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 32 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>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
Joachim: I think I need your teste-by on this to make sure
the LPC machine survives this patch set.
---
drivers/dma/amba-pl08x.c | 80 +++++++++++++++++++++++++++++-----------------
include/linux/amba/pl08x.h | 2 +-
2 files changed, 52 insertions(+), 30 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index dc864846f0a9..9420b9cdbf99 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -95,6 +95,13 @@
#define DRIVER_NAME "pl08xdmac"
+/*
+ * The PL08X IP blocks has up to 32 routable hardware signals. Sometimes a MUX
+ * will be mounted on top of the signals to further extend the available DMA
+ * routes.
+ */
+#define PL08X_DMA_SIGNALS 32
+
#define PL80X_DMA_BUSWIDTHS \
BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
@@ -241,7 +248,7 @@ 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;
@@ -2080,40 +2087,34 @@ 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;
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;
+ }
+ /* Already allocated or coming from platform data */
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)
- 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;
+ if (dma_chan) {
+ struct pl08x_dma_chan *plchan = to_pl08x_chan(dma_chan);
- vchan_init(&chan->vc, &pl08x->slave);
+ dev_dbg(&pl08x->adev->dev,
+ "translated channel for signal %d\n",
+ dma_spec->args[0]);
+ /* Augment channel data for applicable AHB buses */
+ plchan->cd->periph_buses = dma_spec->args[1];
+ return dma_get_slave_channel(dma_chan);
+ }
- return dma_get_slave_channel(&chan->vc.chan);
+ dev_err(&pl08x->adev->dev,
+ "can\'t find DMA slave channel for signal %d\n",
+ dma_spec->args[0]);
+ return NULL;
}
static int pl08x_of_probe(struct amba_device *adev,
@@ -2121,9 +2122,11 @@ 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)
@@ -2225,6 +2228,25 @@ 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_DMA_SIGNALS *
+ sizeof(struct pl08x_channel_data),
+ GFP_KERNEL);
+ if (!chanp)
+ return -ENOMEM;
+ pd->slave_channels = chanp;
+ for (i = 0; i < PL08X_DMA_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_DMA_SIGNALS;
+
pl08x->pd = pd;
return of_dma_controller_register(adev->dev.of_node, pl08x_of_xlate,
@@ -2264,6 +2286,10 @@ 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;
@@ -2314,10 +2340,6 @@ 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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