/* linux/arch/arm/plat-samsung/dma-ops.c * * Copyright (c) 2011 Samsung Electronics Co., Ltd. * http://www.samsung.com * * Samsung DMA Operations * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/amba/pl330.h> #include <linux/scatterlist.h> #include <linux/export.h> #include <mach/dma.h> static unsigned samsung_dmadev_request(enum dma_ch dma_ch, struct samsung_dma_req *param, struct device *dev, char *ch_name) { dma_cap_mask_t mask; dma_cap_zero(mask); dma_cap_set(param->cap, mask); if (dev->of_node) return (unsigned)dma_request_slave_channel(dev, ch_name); else return (unsigned)dma_request_channel(mask, pl330_filter, (void *)dma_ch); } static int samsung_dmadev_release(unsigned ch, void *param) { dma_release_channel((struct dma_chan *)ch); return 0; } static int samsung_dmadev_config(unsigned ch, struct samsung_dma_config *param) { struct dma_chan *chan = (struct dma_chan *)ch; struct dma_slave_config slave_config; if (param->direction == DMA_DEV_TO_MEM) { memset(&slave_config, 0, sizeof(struct dma_slave_config)); slave_config.direction = param->direction; slave_config.src_addr = param->fifo; slave_config.src_addr_width = param->width; slave_config.src_maxburst = 1; dmaengine_slave_config(chan, &slave_config); } else if (param->direction == DMA_MEM_TO_DEV) { memset(&slave_config, 0, sizeof(struct dma_slave_config)); slave_config.direction = param->direction; slave_config.dst_addr = param->fifo; slave_config.dst_addr_width = param->width; slave_config.dst_maxburst = 1; dmaengine_slave_config(chan, &slave_config); } else { pr_warn("unsupported direction\n"); return -EINVAL; } return 0; } static int samsung_dmadev_prepare(unsigned ch, struct samsung_dma_prep *param) { struct scatterlist sg; struct dma_chan *chan = (struct dma_chan *)ch; struct dma_async_tx_descriptor *desc; switch (param->cap) { case DMA_SLAVE: sg_init_table(&sg, 1); sg_dma_len(&sg) = param->len; sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)), param->len, offset_in_page(param->buf)); sg_dma_address(&sg) = param->buf; desc = dmaengine_prep_slave_sg(chan, &sg, 1, param->direction, DMA_PREP_INTERRUPT); break; case DMA_CYCLIC: desc = dmaengine_prep_dma_cyclic(chan, param->buf, param->len, param->period, param->direction, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); break; default: dev_err(&chan->dev->device, "unsupported format\n"); return -EFAULT; } if (!desc) { dev_err(&chan->dev->device, "cannot prepare cyclic dma\n"); return -EFAULT; } desc->callback = param->fp; desc->callback_param = param->fp_param; dmaengine_submit((struct dma_async_tx_descriptor *)desc); return 0; } static inline int samsung_dmadev_trigger(unsigned ch) { dma_async_issue_pending((struct dma_chan *)ch); return 0; } static inline int samsung_dmadev_flush(unsigned ch) { return dmaengine_terminate_all((struct dma_chan *)ch); } static struct samsung_dma_ops dmadev_ops = { .request = samsung_dmadev_request, .release = samsung_dmadev_release, .config = samsung_dmadev_config, .prepare = samsung_dmadev_prepare, .trigger = samsung_dmadev_trigger, .started = NULL, .flush = samsung_dmadev_flush, .stop = samsung_dmadev_flush, }; void *samsung_dmadev_get_ops(void) { return &dmadev_ops; } EXPORT_SYMBOL(samsung_dmadev_get_ops);