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
  27 struct 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
  39 static DEFINE_MUTEX(sram_lock);
  40 static LIST_HEAD(sram_bank_list);
  41
  42 struct 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 }
  62 EXPORT_SYMBOL(sram_get_gpool);
  63
  64 static 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         platform_set_drvdata(pdev, info);
  79
  80         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  81         if (res == NULL) {
  82                 dev_err(&pdev->dev, "no memory resource defined\n");
  83                 ret = -ENODEV;
  84                 goto out;
  85         }
  86
  87         if (!resource_size(res))
  88                 return 0;
  89
  90         info->sram_phys   = (phys_addr_t)res->start;
  91         info->sram_size   = resource_size(res);
  92         info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
  93         info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
  94         info->granularity = pdata->granularity;
  95
  96         info->gpool = gen_pool_create(ilog2(info->granularity), -1);
  97         if (!info->gpool) {
  98                 dev_err(&pdev->dev, "create pool failed\n");
  99                 ret = -ENOMEM;
 100                 goto create_pool_err;
 101         }
 102
 103         ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
 104                                 info->sram_phys, info->sram_size, -1);
 105         if (ret < 0) {
 106                 dev_err(&pdev->dev, "add new chunk failed\n");
 107                 ret = -ENOMEM;
 108                 goto add_chunk_err;
 109         }
 110
 111         mutex_lock(&sram_lock);
 112         list_add(&info->node, &sram_bank_list);
 113         mutex_unlock(&sram_lock);
 114
 115         dev_info(&pdev->dev, "initialized\n");
 116         return 0;
 117
 118 add_chunk_err:
 119         gen_pool_destroy(info->gpool);
 120 create_pool_err:
 121         iounmap(info->sram_virt);
 122         kfree(info->pool_name);
 123 out:
 124         kfree(info);
 125         return ret;
 126 }
 127
 128 static int sram_remove(struct platform_device *pdev)
 129 {
 130         struct sram_bank_info *info;
 131
 132         info = platform_get_drvdata(pdev);
 133
 134         if (info->sram_size) {
 135                 mutex_lock(&sram_lock);
 136                 list_del(&info->node);
 137                 mutex_unlock(&sram_lock);
 138
 139                 gen_pool_destroy(info->gpool);
 140                 iounmap(info->sram_virt);
 141                 kfree(info->pool_name);
 142         }
 143
 144         kfree(info);
 145
 146         return 0;
 147 }
 148
 149 static const struct platform_device_id sram_id_table[] = {
 150         { "asram", MMP_ASRAM },
 151         { "isram", MMP_ISRAM },
 152         { }
 153 };
 154
 155 static struct platform_driver sram_driver = {
 156         .probe          = sram_probe,
 157         .remove         = sram_remove,
 158         .driver         = {
 159                 .name   = "mmp-sram",
 160         },
 161         .id_table       = sram_id_table,
 162 };
 163
 164 static int __init sram_init(void)
 165 {
 166         return platform_driver_register(&sram_driver);
 167 }
 168 core_initcall(sram_init);
 169
 170 MODULE_LICENSE("GPL");