Add generic DMA bindings and register the DMA controller
to DT DMA helpers.
Signed-off-by: Anatolij Gustschin <[email protected]>
---
arch/powerpc/boot/dts/mpc5121.dtsi | 5 ++-
drivers/dma/mpc512x_dma.c | 63 ++++++++++++++++++++++++++++++++++--
2 files changed, 64 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
index 723e292..d1fe070 100644
--- a/arch/powerpc/boot/dts/mpc5121.dtsi
+++ b/arch/powerpc/boot/dts/mpc5121.dtsi
@@ -384,10 +384,13 @@
interrupts = <40 0x8>;
};
- dma@14000 {
+ dma0: dma@14000 {
compatible = "fsl,mpc5121-dma";
reg = <0x14000 0x1800>;
interrupts = <65 0x8>;
+ #dma-cells = <1>;
+ #dma-channels = <64>;
+ #dma-requests = <64>;
};
};
diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
index 2d95673..bc6c356 100644
--- a/drivers/dma/mpc512x_dma.c
+++ b/drivers/dma/mpc512x_dma.c
@@ -40,6 +40,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/of_platform.h>
#include <linux/random.h>
@@ -641,6 +642,44 @@ mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
return &mdesc->desc;
}
+struct mpc_dma_filter_args {
+ struct mpc_dma *mdma;
+ unsigned int chan_id;
+};
+
+static bool mpc_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct mpc_dma_filter_args *fargs = param;
+
+ if (chan->device != &fargs->mdma->dma)
+ return false;
+
+ return (chan->chan_id == fargs->chan_id);
+}
+
+static struct dma_chan *mpc_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ int count = dma_spec->args_count;
+ struct mpc_dma *mdma = ofdma->of_dma_data;
+ struct mpc_dma_filter_args fargs;
+ dma_cap_mask_t cap;
+
+ if (!mdma)
+ return NULL;
+
+ if (count != 1)
+ return NULL;
+
+ fargs.mdma = mdma;
+ fargs.chan_id = dma_spec->args[0];
+
+ dma_cap_zero(cap);
+ dma_cap_set(DMA_SLAVE, cap);
+
+ return dma_request_channel(cap, mpc_dma_filter, &fargs);
+}
+
static int mpc_dma_probe(struct platform_device *op)
{
struct device_node *dn = op->dev.of_node;
@@ -791,11 +830,26 @@ static int mpc_dma_probe(struct platform_device *op)
/* Register DMA engine */
dev_set_drvdata(dev, mdma);
retval = dma_async_device_register(dma);
- if (retval) {
- devm_free_irq(dev, mdma->irq, mdma);
- irq_dispose_mapping(mdma->irq);
+ if (retval)
+ goto reg_err;
+
+ if (dev->of_node) {
+ retval = of_dma_controller_register(dev->of_node,
+ mpc_dma_xlate, mdma);
+ if (retval) {
+ dev_err(&op->dev,
+ "could not register of_dma_controller\n");
+ goto of_err;
+ }
}
+ return 0;
+
+of_err:
+ dma_async_device_unregister(&mdma->dma);
+reg_err:
+ devm_free_irq(dev, mdma->irq, mdma);
+ irq_dispose_mapping(mdma->irq);
return retval;
}
@@ -804,6 +858,9 @@ static int mpc_dma_remove(struct platform_device *op)
struct device *dev = &op->dev;
struct mpc_dma *mdma = dev_get_drvdata(dev);
+ if (dev->of_node)
+ of_dma_controller_free(dev->of_node);
+
dma_async_device_unregister(&mdma->dma);
devm_free_irq(dev, mdma->irq, mdma);
irq_dispose_mapping(mdma->irq);
--
1.7.5.4
Prepare the driver to support slave sg operation.
For memory to memory transfers mpc_dma_execute() used to start
the transfer explicitely, for peripheral transfers the dma transfer
will be started on peripheral's request, so we only need to enable
peripheral's channel request in mpc_dma_execute().
