dmaengine: pl08x: allocate OF slave channel data at probe time

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@free-electrons.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>
Tested-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 9b42c05..81db1c4 100644 (file)
--- 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 +2200,27 @@ 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_kcalloc(&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 +2260,10 @@ 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 +2314,6 @@ 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 +2464,7 @@ 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 +2472,7 @@ 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 +2481,7 @@ 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 +2489,7 @@ 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 10fe2a2..27e9ec8 100644 (file)
--- 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 *);