From faadc6e3d5e0ab718dc1e131fb14bbb52f144238 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Fri, 19 Apr 2013 13:42:55 +0200 Subject: [PATCH] dma: coh901318: add devicetree support This adds support for probing the COH 901 318 DMA controller and channels from the device tree. Contains portions of a sketch patch from Arnd Bergmann. Cc: Arnd Bergmann Acked-by: Vinod Koul Signed-off-by: Linus Walleij --- .../devicetree/bindings/dma/ste-coh901318.txt | 32 ++++++++++++++++ drivers/dma/coh901318.c | 43 ++++++++++++++++++++++ 2 files changed, 75 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/ste-coh901318.txt diff --git a/Documentation/devicetree/bindings/dma/ste-coh901318.txt b/Documentation/devicetree/bindings/dma/ste-coh901318.txt new file mode 100644 index 0000000..091ad05 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/ste-coh901318.txt @@ -0,0 +1,32 @@ +ST-Ericsson COH 901 318 DMA Controller + +This is a DMA controller which has begun as a fork of the +ARM PL08x PrimeCell VHDL code. + +Required properties: +- compatible: should be "stericsson,coh901318" +- reg: register locations and length +- interrupts: the single DMA IRQ +- #dma-cells: must be set to <1>, as the channels on the + COH 901 318 are simple and identified by a single number +- dma-channels: the number of DMA channels handled + +Example: + +dmac: dma-controller@c00020000 { + compatible = "stericsson,coh901318"; + reg = <0xc0020000 0x1000>; + interrupt-parent = <&vica>; + interrupts = <2>; + #dma-cells = <1>; + dma-channels = <40>; +}; + +Consumers example: + +uart0: serial@c0013000 { + compatible = "..."; + (...) + dmas = <&dmac 17 &dmac 18>; + dma-names = "tx", "rx"; +}; diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index 3b23061..9bfaddd 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "coh901318.h" #include "dmaengine.h" @@ -1788,6 +1789,35 @@ bool coh901318_filter_id(struct dma_chan *chan, void *chan_id) } EXPORT_SYMBOL(coh901318_filter_id); +struct coh901318_filter_args { + struct coh901318_base *base; + unsigned int ch_nr; +}; + +static bool coh901318_filter_base_and_id(struct dma_chan *chan, void *data) +{ + struct coh901318_filter_args *args = data; + + if (&args->base->dma_slave == chan->device && + args->ch_nr == to_coh901318_chan(chan)->id) + return true; + + return false; +} + +static struct dma_chan *coh901318_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct coh901318_filter_args args = { + .base = ofdma->of_dma_data, + .ch_nr = dma_spec->args[0], + }; + dma_cap_mask_t cap; + dma_cap_zero(cap); + dma_cap_set(DMA_SLAVE, cap); + + return dma_request_channel(cap, coh901318_filter_base_and_id, &args); +} /* * DMA channel allocation */ @@ -2735,12 +2765,19 @@ static int __init coh901318_probe(struct platform_device *pdev) if (err) goto err_register_memcpy; + err = of_dma_controller_register(pdev->dev.of_node, coh901318_xlate, + base); + if (err) + goto err_register_of_dma; + platform_set_drvdata(pdev, base); dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n", (u32) base->virtbase); return err; + err_register_of_dma: + dma_async_device_unregister(&base->dma_memcpy); err_register_memcpy: dma_async_device_unregister(&base->dma_slave); err_register_slave: @@ -2752,17 +2789,23 @@ static int coh901318_remove(struct platform_device *pdev) { struct coh901318_base *base = platform_get_drvdata(pdev); + of_dma_controller_free(pdev->dev.of_node); dma_async_device_unregister(&base->dma_memcpy); dma_async_device_unregister(&base->dma_slave); coh901318_pool_destroy(&base->pool); return 0; } +static const struct of_device_id coh901318_dt_match[] = { + { .compatible = "stericsson,coh901318" }, + {}, +}; static struct platform_driver coh901318_driver = { .remove = coh901318_remove, .driver = { .name = "coh901318", + .of_match_table = coh901318_dt_match, }, }; -- 2.7.4