drivers/dma/dw/acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2013,2019 Intel Corporation
   3
   4 #include <linux/acpi.h>
   5 #include <linux/acpi_dma.h>
   6
   7 #include "internal.h"
   8
   9 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
  10 {
  11         struct dw_dma *dw = to_dw_dma(chan->device);
  12         struct dw_dma_chip_pdata *data = dev_get_drvdata(dw->dma.dev);
  13         struct acpi_dma_spec *dma_spec = param;
  14         struct dw_dma_slave slave = {
  15                 .dma_dev = dma_spec->dev,
  16                 .src_id = dma_spec->slave_id,
  17                 .dst_id = dma_spec->slave_id,
  18                 .m_master = data->m_master,
  19                 .p_master = data->p_master,
  20         };
  21
  22         return dw_dma_filter(chan, &slave);
  23 }
  24
  25 void dw_dma_acpi_controller_register(struct dw_dma *dw)
  26 {
  27         struct device *dev = dw->dma.dev;
  28         struct acpi_dma_filter_info *info;
  29         int ret;
  30
  31         if (!has_acpi_companion(dev))
  32                 return;
  33
  34         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
  35         if (!info)
  36                 return;
  37
  38         dma_cap_zero(info->dma_cap);
  39         dma_cap_set(DMA_SLAVE, info->dma_cap);
  40         info->filter_fn = dw_dma_acpi_filter;
  41
  42         ret = acpi_dma_controller_register(dev, acpi_dma_simple_xlate, info);
  43         if (ret)
  44                 dev_err(dev, "could not register acpi_dma_controller\n");
  45 }
  46 EXPORT_SYMBOL_GPL(dw_dma_acpi_controller_register);
  47
  48 void dw_dma_acpi_controller_free(struct dw_dma *dw)
  49 {
  50         struct device *dev = dw->dma.dev;
  51
  52         if (!has_acpi_companion(dev))
  53                 return;
  54
  55         acpi_dma_controller_free(dev);
  56 }
  57 EXPORT_SYMBOL_GPL(dw_dma_acpi_controller_free);