1 /* linux/arch/arm/plat-samsung/dma-ops.c
3 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com
6 * Samsung DMA Operations
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/amba/pl330.h>
16 #include <linux/scatterlist.h>
17 #include <linux/export.h>
21 static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
22 struct samsung_dma_req *param,
23 struct device *dev, char *ch_name)
29 dma_cap_set(param->cap, mask);
32 * If a dma channel property of a device node from device tree is
33 * specified, use that as the fliter parameter.
35 filter_param = (dma_ch == DMACH_DT_PROP) ?
36 (void *)param->dt_dmach_prop : (void *)dma_ch;
39 return (unsigned)dma_request_slave_channel(dev, ch_name);
41 return (unsigned)dma_request_channel(mask, pl330_filter,
45 static int samsung_dmadev_release(unsigned ch, void *param)
47 dma_release_channel((struct dma_chan *)ch);
52 static int samsung_dmadev_config(unsigned ch,
53 struct samsung_dma_config *param)
55 struct dma_chan *chan = (struct dma_chan *)ch;
56 struct dma_slave_config slave_config;
58 if (param->direction == DMA_DEV_TO_MEM) {
59 memset(&slave_config, 0, sizeof(struct dma_slave_config));
60 slave_config.direction = param->direction;
61 slave_config.src_addr = param->fifo;
62 slave_config.src_addr_width = param->width;
63 slave_config.src_maxburst = 1;
64 dmaengine_slave_config(chan, &slave_config);
65 } else if (param->direction == DMA_MEM_TO_DEV) {
66 memset(&slave_config, 0, sizeof(struct dma_slave_config));
67 slave_config.direction = param->direction;
68 slave_config.dst_addr = param->fifo;
69 slave_config.dst_addr_width = param->width;
70 slave_config.dst_maxburst = 1;
71 dmaengine_slave_config(chan, &slave_config);
73 pr_warn("unsupported direction\n");
80 static int samsung_dmadev_prepare(unsigned ch,
81 struct samsung_dma_prep *param)
83 struct scatterlist sg;
84 struct dma_chan *chan = (struct dma_chan *)ch;
85 struct dma_async_tx_descriptor *desc;
89 sg_init_table(&sg, 1);
90 sg_dma_len(&sg) = param->len;
91 sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)),
92 param->len, offset_in_page(param->buf));
93 sg_dma_address(&sg) = param->buf;
95 desc = dmaengine_prep_slave_sg(chan,
96 &sg, 1, param->direction, DMA_PREP_INTERRUPT);
99 desc = dmaengine_prep_dma_cyclic(chan, param->buf,
100 param->len, param->period, param->direction,
101 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
104 dev_err(&chan->dev->device, "unsupported format\n");
109 dev_err(&chan->dev->device, "cannot prepare cyclic dma\n");
113 desc->callback = param->fp;
114 desc->callback_param = param->fp_param;
116 dmaengine_submit((struct dma_async_tx_descriptor *)desc);
121 static inline int samsung_dmadev_trigger(unsigned ch)
123 dma_async_issue_pending((struct dma_chan *)ch);
128 static inline int samsung_dmadev_flush(unsigned ch)
130 return dmaengine_terminate_all((struct dma_chan *)ch);
133 static struct samsung_dma_ops dmadev_ops = {
134 .request = samsung_dmadev_request,
135 .release = samsung_dmadev_release,
136 .config = samsung_dmadev_config,
137 .prepare = samsung_dmadev_prepare,
138 .trigger = samsung_dmadev_trigger,
140 .flush = samsung_dmadev_flush,
141 .stop = samsung_dmadev_flush,
144 void *samsung_dmadev_get_ops(void)
148 EXPORT_SYMBOL(samsung_dmadev_get_ops);