linux-imx

/*

 * Atmel SSC driver

 *

 * Copyright (C) 2007 Atmel Corporation

 *

 * 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/list.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/spinlock.h>

#include <linux/atmel-ssc.h>

#include <linux/slab.h>

#include <linux/module.h>

​

#include <linux/of.h>

​

#include "../../sound/soc/atmel/atmel_ssc_dai.h"

​

/* Serialize access to ssc_list and user count */

static DEFINE_SPINLOCK(user_lock);

static LIST_HEAD(ssc_list);

​

struct ssc_device *ssc_request(unsigned int ssc_num)

{

    int ssc_valid = 0;

    struct ssc_device *ssc;

​

    spin_lock(&user_lock);

    list_for_each_entry(ssc, &ssc_list, list) {

        if (ssc->pdev->dev.of_node) {

            if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")

                == ssc_num) {

                ssc->pdev->id = ssc_num;

                ssc_valid = 1;

                break;

            }

        } else if (ssc->pdev->id == ssc_num) {

            ssc_valid = 1;

            break;

        }

    }

​

    if (!ssc_valid) {

        spin_unlock(&user_lock);

        pr_err("ssc: ssc%d platform device is missing\n", ssc_num);

        return ERR_PTR(-ENODEV);

    }

​

    if (ssc->user) {

        spin_unlock(&user_lock);

        dev_dbg(&ssc->pdev->dev, "module busy\n");

        return ERR_PTR(-EBUSY);

    }

    ssc->user++;

    spin_unlock(&user_lock);

​

    clk_prepare(ssc->clk);