* End of Disable Interrupt Status Bit */
> +#define AT_XDMAC_CIS_FIS BIT(3) /* End of Flush Interrupt Status Bit */
> +#define AT_XDMAC_CIS_RBEIS BIT(4) /* Read Bus Error Interrupt Status Bit */
> +#define AT_XDMAC_CIS_WBEIS BIT(5) /* Write Bus Error Interrupt Status Bit */
> +#define AT_XDMAC_CIS_ROIS BIT(6) /* Request Overflow Interrupt Status Bit */
> +#define AT_XDMAC_CSA 0x10 /* Channel Source Address Register */
> +#define AT_XDMAC_CDA 0x14 /* Channel Destination Address Register */
> +#define AT_XDMAC_CNDA 0x18 /* Channel Next Descriptor Address Register */
> +#define AT_XDMAC_CNDA_NDAIF(i) ((i) & 0x1) /* Channel x Next Descriptor Interface */
> +#define AT_XDMAC_CNDA_NDA(i) ((i) & 0xfffffffc) /* Channel x Next Descriptor Address */
> +#define AT_XDMAC_CNDC 0x1C /* Channel Next Descriptor Control Register */
> +#define AT_XDMAC_CNDC_NDE (0x1 << 0) /* Channel x Next Descriptor Enable */
> +#define AT_XDMAC_CNDC_NDSUP (0x1 << 1) /* Channel x Next Descriptor Source Update */
> +#define AT_XDMAC_CNDC_NDDUP (0x1 << 2) /* Channel x Next Descriptor Destination Update */
> +#define AT_XDMAC_CNDC_NDVIEW_NDV0 (0x0 << 3) /* Channel x Next Descriptor View 0 */
> +#define AT_XDMAC_CNDC_NDVIEW_NDV1 (0x1 << 3) /* Channel x Next Descriptor View 1 */
> +#define AT_XDMAC_CNDC_NDVIEW_NDV2 (0x2 << 3) /* Channel x Next Descriptor View 2 */
> +#define AT_XDMAC_CNDC_NDVIEW_NDV3 (0x3 << 3) /* Channel x Next Descriptor View 3 */
> +#define AT_XDMAC_CUBC 0x20 /* Channel Microblock Control Register */
> +#define AT_XDMAC_CBC 0x24 /* Channel Block Control Register */
> +#define AT_XDMAC_CC 0x28 /* Channel Configuration Register */
> +#define AT_XDMAC_CC_TYPE (0x1 << 0) /* Channel Transfer Type */
> +#define AT_XDMAC_CC_TYPE_MEM_TRAN (0x0 << 0) /* Memory to Memory Transfer */
> +#define AT_XDMAC_CC_TYPE_PER_TRAN (0x1 << 0) /* Peripheral to Memory or Memory to Peripheral Transfer */
> +#define AT_XDMAC_CC_MBSIZE_MASK (0x3 << 1)
> +#define AT_XDMAC_CC_MBSIZE_SINGLE (0x0 << 1)
> +#define AT_XDMAC_CC_MBSIZE_FOUR (0x1 << 1)
> +#define AT_XDMAC_CC_MBSIZE_EIGHT (0x2 << 1)
> +#define AT_XDMAC_CC_MBSIZE_SIXTEEN (0x3 << 1)
> +#define AT_XDMAC_CC_DSYNC (0x1 << 4) /* Channel Synchronization */
> +#define AT_XDMAC_CC_DSYNC_PER2MEM (0x0 << 4)
> +#define AT_XDMAC_CC_DSYNC_MEM2PER (0x1 << 4)
> +#define AT_XDMAC_CC_PROT (0x1 << 5) /* Channel Protection */
> +#define AT_XDMAC_CC_PROT_SEC (0x0 << 5)
> +#define AT_XDMAC_CC_PROT_UNSEC (0x1 << 5)
> +#define AT_XDMAC_CC_SWREQ (0x1 << 6) /* Channel Software Request Trigger */
> +#define AT_XDMAC_CC_SWREQ_HWR_CONNECTED (0x0 << 6)
> +#define AT_XDMAC_CC_SWREQ_SWR_CONNECTED (0x1 << 6)
> +#define AT_XDMAC_CC_MEMSET (0x1 << 7) /* Channel Fill Block of memory */
> +#define AT_XDMAC_CC_MEMSET_NORMAL_MODE (0x0 << 7)
