sram.c

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/*
 *  linux/arch/arm/mach-mmp/sram.c
 *
 *  based on mach-davinci/sram.c - DaVinci simple SRAM allocator
 *
 *  Copyright (c) 2011 Marvell Semiconductors Inc.
 *  All Rights Reserved
 *
 *  Add for mmp sram support - Leo Yan <[email protected]>
 *
 *  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/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/genalloc.h>

#include <linux/platform_data/dma-mmp_tdma.h>

struct sram_bank_info {
    char *pool_name;
    struct gen_pool *gpool;
    int granularity;

    phys_addr_t sram_phys;
    void __iomem *sram_virt;
    u32 sram_size;

    struct list_head node;
};

static DEFINE_MUTEX(sram_lock);
static LIST_HEAD(sram_bank_list);

struct gen_pool *sram_get_gpool(char *pool_name)
{
    struct sram_bank_info *info = NULL;

    if (!pool_name)
        return NULL;

    mutex_lock(&sram_lock);

    list_for_each_entry(info, &sram_bank_list, node)
        if (!strcmp(pool_name, info->pool_name))
            break;

    mutex_unlock(&sram_lock);

    if (&info->node == &sram_bank_list)
        return NULL;

    return info->gpool;
}
EXPORT_SYMBOL(sram_get_gpool);

static int __devinit sram_probe(struct platform_device *pdev)
{
    struct sram_platdata *pdata = pdev->dev.platform_data;
    struct sram_bank_info *info;
    struct resource *res;
    int ret = 0;

    if (!pdata || !pdata->pool_name)
        return -ENODEV;

    info = kzalloc(sizeof(*info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (res == NULL) {
        dev_err(&pdev->dev, "no memory resource defined\n");
        ret = -ENODEV;
        goto out;
    }

    if (!resource_size(res))
        return 0;

    info->sram_phys   = (phys_addr_t)res->start;
    info->sram_size   = resource_size(res);
    info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
    info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
    info->granularity = pdata->granularity;

    info->gpool = gen_pool_create(ilog2(info->granularity), -1);
    if (!info->gpool) {
        dev_err(&pdev->dev, "create pool failed\n");
        ret = -ENOMEM;
        goto create_pool_err;
    }

    ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
                info->sram_phys, info->sram_size, -1);
    if (ret < 0) {
        dev_err(&pdev->dev, "add new chunk failed\n");
        ret = -ENOMEM;
        goto add_chunk_err;
    }

    mutex_lock(&sram_lock);
    list_add(&info->node, &sram_bank_list);
    mutex_unlock(&sram_lock);

    platform_set_drvdata(pdev, info);

    dev_info(&pdev->dev, "initialized\n");
    return 0;

add_chunk_err:
    gen_pool_destroy(info->gpool);
create_pool_err:
    iounmap(info->sram_virt);
    kfree(info->pool_name);
out:
    kfree(info);
    return ret;
}

static int __devexit sram_remove(struct platform_device *pdev)
{
    struct sram_bank_info *info;

    info = platform_get_drvdata(pdev);
    if (info == NULL)
        return -ENODEV;

    mutex_lock(&sram_lock);
    list_del(&info->node);
    mutex_unlock(&sram_lock);

    gen_pool_destroy(info->gpool);
    iounmap(info->sram_virt);
    kfree(info->pool_name);
    kfree(info);
    return 0;
}

static const struct platform_device_id sram_id_table[] = {
    { "asram", MMP_ASRAM },
    { "isram", MMP_ISRAM },
    { }
};

static struct platform_driver sram_driver = {
    .probe      = sram_probe,
    .remove     = sram_remove,
    .driver     = {
        .name   = "mmp-sram",
    },
    .id_table   = sram_id_table,
};

static int __init sram_init(void)
{
    return platform_driver_register(&sram_driver);
}
core_initcall(sram_init);

MODULE_LICENSE("GPL");