[PATCH v3] dma: pl08x: allocate OF slave channel data at probe time
Linus Walleij
linus.walleij at linaro.org
Sun Apr 3 12:01:19 PDT 2016
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 at free-electrons.com>
Cc: Joachim Eastwood <manabian at gmail.com>
Cc: Johannes Stezenbach <js at sig21.net>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v2->v3:
- Drop the patch and variable for fixed signal assignment.
- Always assign a fixed channel number when registering
the channels.
ChangeLog v1->v2:
- Rely on the number of signals for the variant coming in
from vendor data.
Joachim: I hope this works with LPC, I assign the signal number
now.
---
drivers/dma/amba-pl08x.c | 85 +++++++++++++++++++++++++++++++---------------
include/linux/amba/pl08x.h | 2 +-
2 files changed, 58 insertions(+), 29 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 9b42c0588550..fafec2d27c72 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -107,16 +107,20 @@ struct pl08x_driver_data;
/**
* struct vendor_data - vendor-specific config parameters for PL08x derivatives
* @channels: the number of channels available in this variant
+ * @signals: the number of request signals available from the hardware
* @dualmaster: whether this version supports dual AHB masters or not.
* @nomadik: whether the channels have Nomadik security extension bits
* that need to be checked for permission before use and some registers are
* missing
* @pl080s: whether this version is a PL080S, which has separate register and
* LLI word for transfer size.
+ * @max_transfer_size: the maximum single element transfer size for this
+ * PL08x variant.
*/
struct vendor_data {
u8 config_offset;
u8 channels;
+ u8 signals;
bool dualmaster;
bool nomadik;
bool pl080s;
@@ -235,7 +239,7 @@ 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;
@@ -1909,6 +1913,12 @@ static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
if (slave) {
chan->cd = &pl08x->pd->slave_channels[i];
+ /*
+ * Some implementations have muxed signals, whereas some
+ * use a mux in front of the signals and need dynamic
+ * assignment of signals.
+ */
+ chan->signal = i;
pl08x_dma_slave_init(chan);
} else {
chan->cd = &pl08x->pd->memcpy_channel;
@@ -2050,40 +2060,33 @@ 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,
@@ -2091,9 +2094,11 @@ 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)
@@ -2195,6 +2200,26 @@ 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,
@@ -2234,6 +2259,10 @@ 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;
@@ -2284,10 +2313,6 @@ 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;
@@ -2438,6 +2463,7 @@ out_no_pl08x:
static struct vendor_data vendor_pl080 = {
.config_offset = PL080_CH_CONFIG,
.channels = 8,
+ .signals = 16,
.dualmaster = true,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
};
@@ -2445,6 +2471,7 @@ static struct vendor_data vendor_pl080 = {
static struct vendor_data vendor_nomadik = {
.config_offset = PL080_CH_CONFIG,
.channels = 8,
+ .signals = 32,
.dualmaster = true,
.nomadik = true,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
@@ -2453,6 +2480,7 @@ static struct vendor_data vendor_nomadik = {
static struct vendor_data vendor_pl080s = {
.config_offset = PL080S_CH_CONFIG,
.channels = 8,
+ .signals = 32,
.pl080s = true,
.max_transfer_size = PL080S_CONTROL_TRANSFER_SIZE_MASK,
};
@@ -2460,6 +2488,7 @@ static struct vendor_data vendor_pl080s = {
static struct vendor_data vendor_pl081 = {
.config_offset = PL080_CH_CONFIG,
.channels = 2,
+ .signals = 16,
.dualmaster = false,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
};
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 *);
--
2.4.11
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