> +#define AT_XDMAC_CC_MEMSET_HW_MODE (0x1 << 7)
> +#define AT_XDMAC_CC_CSIZE_MASK (0x7 << 8) /* Channel Chunk Size */
> +#define AT_XDMAC_CC_CSIZE_CHK_1 (0x0 << 8)
> +#define AT_XDMAC_CC_CSIZE_CHK_2 (0x1 << 8)
> +#define AT_XDMAC_CC_CSIZE_CHK_4 (0x2 << 8)
> +#define AT_XDMAC_CC_CSIZE_CHK_8 (0x3 << 8)
> +#define AT_XDMAC_CC_CSIZE_CHK_16 (0x4 << 8)
> +#define AT_XDMAC_CC_DWIDTH(i) ((i) << 11) /* Channel Data Width */
> +#define AT_XDMAC_CC_DWIDTH_BYTE 0x0
> +#define AT_XDMAC_CC_DWIDTH_HALFWORD 0x1
> +#define AT_XDMAC_CC_DWIDTH_WORD 0x2
> +#define AT_XDMAC_CC_DWIDTH_DWORD 0x3
> +#define AT_XDMAC_CC_SIF(i) ((0x1 & (i)) << 13) /* Channel Source Interface Identifier */
> +#define AT_XDMAC_CC_DIF(i) ((0x1 & (i)) << 14) /* Channel Destination Interface Identifier */
> +#define AT_XDMAC_CC_SAM_MASK (0x3 << 16) /* Channel Source Addressing Mode */
> +#define AT_XDMAC_CC_SAM_FIXED_AM (0x0 << 16)
> +#define AT_XDMAC_CC_SAM_INCREMENTED_AM (0x1 << 16)
> +#define AT_XDMAC_CC_SAM_UBS_AM (0x2 << 16)
> +#define AT_XDMAC_CC_SAM_UBS_DS_AM (0x3 << 16)
> +#define AT_XDMAC_CC_DAM_MASK (0x3 << 18) /* Channel Source Addressing Mode */
> +#define AT_XDMAC_CC_DAM_FIXED_AM (0x0 << 18)
> +#define AT_XDMAC_CC_DAM_INCREMENTED_AM (0x1 << 18)
> +#define AT_XDMAC_CC_DAM_UBS_AM (0x2 << 18)
> +#define AT_XDMAC_CC_DAM_UBS_DS_AM (0x3 << 18)
> +#define AT_XDMAC_CC_INITD (0x1 << 21) /* Channel Initialization Terminated (read only) */
> +#define AT_XDMAC_CC_INITD_TERMINATED (0x0 << 21)
> +#define AT_XDMAC_CC_INITD_IN_PROGRESS (0x1 << 21)
> +#define AT_XDMAC_CC_RDIP (0x1 << 22) /* Read in Progress (read only) */
> +#define AT_XDMAC_CC_RDIP_DONE (0x0 << 22)
> +#define AT_XDMAC_CC_RDIP_IN_PROGRESS (0x1 << 22)
> +#define AT_XDMAC_CC_WDIP (0x1 << 23) /* Write in Progress (read only) */
> +#define AT_XDMAC_CC_WDIP_DONE (0x0 << 23)
> +#define AT_XDMAC_CC_WDIP_IN_PROGRESS (0x1 << 23)
> +#define AT_XDMAC_CC_PERID(i) (0x7f & (h) << 24) /* Channel Peripheral Identifier */
> +#define AT_XDMAC_CDS_MSP 0x2C /* Channel Data Stride Memory Set Pattern */
> +#define AT_XDMAC_CSUS 0x30 /* Channel Source Microblock Stride */
> +#define AT_XDMAC_CDUS 0x34 /* Channel Destination Microblock Stride */
> +
> +#define AT_XDMAC_CHAN_REG_BASE 0x50 /* Channel registers base address */
> +
> +/* Microblock control members */
> +#define AT_XDMAC_MBR_UBC_UBLEN_MAX 0xFFFFFFUL /* Maximum Microblock Length */
> +#define AT_XDMAC_MBR_UBC_NDE (0x1 << 24) /* Next Descriptor Enable */
> +#define AT_XDMAC_MBR_UBC_NSEN (0x1 << 25) /* Next Descriptor Source Update */
> +#define AT_XDMAC_MBR_UBC_NDEN (0x1 << 26) /* Next Descriptor Destination Update */
> +#define AT_XDMAC_MBR_UBC_NDV0 (0x0 << 27) /* Next Descriptor View 0 */
> +#define AT_XDMAC_MBR_UBC_NDV1 (0x1 << 27) /* Next Descriptor View 1 */
