/* Prepares DMA data for current or next transfer.
* A request can be in-flight when this is called.
*/
static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
struct mmc_data *data,
int cookie)
{
struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
enum dma_data_direction dir = mmc_get_dma_dir(data);
int sg_count;
if (data->host_cookie == COOKIE_PREMAPPED)
return data->sg_count;
sg_count = dma_map_sg(chan->device->dev,
data->sg,
data->sg_len,
dir);
if (sg_count <= 0) {
dev_err(mmc_dev(host->mmc),
"Failed to map scatterlist for DMA operation\n");
return -EINVAL;
}
data->sg_count = sg_count;
data->host_cookie = cookie;
return data->sg_count;
}
static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host,
struct mmc_data *data)
{
struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
enum dma_data_direction dir = jz4740_mmc_get_dma_dir(data);
dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
}
static int jz4740_mmc_start_dma_transfer(struct jz4740_mmc_host *host,
struct mmc_data *data)
{
struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
struct dma_async_tx_descriptor *desc;
struct dma_slave_config conf = {
.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
.src_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
.dst_maxburst = JZ4740_MMC_FIFO_HALF_SIZE,
};
int sg_count;
if (data->flags & MMC_DATA_WRITE) {
conf.direction = DMA_MEM_TO_DEV;
conf.dst_addr = host->mem_res->start + JZ_REG_MMC_TXFIFO;
conf.slave_id = JZ4740_DMA_TYPE_MMC_TRANSMIT;
} else {
conf.direction = DMA_DEV_TO_MEM;
conf.src_addr = host->mem_res->start + JZ_REG_MMC_RXFIFO;
conf.slave_id = JZ4740_DMA_TYPE_MMC_RECEIVE;
}
sg_count = jz4740_mmc_prepare_dma_data(host, data, COOKIE_MAPPED);
if (sg_count < 0)
return sg_count;
dmaengine_slave_config(chan, &conf);
desc = dmaengine_prep_slave_sg(chan, data->sg, sg_count,
conf.direction,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dev_err(mmc_dev(host->mmc),
"Failed to allocate DMA %s descriptor",
conf.direction == DMA_MEM_TO_DEV ? "TX" : "RX");
goto dma_unmap;
}
dmaengine_submit(desc);
dma_async_issue_pending(chan);
return 0;
dma_unmap:
if (data->host_cookie == COOKIE_MAPPED)
jz4740_mmc_dma_unmap(host, data);
return -ENOMEM;
}
static void jz4740_mmc_post_request(struct mmc_host *mmc,
struct mmc_request *mrq,
int err)
{
struct jz4740_mmc_host *host = mmc_priv(mmc);
struct mmc_data *data = mrq->data;
if (data && data->host_cookie != COOKIE_UNMAPPED)
jz4740_mmc_dma_unmap(host, data);
if (err) {
struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
dmaengine_terminate_all(chan);
}
}
static void jz4740_mmc_pre_request(struct mmc_host *mmc,
struct mmc_request *mrq,
bool is_first_req)
{
struct jz4740_mmc_host *host = mmc_priv(mmc);
struct mmc_data *data = mrq->data;
struct jz4740_mmc_host_next *next_data = &host->next_data;
BUG_ON(data->host_cookie);
if (host->use_dma) {
struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
if (jz4740_mmc_prepare_dma_data(host, data, next_data, chan))
data->host_cookie = 0;
}
}
