spi: pl022: use generic DMA slave configuration if possible

With the new OF DMA binding, it is possible to completely avoid the
need for platform_data for configuring a DMA channel. In cases where the
platform has already been converted, calling dma_request_slave_channel
should get all the necessary information from the device tree.

Like the patch that converts the dw_dma controller, this is completely
untested and is looking for someone to try it out.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: spi-devel-general@lists.sourceforge.net
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Vinod Koul <vinod.koul@linux.intel.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org

1 files changed, 36 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt
index f158fd31cfda..22ed6797216d 100644
--- a/Documentation/devicetree/bindings/spi/spi_pl022.txt
+++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt
@@ -16,6 +16,11 @@ Optional properties:
                             device will be suspended immediately
 - pl022,rt : indicates the controller should run the message pump with realtime
              priority to minimise the transfer latency on the bus (boolean)
+- dmas : Two or more DMA channel specifiers following the convention outlined
+         in bindings/dma/dma.txt
+- dma-names: Names for the dma channels, if present. There must be at
+             least one channel named "tx" for transmit and named "rx" for
+             receive.
 
 
 SPI slave nodes must be children of the SPI master node and can
@@ -32,3 +37,34 @@ contain the following properties.
 - pl022,wait-state : Microwire interface: Wait state
 - pl022,duplex : Microwire interface: Full/Half duplex
 
+
+Example:
+
+        spi@e0100000 {
+                compatible = "arm,pl022", "arm,primecell";
+                reg = <0xe0100000 0x1000>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+                interrupts = <0 31 0x4>;
+                dmas = <&dma-controller 23 1>,
+                        <&dma-controller 24 0>;
+                dma-names = "rx", "tx";
+
+                m25p80@1 {
+                        compatible = "st,m25p80";
+                        reg = <1>;
+                        spi-max-frequency = <12000000>;
+                        spi-cpol;
+                        spi-cpha;
+                        pl022,hierarchy = <0>;
+                        pl022,interface = <0>;
+                        pl022,slave-tx-disable;
+                        pl022,com-mode = <0x2>;
+                        pl022,rx-level-trig = <0>;
+                        pl022,tx-level-trig = <0>;
+                        pl022,ctrl-len = <0x11>;
+                        pl022,wait-state = <0>;
+                        pl022,duplex = <0>;
+                };
+        };
+