diff options
Diffstat (limited to 'drivers/dma/dw/of.c')
| -rw-r--r-- | drivers/dma/dw/of.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/dma/dw/of.c b/drivers/dma/dw/of.c new file mode 100644 index 000000000..523ca8068 --- /dev/null +++ b/drivers/dma/dw/of.c @@ -0,0 +1,122 @@ +// 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 || dma_spec->args_count > 4) + 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 (dma_spec->args_count >= 4) + slave.channels = dma_spec->args[3]; + + 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 || + slave.channels >= BIT(dw->pdata->nr_channels))) + 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]; + u32 nr_masters; + u32 nr_channels; + + 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; + + of_property_read_u32(np, "chan_allocation_order", &pdata->chan_allocation_order); + of_property_read_u32(np, "chan_priority", &pdata->chan_priority); + + of_property_read_u32(np, "block_size", &pdata->block_size); + + /* Try deprecated property first */ + 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 "data_width" and "data-width" both provided use the latter one */ + of_property_read_u32_array(np, "data-width", pdata->data_width, nr_masters); + + memset32(pdata->multi_block, 1, nr_channels); + of_property_read_u32_array(np, "multi-block", pdata->multi_block, nr_channels); + + memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels); + of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst, nr_channels); + + of_property_read_u32(np, "snps,dma-protection-control", &pdata->protctl); + if (pdata->protctl > CHAN_PROTCTL_MASK) + return NULL; + + 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); +} |