dma: imx-sdma: move to generic device tree bindings

Update imx-sdma driver to adopt generic DMA device tree bindings.  It
calls of_dma_controller_register() with imx-sdma specific of_dma_xlate
to get the generic DMA device tree helper support.  The #dma-cells for
imx-sdma must be 3, which includes request ID, peripheral type and
priority.

The existing way of requesting channel, clients directly call
dma_request_channel(), still work there, and will be removed after
all imx-sdma clients get converted to generic DMA device tree helper.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 56 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
index d1e3f443e205..68cee4f5539f 100644
--- a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
+++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
@@ -4,14 +4,70 @@ Required properties:
 - compatible : Should be "fsl,<chip>-sdma"
 - reg : Should contain SDMA registers location and length
 - interrupts : Should contain SDMA interrupt
+- #dma-cells : Must be <3>.
+  The first cell specifies the DMA request/event ID.  See details below
+  about the second and third cell.
 - fsl,sdma-ram-script-name : Should contain the full path of SDMA RAM
   scripts firmware
 
+The second cell of dma phandle specifies the peripheral type of DMA transfer.
+The full ID of peripheral types can be found below.
+
+        ID      transfer type
+        ---------------------
+        0       MCU domain SSI
+        1       Shared SSI
+        2       MMC
+        3       SDHC
+        4       MCU domain UART
+        5       Shared UART
+        6       FIRI
+        7       MCU domain CSPI
+        8       Shared CSPI
+        9       SIM
+        10      ATA
+        11      CCM
+        12      External peripheral
+        13      Memory Stick Host Controller
+        14      Shared Memory Stick Host Controller
+        15      DSP
+        16      Memory
+        17      FIFO type Memory
+        18      SPDIF
+        19      IPU Memory
+        20      ASRC
+        21      ESAI
+
+The third cell specifies the transfer priority as below.
+
+        ID      transfer priority
+        -------------------------
+        0       High
+        1       Medium
+        2       Low
+
 Examples:
 
 sdma@83fb0000 {
         compatible = "fsl,imx51-sdma", "fsl,imx35-sdma";
         reg = <0x83fb0000 0x4000>;
         interrupts = <6>;
+        #dma-cells = <3>;
         fsl,sdma-ram-script-name = "sdma-imx51.bin";
 };
+
+DMA clients connected to the i.MX SDMA controller must use the format
+described in the dma.txt file.
+
+Examples:
+
+ssi2: ssi@70014000 {
+        compatible = "fsl,imx51-ssi", "fsl,imx21-ssi";
+        reg = <0x70014000 0x4000>;
+        interrupts = <30>;
+        clocks = <&clks 49>;
+        dmas = <&sdma 24 1 0>,
+               <&sdma 25 1 0>;
+        dma-names = "rx", "tx";
+        fsl,fifo-depth = <15>;
+};