WSL2-Linux-Kernel/drivers/dma/dw/of.c

132 строки
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Platform driver for the Synopsys DesignWare DMA Controller
*
* Copyright (C) 2007-2008 Atmel Corporation
* Copyright (C) 2010-2011 ST Microelectronics
* Copyright (C) 2013 Intel Corporation
*/
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include "internal.h"
static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct dw_dma *dw = ofdma->of_dma_data;
struct dw_dma_slave slave = {
.dma_dev = dw->dma.dev,
};
dma_cap_mask_t cap;
if (dma_spec->args_count != 3)
return NULL;
slave.src_id = dma_spec->args[0];
slave.dst_id = dma_spec->args[0];
slave.m_master = dma_spec->args[1];
slave.p_master = dma_spec->args[2];
if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
slave.m_master >= dw->pdata->nr_masters ||
slave.p_master >= dw->pdata->nr_masters))
return NULL;
dma_cap_zero(cap);
dma_cap_set(DMA_SLAVE, cap);
/* TODO: there should be a simpler way to do this */
return dma_request_channel(cap, dw_dma_filter, &slave);
}
struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct dw_dma_platform_data *pdata;
u32 tmp, arr[DW_DMA_MAX_NR_MASTERS], mb[DW_DMA_MAX_NR_CHANNELS];
u32 nr_masters;
u32 nr_channels;
if (!np) {
dev_err(&pdev->dev, "Missing DT data\n");
return NULL;
}
if (of_property_read_u32(np, "dma-masters", &nr_masters))
return NULL;
if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
return NULL;
if (of_property_read_u32(np, "dma-channels", &nr_channels))
return NULL;
if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
return NULL;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return NULL;
pdata->nr_masters = nr_masters;
pdata->nr_channels = nr_channels;
if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
pdata->chan_allocation_order = (unsigned char)tmp;
if (!of_property_read_u32(np, "chan_priority", &tmp))
pdata->chan_priority = tmp;
if (!of_property_read_u32(np, "block_size", &tmp))
pdata->block_size = tmp;
if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
for (tmp = 0; tmp < nr_masters; tmp++)
pdata->data_width[tmp] = arr[tmp];
} else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
for (tmp = 0; tmp < nr_masters; tmp++)
pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
}
if (!of_property_read_u32_array(np, "multi-block", mb, nr_channels)) {
for (tmp = 0; tmp < nr_channels; tmp++)
pdata->multi_block[tmp] = mb[tmp];
} else {
for (tmp = 0; tmp < nr_channels; tmp++)
pdata->multi_block[tmp] = 1;
}
if (!of_property_read_u32(np, "snps,dma-protection-control", &tmp)) {
if (tmp > CHAN_PROTCTL_MASK)
return NULL;
pdata->protctl = tmp;
}
return pdata;
}
void dw_dma_of_controller_register(struct dw_dma *dw)
{
struct device *dev = dw->dma.dev;
int ret;
if (!dev->of_node)
return;
ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);
if (ret)
dev_err(dev, "could not register of_dma_controller\n");
}
void dw_dma_of_controller_free(struct dw_dma *dw)
{
struct device *dev = dw->dma.dev;
if (!dev->of_node)
return;
of_dma_controller_free(dev->of_node);
}