Signed-off-by: Anatolij Gustschin <[email protected]>
---
drivers/dma/mpc512x_dma.c | 150 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 148 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
index bc6c356..1c822b1 100644
--- a/drivers/dma/mpc512x_dma.c
+++ b/drivers/dma/mpc512x_dma.c
@@ -194,6 +194,9 @@ struct mpc_dma_chan {
/* Lock for this structure */
spinlock_t lock;
+
+ /* Channel's peripheral fifo address */
+ dma_addr_t per_paddr;
};
struct mpc_dma {
@@ -257,7 +260,9 @@ static void mpc_dma_execute(struct mpc_dma_chan *mchan)
prev->tcd->dlast_sga = mdesc->tcd_paddr;
prev->tcd->e_sg = 1;
- mdesc->tcd->start = 1;
+ /* only start explicitly on MDDRC channel */
+ if (cid == 32)
+ mdesc->tcd->start = 1;
prev = mdesc;
}
@@ -269,7 +274,15 @@ static void mpc_dma_execute(struct mpc_dma_chan *mchan)
if (first != prev)
mdma->tcd[cid].e_sg = 1;
- out_8(&mdma->regs->dmassrt, cid);
+
+ switch (cid) {
+ case 30:
+ out_8(&mdma->regs->dmaserq, cid);
+ break;
+ case 32:
+ out_8(&mdma->regs->dmassrt, cid);
+ break;
+ }
}
/* Handle interrupt on one half of DMA controller (32 channels) */
@@ -642,6 +655,136 @@ mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
return &mdesc->desc;
}
+static struct dma_async_tx_descriptor *mpc_dma_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 mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
+ struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
+ struct mpc_dma_desc *mdesc = NULL;
+ struct mpc_dma_tcd *tcd;
+ unsigned long flags;
+ struct scatterlist *sg;
+ dma_addr_t dst, src;
+ size_t len;
+ int iter, i;
+
+ if (!list_empty(&mchan->active))
+ return NULL;
+
+ for_each_sg(sgl, sg, sg_len, i) {
+ spin_lock_irqsave(&mchan->lock, flags);
+
+ mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
+ node);
+ if (!mdesc) {
+ spin_unlock_irqrestore(&mchan->lock, flags);
+ /* try to free completed descriptors */
+ mpc_dma_process_completed(mdma);
+ return NULL;
+ }
+
+ list_del(&mdesc->node);
+
+ spin_unlock_irqrestore(&mchan->lock, flags);
+
+ mdesc->error = 0;
+ tcd = mdesc->tcd;
+
+ /* Prepare Transfer Control Descriptor for this transaction */
+ memset(tcd, 0, sizeof(struct mpc_dma_tcd));
+
+ if (direction == DMA_DEV_TO_MEM) {
+ dst = sg_dma_address(sg);
+ src = mchan->per_paddr;
+ } else if (direction == DMA_MEM_TO_DEV) {
+ dst = mchan->per_paddr;
+ src = sg_dma_address(sg);
+ } else {
+ return NULL;
+ }
+
+ len = sg_dma_len(sg);
+
+ if (direction == DMA_MEM_TO_DEV) {
+ tcd->saddr = sg_dma_address(sg);
+ tcd->daddr = mchan->per_paddr;
+ tcd->soff = 4;
+ tcd->doff = 0;
+ } else {
+ tcd->saddr = mchan->per_paddr;
+ tcd->daddr = sg_dma_address(sg);
+ tcd->soff = 0;
+ tcd->doff = 4;
+ }
+
+ tcd->ssize = MPC_DMA_TSIZE_4;
+ tcd->dsize = MPC_DMA_TSIZE_4;
+ tcd->nbytes = 64;
+
+ iter = sg_dma_len(sg) / 64;
+
+ /* citer_linkch contains the high bits of iter */
+ tcd->citer_linkch = iter >> 9;
+ tcd->biter_linkch = iter >> 9;
+ tcd->citer = iter & 0x1ff;
+ tcd->biter = iter & 0x1ff;
+
+ tcd->e_sg = 0;
+
+ if (i != (sg_len - 1)) {
+ struct scatterlist *s = sg_next(sg);
+
+ if (!s)
+ tcd->dlast_sga = sg_dma_address(s);
+ tcd->e_sg = 1;
+ } else {
+ tcd->d_req = 1;
+ }
+ }
+
+ /* Place descriptor in prepared list */
+ spin_lock_irqsave(&mchan->lock, flags);
+ list_add_tail(&mdesc->node, &mchan->prepared);
+ spin_unlock_irqrestore(&mchan->lock, flags);
+
+ return &mdesc->desc;
+}
+
