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