示例#1
0
文件: omap.c 项目: AllenDou/linux
static void
mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
{
	struct mmc_data *data = req->data;
	int i, use_dma, block_size;
	unsigned sg_len;

	host->data = data;
	if (data == NULL) {
		OMAP_MMC_WRITE(host, BLEN, 0);
		OMAP_MMC_WRITE(host, NBLK, 0);
		OMAP_MMC_WRITE(host, BUF, 0);
		host->dma_in_use = 0;
		set_cmd_timeout(host, req);
		return;
	}

	block_size = data->blksz;

	OMAP_MMC_WRITE(host, NBLK, data->blocks - 1);
	OMAP_MMC_WRITE(host, BLEN, block_size - 1);
	set_data_timeout(host, req);

	/* cope with calling layer confusion; it issues "single
	 * block" writes using multi-block scatterlists.
	 */
	sg_len = (data->blocks == 1) ? 1 : data->sg_len;

	/* Only do DMA for entire blocks */
	use_dma = host->use_dma;
	if (use_dma) {
		for (i = 0; i < sg_len; i++) {
			if ((data->sg[i].length % block_size) != 0) {
				use_dma = 0;
				break;
			}
		}
	}

	host->sg_idx = 0;
	if (use_dma) {
		enum dma_data_direction dma_data_dir;
		struct dma_async_tx_descriptor *tx;
		struct dma_chan *c;
		u32 burst, *bp;
		u16 buf;

		/*
		 * FIFO is 16x2 bytes on 15xx, and 32x2 bytes on 16xx
		 * and 24xx. Use 16 or 32 word frames when the
		 * blocksize is at least that large. Blocksize is
		 * usually 512 bytes; but not for some SD reads.
		 */
		burst = cpu_is_omap15xx() ? 32 : 64;
		if (burst > data->blksz)
			burst = data->blksz;

		burst >>= 1;

		if (data->flags & MMC_DATA_WRITE) {
			c = host->dma_tx;
			bp = &host->dma_tx_burst;
			buf = 0x0f80 | (burst - 1) << 0;
			dma_data_dir = DMA_TO_DEVICE;
		} else {
			c = host->dma_rx;
			bp = &host->dma_rx_burst;
			buf = 0x800f | (burst - 1) << 8;
			dma_data_dir = DMA_FROM_DEVICE;
		}

		if (!c)
			goto use_pio;

		/* Only reconfigure if we have a different burst size */
		if (*bp != burst) {
			struct dma_slave_config cfg;

			cfg.src_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
			cfg.dst_addr = host->phys_base + OMAP_MMC_REG(host, DATA);
			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
			cfg.src_maxburst = burst;
			cfg.dst_maxburst = burst;

			if (dmaengine_slave_config(c, &cfg))
				goto use_pio;

			*bp = burst;
		}

		host->sg_len = dma_map_sg(c->device->dev, data->sg, sg_len,
					  dma_data_dir);
		if (host->sg_len == 0)
			goto use_pio;

		tx = dmaengine_prep_slave_sg(c, data->sg, host->sg_len,
			data->flags & MMC_DATA_WRITE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
		if (!tx)
			goto use_pio;

		OMAP_MMC_WRITE(host, BUF, buf);

		tx->callback = mmc_omap_dma_callback;
		tx->callback_param = host;
		dmaengine_submit(tx);
		host->brs_received = 0;
		host->dma_done = 0;
		host->dma_in_use = 1;
		return;
	}
 use_pio:

	/* Revert to PIO? */
	OMAP_MMC_WRITE(host, BUF, 0x1f1f);
	host->total_bytes_left = data->blocks * block_size;
	host->sg_len = sg_len;
	mmc_omap_sg_to_buf(host);
	host->dma_in_use = 0;
}
示例#2
0
static void
mmc_omap_prepare_data(struct mmc_omap_host *host, struct mmc_request *req)
{
	struct mmc_data *data = req->data;
	int i, use_dma, block_size;
	unsigned sg_len;

	host->data = data;
	if (data == NULL) {
		OMAP_MMC_WRITE(host, BLEN, 0);
		OMAP_MMC_WRITE(host, NBLK, 0);
		OMAP_MMC_WRITE(host, BUF, 0);
		host->dma_in_use = 0;
		set_cmd_timeout(host, req);
		return;
	}

	block_size = data->blksz;

	OMAP_MMC_WRITE(host, NBLK, data->blocks - 1);
	OMAP_MMC_WRITE(host, BLEN, block_size - 1);
	set_data_timeout(host, req);

	/* cope with calling layer confusion; it issues "single
	 * block" writes using multi-block scatterlists.
	 */
	sg_len = (data->blocks == 1) ? 1 : data->sg_len;

	/* Only do DMA for entire blocks */
	use_dma = host->use_dma;
	if (use_dma) {
		for (i = 0; i < sg_len; i++) {
			if ((data->sg[i].length % block_size) != 0) {
				use_dma = 0;
				break;
			}
		}
	}

	host->sg_idx = 0;
	if (use_dma) {
		if (mmc_omap_get_dma_channel(host, data) == 0) {
			enum dma_data_direction dma_data_dir;

			if (data->flags & MMC_DATA_WRITE)
				dma_data_dir = DMA_TO_DEVICE;
			else
				dma_data_dir = DMA_FROM_DEVICE;

			host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
						sg_len, dma_data_dir);
			host->total_bytes_left = 0;
			mmc_omap_prepare_dma(host, req->data);
			host->brs_received = 0;
			host->dma_done = 0;
			host->dma_in_use = 1;
		} else
			use_dma = 0;
	}

	/* Revert to PIO? */
	if (!use_dma) {
		OMAP_MMC_WRITE(host, BUF, 0x1f1f);
		host->total_bytes_left = data->blocks * block_size;
		host->sg_len = sg_len;
		mmc_omap_sg_to_buf(host);
		host->dma_in_use = 0;
	}
}