123 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * Platform driver for the Synopsys DesignWare DMA Controller
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|  *
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|  * Copyright (C) 2007-2008 Atmel Corporation
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|  * Copyright (C) 2010-2011 ST Microelectronics
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|  * Copyright (C) 2013 Intel Corporation
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|  */
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| 
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| #include <linux/of.h>
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| #include <linux/of_dma.h>
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| #include <linux/platform_device.h>
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| 
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| #include "internal.h"
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| 
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| static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
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| 					struct of_dma *ofdma)
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| {
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| 	struct dw_dma *dw = ofdma->of_dma_data;
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| 	struct dw_dma_slave slave = {
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| 		.dma_dev = dw->dma.dev,
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| 	};
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| 	dma_cap_mask_t cap;
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| 
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| 	if (dma_spec->args_count < 3 || dma_spec->args_count > 4)
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| 		return NULL;
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| 
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| 	slave.src_id = dma_spec->args[0];
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| 	slave.dst_id = dma_spec->args[0];
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| 	slave.m_master = dma_spec->args[1];
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| 	slave.p_master = dma_spec->args[2];
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| 	if (dma_spec->args_count >= 4)
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| 		slave.channels = dma_spec->args[3];
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| 
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| 	if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
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| 		    slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
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| 		    slave.m_master >= dw->pdata->nr_masters ||
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| 		    slave.p_master >= dw->pdata->nr_masters ||
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| 		    slave.channels >= BIT(dw->pdata->nr_channels)))
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| 		return NULL;
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| 
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| 	dma_cap_zero(cap);
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| 	dma_cap_set(DMA_SLAVE, cap);
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| 
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| 	/* TODO: there should be a simpler way to do this */
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| 	return dma_request_channel(cap, dw_dma_filter, &slave);
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| }
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| 
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| struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
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| {
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| 	struct device_node *np = pdev->dev.of_node;
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| 	struct dw_dma_platform_data *pdata;
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| 	u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
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| 	u32 nr_masters;
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| 	u32 nr_channels;
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| 
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| 	if (of_property_read_u32(np, "dma-masters", &nr_masters))
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| 		return NULL;
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| 	if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
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| 		return NULL;
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| 
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| 	if (of_property_read_u32(np, "dma-channels", &nr_channels))
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| 		return NULL;
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| 	if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
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| 		return NULL;
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| 
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| 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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| 	if (!pdata)
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| 		return NULL;
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| 
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| 	pdata->nr_masters = nr_masters;
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| 	pdata->nr_channels = nr_channels;
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| 
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| 	of_property_read_u32(np, "chan_allocation_order", &pdata->chan_allocation_order);
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| 	of_property_read_u32(np, "chan_priority", &pdata->chan_priority);
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| 
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| 	of_property_read_u32(np, "block_size", &pdata->block_size);
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| 
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| 	/* Try deprecated property first */
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| 	if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
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| 		for (tmp = 0; tmp < nr_masters; tmp++)
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| 			pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
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| 	}
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| 
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| 	/* If "data_width" and "data-width" both provided use the latter one */
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| 	of_property_read_u32_array(np, "data-width", pdata->data_width, nr_masters);
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| 
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| 	memset32(pdata->multi_block, 1, nr_channels);
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| 	of_property_read_u32_array(np, "multi-block", pdata->multi_block, nr_channels);
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| 
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| 	memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels);
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| 	of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst, nr_channels);
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| 
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| 	of_property_read_u32(np, "snps,dma-protection-control", &pdata->protctl);
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| 	if (pdata->protctl > CHAN_PROTCTL_MASK)
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| 		return NULL;
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| 
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| 	return pdata;
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| }
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| 
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| void dw_dma_of_controller_register(struct dw_dma *dw)
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| {
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| 	struct device *dev = dw->dma.dev;
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| 	int ret;
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| 
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| 	if (!dev->of_node)
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| 		return;
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| 
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| 	ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);
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| 	if (ret)
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| 		dev_err(dev, "could not register of_dma_controller\n");
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| }
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| 
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| void dw_dma_of_controller_free(struct dw_dma *dw)
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| {
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| 	struct device *dev = dw->dma.dev;
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| 
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| 	if (!dev->of_node)
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| 		return;
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| 
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| 	of_dma_controller_free(dev->of_node);
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| }
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