> +#define AT_XDMAC_MBR_UBC_NDV2 (0x2 << 27) /* Next Descriptor View 2 */
> +#define AT_XDMAC_MBR_UBC_NDV3 (0x3 << 27) /* Next Descriptor View 3 */
> +
> +#define AT_XDMAC_MAX_CHAN 0x20
> +
> +enum atc_status {
> + AT_XDMAC_CHAN_IS_CYCLIC = 0,
> + AT_XDMAC_CHAN_IS_PAUSED,
> +};
> +
> +/* ----- Channels ----- */
> +struct at_xdmac_chan {
> + struct dma_chan chan;
> + void __iomem *ch_regs;
> + u32 mask; /* Channel Mask */
> + u32 cfg; /* Channel Configuration Register */
> + u8 perid; /* Peripheral ID */
> + u8 dwidth; /* Data Width */
> + u8 perif; /* Peripheral Interface */
> + u8 memif; /* Memory Interface */
> + u32 save_cim;
> + u32 save_cnda;
> + u32 save_cndc;
> + unsigned long status;
> + struct tasklet_struct tasklet;
> + struct dma_slave_config dma_sconfig;
> +
> + spinlock_t lock;
> +
> + struct list_head xfers_list;
> + struct list_head free_descs_list;
> +};
> +
> +
> +/* ----- Controller ----- */
> +struct at_xdmac {
> + struct dma_device dma;
> + void __iomem *regs;
> + int irq;
> + struct clk *clk;
> + u32 save_gim;
> + u32 save_gs;
> + struct dma_pool *at_xdmac_desc_pool;
> + struct at_xdmac_chan chan[0];
> +};
> +
> +
> +/* ----- Descriptors ----- */
> +
> +/* Linked List Descriptor */
> +struct at_xdmac_lld {
> + dma_addr_t mbr_nda; /* Next Descriptor Member */
> + u32 mbr_ubc; /* Microblock Control Member */
> + dma_addr_t mbr_sa; /* Source Address Member */
> + dma_addr_t mbr_da; /* Destination Address Member */
> + u32 mbr_cfg; /* Configuration Register */
> +};
> +
> +
> +struct at_xdmac_desc {
> + struct at_xdmac_lld lld;
> + enum dma_transfer_direction direction;
> + struct dma_async_tx_descriptor tx_dma_desc;
> + struct list_head desc_node;
> + /* Following members are only used by the first descriptor */
> + bool active_xfer;
> + unsigned int xfer_size;
> + struct list_head descs_list;
> + struct list_head xfer_node;
> +};
> +
> +static inline void __iomem *at_xdmac_chan_reg_base(struct at_xdmac *atxdmac, unsigned int chan_nb)
> +{
> + return (void __iomem *)(atxdmac->regs + (AT_XDMAC_CHAN_REG_BASE + chan_nb * 0x40));
> +}
> +
> +#define at_xdmac_read(atxdmac, reg) readl_relaxed((atxdmac)->regs + (reg))
> +#define at_xdmac_write(atxdmac, reg, value) \
> + writel_relaxed((value), (atxdmac)->regs + (reg))
> +
> +#define at_xdmac_chan_read(atchan, reg) readl_relaxed((atchan)->ch_regs + (reg))
> +#define at_xdmac_chan_write(atchan, reg, value) writel_relaxed((value), (atchan)->ch_regs + (reg))
> +
> +static inline struct at_xdmac_chan *to_at_xdmac_chan(struct dma_chan *dchan)
> +{
> + return container_of(dchan, struct at_xdmac_chan, chan);
> +}
> +
> +static struct device *chan2dev(struct dma_chan *chan)
> +{
> + return &chan->dev->device;
> +}
> +
> +static inline struct at_xdmac *to_at_xdmac(struct dma_device *ddev)
