dma/dw/acpi.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 // Copyright (C) 2013,2019 Intel Corporation
0003
0004 #include <linux/acpi.h>
0005 #include <linux/acpi_dma.h>
0006
0007 #include "internal.h"
0008
0009 static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
0010 {
0011     struct acpi_dma_spec *dma_spec = param;
0012     struct dw_dma_slave slave = {
0013         .dma_dev = dma_spec->dev,
0014         .src_id = dma_spec->slave_id,
0015         .dst_id = dma_spec->slave_id,
0016         .m_master = 0,
0017         .p_master = 1,
0018     };
0019
0020     return dw_dma_filter(chan, &slave);
0021 }
0022
0023 void dw_dma_acpi_controller_register(struct dw_dma *dw)
0024 {
0025     struct device *dev = dw->dma.dev;
0026     struct acpi_dma_filter_info *info;
0027     int ret;
0028
0029     if (!has_acpi_companion(dev))
0030         return;
0031
0032     info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
0033     if (!info)
0034         return;
0035
0036     dma_cap_zero(info->dma_cap);
0037     dma_cap_set(DMA_SLAVE, info->dma_cap);
0038     info->filter_fn = dw_dma_acpi_filter;
0039
0040     ret = acpi_dma_controller_register(dev, acpi_dma_simple_xlate, info);
0041     if (ret)
0042         dev_err(dev, "could not register acpi_dma_controller\n");
0043 }
0044 EXPORT_SYMBOL_GPL(dw_dma_acpi_controller_register);
0045
0046 void dw_dma_acpi_controller_free(struct dw_dma *dw)
0047 {
0048     struct device *dev = dw->dma.dev;
0049
0050     if (!has_acpi_companion(dev))
0051         return;
0052
0053     acpi_dma_controller_free(dev);
0054 }
0055 EXPORT_SYMBOL_GPL(dw_dma_acpi_controller_free);