[RFC PATCH] dma: at_xdmac: creation of the atmel eXtended DMA Controller driver
Ludovic Desroches
ludovic.desroches at atmel.com
Wed Jun 11 00:59:29 PDT 2014
Hi Maxime,
Thanks for the review. Some answer above.
On Tue, Jun 10, 2014 at 05:41:18PM +0200, Maxime Ripard wrote:
> Hi Ludovic,
>
> On Tue, May 27, 2014 at 10:35:36AM +0200, Ludovic Desroches wrote:
> > Introduction of a new atmel DMA controller known as xdmac.
> >
> > Signed-off-by: Ludovic Desroches <ludovic.desroches at atmel.com>
> > ---
> >
> > Hi,
> >
> > All comments are welcomed to improve this driver!
> >
> > Thanks
> >
> > .../devicetree/bindings/dma/atmel-xdma.txt | 44 +
> > drivers/dma/Kconfig | 7 +
> > drivers/dma/Makefile | 1 +
> > drivers/dma/at_xdmac.c | 1053 ++++++++++++++++++++
> > drivers/dma/at_xdmac.h | 257 +++++
> > include/dt-bindings/dma/at91.h | 46 +
> > 6 files changed, 1408 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt
> > create mode 100644 drivers/dma/at_xdmac.c
> > create mode 100644 drivers/dma/at_xdmac.h
> >
> > diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> > new file mode 100644
> > index 0000000..47efedd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> > @@ -0,0 +1,44 @@
> > +* Atmel Extensible Direct Memory Access Controller (XDMA)
> > +
> > +Required properties:
> > +- compatible: Should be "atmel,<chip>-dma".
> > +- reg: Should contain DMA registers location and length.
> > +- interrupts: Should contain DMA interrupt.
> > +- #dma-cells: Must be <2>, used to represent the number of integer cells in
> > +the dmas property of client devices.
> > +
> > +Example:
> > +
> > +dma1: dma-controller at f0004000 {
> > + compatible = "atmel,sama5d4-dma";
> > + reg = <0xf0004000 0x200>;
> > + interrupts = <50 4 0>;
> > + #dma-cells = <2>;
> > +};
> > +
> > +DMA clients connected to the Atmel XDMA controller must use the format
> > +described in the dma.txt file, using a three-cell specifier for each channel:
> > +a phandle plus two integer cells.
> > +The three cells in order are:
> > +
> > +1. A phandle pointing to the DMA controller.
> > +2. The memory interface (16 most significant bits), the peripheral interface
> > +(16 less significant bits).
>
> Can you elaborate on this? What are they? The request IDs on both ends
> of the transfers?
It is the DMA connection on our matrixes. Due to the way the connection
is done, some devices can be accessed only through one of these
interfaces.
>
> > +3. Channel configuration register. Configurable fields are:
> > + - bit 2-1: MBSIZE, memory burst size.
> > + - bit 10-8: CSIZE, chunk size.
> > + - bit 12-11: DWIDTH, data width.
>
> I'd rather see those as generic properties.
>
I agree, I am wondering why I did that... So until I retrieve the
reason, I will get it with dma_slave_config.
> > + - bit 30-24: PERID, peripheral identifier.
>
> Hmmm. That looks like it's the request id. What's the peripheral
> interface you were mentioning?
>
> > +Please refer to the 'XDMAC Channel x Configuration Register' description in the
> > +datasheet to get the values for these fields.