+static int mpc_dma_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
+ struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
+ struct dma_slave_config *cfg = (void *)arg;
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ /* disable channel requests */
+ out_8(&mdma->regs->dmaserq, chan->chan_id);
+ list_splice_tail_init(&mchan->prepared, &mchan->free);
+ list_splice_tail_init(&mchan->queued, &mchan->free);
+ list_splice_tail_init(&mchan->active, &mchan->free);
+ return 0;
+ case DMA_SLAVE_CONFIG:
+ if (cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES &&
+ cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
+ return -EINVAL;
+
+ if (cfg->direction == DMA_DEV_TO_MEM)
+ mchan->per_paddr = cfg->src_addr;
+ else
+ mchan->per_paddr = cfg->dst_addr;
+
+ return 0;
+ default:
+ return -ENOSYS;
+ }
+
+ return -EINVAL;
+}
+
struct mpc_dma_filter_args {
struct mpc_dma *mdma;
unsigned int chan_id;
@@ -764,9 +907,12 @@ static int mpc_dma_probe(struct platform_device *op)
dma->device_issue_pending = mpc_dma_issue_pending;
dma->device_tx_status = mpc_dma_tx_status;
dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
+ dma->device_prep_slave_sg = mpc_dma_prep_slave_sg;
+ dma->device_control = mpc_dma_device_control;
INIT_LIST_HEAD(&dma->channels);
dma_cap_set(DMA_MEMCPY, dma->cap_mask);
+ dma_cap_set(DMA_SLAVE, dma->cap_mask);
for (i = 0; i < dma->chancnt; i++) {
mchan = &mdma->channels[i];
--
1.7.5.4
On Sun, Mar 31, 2013 at 06:17:59PM +0200, Anatolij Gustschin wrote:
> Add generic DMA bindings and register the DMA controller
> to DT DMA helpers.
I need someone who understands DT better than me to comment/ack...
Arnd...?
>
> Signed-off-by: Anatolij Gustschin <[email protected]>
> ---
> arch/powerpc/boot/dts/mpc5121.dtsi | 5 ++-
> drivers/dma/mpc512x_dma.c | 63 ++++++++++++++++++++++++++++++++++--
> 2 files changed, 64 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
> index 723e292..d1fe070 100644
> --- a/arch/powerpc/boot/dts/mpc5121.dtsi
> +++ b/arch/powerpc/boot/dts/mpc5121.dtsi
> @@ -384,10 +384,13 @@
> interrupts = <40 0x8>;
> };
>
> - dma@14000 {
> + dma0: dma@14000 {
> compatible = "fsl,mpc5121-dma";
> reg = <0x14000 0x1800>;
> interrupts = <65 0x8>;
> + #dma-cells = <1>;
> + #dma-channels = <64>;
> + #dma-requests = <64>;
> };
> };
>
> diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
> index 2d95673..bc6c356 100644
> --- a/drivers/dma/mpc512x_dma.c
> +++ b/drivers/dma/mpc512x_dma.c
> @@ -40,6 +40,7 @@
> #include <linux/io.h>
> #include <linux/slab.h>
> #include <linux/of_device.h>
> +#include <linux/of_dma.h>
> #include <linux/of_platform.h>
>
> #include <linux/random.h>
> @@ -641,6 +642,44 @@ mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
> return &mdesc->desc;
> }
>
> +struct mpc_dma_filter_args {
> + struct mpc_dma *mdma;
> + unsigned int chan_id;
> +};
> +
> +static bool mpc_dma_filter(struct dma_chan *chan, void *param)
> +{
> + struct mpc_dma_filter_args *fargs = param;
> +
> + if (chan->device != &fargs->mdma->dma)
> + return false;
> +
> + return (chan->chan_id == fargs->chan_id);
> +}
> +
> +static struct dma_chan *mpc_dma_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + int count = dma_spec->args_count;
> + struct mpc_dma *mdma = ofdma->of_dma_data;
> + struct mpc_dma_filter_args fargs;
> + dma_cap_mask_t cap;
> +
> + if (!mdma)
> + return NULL;
> +
> + if (count != 1)
> + return NULL;
> +
> + fargs.mdma = mdma;