> +{
> + return container_of(ddev, struct at_xdmac, dma);
> +}
> +
> +static inline struct at_xdmac_desc *txd_to_at_desc(struct dma_async_tx_descriptor *txd)
> +{
> + return container_of(txd, struct at_xdmac_desc, tx_dma_desc);
> +}
> +
> +static inline int at_xdmac_chan_is_cyclic(struct at_xdmac_chan *atchan)
> +{
> + return test_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
> +}
> +
> +static inline int at_xdmac_chan_is_paused(struct at_xdmac_chan *atchan)
> +{
> + return test_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
> +}
> +
> +static inline u32 at_xdmac_csize(u32 maxburst)
> +{
> + u32 csize;
> +
> + switch (ffs(maxburst) - 1) {
> + case 1:
> + csize = AT_XDMAC_CC_CSIZE_CHK_2;
> + break;
> + case 2:
> + csize = AT_XDMAC_CC_CSIZE_CHK_4;
> + break;
> + case 3:
> + csize = AT_XDMAC_CC_CSIZE_CHK_8;
> + break;
> + case 4:
> + csize = AT_XDMAC_CC_CSIZE_CHK_16;
> + default:
> + csize = AT_XDMAC_CC_CSIZE_CHK_1;
> + }
> +
> + return csize;
> +};
> +#endif /* __AT_XDMAC_H__ */
> diff --git a/include/dt-bindings/dma/at91.h b/include/dt-bindings/dma/at91.h
> index e835037..4875a50 100644
> --- a/include/dt-bindings/dma/at91.h
> +++ b/include/dt-bindings/dma/at91.h
> @@ -9,6 +9,8 @@
> #ifndef __DT_BINDINGS_AT91_DMA_H__
> #define __DT_BINDINGS_AT91_DMA_H__
>
> +/* ---------- HDMAC ---------- */
> +
> /*
> * Source and/or destination peripheral ID
> */
> @@ -24,4 +26,27 @@
> #define AT91_DMA_CFG_FIFOCFG_ALAP (0x1 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* largest defined AHB burst */
> #define AT91_DMA_CFG_FIFOCFG_ASAP (0x2 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* single AHB access */
>
> +
> +/* ---------- XDMAC ---------- */
> +#define AT91_XDMAC_DT_MEM_IF_MASK (0x1)
> +#define AT91_XDMAC_DT_MEM_IF_OFFSET (16)
> +#define AT91_XDMAC_DT_MEM_IF(mem_if) (((mem_if) & AT91_XDMAC_DT_MEM_IF_MASK) \
> + << AT91_XDMAC_DT_MEM_IF_OFFSET)
> +#define AT91_XDMAC_DT_GET_MEM_IF(cfg) (((cfg) >> AT91_XDMAC_DT_MEM_IF_OFFSET) \
> + & AT91_XDMAC_DT_MEM_IF_MASK)
> +
> +#define AT91_XDMAC_DT_PER_IF_MASK (0x1)
> +#define AT91_XDMAC_DT_PER_IF_OFFSET (0)
> +#define AT91_XDMAC_DT_PER_IF(per_if) (((per_if) & AT91_XDMAC_DT_PER_IF_MASK) \
> + << AT91_XDMAC_DT_PER_IF_OFFSET)
> +#define AT91_XDMAC_DT_GET_PER_IF(cfg) (((cfg) >> AT91_XDMAC_DT_PER_IF_OFFSET) \
> + & AT91_XDMAC_DT_PER_IF_MASK)
> +
> +#define AT91_XDMAC_DT_PERID_MASK (0x7f)
> +#define AT91_XDMAC_DT_PERID_OFFSET (24)
> +#define AT91_XDMAC_DT_PERID(perid) (((perid) & AT91_XDMAC_DT_PERID_MASK) \
> + << AT91_XDMAC_DT_PERID_OFFSET)
> +#define AT91_XDMAC_DT_GET_PERID(cfg) (((cfg) >> AT91_XDMAC_DT_PERID_OFFSET) \
> + & AT91_XDMAC_DT_PERID_MASK)
> +
> #endif /* __DT_BINDINGS_AT91_DMA_H__ */
>
--
Nicolas Ferre
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