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/mod_devicetable.h>
  19 #include <linux/init.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/io.h>
  22 #include <linux/err.h>
  23 #include <linux/slab.h>
  24 #include <linux/genalloc.h>
  25
  26 #include <linux/platform_data/dma-mmp_tdma.h>
  27
  28 struct sram_bank_info {
  29         char *pool_name;
  30         struct gen_pool *gpool;
  31         int granularity;
  32
  33         phys_addr_t sram_phys;
  34         void __iomem *sram_virt;
  35         u32 sram_size;
  36
  37         struct list_head node;
  38 };
  39
  40 static DEFINE_MUTEX(sram_lock);
  41 static LIST_HEAD(sram_bank_list);
  42
  43 struct gen_pool *sram_get_gpool(char *pool_name)
  44 {
  45         struct sram_bank_info *info = NULL;
  46
  47         if (!pool_name)
  48                 return NULL;
  49
  50         mutex_lock(&sram_lock);
  51
  52         list_for_each_entry(info, &sram_bank_list, node)
  53                 if (!strcmp(pool_name, info->pool_name))
  54                         break;
  55
  56         mutex_unlock(&sram_lock);
  57
  58         if (&info->node == &sram_bank_list)
  59                 return NULL;
  60
  61         return info->gpool;
  62 }
  63 EXPORT_SYMBOL(sram_get_gpool);
  64
  65 static int sram_probe(struct platform_device *pdev)
  66 {
  67         struct sram_platdata *pdata = pdev->dev.platform_data;
  68         struct sram_bank_info *info;
  69         struct resource *res;
  70         int ret = 0;
  71
  72         if (!pdata || !pdata->pool_name)
  73                 return -ENODEV;
  74
  75         info = kzalloc(sizeof(*info), GFP_KERNEL);
  76         if (!info)
  77                 return -ENOMEM;
  78
  79         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  80         if (res == NULL) {
  81                 dev_err(&pdev->dev, "no memory resource defined\n");
  82                 ret = -ENODEV;
  83                 goto out;
  84         }
  85
  86         if (!resource_size(res))
  87                 return 0;
  88
  89         info->sram_phys   = (phys_addr_t)res->start;
  90         info->sram_size   = resource_size(res);
  91         info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
  92         info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
  93         info->granularity = pdata->granularity;
  94
  95         info->gpool = gen_pool_create(ilog2(info->granularity), -1);
  96         if (!info->gpool) {
  97                 dev_err(&pdev->dev, "create pool failed\n");
  98                 ret = -ENOMEM;
  99                 goto create_pool_err;
 100         }
 101
 102         ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
 103                                 info->sram_phys, info->sram_size, -1);
 104         if (ret < 0) {
 105                 dev_err(&pdev->dev, "add new chunk failed\n");
 106                 ret = -ENOMEM;
 107                 goto add_chunk_err;
 108         }
 109
 110         mutex_lock(&sram_lock);
 111         list_add(&info->node, &sram_bank_list);
 112         mutex_unlock(&sram_lock);
 113
 114         platform_set_drvdata(pdev, info);
 115
 116         dev_info(&pdev->dev, "initialized\n");
 117         return 0;
 118
 119 add_chunk_err:
 120         gen_pool_destroy(info->gpool);
 121 create_pool_err:
 122         iounmap(info->sram_virt);
 123         kfree(info->pool_name);
 124 out:
 125         kfree(info);
 126         return ret;
 127 }
 128
 129 static int sram_remove(struct platform_device *pdev)
 130 {
 131         struct sram_bank_info *info;
 132
 133         info = platform_get_drvdata(pdev);
 134         if (info == NULL)
 135                 return -ENODEV;
 136
 137         mutex_lock(&sram_lock);
 138         list_del(&info->node);
 139         mutex_unlock(&sram_lock);
 140
 141         gen_pool_destroy(info->gpool);
 142         iounmap(info->sram_virt);
 143         kfree(info->pool_name);
 144         kfree(info);
 145         return 0;
 146 }
 147
 148 static const struct platform_device_id sram_id_table[] = {
 149         { "asram", MMP_ASRAM },
 150         { "isram", MMP_ISRAM },
 151         { }
 152 };
 153
 154 static struct platform_driver sram_driver = {
 155         .probe          = sram_probe,
 156         .remove         = sram_remove,
 157         .driver         = {
 158                 .name   = "mmp-sram",
 159         },
 160         .id_table       = sram_id_table,
 161 };
 162
 163 static int __init sram_init(void)
 164 {
 165         return platform_driver_register(&sram_driver);
 166 }
 167 core_initcall(sram_init);
 168
 169 MODULE_LICENSE("GPL");