[PATCH v5] dmaengine: sirf: enable generic dt binding for dma channels
From: Barry Song <hidden>
Date: 2014-01-26 02:08:45
Also in:
linux-arm-kernel
Subsystem:
dma generic offload engine subsystem, open firmware and flattened device tree bindings, the rest · Maintainers:
Vinod Koul, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
From: Barry Song <redacted> move to support of_dma_request_slave_channel() and dma_request_slave_channel. we add a xlate() to let dma clients be able to find right dma_chan by generic "dmas" properties in dts. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Barry Song <redacted> --- -v5: add Acked-by: vinod.koul@intel.com; cc devicetree guys as Acked from dt was required .../devicetree/bindings/dma/sirfsoc-dma.txt | 43 ++++++++++++++++++++ arch/arm/boot/dts/atlas6.dtsi | 2 + arch/arm/boot/dts/prima2.dtsi | 2 + drivers/dma/sirf-dma.c | 23 ++++++++++ 4 files changed, 70 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/dma/sirfsoc-dma.txt
diff --git a/Documentation/devicetree/bindings/dma/sirfsoc-dma.txt b/Documentation/devicetree/bindings/dma/sirfsoc-dma.txt
new file mode 100644
index 0000000..ecbc96a
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/sirfsoc-dma.txt@@ -0,0 +1,43 @@ +* CSR SiRFSoC DMA controller + +See dma.txt first + +Required properties: +- compatible: Should be "sirf,prima2-dmac" or "sirf,marco-dmac" +- reg: Should contain DMA registers location and length. +- interrupts: Should contain one interrupt shared by all channel +- #dma-cells: must be <1>. used to represent the number of integer + cells in the dmas property of client device. +- clocks: clock required + +Example: + +Controller: +dmac0: dma-controller@b00b0000 { + compatible = "sirf,prima2-dmac"; + reg = <0xb00b0000 0x10000>; + interrupts = <12>; + clocks = <&clks 24>; + #dma-cells = <1>; +}; + + +Client: +Fill the specific dma request line in dmas. In the below example, spi0 read +channel request line is 9 of the 2nd dma controller, while write channel uses +4 of the 2nd dma controller; spi1 read channel request line is 12 of the 1st +dma controller, while write channel uses 13 of the 1st dma controller: + +spi0: spi@b00d0000 { + compatible = "sirf,prima2-spi"; + dmas = <&dmac1 9>, + <&dmac1 4>; + dma-names = "rx", "tx"; +}; + +spi1: spi@b0170000 { + compatible = "sirf,prima2-spi"; + dmas = <&dmac0 12>, + <&dmac0 13>; + dma-names = "rx", "tx"; +};
diff --git a/arch/arm/boot/dts/atlas6.dtsi b/arch/arm/boot/dts/atlas6.dtsi
index b63cfef..4f41f0a 100644
--- a/arch/arm/boot/dts/atlas6.dtsi
+++ b/arch/arm/boot/dts/atlas6.dtsi@@ -260,6 +260,7 @@ reg = <0xb00b0000 0x10000>; interrupts = <12>; clocks = <&clks 24>; + #dma-cells = <1>; }; dmac1: dma-controller@b0160000 {
@@ -268,6 +269,7 @@ reg = <0xb0160000 0x10000>; interrupts = <13>; clocks = <&clks 25>; + #dma-cells = <1>; }; vip@b00C0000 {
diff --git a/arch/arm/boot/dts/prima2.dtsi b/arch/arm/boot/dts/prima2.dtsi
index b292a5c..19e4e22 100644
--- a/arch/arm/boot/dts/prima2.dtsi
+++ b/arch/arm/boot/dts/prima2.dtsi@@ -277,6 +277,7 @@ reg = <0xb00b0000 0x10000>; interrupts = <12>; clocks = <&clks 24>; + #dma-cells = <1>; }; dmac1: dma-controller@b0160000 {
@@ -285,6 +286,7 @@ reg = <0xb0160000 0x10000>; interrupts = <13>; clocks = <&clks 25>; + #dma-cells = <1>; }; vip@b00C0000 {
diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
index 6aec3ad..8b74c0d 100644
--- a/drivers/dma/sirf-dma.c
+++ b/drivers/dma/sirf-dma.c@@ -18,6 +18,7 @@ #include <linux/of_device.h> #include <linux/of_platform.h> #include <linux/clk.h> +#include <linux/of_dma.h> #include <linux/sirfsoc_dma.h> #include "dmaengine.h"
@@ -640,6 +641,18 @@ bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id) } EXPORT_SYMBOL(sirfsoc_dma_filter_id); +static struct dma_chan *of_dma_sirfsoc_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct sirfsoc_dma *sdma = ofdma->of_dma_data; + unsigned int request = dma_spec->args[0]; + + if (request > SIRFSOC_DMA_CHANNELS) + return NULL; + + return dma_get_slave_channel(&sdma->channels[request].chan); +} + static int sirfsoc_dma_probe(struct platform_device *op) { struct device_node *dn = op->dev.of_node;
@@ -744,11 +757,20 @@ static int sirfsoc_dma_probe(struct platform_device *op) if (ret) goto free_irq; + /* Device-tree DMA controller registration */ + ret = of_dma_controller_register(dn, of_dma_sirfsoc_xlate, sdma); + if (ret) { + dev_err(dev, "failed to register DMA controller\n"); + goto unreg_dma_dev; + } + pm_runtime_enable(&op->dev); dev_info(dev, "initialized SIRFSOC DMAC driver\n"); return 0; +unreg_dma_dev: + dma_async_device_unregister(dma); free_irq: free_irq(sdma->irq, sdma); irq_dispose:
@@ -761,6 +783,7 @@ static int sirfsoc_dma_remove(struct platform_device *op) struct device *dev = &op->dev; struct sirfsoc_dma *sdma = dev_get_drvdata(dev); + of_dma_controller_free(op->dev.of_node); dma_async_device_unregister(&sdma->dma); free_irq(sdma->irq, sdma); irq_dispose_mapping(sdma->irq);
--
1.7.5.4