The current OF translation of channels can never work with
any DMA client using the DMA channels directly: the only way
to get the channels initialized properly is in the
dma_async_device_register() call, where chan->dev etc is
allocated and initialized.
Allocate and initialize all possible DMA channels and
only augment a target channel with the periph_buses at
of_xlate(). Remove some const settings to make things work.
Cc: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Cc: Joachim Eastwood <manabian@xxxxxxxxx>
Cc: Johannes Stezenbach <js@xxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- Rely on the number of signals for the variant coming in
from vendor data.
Joachim: Can you please help to try to figure out if this
still crashes with LPC, it must be something with the mux
layer thing. This is doing the right thing and is needed
for atleast 2 platforms to use this driver.
---
drivers/dma/amba-pl08x.c | 71 ++++++++++++++++++++++++++++------------------
include/linux/amba/pl08x.h | 2 +-
2 files changed, 44 insertions(+), 29 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 2ef80200d110..2252e48da1f1 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -243,7 +243,7 @@ struct pl08x_dma_chan {
struct virt_dma_chan vc;
struct pl08x_phy_chan *phychan;
const char *name;
- const struct pl08x_channel_data *cd;
+ struct pl08x_channel_data *cd;
struct dma_slave_config cfg;
struct pl08x_txd *at;
struct pl08x_driver_data *host;
@@ -2082,40 +2082,33 @@ static struct dma_chan *pl08x_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct pl08x_driver_data *pl08x = ofdma->of_dma_data;
- struct pl08x_channel_data *data;
- struct pl08x_dma_chan *chan;
struct dma_chan *dma_chan;
+ struct pl08x_dma_chan *plchan;
if (!pl08x)
return NULL;
- if (dma_spec->args_count != 2)
+ if (dma_spec->args_count != 2) {
+ dev_err(&pl08x->adev->dev,
+ "DMA channel translation requires two cells\n");
return NULL;
+ }
dma_chan = pl08x_find_chan_id(pl08x, dma_spec->args[0]);
- if (dma_chan)
- return dma_get_slave_channel(dma_chan);
-
- chan = devm_kzalloc(pl08x->slave.dev, sizeof(*chan) + sizeof(*data),
- GFP_KERNEL);
- if (!chan)
+ if (!dma_chan) {
+ dev_err(&pl08x->adev->dev,
+ "DMA slave channel not found\n");
return NULL;
+ }
- data = (void *)&chan[1];
- data->bus_id = "(none)";
- data->periph_buses = dma_spec->args[1];
-
- chan->cd = data;
- chan->host = pl08x;
- chan->slave = true;
- chan->name = data->bus_id;
- chan->state = PL08X_CHAN_IDLE;
- chan->signal = dma_spec->args[0];
- chan->vc.desc_free = pl08x_desc_free;
-
- vchan_init(&chan->vc, &pl08x->slave);
+ plchan = to_pl08x_chan(dma_chan);
+ dev_dbg(&pl08x->adev->dev,
+ "translated channel for signal %d\n",
+ dma_spec->args[0]);
- return dma_get_slave_channel(&chan->vc.chan);
+ /* Augment channel data for applicable AHB buses */
+ plchan->cd->periph_buses = dma_spec->args[1];
+ return dma_get_slave_channel(dma_chan);
}
static int pl08x_of_probe(struct amba_device *adev,
@@ -2123,9 +2116,11 @@ static int pl08x_of_probe(struct amba_device *adev,
struct device_node *np)
{
struct pl08x_platform_data *pd;
+ struct pl08x_channel_data *chanp = NULL;
u32 cctl_memcpy = 0;
u32 val;
int ret;
+ int i;
pd = devm_kzalloc(&adev->dev, sizeof(*pd), GFP_KERNEL);
if (!pd)
@@ -2227,6 +2222,26 @@ static int pl08x_of_probe(struct amba_device *adev,
/* Use the buses that can access memory, obviously */
pd->memcpy_channel.periph_buses = pd->mem_buses;
+ /*
+ * Allocate channel data for all possible slave channels (one
+ * for each possible signal), channels will then be allocated
+ * for a device and have it's AHB interfaces set up at
+ * translation time.
+ */
+ chanp = devm_kzalloc(&adev->dev,
+ pl08x->vd->signals *
+ sizeof(struct pl08x_channel_data),
+ GFP_KERNEL);
+ if (!chanp)
+ return -ENOMEM;
+ pd->slave_channels = chanp;
+ for (i = 0; i < pl08x->vd->signals; i++) {
+ /* chanp->periph_buses will be assigned at translation */
+ chanp->bus_id = kasprintf(GFP_KERNEL, "slave%d", i);
+ chanp++;
+ }
+ pd->num_slave_channels = pl08x->vd->signals;
+
pl08x->pd = pd;
return of_dma_controller_register(adev->dev.of_node, pl08x_of_xlate,
@@ -2266,6 +2281,10 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
goto out_no_pl08x;
}
+ /* Assign useful pointers to the driver state */
+ pl08x->adev = adev;
+ pl08x->vd = vd;
+
/* Initialize memcpy engine */
dma_cap_set(DMA_MEMCPY, pl08x->memcpy.cap_mask);
pl08x->memcpy.dev = &adev->dev;
@@ -2316,10 +2335,6 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
}
}
- /* Assign useful pointers to the driver state */
- pl08x->adev = adev;
- pl08x->vd = vd;
-
/* By default, AHB1 only. If dualmaster, from platform */
pl08x->lli_buses = PL08X_AHB1;
pl08x->mem_buses = PL08X_AHB1;
diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h
index 10fe2a211c2e..27e9ec8778eb 100644
--- a/include/linux/amba/pl08x.h
+++ b/include/linux/amba/pl08x.h
@@ -86,7 +86,7 @@ struct pl08x_channel_data {
* @mem_buses: buses which memory can be accessed from: PL08X_AHB1 | PL08X_AHB2
*/
struct pl08x_platform_data {
- const struct pl08x_channel_data *slave_channels;
+ struct pl08x_channel_data *slave_channels;
unsigned int num_slave_channels;
struct pl08x_channel_data memcpy_channel;
int (*get_xfer_signal)(const struct pl08x_channel_data *);
--
2.4.3
--
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