> > +
> > +Example:
> > +
> > +i2c2: i2c at f8024000 {
> > + compatible = "atmel,at91sam9x5-i2c";
> > + reg = <0xf8024000 0x4000>;
> > + interrupts = <34 4 6>;
> > + dmas = <&dma0 0x00000001 0x06000000>,
> > + <&dma0 0x00000001 0x07000000>;
> > + dma-names = "tx", "rx";
> > +};
> > diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> > index 5c58638..9d36813 100644
> > --- a/drivers/dma/Kconfig
> > +++ b/drivers/dma/Kconfig
> > @@ -89,6 +89,13 @@ 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 5150c82..b379b62 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..de3ad790
> > --- /dev/null
> > +++ b/drivers/dma/at_xdmac.c
> > @@ -0,0 +1,1053 @@
> > +#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 "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)) {
> > + dev_err(chan2dev(&atchan->chan),
> > + "BUG: Attempted to start a non-idle channel\n");
> > + 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= %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_ATOMIC);
> > + } 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_chan *atchan;
> > + struct dma_chan *chan;
> > + dma_cap_mask_t mask;
> > + struct platform_device *pdev = of_find_device_by_node(dma_spec->np);
> > +
> > + if (dma_spec->args_count != 2) {
> > + dev_err(&pdev->dev, "dma phandler args: bad number of args\n");
> > + return NULL;
> > + }
> > +
> > + dma_cap_zero(mask);
> > + dma_cap_set(DMA_SLAVE, mask);
> > + chan = dma_request_channel(mask, NULL, NULL);
> > + if (!chan) {
> > + dev_err(&pdev->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]);
> > + atchan->dwidth = AT91_XDMAC_DT_GET_DWIDTH(dma_spec->args[1]);
> > + atchan->csize = AT91_XDMAC_DT_GET_CSIZE(dma_spec->args[1]);
> > + atchan->mbsize = AT91_XDMAC_DT_GET_MBSIZE(dma_spec->args[1]);
> > + dev_info(&pdev->dev, "chan dt cfg: memif=%u perif=%u perid=%u dwidth=%u csize=%u mbsize=%u\n",
> > + atchan->memif, atchan->perif, atchan->perid, atchan->dwidth, atchan->csize, atchan->mbsize);
> > +
> > + 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)
> > + | AT91_XDMAC_DT_DWIDTH(atchan->dwidth)
> > + | AT91_XDMAC_DT_CSIZE(atchan->csize)
> > + | AT_XDMAC_CC_SWREQ_HWR_CONNECTED
> > + | AT91_XDMAC_DT_MBSIZE(atchan->mbsize)
> > + | 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;
> > + } 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;
> > + } 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");
> > + 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);
> > + 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, 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;
> > + 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;
> > + u32 chan_cc = AT_XDMAC_CC_DAM_INCREMENTED_AM
> > + | AT_XDMAC_CC_SAM_INCREMENTED_AM
> > + | AT_XDMAC_CC_DIF(0) /* One interface for the destination */
> > + | AT_XDMAC_CC_SIF(1) /* The other one for the source */
> > + | 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. */
> > + 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_SUCCESS)
> > + return ret;
> > +
> > + spin_lock_irqsave(&atchan->lock, flags);
> > +
> > + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
> > +
> > + if (!desc->active_xfer)
> > + dev_err(chan2dev(chan),
> > + "something goes wrong, there is no active transfer\n");
> > +
> > + 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_terminate_xfer(struct at_xdmac_chan *atchan,
> > + struct at_xdmac_desc *desc)
> > +{
> > + dev_dbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
> > +
> > + /*
> > + * It's necessary to remove the transfer before calling the callback
> > + * because some devices can call dma_engine_terminate_all causing to do
> > + * dma_cookie_complete two times on the same cookie.
> > + */
> > + 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)) {
> > + dev_dbg(chan2dev(&atchan->chan), "%s: chan enabled\n",
> > + __func__);
> > + } else if (!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_terminate_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 ret = IRQ_NONE;
> > + int i;
> > +
> > + 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);
> > + break;
> > + case DMA_RESUME:
> > + at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask);
> > + 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_terminate_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_KERNEL);
> > + 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;
> > +}
> > +
> > +static int __init at_xdmac_probe(struct platform_device *pdev)
>
> This will trigger a section mismatch, because it's referenced later by
> your platform_driver structure, that is not stored in the __init
> section.
>
> You can either drop the __init here, or you
> module_platform_driver_probe.
>
ok
> > +{
> > + struct resource *res;
> > + struct at_xdmac *atxdmac;
> > + int irq, size, nr_channels, i, ret;
> > + void __iomem *base;
>
> You seem to sometimes align the variable names, sometimes you don't,
> and sometimes, you do both. You probably want to do it in a consistent
> way.
