root/arch/arm/mach-mmp/sram.c

DEFINITIONS

1. sram_get_gpool
2. sram_probe
3. sram_remove
4. sram_init

   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         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  76         if (res == NULL) {
  77                 dev_err(&pdev->dev, "no memory resource defined\n");
  78                 ret = -ENODEV;
  79                 goto out;
  80         }
  81 
  82         if (!resource_size(res))
  83                 return 0;
  84 
  85         info->sram_phys   = (phys_addr_t)res->start;
  86         info->sram_size   = resource_size(res);
  87         info->sram_virt   = ioremap(info->sram_phys, info->sram_size);
  88         info->pool_name   = kstrdup(pdata->pool_name, GFP_KERNEL);
  89         info->granularity = pdata->granularity;
  90 
  91         info->gpool = gen_pool_create(ilog2(info->granularity), -1);
  92         if (!info->gpool) {
  93                 dev_err(&pdev->dev, "create pool failed\n");
  94                 ret = -ENOMEM;
  95                 goto create_pool_err;
  96         }
  97 
  98         ret = gen_pool_add_virt(info->gpool, (unsigned long)info->sram_virt,
  99                                 info->sram_phys, info->sram_size, -1);
 100         if (ret < 0) {
 101                 dev_err(&pdev->dev, "add new chunk failed\n");
 102                 ret = -ENOMEM;
 103                 goto add_chunk_err;
 104         }
 105 
 106         mutex_lock(&sram_lock);
 107         list_add(&info->node, &sram_bank_list);
 108         mutex_unlock(&sram_lock);
 109 
 110         platform_set_drvdata(pdev, info);
 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         if (info == NULL)
 131                 return -ENODEV;
 132 
 133         mutex_lock(&sram_lock);
 134         list_del(&info->node);
 135         mutex_unlock(&sram_lock);
 136 
 137         gen_pool_destroy(info->gpool);
 138         iounmap(info->sram_virt);
 139         kfree(info->pool_name);
 140         kfree(info);
 141         return 0;
 142 }
 143 
 144 static const struct platform_device_id sram_id_table[] = {
 145         { "asram", MMP_ASRAM },
 146         { "isram", MMP_ISRAM },
 147         { }
 148 };
 149 
 150 static struct platform_driver sram_driver = {
 151         .probe          = sram_probe,
 152         .remove         = sram_remove,
 153         .driver         = {
 154                 .name   = "mmp-sram",
 155         },
 156         .id_table       = sram_id_table,
 157 };
 158 
 159 static int __init sram_init(void)
 160 {
 161         return platform_driver_register(&sram_driver);
 162 }
 163 core_initcall(sram_init);
 164 
 165 MODULE_LICENSE("GPL");