LXR linux/arch/arm/mach-mmp/sram.c

   1/*
   2 *  linux/arch/arm/mach-mmp/sram.c
   3 *
   4 *  based on mach-davinci/sram.c - DaVinci simple SRAM allocator
   5 *
   6 *  Copyright (c) 2011 Marvell Semiconductors Inc.
   7 *  All Rights Reserved
   8 *
   9 *  Add for mmp sram support - Leo Yan <leoy@marvell.com>
  10 *
  11 *  This program is free software; you can redistribute it and/or modify
  12 *  it under the terms of the GNU General Public License version 2 as
  13 *  published by the Free Software Foundation.
  14 *
  15 */
  16
  17#include <linux/module.h>
  18#include <linux/init.h>
  19#include <linux/platform_device.h>
  20#include <linux/io.h>
  21#include <linux/err.h>
  22#include <linux/slab.h>
  23#include <linux/genalloc.h>
  24
  25#include <linux/platform_data/dma-mmp_tdma.h>
  26
  27struct sram_bank_info {
  28        char *pool_name;
  29        struct gen_pool *gpool;
  30        int granularity;
  31
  32        phys_addr_t sram_phys;
  33        void __iomem *sram_virt;
  34        u32 sram_size;
  35
  36        struct list_head node;
  37};
  38
  39static DEFINE_MUTEX(sram_lock);
  40static LIST_HEAD(sram_bank_list);
  41
  42struct gen_pool *sram_get_gpool(char *pool_name)
  43{
  44        struct sram_bank_info *info = NULL;
  45
  46        if (!pool_name)
  47                return NULL;
  48
  49        mutex_lock(&sram_lock);
  50
  51        list_for_each_entry(info, &sram_bank_list, node)
  52                if (!strcmp(pool_name, info->pool_name))
  53                        break;
  54
  55        mutex_unlock(&sram_lock);
  56
  57        if (&info->node == &sram_bank_list)
  58                return NULL;
  59
  60        return info->gpool;
  61}
  62EXPORT_SYMBOL(sram_get_gpool);
  63
  64static int sram_probe(struct platform_device *pdev)
  65{
  66        struct sram_platdata *pdata = pdev->dev.platform_data;
  67        struct sram_bank_info *info;
  68        struct resource *res;
  69        int ret = 0;
  70
  71        if (!pdata || !pdata->pool_name)
  72                return -ENODEV;
  73
  74        info = kzalloc(sizeof(*info), GFP_KERNEL);
  75        if (!info)
  76                return -ENOMEM;
  77
  78        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  79        if (res == NULL) {
  80                dev_err(&pdev->dev, "no memory resource defined\n");
  81                ret = -ENODEV;
  82                goto out;
  83        }
  84
  85        if (!resource_size(res))
  86                return 0;
  87
  88        info->sram_phys   = (phys_addr_t)res->start;
  89        info->sram_size   = resource_size(res);
  90        info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
  91        info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
  92        info->granularity = pdata->granularity;
  93
  94        info->gpool = gen_pool_create(ilog2(info->granularity), -1);
  95        if (!info->gpool) {
  96                dev_err(&pdev->dev, "create pool failed\n");
  97                ret = -ENOMEM;
  98                goto create_pool_err;
  99        }
 100
 101        ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
 102                                info->sram_phys, info->sram_size, -1);
 103        if (ret < 0) {
 104                dev_err(&pdev->dev, "add new chunk failed\n");
 105                ret = -ENOMEM;
 106                goto add_chunk_err;
 107        }
 108
 109        mutex_lock(&sram_lock);
 110        list_add(&info->node, &sram_bank_list);
 111        mutex_unlock(&sram_lock);
 112
 113        platform_set_drvdata(pdev, info);
 114
 115        dev_info(&pdev->dev, "initialized\n");
 116        return 0;
 117
 118add_chunk_err:
 119        gen_pool_destroy(info->gpool);
 120create_pool_err:
 121        iounmap(info->sram_virt);
 122        kfree(info->pool_name);
 123out:
 124        kfree(info);
 125        return ret;
 126}
 127
 128static int sram_remove(struct platform_device *pdev)
 129{
 130        struct sram_bank_info *info;
 131
 132        info = platform_get_drvdata(pdev);
 133        if (info == NULL)
 134                return -ENODEV;
 135
 136        mutex_lock(&sram_lock);
 137        list_del(&info->node);
 138        mutex_unlock(&sram_lock);
 139
 140        gen_pool_destroy(info->gpool);
 141        iounmap(info->sram_virt);
 142        kfree(info->pool_name);
 143        kfree(info);
 144        return 0;
 145}
 146
 147static const struct platform_device_id sram_id_table[] = {
 148        { "asram", MMP_ASRAM },
 149        { "isram", MMP_ISRAM },
 150        { }
 151};
 152
 153static struct platform_driver sram_driver = {
 154        .probe          = sram_probe,
 155        .remove         = sram_remove,
 156        .driver         = {
 157                .name   = "mmp-sram",
 158        },
 159        .id_table       = sram_id_table,
 160};
 161
 162static int __init sram_init(void)
 163{
 164        return platform_driver_register(&sram_driver);
 165}
 166core_initcall(sram_init);
 167
 168MODULE_LICENSE("GPL");
 169