> + fargs.chan_id = dma_spec->args[0];
> +
> + dma_cap_zero(cap);
> + dma_cap_set(DMA_SLAVE, cap);
> +
> + return dma_request_channel(cap, mpc_dma_filter, &fargs);
> +}
> +
> static int mpc_dma_probe(struct platform_device *op)
> {
> struct device_node *dn = op->dev.of_node;
> @@ -791,11 +830,26 @@ static int mpc_dma_probe(struct platform_device *op)
> /* Register DMA engine */
> dev_set_drvdata(dev, mdma);
> retval = dma_async_device_register(dma);
> - if (retval) {
> - devm_free_irq(dev, mdma->irq, mdma);
> - irq_dispose_mapping(mdma->irq);
> + if (retval)
> + goto reg_err;
> +
> + if (dev->of_node) {
> + retval = of_dma_controller_register(dev->of_node,
> + mpc_dma_xlate, mdma);
> + if (retval) {
> + dev_err(&op->dev,
> + "could not register of_dma_controller\n");
> + goto of_err;
> + }
> }
>
> + return 0;
> +
> +of_err:
> + dma_async_device_unregister(&mdma->dma);
> +reg_err:
> + devm_free_irq(dev, mdma->irq, mdma);
> + irq_dispose_mapping(mdma->irq);
> return retval;
> }
>
> @@ -804,6 +858,9 @@ static int mpc_dma_remove(struct platform_device *op)
> struct device *dev = &op->dev;
> struct mpc_dma *mdma = dev_get_drvdata(dev);
>
> + if (dev->of_node)
> + of_dma_controller_free(dev->of_node);
> +
> dma_async_device_unregister(&mdma->dma);
> devm_free_irq(dev, mdma->irq, mdma);
> irq_dispose_mapping(mdma->irq);
> --
> 1.7.5.4
>
On Tuesday 02 April 2013, Vinod Koul wrote:
> On Sun, Mar 31, 2013 at 06:17:59PM +0200, Anatolij Gustschin wrote:
> > Add generic DMA bindings and register the DMA controller
> > to DT DMA helpers.
> I need someone who understands DT better than me to comment/ack...
> Arnd...?
> >
> > +struct mpc_dma_filter_args {
> > + struct mpc_dma *mdma;
> > + unsigned int chan_id;
> > +};
> > +
> > +static bool mpc_dma_filter(struct dma_chan *chan, void *param)
> > +{
> > + struct mpc_dma_filter_args *fargs = param;
> > +
> > + if (chan->device != &fargs->mdma->dma)
> > + return false;
> > +
> > + return (chan->chan_id == fargs->chan_id);
> > +}
This assumes that there is a 1:1 mapping between channels and request lines,
which is unusual, but I assume it's correct for the hardware.
> > @@ -791,11 +830,26 @@ static int mpc_dma_probe(struct platform_device *op)
> > /* Register DMA engine */
> > dev_set_drvdata(dev, mdma);
> > retval = dma_async_device_register(dma);
> > - if (retval) {
> > - devm_free_irq(dev, mdma->irq, mdma);
> > - irq_dispose_mapping(mdma->irq);
> > + if (retval)
> > + goto reg_err;
> > +
> > + if (dev->of_node) {
> > + retval = of_dma_controller_register(dev->of_node,
> > + mpc_dma_xlate, mdma);
> > + if (retval) {
> > + dev_err(&op->dev,
> > + "could not register of_dma_controller\n");
> > + goto of_err;
> > + }
> > }
Here we rely on the fact that all device trees including this dma engine
have a correct representation of the device, which breaks backwards
compatibility with old device trees, which don't yet follow the binding
or don't need to because they only use memory-to-memory channels.
You can easily make it backwards compatible by making the above a
non-fatal error and just continuing here even if of_dma_controller_register
failed. If compatiblity is not a concern, the above is good.
The main thing missing is a binding file in
Documentation/devicetree/bindings/dma/mpc512x-dma.txt
Arnd
On 03/31/2013 06:17 PM, Anatolij Gustschin wrote:
> Add generic DMA bindings and register the DMA controller
> to DT DMA helpers.
