drivers/dma/bestcomm/sram.c

   1 /*
   2  * Simple memory allocator for on-board SRAM
   3  *
   4  *
   5  * Maintainer : Sylvain Munaut <tnt@246tNt.com>
   6  *
   7  * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com>
   8  *
   9  * This file is licensed under the terms of the GNU General Public License
  10  * version 2. This program is licensed "as is" without any warranty of any
  11  * kind, whether express or implied.
  12  */
  13
  14 #include <linux/err.h>
  15 #include <linux/kernel.h>
  16 #include <linux/export.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/string.h>
  20 #include <linux/ioport.h>
  21 #include <linux/of.h>
  22
  23 #include <asm/io.h>
  24 #include <asm/mmu.h>
  25
  26 #include <linux/fsl/bestcomm/sram.h>
  27
  28
  29 /* Struct keeping our 'state' */
  30 struct bcom_sram *bcom_sram = NULL;
  31 EXPORT_SYMBOL_GPL(bcom_sram);   /* needed for inline functions */
  32
  33
  34 /* ======================================================================== */
  35 /* Public API                                                               */
  36 /* ======================================================================== */
  37 /* DO NOT USE in interrupts, if needed in irq handler, we should use the
  38    _irqsave version of the spin_locks */
  39
  40 int bcom_sram_init(struct device_node *sram_node, char *owner)
  41 {
  42         int rv;
  43         const u32 *regaddr_p;
  44         u64 regaddr64, size64;
  45         unsigned int psize;
  46
  47         /* Create our state struct */
  48         if (bcom_sram) {
  49                 printk(KERN_ERR "%s: bcom_sram_init: "
  50                         "Already initialized !\n", owner);
  51                 return -EBUSY;
  52         }
  53
  54         bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL);
  55         if (!bcom_sram) {
  56                 printk(KERN_ERR "%s: bcom_sram_init: "
  57                         "Couldn't allocate internal state !\n", owner);
  58                 return -ENOMEM;
  59         }
  60
  61         /* Get address and size of the sram */
  62         regaddr_p = of_get_address(sram_node, 0, &size64, NULL);
  63         if (!regaddr_p) {
  64                 printk(KERN_ERR "%s: bcom_sram_init: "
  65                         "Invalid device node !\n", owner);
  66                 rv = -EINVAL;
  67                 goto error_free;
  68         }
  69
  70         regaddr64 = of_translate_address(sram_node, regaddr_p);
  71
  72         bcom_sram->base_phys = (phys_addr_t) regaddr64;
  73         bcom_sram->size = (unsigned int) size64;
  74
  75         /* Request region */
  76         if (!request_mem_region(bcom_sram->base_phys, bcom_sram->size, owner)) {
  77                 printk(KERN_ERR "%s: bcom_sram_init: "
  78                         "Couldn't request region !\n", owner);
  79                 rv = -EBUSY;
  80                 goto error_free;
  81         }
  82
  83         /* Map SRAM */
  84                 /* sram is not really __iomem */
  85         bcom_sram->base_virt = (void*) ioremap(bcom_sram->base_phys, bcom_sram->size);
  86
  87         if (!bcom_sram->base_virt) {
  88                 printk(KERN_ERR "%s: bcom_sram_init: "
  89                         "Map error SRAM zone 0x%08lx (0x%0x)!\n",
  90                         owner, (long)bcom_sram->base_phys, bcom_sram->size );
  91                 rv = -ENOMEM;
  92                 goto error_release;
  93         }
  94
  95         /* Create an rheap (defaults to 32 bits word alignment) */
  96         bcom_sram->rh = rh_create(4);
  97
  98         /* Attach the free zones */
  99 #if 0
 100         /* Currently disabled ... for future use only */
 101         reg_addr_p = of_get_property(sram_node, "available", &psize);
 102 #else
 103         regaddr_p = NULL;
 104         psize = 0;
 105 #endif
 106
 107         if (!regaddr_p || !psize) {
 108                 /* Attach the whole zone */
 109                 rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
 110         } else {
 111                 /* Attach each zone independently */
 112                 while (psize >= 2 * sizeof(u32)) {
 113                         phys_addr_t zbase = of_translate_address(sram_node, regaddr_p);
 114                         rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
 115                         regaddr_p += 2;
 116                         psize -= 2 * sizeof(u32);
 117                 }
 118         }
 119
 120         /* Init our spinlock */
 121         spin_lock_init(&bcom_sram->lock);
 122
 123         return 0;
 124
 125 error_release:
 126         release_mem_region(bcom_sram->base_phys, bcom_sram->size);
 127 error_free:
 128         kfree(bcom_sram);
 129         bcom_sram = NULL;
 130
 131         return rv;
 132 }
 133 EXPORT_SYMBOL_GPL(bcom_sram_init);
 134
 135 void bcom_sram_cleanup(void)
 136 {
 137         /* Free resources */
 138         if (bcom_sram) {
 139                 rh_destroy(bcom_sram->rh);
 140                 iounmap((void __iomem *)bcom_sram->base_virt);
 141                 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
 142                 kfree(bcom_sram);
 143                 bcom_sram = NULL;
 144         }
 145 }
 146 EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
 147
 148 void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
 149 {
 150         unsigned long offset;
 151
 152         spin_lock(&bcom_sram->lock);
 153         offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
 154         spin_unlock(&bcom_sram->lock);
 155
 156         if (IS_ERR_VALUE(offset))
 157                 return NULL;
 158
 159         *phys = bcom_sram->base_phys + offset;
 160         return bcom_sram->base_virt + offset;
 161 }
 162 EXPORT_SYMBOL_GPL(bcom_sram_alloc);
 163
 164 void bcom_sram_free(void *ptr)
 165 {
 166         unsigned long offset;
 167
 168         if (!ptr)
 169                 return;
 170
 171         offset = ptr - bcom_sram->base_virt;
 172
 173         spin_lock(&bcom_sram->lock);
 174         rh_free(bcom_sram->rh, offset);
 175         spin_unlock(&bcom_sram->lock);
 176 }
 177 EXPORT_SYMBOL_GPL(bcom_sram_free);
 178