linux-imx

/*

 * drivers/uio/uio_dmem_genirq.c

 *

 * Userspace I/O platform driver with generic IRQ handling code.

 *

 * Copyright (C) 2012 Damian Hobson-Garcia

 *

 * Based on uio_pdrv_genirq.c by Magnus Damm

 *

 * 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.

 */

​

#include <linux/platform_device.h>

#include <linux/uio_driver.h>

#include <linux/spinlock.h>

#include <linux/bitops.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/platform_data/uio_dmem_genirq.h>

#include <linux/stringify.h>

#include <linux/pm_runtime.h>

#include <linux/dma-mapping.h>

#include <linux/slab.h>

​

#include <linux/of.h>

#include <linux/of_platform.h>

#include <linux/of_address.h>

​

#define DRIVER_NAME "uio_dmem_genirq"

#define DMEM_MAP_ERROR (~0)

​

struct uio_dmem_genirq_platdata {

    struct uio_info *uioinfo;

    spinlock_t lock;

    unsigned long flags;

    struct platform_device *pdev;

    unsigned int dmem_region_start;

    unsigned int num_dmem_regions;

    void *dmem_region_vaddr[MAX_UIO_MAPS];

    struct mutex alloc_lock;

    unsigned int refcnt;

};

​

static int uio_dmem_genirq_open(struct uio_info *info, struct inode *inode)

{

    struct uio_dmem_genirq_platdata *priv = info->priv;

    struct uio_mem *uiomem;

    int ret = 0;

    int dmem_region = priv->dmem_region_start;

​

    uiomem = &priv->uioinfo->mem[priv->dmem_region_start];

​

    mutex_lock(&priv->alloc_lock);

    while (!priv->refcnt && uiomem < &priv->uioinfo->mem[MAX_UIO_MAPS]) {

        void *addr;

        if (!uiomem->size)

            break;

​

        addr = dma_alloc_coherent(&priv->pdev->dev, uiomem->size,

                (dma_addr_t *)&uiomem->addr, GFP_KERNEL);

        if (!addr) {