>
> Signed-off-by: Anatolij Gustschin <[email protected]>
> ---
> arch/powerpc/boot/dts/mpc5121.dtsi | 5 ++-
> drivers/dma/mpc512x_dma.c | 63 ++++++++++++++++++++++++++++++++++--
> 2 files changed, 64 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi
> index 723e292..d1fe070 100644
> --- a/arch/powerpc/boot/dts/mpc5121.dtsi
> +++ b/arch/powerpc/boot/dts/mpc5121.dtsi
> @@ -384,10 +384,13 @@
> interrupts = <40 0x8>;
> };
>
> - dma@14000 {
> + dma0: dma@14000 {
> compatible = "fsl,mpc5121-dma";
> reg = <0x14000 0x1800>;
> interrupts = <65 0x8>;
> + #dma-cells = <1>;
> + #dma-channels = <64>;
> + #dma-requests = <64>;
> };
> };
>
> diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
> index 2d95673..bc6c356 100644
> --- a/drivers/dma/mpc512x_dma.c
> +++ b/drivers/dma/mpc512x_dma.c
> @@ -40,6 +40,7 @@
> #include <linux/io.h>
> #include <linux/slab.h>
> #include <linux/of_device.h>
> +#include <linux/of_dma.h>
> #include <linux/of_platform.h>
>
> #include <linux/random.h>
> @@ -641,6 +642,44 @@ mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
> return &mdesc->desc;
> }
>
> +struct mpc_dma_filter_args {
> + struct mpc_dma *mdma;
> + unsigned int chan_id;
> +};
> +
> +static bool mpc_dma_filter(struct dma_chan *chan, void *param)
> +{
> + struct mpc_dma_filter_args *fargs = param;
> +
> + if (chan->device != &fargs->mdma->dma)
> + return false;
> +
> + return (chan->chan_id == fargs->chan_id);
> +}
> +
> +static struct dma_chan *mpc_dma_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + int count = dma_spec->args_count;
> + struct mpc_dma *mdma = ofdma->of_dma_data;
> + struct mpc_dma_filter_args fargs;
> + dma_cap_mask_t cap;
> +
> + if (!mdma)
> + return NULL;
> +
> + if (count != 1)
> + return NULL;
> +
> + fargs.mdma = mdma;
> + fargs.chan_id = dma_spec->args[0];
> +
> + dma_cap_zero(cap);
> + dma_cap_set(DMA_SLAVE, cap);
> +
> + return dma_request_channel(cap, mpc_dma_filter, &fargs);
> +}
> +
This is more or less the same as the generic of_dma_xlate_by_chan_id
function I posted about two weeks ago:
https://patchwork.kernel.org/patch/2331091/
Vinod, can you take a look at that patch again? I'm not quite sure what you
meant by your question 'how will the client know which "id" to request?'.
- Lars
On Mon, 08 Apr 2013 12:46:47 +0200
Lars-Peter Clausen <[email protected]> wrote:
...
> > +static struct dma_chan *mpc_dma_xlate(struct of_phandle_args *dma_spec,
> > + struct of_dma *ofdma)
> > +{
> > + int count = dma_spec->args_count;
> > + struct mpc_dma *mdma = ofdma->of_dma_data;
> > + struct mpc_dma_filter_args fargs;
> > + dma_cap_mask_t cap;
> > +
> > + if (!mdma)
> > + return NULL;
> > +
> > + if (count != 1)
> > + return NULL;
> > +
> > + fargs.mdma = mdma;
> > + fargs.chan_id = dma_spec->args[0];
> > +
> > + dma_cap_zero(cap);
> > + dma_cap_set(DMA_SLAVE, cap);
> > +
> > + return dma_request_channel(cap, mpc_dma_filter, &fargs);
> > +}
> > +
>
> This is more or less the same as the generic of_dma_xlate_by_chan_id
> function I posted about two weeks ago:
> https://patchwork.kernel.org/patch/2331091/
Thanks. I can use the generic of_dma_xlate_by_chan_id() when above patch
will be accepted.
Anatolij
Hello Anatolij,
I've made SCLPC device driver use .device_prep_slave_sg() from your patch
and before I send the second version of it I would like to propose
some improvements:
diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
index 1c822b1..80d8633 100644
--- a/drivers/dma/mpc512x_dma.c
+++ b/drivers/dma/mpc512x_dma.c
@@ -28,11 +28,6 @@
* file called COPYING.
*/
-/*
- * This is initial version of MPC5121 DMA driver. Only memory to memory
- * transfers are supported (tested using dmatest module).
