* [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-15 14:50 ` Ludovic Desroches
0 siblings, 0 replies; 14+ messages in thread
From: Ludovic Desroches @ 2014-09-15 14:50 UTC (permalink / raw)
To: dmaengine-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA
Cc: nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w,
plagnioj-sclMFOaUSTBWk0Htik3J/w,
vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
josh.wu-AIFe0yeh4nAAvxtiuMwx3w,
maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8, arnd-r2nGTMty4D4,
sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8,
mark.rutland-5wv7dgnIgG8, Ludovic Desroches
New atmel DMA controller known as XDMAC, introduced with SAMA5D4
devices.
Signed-off-by: Ludovic Desroches <ludovic.desroches-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *
+ * 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
+ 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);
+ 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
+ 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.
+ * 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);
+ 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)
+{
+ 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);
+ 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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>");
+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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *
+ * 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__ */
--
2.0.3
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-15 16:47 ` Arnd Bergmann
0 siblings, 0 replies; 14+ messages in thread
From: Arnd Bergmann @ 2014-09-15 16:47 UTC (permalink / raw)
To: linux-arm-kernel
On Monday 15 September 2014, Ludovic Desroches wrote:
>
> +config AT_XDMAC
> + tristate "Atmel XDMA support"
> + depends on ARCH_AT91
> + select DMA_ENGINE
> + help
> + Support the Atmel XDMA controller.
This should depend on (ARCH_AT91 || COMPILE_TEST) and built on x86 to
get into the usual automated build checkers.
> +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);
The mask is unused, just remove it.
> + 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);
Maybe dev_dbg instead of dev_info?
I think having three cells would be nicer here, so you can get rid of the
macros.
> 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
The header is only used in one file, so just move the contents into that file.
> +
> +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));
> +}
That type cast should not be needed. Is atxdmac->regs not already a void __iomem *
> +#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))
Is writel_relaxed the right accessor here? I haven't reviewed all uses of this,
but you have to ensure that every use that needs synchronization against the
actual DMA has explicit barriers here.
(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)
As mentioned, I think it would be much better to keep the macros inside of the
driver and not visible to the binding, so you can use simple numbers in DT.
Arnd
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-15 16:47 ` Arnd Bergmann
0 siblings, 0 replies; 14+ messages in thread
From: Arnd Bergmann @ 2014-09-15 16:47 UTC (permalink / raw)
To: Ludovic Desroches
Cc: dmaengine-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w,
plagnioj-sclMFOaUSTBWk0Htik3J/w,
vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
josh.wu-AIFe0yeh4nAAvxtiuMwx3w,
maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8,
sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8,
mark.rutland-5wv7dgnIgG8
On Monday 15 September 2014, Ludovic Desroches wrote:
>
> +config AT_XDMAC
> + tristate "Atmel XDMA support"
> + depends on ARCH_AT91
> + select DMA_ENGINE
> + help
> + Support the Atmel XDMA controller.
This should depend on (ARCH_AT91 || COMPILE_TEST) and built on x86 to
get into the usual automated build checkers.
> +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);
The mask is unused, just remove it.
> + 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);
Maybe dev_dbg instead of dev_info?
I think having three cells would be nicer here, so you can get rid of the
macros.
> 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
The header is only used in one file, so just move the contents into that file.
> +
> +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));
> +}
That type cast should not be needed. Is atxdmac->regs not already a void __iomem *
> +#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))
Is writel_relaxed the right accessor here? I haven't reviewed all uses of this,
but you have to ensure that every use that needs synchronization against the
actual DMA has explicit barriers here.
(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)
As mentioned, I think it would be much better to keep the macros inside of the
driver and not visible to the binding, so you can use simple numbers in DT.
Arnd
--
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^ permalink raw reply [flat|nested] 14+ messages in thread* [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-16 9:34 ` Ludovic Desroches
0 siblings, 0 replies; 14+ messages in thread
From: Ludovic Desroches @ 2014-09-16 9:34 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Sep 15, 2014 at 06:47:22PM +0200, Arnd Bergmann wrote:
> On Monday 15 September 2014, Ludovic Desroches wrote:
> >
> > +config AT_XDMAC
> > + tristate "Atmel XDMA support"
> > + depends on ARCH_AT91
> > + select DMA_ENGINE
> > + help
> > + Support the Atmel XDMA controller.
>
> This should depend on (ARCH_AT91 || COMPILE_TEST) and built on x86 to
> get into the usual automated build checkers.
