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
  22 static 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
  44 static 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
  61 static const struct of_device_id shdma_of_match[] = {
  62         { .compatible = "renesas,shdma-mux", },
  63         { }
  64 };
  65 MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
  66
  67 static 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
  75 module_platform_driver(shdma_of);
  76
  77 MODULE_LICENSE("GPL v2");
  78 MODULE_DESCRIPTION("SH-DMA driver DT glue");
  79 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");