>
Yes most are aligned. It will correct it for those which are not.
> > + 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 = __raw_readl(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;
> > +
> > + ret = devm_request_irq(&pdev->dev, irq, at_xdmac_interrupt, 0,
> > + "at_xdmac", atxdmac);
> > + if (ret) {
> > + dev_err(&pdev->dev, "can't request irq\n");
> > + return ret;
> > + }
> > +
> > + 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);
> > + }
> > +
> > + ret = clk_prepare_enable(atxdmac->clk);
> > + if (ret) {
> > + dev_err(&pdev->dev, "can't prepare or enable clock\n");
> > + return ret;
> > + }
> > +
> > + 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;
> > +
> > + /* 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, "Failed 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);
> > + 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);
> > +
> > + for (i = 0; i < atxdmac->dma.chancnt; i++) {
> > + struct at_xdmac_chan *atchan = &atxdmac->chan[i];
> > +
> > + tasklet_kill(&atchan->tasklet);
>
> The usual sequence to kill a tasklet is:
> 1) Disable the device irq so that the handler should not be called
> anymore, and wouldn't schedule the tasklet.
>
> 2) Set some flag to prevent the handler from scheduling the tasklet
> in case of a spurious interrupt.
>
> 3) Call synchronize_irq to make sure all the pending interrupts are
> handled
>
> 4) Kill the tasklet.
>
> You're doing 1), I don't think 2 can happen from your code, 4 is done,
> but you're missing 3.
>
> You can look here for more details: https://lwn.net/Articles/588457/
Thanks to point this.
>
> > + at_xdmac_free_chan_resources(&atchan->chan);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +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",
> > + .of_match_table = of_match_ptr(atmel_xdmac_dt_ids),
> > + }
> > +};
> > +
> > +static int __init at_xdmac_init(void)
> > +{
> > + return platform_driver_probe(&at_xdmac_driver, at_xdmac_probe);
> > +}
> > +subsys_initcall(at_xdmac_init);
>
> Why do you need a subsys initcall here? dma_request_channel can return
> EPROBE_DEFER, so I think you can use module_platform_driver here.
>
I get some issues without it, some drivers didn't get their dma channel.
I'll have a deeper look and try again.
> > +MODULE_DESCRIPTION("Atmel Extended DMA Controller driver");
> > +MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches at atmel.com>");
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/dma/at_xdmac.h b/drivers/dma/at_xdmac.h
> > new file mode 100644
> > index 0000000..79e5ad8
> > --- /dev/null
> > +++ b/drivers/dma/at_xdmac.h
> > @@ -0,0 +1,257 @@
> > +#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 (0x1 << 0) /* End of Block Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_LIE (0x1 << 1) /* End of Linked List Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_DIE (0x1 << 2) /* End of Disable Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_FIE (0x1 << 3) /* End of Flush Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_RBEIE (0x1 << 4) /* Read Bus Error Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_WBEIE (0x1 << 5) /* Write Bus Error Interrupt Enable Bit */
> > +#define AT_XDMAC_CIE_ROIE (0x1 << 6) /* Request Overflow Interrupt Enable Bit */
> > +#define AT_XDMAC_CID 0x04 /* Channel Interrupt Disable Register */
> > +#define AT_XDMAC_CID_BID (0x1 << 0) /* End of Block Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_LID (0x1 << 1) /* End of Linked List Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_DID (0x1 << 2) /* End of Disable Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_FID (0x1 << 3) /* End of Flush Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_RBEID (0x1 << 4) /* Read Bus Error Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_WBEID (0x1 << 5) /* Write Bus Error Interrupt Disable Bit */
> > +#define AT_XDMAC_CID_ROID (0x1 << 6) /* Request Overflow Interrupt Disable Bit */
> > +#define AT_XDMAC_CIM 0x08 /* Channel Interrupt Mask Register */
> > +#define AT_XDMAC_CIM_BIM (0x1 << 0) /* End of Block Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_LIM (0x1 << 1) /* End of Linked List Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_DIM (0x1 << 2) /* End of Disable Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_FIM (0x1 << 3) /* End of Flush Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_RBEIM (0x1 << 4) /* Read Bus Error Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_WBEIM (0x1 << 5) /* Write Bus Error Interrupt Mask Bit */
> > +#define AT_XDMAC_CIM_ROIM (0x1 << 6) /* Request Overflow Interrupt Mask Bit */
> > +#define AT_XDMAC_CIS 0x0C /* Channel Interrupt Status Register */
> > +#define AT_XDMAC_CIS_BIS (0x1 << 0) /* End of Block Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_LIS (0x1 << 1) /* End of Linked List Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_DIS (0x1 << 2) /* End of Disable Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_FIS (0x1 << 3) /* End of Flush Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_RBEIS (0x1 << 4) /* Read Bus Error Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_WBEIS (0x1 << 5) /* Write Bus Error Interrupt Status Bit */
> > +#define AT_XDMAC_CIS_ROIS (0x1 << 6) /* Request Overflow Interrupt Status Bit */
>
> You should use BIT() for all of these.
