arch/arm/mach-mmp/sram.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/arch/arm/mach-mmp/sram.c
   4  *
   5  *  based on mach-davinci/sram.c - DaVinci simple SRAM allocator
   6  *
   7  *  Copyright (c) 2011 Marvell Semiconductors Inc.
   8  *  All Rights Reserved
   9  *
  10  *  Add for mmp sram support - Leo Yan <leoy@marvell.com>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/init.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/io.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/genalloc.h>
  21
  22 #include <linux/platform_data/dma-mmp_tdma.h>
  23
  24 struct sram_bank_info {
  25         char *pool_name;
  26         struct gen_pool *gpool;
  27         int granularity;
  28
  29         phys_addr_t sram_phys;
  30         void __iomem *sram_virt;
  31         u32 sram_size;
  32
  33         struct list_head node;
  34 };
  35
  36 static DEFINE_MUTEX(sram_lock);
  37 static LIST_HEAD(sram_bank_list);
  38
  39 struct gen_pool *sram_get_gpool(char *pool_name)
  40 {
  41         struct sram_bank_info *info = NULL;
  42
  43         if (!pool_name)
  44                 return NULL;
  45
  46         mutex_lock(&sram_lock);
  47
  48         list_for_each_entry(info, &sram_bank_list, node)
  49                 if (!strcmp(pool_name, info->pool_name))
  50                         break;
  51
  52         mutex_unlock(&sram_lock);
  53
  54         if (&info->node == &sram_bank_list)
  55                 return NULL;
  56
  57         return info->gpool;
  58 }
  59 EXPORT_SYMBOL(sram_get_gpool);
  60
  61 static int sram_probe(struct platform_device *pdev)
  62 {
  63         struct sram_platdata *pdata = pdev->dev.platform_data;
  64         struct sram_bank_info *info;
  65         struct resource *res;
  66         int ret = 0;
  67
  68         if (!pdata || !pdata->pool_name)
  69                 return -ENODEV;
  70
  71         info = kzalloc(sizeof(*info), GFP_KERNEL);
  72         if (!info)
  73                 return -ENOMEM;
  74
  75         platform_set_drvdata(pdev, info);
  76
  77         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  78         if (res == NULL) {
  79                 dev_err(&pdev->dev, "no memory resource defined\n");
  80                 ret = -ENODEV;
  81                 goto out;
  82         }
  83
  84         if (!resource_size(res))
  85                 return 0;
  86
  87         info->sram_phys   = (phys_addr_t)res->start;
  88         info->sram_size   = resource_size(res);
  89         info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
  90         info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
  91         info->granularity = pdata->granularity;
  92
  93         info->gpool = gen_pool_create(ilog2(info->granularity), -1);
  94         if (!info->gpool) {
  95                 dev_err(&pdev->dev, "create pool failed\n");
  96                 ret = -ENOMEM;
  97                 goto create_pool_err;
  98         }
  99
 100         ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
 101                                 info->sram_phys, info->sram_size, -1);
 102         if (ret < 0) {
 103                 dev_err(&pdev->dev, "add new chunk failed\n");
 104                 ret = -ENOMEM;
 105                 goto add_chunk_err;
 106         }
 107
 108         mutex_lock(&sram_lock);
 109         list_add(&info->node, &sram_bank_list);
 110         mutex_unlock(&sram_lock);
 111
 112         dev_info(&pdev->dev, "initialized\n");
 113         return 0;
 114
 115 add_chunk_err:
 116         gen_pool_destroy(info->gpool);
 117 create_pool_err:
 118         iounmap(info->sram_virt);
 119         kfree(info->pool_name);
 120 out:
 121         kfree(info);
 122         return ret;
 123 }
 124
 125 static int sram_remove(struct platform_device *pdev)
 126 {
 127         struct sram_bank_info *info;
 128
 129         info = platform_get_drvdata(pdev);
 130
 131         if (info->sram_size) {
 132                 mutex_lock(&sram_lock);
 133                 list_del(&info->node);
 134                 mutex_unlock(&sram_lock);
 135
 136                 gen_pool_destroy(info->gpool);
 137                 iounmap(info->sram_virt);
 138                 kfree(info->pool_name);
 139         }
 140
 141         kfree(info);
 142
 143         return 0;
 144 }
 145
 146 static const struct platform_device_id sram_id_table[] = {
 147         { "asram", MMP_ASRAM },
 148         { "isram", MMP_ISRAM },
 149         { }
 150 };
 151
 152 static struct platform_driver sram_driver = {
 153         .probe          = sram_probe,
 154         .remove         = sram_remove,
 155         .driver         = {
 156                 .name   = "mmp-sram",
 157         },
 158         .id_table       = sram_id_table,
 159 };
 160
 161 static int __init sram_init(void)
 162 {
 163         return platform_driver_register(&sram_driver);
 164 }
 165 core_initcall(sram_init);
 166
 167 MODULE_LICENSE("GPL");