LXR linux/drivers/dma/sh/shdma-of.c

   1/*
   2 * SHDMA Device Tree glue
   3 *
   4 * Copyright (C) 2013 Renesas Electronics Inc.
   5 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   6 *
   7 * This is free software; you can redistribute it and/or modify
   8 * it under the terms of version 2 of the GNU General Public License as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/dmaengine.h>
  13#include <linux/module.h>
  14#include <linux/of.h>
  15#include <linux/of_dma.h>
  16#include <linux/of_platform.h>
  17#include <linux/platform_device.h>
  18#include <linux/shdma-base.h>
  19
  20#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
  21
  22static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,
  23                                       struct of_dma *ofdma)
  24{
  25        u32 id = dma_spec->args[0];
  26        dma_cap_mask_t mask;
  27        struct dma_chan *chan;
  28
  29        if (dma_spec->args_count != 1)
  30                return NULL;
  31
  32        dma_cap_zero(mask);
  33        /* Only slave DMA channels can be allocated via DT */
  34        dma_cap_set(DMA_SLAVE, mask);
  35
  36        chan = dma_request_channel(mask, shdma_chan_filter,
  37                                   (void *)(uintptr_t)id);
  38        if (chan)
  39                to_shdma_chan(chan)->hw_req = id;
  40
  41        return chan;
  42}
  43
  44static int shdma_of_probe(struct platform_device *pdev)
  45{
  46        const struct of_dev_auxdata *lookup = dev_get_platdata(&pdev->dev);
  47        int ret;
  48
  49        ret = of_dma_controller_register(pdev->dev.of_node,
  50                                         shdma_of_xlate, pdev);
  51        if (ret < 0)
  52                return ret;
  53
  54        ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
  55        if (ret < 0)
  56                of_dma_controller_free(pdev->dev.of_node);
  57
  58        return ret;
  59}
  60
  61static const struct of_device_id shdma_of_match[] = {
  62        { .compatible = "renesas,shdma-mux", },
  63        { }
  64};
  65MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
  66
  67static struct platform_driver shdma_of = {
  68        .driver         = {
  69                .name   = "shdma-of",
  70                .of_match_table = shdma_of_match,
  71        },
  72        .probe          = shdma_of_probe,
  73};
  74
  75module_platform_driver(shdma_of);
  76
  77MODULE_LICENSE("GPL v2");
  78MODULE_DESCRIPTION("SH-DMA driver DT glue");
  79MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
  80