>
Ok
> > +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);
>
> The mask is unused, just remove it.
>
Ok
> > + 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);
>
> Maybe dev_dbg instead of dev_info?
>
> I think having three cells would be nicer here, so you can get rid of the
> macros.
I can split the memory and peripheral interface in two cells. But I
would like to keep the macro for the third cell which is in fact the
channel configuration register. The idea is to not have to change the
bindings if one day we need to setup an extra field from this register.
We had this case with the hdma controller: we didn't planned to exhibit
the fifo configuration but we had to do it to allow dma use with usart.
> > 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
>
> The header is only used in one file, so just move the contents into that file.
>
I'll merge the two files.
> > +
> > +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));
> > +}
>
> That type cast should not be needed. Is atxdmac->regs not already a void __iomem *
>
Right.
> > +#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))
>
> Is writel_relaxed the right accessor here? I haven't reviewed all uses of this,
> but you have to ensure that every use that needs synchronization against the
> actual DMA has explicit barriers here.
I'll try to check if relaxed ordering can cause some issues.
> (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)
>
> As mentioned, I think it would be much better to keep the macros inside of the
> driver and not visible to the binding, so you can use simple numbers in DT.
>
> Arnd
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-16 9:34 ` Ludovic Desroches
0 siblings, 0 replies; 14+ messages in thread
From: Ludovic Desroches @ 2014-09-16 9:34 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Ludovic Desroches, dmaengine-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA,
nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w,
plagnioj-sclMFOaUSTBWk0Htik3J/w,
vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
josh.wu-AIFe0yeh4nAAvxtiuMwx3w,
maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8,
sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8,
mark.rutland-5wv7dgnIgG8
On Mon, Sep 15, 2014 at 06:47:22PM +0200, Arnd Bergmann wrote:
> On Monday 15 September 2014, Ludovic Desroches wrote:
> >
> > +config AT_XDMAC
> > + tristate "Atmel XDMA support"
> > + depends on ARCH_AT91
> > + select DMA_ENGINE
> > + help
> > + Support the Atmel XDMA controller.
>
> This should depend on (ARCH_AT91 || COMPILE_TEST) and built on x86 to
> get into the usual automated build checkers.
>
Ok
> > +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);
>
> The mask is unused, just remove it.
>
Ok
> > + 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);
>
> Maybe dev_dbg instead of dev_info?
>
> I think having three cells would be nicer here, so you can get rid of the
> macros.
I can split the memory and peripheral interface in two cells. But I
would like to keep the macro for the third cell which is in fact the
channel configuration register. The idea is to not have to change the
bindings if one day we need to setup an extra field from this register.
We had this case with the hdma controller: we didn't planned to exhibit
the fifo configuration but we had to do it to allow dma use with usart.
> > 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
>
> The header is only used in one file, so just move the contents into that file.
>
I'll merge the two files.
> > +
> > +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));
> > +}
>
> That type cast should not be needed. Is atxdmac->regs not already a void __iomem *
>
Right.
> > +#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))
>
> Is writel_relaxed the right accessor here? I haven't reviewed all uses of this,
> but you have to ensure that every use that needs synchronization against the
> actual DMA has explicit barriers here.
I'll try to check if relaxed ordering can cause some issues.
> (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)
>
> As mentioned, I think it would be much better to keep the macros inside of the
> driver and not visible to the binding, so you can use simple numbers in DT.
>
> Arnd
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^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-17 12:10 ` Nicolas Ferre
0 siblings, 0 replies; 14+ messages in thread
From: Nicolas Ferre @ 2014-09-17 12:10 UTC (permalink / raw)
To: linux-arm-kernel
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@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@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@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@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
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v4 1/2] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
@ 2014-09-17 12:10 ` Nicolas Ferre
0 siblings, 0 replies; 14+ messages in thread
From: Nicolas Ferre @ 2014-09-17 12:10 UTC (permalink / raw)
To: Ludovic Desroches, dmaengine-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA, arnd-r2nGTMty4D4
Cc: plagnioj-sclMFOaUSTBWk0Htik3J/w,
vinod.koul-ral2JQCrhuEAvxtiuMwx3w,
dan.j.williams-ral2JQCrhuEAvxtiuMwx3w,
josh.wu-AIFe0yeh4nAAvxtiuMwx3w,
maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8,
sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8,
mark.rutland-5wv7dgnIgG8
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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> ---
> 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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> + *
> + * 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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>");
> +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-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> + *
> + * 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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