Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma

Pull second set of slave-dmaengine updates from Vinod Koul:
 "Arnd's patch moves the dw_dmac to use generic DMA binding.  I agreed
  to merge this late as it will avoid the conflicts between trees.

  The second patch from Matt adding a dma_request_slave_channel_compat
  API was supposed to be picked up, but somehow never got picked up.
  Some patches dependent on this are already in -next :("

* 'next' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw_dmac: move to generic DMA binding
  dmaengine: add dma_request_slave_channel_compat()

5 files changed, 127 insertions, 116 deletions

diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt
index 5bb3dfb6f1d8..d58675ea1abf 100644
--- a/Documentation/devicetree/bindings/dma/snps-dma.txt
+++ b/Documentation/devicetree/bindings/dma/snps-dma.txt
@@ -3,59 +3,61 @@
 Required properties:
 - compatible: "snps,dma-spear1340"
 - reg: Address range of the DMAC registers
-- interrupt-parent: Should be the phandle for the interrupt controller
-  that services interrupts for this device
 - interrupt: Should contain the DMAC interrupt number
-- nr_channels: Number of channels supported by hardware
-- is_private: The device channels should be marked as private and not for by the
-  general purpose DMA channel allocator. False if not passed.
+- dma-channels: Number of channels supported by hardware
+- dma-requests: Number of DMA request lines supported, up to 16
+- dma-masters: Number of AHB masters supported by the controller
+- #dma-cells: must be <3>
 - chan_allocation_order: order of allocation of channel, 0 (default): ascending,
   1: descending
 - chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1:
   increase from chan n->0
 - block_size: Maximum block size supported by the controller
-- nr_masters: Number of AHB masters supported by the controller
 - data_width: Maximum data width supported by hardware per AHB master
   (0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
-- slave_info:
-        - bus_id: name of this device channel, not just a device name since
-          devices may have more than one channel e.g. "foo_tx". For using the
-          dw_generic_filter(), slave drivers must pass exactly this string as
-          param to filter function.
-        - cfg_hi: Platform-specific initializer for the CFG_HI register
-        - cfg_lo: Platform-specific initializer for the CFG_LO register
-        - src_master: src master for transfers on allocated channel.
-        - dst_master: dest master for transfers on allocated channel.
+
+
+Optional properties:
+- interrupt-parent: Should be the phandle for the interrupt controller
+  that services interrupts for this device
+- is_private: The device channels should be marked as private and not for by the
+  general purpose DMA channel allocator. False if not passed.
 
 Example:
 
-        dma@fc000000 {
+        dmahost: dma@fc000000 {
                 compatible = "snps,dma-spear1340";
                 reg = <0xfc000000 0x1000>;
                 interrupt-parent = <&vic1>;
                 interrupts = <12>;
 
-                nr_channels = <8>;
+                dma-channels = <8>;
+                dma-requests = <16>;
+                dma-masters = <2>;
+                #dma-cells = <3>;
                 chan_allocation_order = <1>;
                 chan_priority = <1>;
                 block_size = <0xfff>;
-                nr_masters = <2>;
                 data_width = <3 3 0 0>;
+        };
 
-                slave_info {
-                        uart0-tx {
-                                bus_id = "uart0-tx";
-                                cfg_hi = <0x4000>;      /* 0x8 << 11 */
-                                cfg_lo = <0>;
-                                src_master = <0>;
-                                dst_master = <1>;
-                        };
-                        spi0-tx {
-                                bus_id = "spi0-tx";
-                                cfg_hi = <0x2000>;      /* 0x4 << 11 */
-                                cfg_lo = <0>;
-                                src_master = <0>;
-                                dst_master = <0>;
-                        };
-                };
+DMA clients connected to the Designware DMA controller must use the format
+described in the dma.txt file, using a four-cell specifier for each channel.
+The four cells in order are:
+
+1. A phandle pointing to the DMA controller
+2. The DMA request line number
+3. Source master for transfers on allocated channel
+4. Destination master for transfers on allocated channel
+
+Example:
+        
+        serial@e0000000 {
+                compatible = "arm,pl011", "arm,primecell";
+                reg = <0xe0000000 0x1000>;
+                interrupts = <0 35 0x4>;
+                status = "disabled";
+                dmas = <&dmahost 12 0 1>,
+                        <&dmahost 13 0 1 0>;
+                dma-names = "rx", "rx";
         };
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 51c3ea2ed41a..c599558faeda 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -20,6 +20,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_dma.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -171,7 +172,13 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
         if (dwc->initialized == true)
                 return;
 
-        if (dws) {
+        if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
+                /* autoconfigure based on request line from DT */
+                if (dwc->direction == DMA_MEM_TO_DEV)
+                        cfghi = DWC_CFGH_DST_PER(dwc->request_line);
+                else if (dwc->direction == DMA_DEV_TO_MEM)
+                        cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
+        } else if (dws) {
                 /*
                  * We need controller-specific data to set up slave
                  * transfers.
@@ -1226,49 +1233,64 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
         dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
 }
 
-bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
+struct dw_dma_filter_args {
+        struct dw_dma *dw;
+        unsigned int req;
+        unsigned int src;
+        unsigned int dst;
+};
+
+static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
 {
+        struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
         struct dw_dma *dw = to_dw_dma(chan->device);
-        static struct dw_dma *last_dw;
-        static char *last_bus_id;
-        int i = -1;
+        struct dw_dma_filter_args *fargs = param;
+        struct dw_dma_slave *dws = &dwc->slave;
 
-        /*
-         * dmaengine framework calls this routine for all channels of all dma
-         * controller, until true is returned. If 'param' bus_id is not
-         * registered with a dma controller (dw), then there is no need of
-         * running below function for all channels of dw.
-         *
-         * This block of code does this by saving the parameters of last
-         * failure. If dw and param are same, i.e. trying on same dw with
-         * different channel, return false.
-         */
-        if ((last_dw == dw) && (last_bus_id == param))
-                return false;
-        /*
-         * Return true:
-         * - If dw_dma's platform data is not filled with slave info, then all
-         *   dma controllers are fine for transfer.
-         * - Or if param is NULL
-         */
-        if (!dw->sd || !param)
-                return true;
+        /* ensure the device matches our channel */
+        if (chan->device != &fargs->dw->dma)
+                return false;
 
-        while (++i < dw->sd_count) {
-                if (!strcmp(dw->sd[i].bus_id, param)) {
-                        chan->private = &dw->sd[i];
-                        last_dw = NULL;
-                        last_bus_id = NULL;
+        dws->dma_dev    = dw->dma.dev;
+        dws->cfg_hi     = ~0;
+        dws->cfg_lo     = ~0;
+        dws->src_master = fargs->src;
+        dws->dst_master = fargs->dst;
 
-                        return true;
-                }
-        }
+        dwc->request_line = fargs->req;
 
-        last_dw = dw;
-        last_bus_id = param;
-        return false;
+        chan->private = dws;
+
+        return true;
+}
+
+static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec,
+                                         struct of_dma *ofdma)
+{
+        struct dw_dma *dw = ofdma->of_dma_data;
+        struct dw_dma_filter_args fargs = {
+                .dw = dw,
+        };
+        dma_cap_mask_t cap;
+
+        if (dma_spec->args_count != 3)
+                return NULL;
+
+        fargs.req = be32_to_cpup(dma_spec->args+0);
+        fargs.src = be32_to_cpup(dma_spec->args+1);
+        fargs.dst = be32_to_cpup(dma_spec->args+2);
+
+        if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
+                    fargs.src >= dw->nr_masters ||
+                    fargs.dst >= dw->nr_masters))
+                return NULL;
+
+        dma_cap_zero(cap);
+        dma_cap_set(DMA_SLAVE, cap);
+
+        /* TODO: there should be a simpler way to do this */
+        return dma_request_channel(cap, dw_dma_generic_filter, &fargs);
 }
-EXPORT_SYMBOL(dw_dma_generic_filter);
 
 /* --------------------- Cyclic DMA API extensions -------------------- */
 
@@ -1554,9 +1576,8 @@ static void dw_dma_off(struct dw_dma *dw)
 static struct dw_dma_platform_data *
 dw_dma_parse_dt(struct platform_device *pdev)
 {
-        struct device_node *sn, *cn, *np = pdev->dev.of_node;
+        struct device_node *np = pdev->dev.of_node;
         struct dw_dma_platform_data *pdata;
-        struct dw_dma_slave *sd;
         u32 tmp, arr[4];
 
         if (!np) {
@@ -1568,7 +1589,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
         if (!pdata)
                 return NULL;
 
-        if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels))
+        if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
                 return NULL;
 
         if (of_property_read_bool(np, "is_private"))
@@ -1583,7 +1604,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
         if (!of_property_read_u32(np, "block_size", &tmp))
                 pdata->block_size = tmp;
 
-        if (!of_property_read_u32(np, "nr_masters", &tmp)) {
+        if (!of_property_read_u32(np, "dma-masters", &tmp)) {
                 if (tmp > 4)
                         return NULL;
 
@@ -1595,36 +1616,6 @@ dw_dma_parse_dt(struct platform_device *pdev)
                 for (tmp = 0; tmp < pdata->nr_masters; tmp++)
                         pdata->data_width[tmp] = arr[tmp];
 
