dmaengine: dw_dmac: Enhance device tree support

dw_dmac driver already supports device tree but it used to have its platform
data passed the non-DT way.

This patch does following changes:
- pass platform data via DT, non-DT way still takes precedence if both are used.
- create generic filter routine
- Earlier slave information was made available by slave specific filter routines
  in chan->private field. Now, this information would be passed from within dmac
  DT node. Slave drivers would now be required to pass bus_id (a string) as
  parameter to this generic filter(), which would be compared against the slave
  data passed from DT, by the generic filter routine.
- Update binding document

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Fixed __devinit usage]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt
index c0d85dbcada5..5bb3dfb6f1d8 100644
--- a/Documentation/devicetree/bindings/dma/snps-dma.txt
+++ b/Documentation/devicetree/bindings/dma/snps-dma.txt
@@ -6,6 +6,26 @@ Required properties:
 - 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.
+- 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.
 
 Example:
 
@@ -14,4 +34,28 @@ Example:
                 reg = <0xfc000000 0x1000>;
                 interrupt-parent = <&vic1>;
                 interrupts = <12>;
+
+                nr_channels = <8>;
+                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>;
+                        };
+                };
         };