- */
-
#include <linux/module.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -191,6 +186,7 @@ struct mpc_dma_chan {
struct list_head completed;
struct mpc_dma_tcd *tcd;
dma_addr_t tcd_paddr;
+ u32 tcd_nunits;
/* Lock for this structure */
spinlock_t lock;
@@ -276,6 +272,7 @@ static void mpc_dma_execute(struct mpc_dma_chan *mchan)
mdma->tcd[cid].e_sg = 1;
switch (cid) {
+ case 26:
case 30:
out_8(&mdma->regs->dmaserq, cid);
break;
@@ -664,9 +661,8 @@ static struct dma_async_tx_descriptor
*mpc_dma_prep_slave_sg(
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma_desc *mdesc = NULL;
struct mpc_dma_tcd *tcd;
- unsigned long flags;
+ unsigned long iflags;
struct scatterlist *sg;
- dma_addr_t dst, src;
size_t len;
int iter, i;
@@ -674,12 +670,12 @@ static struct dma_async_tx_descriptor
*mpc_dma_prep_slave_sg(
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
- spin_lock_irqsave(&mchan->lock, flags);
+ spin_lock_irqsave(&mchan->lock, iflags);
mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
node);
if (!mdesc) {
- spin_unlock_irqrestore(&mchan->lock, flags);
+ spin_unlock_irqrestore(&mchan->lock, iflags);
/* try to free completed descriptors */
mpc_dma_process_completed(mdma);
return NULL;
@@ -687,7 +683,7 @@ static struct dma_async_tx_descriptor
*mpc_dma_prep_slave_sg(
list_del(&mdesc->node);
- spin_unlock_irqrestore(&mchan->lock, flags);
+ spin_unlock_irqrestore(&mchan->lock, iflags);
mdesc->error = 0;
tcd = mdesc->tcd;
@@ -696,40 +692,43 @@ static struct dma_async_tx_descriptor
*mpc_dma_prep_slave_sg(
memset(tcd, 0, sizeof(struct mpc_dma_tcd));
if (direction == DMA_DEV_TO_MEM) {
- dst = sg_dma_address(sg);
- src = mchan->per_paddr;
+ tcd->saddr = mchan->per_paddr;
+ tcd->daddr = sg_dma_address(sg);
+ tcd->soff = 0;
+ tcd->doff = 4;
} else if (direction == DMA_MEM_TO_DEV) {
- dst = mchan->per_paddr;
- src = sg_dma_address(sg);
- } else {
- return NULL;
- }
-
- len = sg_dma_len(sg);
-
- if (direction == DMA_MEM_TO_DEV) {
tcd->saddr = sg_dma_address(sg);
tcd->daddr = mchan->per_paddr;
tcd->soff = 4;
tcd->doff = 0;
} else {
- tcd->saddr = mchan->per_paddr;
- tcd->daddr = sg_dma_address(sg);
- tcd->soff = 0;
- tcd->doff = 4;
+ return NULL;
}
-
tcd->ssize = MPC_DMA_TSIZE_4;
tcd->dsize = MPC_DMA_TSIZE_4;
- tcd->nbytes = 64;
- iter = sg_dma_len(sg) / 64;
+ if (!IS_ALIGNED(sg_dma_address(sg), 4))
+ return NULL;
+
+ len = sg_dma_len(sg);
+ if (mchan->tcd_nunits)
+ tcd->nbytes = mchan->tcd_nunits * 4;
+ else
+ tcd->nbytes = 64;
- /* citer_linkch contains the high bits of iter */
- tcd->citer_linkch = iter >> 9;
- tcd->biter_linkch = iter >> 9;
- tcd->citer = iter & 0x1ff;
- tcd->biter = iter & 0x1ff;
+ if (!IS_ALIGNED(len, tcd->nbytes))
+ return NULL;
+
+ iter = len / tcd->nbytes;
+ if (iter > ((1 << 15) - 1)) { /* maximum biter */
+ return NULL; /* len is too big */
+ } else {
+ /* citer_linkch contains the high bits of iter */
+ tcd->biter = iter & 0x1ff;
+ tcd->biter_linkch = iter >> 9;
+ tcd->citer = tcd->biter;
+ tcd->citer_linkch = tcd->biter_linkch;
+ }
tcd->e_sg = 0;
@@ -745,9 +744,9 @@ static struct dma_async_tx_descriptor
*mpc_dma_prep_slave_sg(
}
/* Place descriptor in prepared list */
- spin_lock_irqsave(&mchan->lock, flags);
+ spin_lock_irqsave(&mchan->lock, iflags);
list_add_tail(&mdesc->node, &mchan->prepared);
- spin_unlock_irqrestore(&mchan->lock, flags);
+ spin_unlock_irqrestore(&mchan->lock, iflags);
return &mdesc->desc;
}
@@ -772,10 +771,13 @@ static int mpc_dma_device_control(struct
dma_chan *chan, enum dma_ctrl_cmd cmd,
cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES)
return -EINVAL;
- if (cfg->direction == DMA_DEV_TO_MEM)
+ if (cfg->direction == DMA_DEV_TO_MEM) {
mchan->per_paddr = cfg->src_addr;
- else
+ mchan->tcd_nunits = cfg->src_maxburst;
+ } else {
mchan->per_paddr = cfg->dst_addr;
+ mchan->tcd_nunits = cfg->dst_maxburst;
+ }
return 0;
default:
2013/3/31 Anatolij Gustschin <[email protected]>:
> Prepare the driver to support slave sg operation.
>
Thanks.
Best regards,
Alexander