linux-imx

/*

 * Generic PXA PATA driver

 *

 * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2, or (at your option)

 *  any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; see the file COPYING.  If not, write to

 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/blkdev.h>

#include <linux/ata.h>

#include <linux/libata.h>

#include <linux/platform_device.h>

#include <linux/dmaengine.h>

#include <linux/slab.h>

#include <linux/completion.h>

​

#include <scsi/scsi_host.h>

​

#include <linux/platform_data/ata-pxa.h>

​

#define DRV_NAME    "pata_pxa"

#define DRV_VERSION "0.1"

​

struct pata_pxa_data {

    struct dma_chan     *dma_chan;

    dma_cookie_t        dma_cookie;

    struct completion   dma_done;

};

​

/*

 * DMA interrupt handler.

 */

static void pxa_ata_dma_irq(void *d)

{

    struct pata_pxa_data *pd = d;

    enum dma_status status;

​

    status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);

    if (status == DMA_ERROR || status == DMA_COMPLETE)

        complete(&pd->dma_done);

}

​

/*

 * Prepare taskfile for submission.

 */

static void pxa_qc_prep(struct ata_queued_cmd *qc)

{

    struct pata_pxa_data *pd = qc->ap->private_data;

    struct dma_async_tx_descriptor *tx;

    enum dma_transfer_direction dir;

​

    if (!(qc->flags & ATA_QCFLAG_DMAMAP))

        return;

​

    dir = (qc->dma_dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);

    tx = dmaengine_prep_slave_sg(pd->dma_chan, qc->sg, qc->n_elem, dir,

                     DMA_PREP_INTERRUPT);

    if (!tx) {

        ata_dev_err(qc->dev, "prep_slave_sg() failed\n");

        return;

    }

    tx->callback = pxa_ata_dma_irq;

    tx->callback_param = pd;

    pd->dma_cookie = dmaengine_submit(tx);

}

​

/*

 * Configure the DMA controller, load the DMA descriptors, but don't start the

 * DMA controller yet. Only issue the ATA command.

 */

static void pxa_bmdma_setup(struct ata_queued_cmd *qc)

{

    qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);

}

​

/*

 * Execute the DMA transfer.

 */