/* * linux/drivers/mmc/tmio_mmc_dma.c * * Copyright (C) 2010-2011 Guennadi Liakhovetski * * 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. * * DMA function for TMIO MMC implementations */ #include <linux/device.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/mfd/tmio.h> #include <linux/mmc/host.h> #include <linux/mmc/tmio.h> #include <linux/pagemap.h> #include <linux/scatterlist.h> #include "tmio_mmc.h" #define TMIO_MMC_MIN_DMA_LEN 8 void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable) { if (!host->chan_tx || !host->chan_rx) return; if (host->pdata->flags & TMIO_MMC_HAVE_CTL_DMA_REG) sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0); } void tmio_mmc_abort_dma(struct tmio_mmc_host *host) { tmio_mmc_enable_dma(host, false); if (host->chan_rx) dmaengine_terminate_all(host->chan_rx); if (host->chan_tx) dmaengine_terminate_all(host->chan_tx); tmio_mmc_enable_dma(host, true); } static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host) { struct scatterlist *sg = host->sg_ptr, *sg_tmp; struct dma_async_tx_descriptor *desc = NULL; struct dma_chan *chan = host->chan_rx; struct tmio_mmc_data *pdata = host->pdata; dma_cookie_t cookie; int ret, i; bool aligned = true, multiple = true; unsigned int align = (1 << pdata->dma->alignment_shift) - 1; for_each_sg(sg, sg_tmp, host->sg_len, i) { if (sg_tmp->offset & align) aligned = false; if (sg_tmp->length & align) { multiple = false; break; } } if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE || (align & PAGE_MASK))) || !multiple) { ret = -EINVAL; goto pio; } if (sg->length < TMIO_MMC_MIN_DMA_LEN) { host->force_pio = true; return; } tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY); /* The only sg element can be unaligned, use our bounce buffer then */ if (!aligned) { sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length); host->sg_ptr = &host->bounce_sg; sg = host->sg_ptr; } ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE); if (ret > 0) desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM, DMA_CTRL_ACK); if (desc) { cookie = dmaengine_submit(desc); if (cookie < 0) { desc = NULL; ret = cookie; } } dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n", __func__, host->sg_len, ret, cookie, host->mrq); pio: if (!desc) { /* DMA failed, fall back to PIO */ tmio_mmc_enable_dma(host, false); if (ret >= 0) ret = -EIO; host->chan_rx = NULL; dma_release_channel(chan); /* Free the Tx channel too */ chan = host->chan_tx; if (chan) { host->chan_tx = NULL; dma_release_channel(chan); } dev_warn(&host->pdev->dev, "DMA failed: %d, falling back to PIO\n", ret); } dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__, desc, cookie, host->sg_len); } static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host) { struct scatterlist *sg = host->sg_ptr, *sg_tmp; struct dma_async_tx_descriptor *desc = NULL; struct dma_chan *chan = host->chan_tx; struct tmio_mmc_data *pdata = host->pdata; dma_cookie_t cookie; int ret, i; bool aligned = true, multiple = true; unsigned int align = (1 << pdata->dma->alignment_shift) - 1; for_each_sg(sg, sg_tmp, host->sg_len, i) { if (sg_tmp->offset & align) aligned = false; if (sg_tmp->length & align) { multiple = false; break; } } if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE || (align & PAGE_MASK))) || !multiple) { ret = -EINVAL; goto pio; } if (sg->length < TMIO_MMC_MIN_DMA_LEN) { host->force_pio = true; return; } tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ); /* The only sg element can be unaligned, use our bounce buffer then */ if (!aligned) { unsigned long flags; void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags); sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length); memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length); tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr); host->sg_ptr = &host->bounce_sg; sg = host->sg_ptr; } ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE); if (ret > 0) desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV, DMA_CTRL_ACK); if (desc) { cookie = dmaengine_submit(desc); if (cookie < 0) { desc = NULL; ret = cookie; } } dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n", __func__, host->sg_len, ret, cookie, host->mrq); pio: if (!desc) { /* DMA failed, fall back to PIO */ tmio_mmc_enable_dma(host, false); if (ret >= 0) ret = -EIO; host->chan_tx = NULL; dma_release_channel(chan); /* Free the Rx channel too */ chan = host->chan_rx; if (chan) { host->chan_rx = NULL; dma_release_channel(chan); } dev_warn(&host->pdev->dev, "DMA failed: %d, falling back to PIO\n", ret); } dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__, desc, cookie); } void tmio_mmc_start_dma(struct tmio_mmc_host *host, struct mmc_data *data) { if (data->flags & MMC_DATA_READ) { if (host->chan_rx) tmio_mmc_start_dma_rx(host); } else { if (host->chan_tx) tmio_mmc_start_dma_tx(host); } } static void tmio_mmc_issue_tasklet_fn(unsigned long priv) { struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv; struct dma_chan *chan = NULL; spin_lock_irq(&host->lock); if (host && host->data) { if (host->data->flags & MMC_DATA_READ) chan = host->chan_rx; else chan = host->chan_tx; } spin_unlock_irq(&host->lock); tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND); if (chan) dma_async_issue_pending(chan); } static void tmio_mmc_tasklet_fn(unsigned long arg) { struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; spin_lock_irq(&host->lock); if (!host->data) goto out; if (host->data->flags & MMC_DATA_READ) dma_unmap_sg(host->chan_rx->device->dev, host->sg_ptr, host->sg_len, DMA_FROM_DEVICE); else dma_unmap_sg(host->chan_tx->device->dev, host->sg_ptr, host->sg_len, DMA_TO_DEVICE); tmio_mmc_do_data_irq(host); out: spin_unlock_irq(&host->lock); } void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata) { /* We can only either use DMA for both Tx and Rx or not use it at all */ if (!pdata->dma || (!host->pdev->dev.of_node && (!pdata->dma->chan_priv_tx || !pdata->dma->chan_priv_rx))) return; if (!host->chan_tx && !host->chan_rx) { struct resource *res = platform_get_resource(host->pdev, IORESOURCE_MEM, 0); struct dma_slave_config cfg = {}; dma_cap_mask_t mask; int ret; if (!res) return; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); host->chan_tx = dma_request_slave_channel_compat(mask, pdata->dma->filter, pdata->dma->chan_priv_tx, &host->pdev->dev, "tx"); dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__, host->chan_tx); if (!host->chan_tx) return; if (pdata->dma->chan_priv_tx) cfg.slave_id = pdata->dma->slave_id_tx; cfg.direction = DMA_MEM_TO_DEV; cfg.dst_addr = res->start + (CTL_SD_DATA_PORT << host->pdata->bus_shift); cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; cfg.src_addr = 0; ret = dmaengine_slave_config(host->chan_tx, &cfg); if (ret < 0) goto ecfgtx; host->chan_rx = dma_request_slave_channel_compat(mask, pdata->dma->filter, pdata->dma->chan_priv_rx, &host->pdev->dev, "rx"); dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__, host->chan_rx); if (!host->chan_rx) goto ereqrx; if (pdata->dma->chan_priv_rx) cfg.slave_id = pdata->dma->slave_id_rx; cfg.direction = DMA_DEV_TO_MEM; cfg.src_addr = cfg.dst_addr + pdata->dma->dma_rx_offset; cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; cfg.dst_addr = 0; ret = dmaengine_slave_config(host->chan_rx, &cfg); if (ret < 0) goto ecfgrx; host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA); if (!host->bounce_buf) goto ebouncebuf; tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host); tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host); } tmio_mmc_enable_dma(host, true); return; ebouncebuf: ecfgrx: dma_release_channel(host->chan_rx); host->chan_rx = NULL; ereqrx: ecfgtx: dma_release_channel(host->chan_tx); host->chan_tx = NULL; } void tmio_mmc_release_dma(struct tmio_mmc_host *host) { if (host->chan_tx) { struct dma_chan *chan = host->chan_tx; host->chan_tx = NULL; dma_release_channel(chan); } if (host->chan_rx) { struct dma_chan *chan = host->chan_rx; host->chan_rx = NULL; dma_release_channel(chan); } if (host->bounce_buf) { free_pages((unsigned long)host->bounce_buf, 0); host->bounce_buf = NULL; } }