diff options
Diffstat (limited to 'arch/arm/plat-samsung/dma-ops.c')
-rw-r--r-- | arch/arm/plat-samsung/dma-ops.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c new file mode 100644 index 00000000..eb9f4f53 --- /dev/null +++ b/arch/arm/plat-samsung/dma-ops.c @@ -0,0 +1,133 @@ +/* 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_info *info) +{ + struct dma_chan *chan; + dma_cap_mask_t mask; + struct dma_slave_config slave_config; + void *filter_param; + + dma_cap_zero(mask); + dma_cap_set(info->cap, mask); + + /* + * If a dma channel property of a device node from device tree is + * specified, use that as the fliter parameter. + */ + filter_param = (dma_ch == DMACH_DT_PROP) ? (void *)info->dt_dmach_prop : + (void *)dma_ch; + chan = dma_request_channel(mask, pl330_filter, filter_param); + + if (info->direction == DMA_DEV_TO_MEM) { + memset(&slave_config, 0, sizeof(struct dma_slave_config)); + slave_config.direction = info->direction; + slave_config.src_addr = info->fifo; + slave_config.src_addr_width = info->width; + slave_config.src_maxburst = 1; + dmaengine_slave_config(chan, &slave_config); + } else if (info->direction == DMA_MEM_TO_DEV) { + memset(&slave_config, 0, sizeof(struct dma_slave_config)); + slave_config.direction = info->direction; + slave_config.dst_addr = info->fifo; + slave_config.dst_addr_width = info->width; + slave_config.dst_maxburst = 1; + dmaengine_slave_config(chan, &slave_config); + } + + return (unsigned)chan; +} + +static int samsung_dmadev_release(unsigned ch, + struct s3c2410_dma_client *client) +{ + dma_release_channel((struct dma_chan *)ch); + + return 0; +} + +static int samsung_dmadev_prepare(unsigned ch, + struct samsung_dma_prep_info *info) +{ + struct scatterlist sg; + struct dma_chan *chan = (struct dma_chan *)ch; + struct dma_async_tx_descriptor *desc; + + switch (info->cap) { + case DMA_SLAVE: + sg_init_table(&sg, 1); + sg_dma_len(&sg) = info->len; + sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)), + info->len, offset_in_page(info->buf)); + sg_dma_address(&sg) = info->buf; + + desc = dmaengine_prep_slave_sg(chan, + &sg, 1, info->direction, DMA_PREP_INTERRUPT); + break; + case DMA_CYCLIC: + desc = dmaengine_prep_dma_cyclic(chan, + info->buf, info->len, info->period, info->direction); + 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 = info->fp; + desc->callback_param = info->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, + .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); |