Thanks for the tip.
>
> > +#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,
> > +};
> > +
> > +/* ----- 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 csize; /* Chunk Size */
> > + u8 mbsize; /* Memory Burst Size */
> > + u8 perif; /* Peripheral Interface */
> > + u8 memif; /* Memory Interface */
> > + 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;
> > + struct clk *clk;
> > + 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) __raw_readl((atxdmac)->regs + (reg))
> > +#define at_xdmac_write(atxdmac, reg, value) \
> > + __raw_writel((value), (atxdmac)->regs + (reg))
> > +
> > +#define at_xdmac_chan_read(atchan, reg) __raw_readl((atchan)->ch_regs + (reg))
> > +#define at_xdmac_chan_write(atchan, reg, value) __raw_writel((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);
> > +}
> > +
> > +#endif /* __AT_XDMAC_H__ */
> > diff --git a/include/dt-bindings/dma/at91.h b/include/dt-bindings/dma/at91.h
> > index e835037..bef5b68 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 +26,48 @@
> > #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)
> > +
> > +#define AT91_XDMAC_DT_DWIDTH_MASK (0x3)
> > +#define AT91_XDMAC_DT_DWIDTH_OFFSET (11)
> > +#define AT91_XDMAC_DT_DWIDTH(dwidth) (((dwidth) & AT91_XDMAC_DT_DWIDTH_MASK) \
> > + << AT91_XDMAC_DT_DWIDTH_OFFSET)
> > +#define AT91_XDMAC_DT_GET_DWIDTH(cfg) (((cfg) >> AT91_XDMAC_DT_DWIDTH_OFFSET) \
> > + & AT91_XDMAC_DT_DWIDTH_MASK)
> > +
> > +#define AT91_XDMAC_DT_CSIZE_MASK (0x7)
> > +#define AT91_XDMAC_DT_CSIZE_OFFSET (8)
> > +#define AT91_XDMAC_DT_CSIZE(csize) (((csize) & AT91_XDMAC_DT_CSIZE_MASK) \
> > + << AT91_XDMAC_DT_CSIZE_OFFSET)
> > +#define AT91_XDMAC_DT_GET_CSIZE(cfg) (((cfg) >> AT91_XDMAC_DT_CSIZE_OFFSET) \
> > + & AT91_XDMAC_DT_CSIZE_MASK)
> > +
> > +#define AT91_XDMAC_DT_MBSIZE_MASK (0x3)
> > +#define AT91_XDMAC_DT_MBSIZE_OFFSET (1)
> > +#define AT91_XDMAC_DT_MBSIZE(mbsize) (((mbsize) & AT91_XDMAC_DT_MBSIZE_MASK) \
> > + << AT91_XDMAC_DT_MBSIZE_OFFSET)
> > +#define AT91_XDMAC_DT_GET_MBSIZE(cfg) (((cfg) >> AT91_XDMAC_DT_MBSIZE_OFFSET) \
> > + & AT91_XDMAC_DT_MBSIZE_MASK)
> > +
> > #endif /* __DT_BINDINGS_AT91_DMA_H__ */
> > --
> > 1.7.9.5
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
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