-        /* parse slave data */
-        sn = of_find_node_by_name(np, "slave_info");
-        if (!sn)
-                return pdata;
-
-        /* calculate number of slaves */
-        tmp = of_get_child_count(sn);
-        if (!tmp)
-                return NULL;
-
-        sd = devm_kzalloc(&pdev->dev, sizeof(*sd) * tmp, GFP_KERNEL);
-        if (!sd)
-                return NULL;
-
-        pdata->sd = sd;
-        pdata->sd_count = tmp;
-
-        for_each_child_of_node(sn, cn) {
-                sd->dma_dev = &pdev->dev;
-                of_property_read_string(cn, "bus_id", &sd->bus_id);
-                of_property_read_u32(cn, "cfg_hi", &sd->cfg_hi);
-                of_property_read_u32(cn, "cfg_lo", &sd->cfg_lo);
-                if (!of_property_read_u32(cn, "src_master", &tmp))
-                        sd->src_master = tmp;
-
-                if (!of_property_read_u32(cn, "dst_master", &tmp))
-                        sd->dst_master = tmp;
-                sd++;
-        }
-
         return pdata;
 }
 #else
@@ -1705,8 +1696,6 @@ static int dw_probe(struct platform_device *pdev)
         clk_prepare_enable(dw->clk);
 
         dw->regs = regs;
-        dw->sd = pdata->sd;
-        dw->sd_count = pdata->sd_count;
 
         /* get hardware configuration parameters */
         if (autocfg) {
@@ -1837,6 +1826,14 @@ static int dw_probe(struct platform_device *pdev)
 
         dma_async_device_register(&dw->dma);
 
+        if (pdev->dev.of_node) {
+                err = of_dma_controller_register(pdev->dev.of_node,
+                                                 dw_dma_xlate, dw);
+                if (err && err != -ENODEV)
+                        dev_err(&pdev->dev,
+                                "could not register of_dma_controller\n");
+        }
+
         return 0;
 }
 
@@ -1845,6 +1842,8 @@ static int dw_remove(struct platform_device *pdev)
         struct dw_dma           *dw = platform_get_drvdata(pdev);
         struct dw_dma_chan      *dwc, *_dwc;
 
+        if (pdev->dev.of_node)
+                of_dma_controller_free(pdev->dev.of_node);
         dw_dma_off(dw);
         dma_async_device_unregister(&dw->dma);
 
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index 88dd8eb31957..cf0ce5c77d60 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -13,6 +13,7 @@
 #include <linux/dw_dmac.h>
 
 #define DW_DMA_MAX_NR_CHANNELS  8
+#define DW_DMA_MAX_NR_REQUESTS  16
 
 /* flow controller */
 enum dw_dma_fc {
@@ -211,6 +212,8 @@ struct dw_dma_chan {
         /* hardware configuration */
         unsigned int            block_size;
         bool                    nollp;
+        unsigned int            request_line;
+        struct dw_dma_slave     slave;
 
         /* configuration passed via DMA_SLAVE_CONFIG */
         struct dma_slave_config dma_sconfig;
@@ -239,10 +242,6 @@ struct dw_dma {
         struct tasklet_struct   tasklet;
         struct clk              *clk;
 
-        /* slave information */
-        struct dw_dma_slave     *sd;
-        unsigned int            sd_count;
-
         u8                      all_chan_mask;
 
         /* hardware configuration */
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index f5939999cb65..91ac8da25020 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -1001,6 +1001,22 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
 struct dma_chan *net_dma_find_channel(void);
 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
+#define dma_request_slave_channel_compat(mask, x, y, dev, name) \
+        __dma_request_slave_channel_compat(&(mask), x, y, dev, name)
+
+static inline struct dma_chan
+*__dma_request_slave_channel_compat(dma_cap_mask_t *mask, dma_filter_fn fn,
+                                  void *fn_param, struct device *dev,
+                                  char *name)
+{
+        struct dma_chan *chan;
+
+        chan = dma_request_slave_channel(dev, name);
+        if (chan)
+                return chan;
+
+        return __dma_request_channel(mask, fn, fn_param);
+}
 
 /* --- Helper iov-locking functions --- */
 
diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h
index 41766de66e33..481ab2345d6b 100644
--- a/include/linux/dw_dmac.h
+++ b/include/linux/dw_dmac.h
@@ -27,7 +27,6 @@
  */
 struct dw_dma_slave {
         struct device           *dma_dev;
-        const char              *bus_id;
         u32                     cfg_hi;
         u32                     cfg_lo;
         u8                      src_master;
@@ -60,9 +59,6 @@ struct dw_dma_platform_data {
         unsigned short  block_size;
         unsigned char   nr_masters;
         unsigned char   data_width[4];
-
-        struct dw_dma_slave *sd;
-        unsigned int sd_count;
 };
 
 /* bursts size */
@@ -114,6 +110,5 @@ void dw_dma_cyclic_stop(struct dma_chan *chan);
 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan);
 
 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan);
-bool dw_dma_generic_filter(struct dma_chan *chan, void *param);
 
 #endif /* DW_DMAC_H */