drivers/dma/sh/shdma-of.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SHDMA Device Tree glue
   4  *
   5  * Copyright (C) 2013 Renesas Electronics Inc.
   6  * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   7  */
   8
   9 #include <linux/dmaengine.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/of_dma.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/shdma-base.h>
  16
  17 #define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
  18
  19 static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,
  20                                        struct of_dma *ofdma)
  21 {
  22         u32 id = dma_spec->args[0];
  23         dma_cap_mask_t mask;
  24         struct dma_chan *chan;
  25
  26         if (dma_spec->args_count != 1)
  27                 return NULL;
  28
  29         dma_cap_zero(mask);
  30         /* Only slave DMA channels can be allocated via DT */
  31         dma_cap_set(DMA_SLAVE, mask);
  32
  33         chan = dma_request_channel(mask, shdma_chan_filter,
  34                                    (void *)(uintptr_t)id);
  35         if (chan)
  36                 to_shdma_chan(chan)->hw_req = id;
  37
  38         return chan;
  39 }
  40
  41 static int shdma_of_probe(struct platform_device *pdev)
  42 {
  43         const struct of_dev_auxdata *lookup = dev_get_platdata(&pdev->dev);
  44         int ret;
  45
  46         ret = of_dma_controller_register(pdev->dev.of_node,
  47                                          shdma_of_xlate, pdev);
  48         if (ret < 0)
  49                 return ret;
  50
  51         ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
  52         if (ret < 0)
  53                 of_dma_controller_free(pdev->dev.of_node);
  54
  55         return ret;
  56 }
  57
  58 static const struct of_device_id shdma_of_match[] = {
  59         { .compatible = "renesas,shdma-mux", },
  60         { }
  61 };
  62 MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
  63
  64 static struct platform_driver shdma_of = {
  65         .driver         = {
  66                 .name   = "shdma-of",
  67                 .of_match_table = shdma_of_match,
  68         },
  69         .probe          = shdma_of_probe,
  70 };
  71
  72 module_platform_driver(shdma_of);
  73
  74 MODULE_LICENSE("GPL v2");
  75 MODULE_DESCRIPTION("SH-DMA driver DT glue");
  76 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");