drivers/media/pci/cobalt/cobalt-flash.c

   1 /*
   2  *  Cobalt NOR flash functions
   3  *
   4  *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
   5  *  All rights reserved.
   6  *
   7  *  This program is free software; you may redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; version 2 of the License.
  10  *
  11  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  12  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  13  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  14  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  15  *  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  16  *  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  17  *  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  18  *  SOFTWARE.
  19  */
  20
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/map.h>
  23 #include <linux/mtd/cfi.h>
  24 #include <linux/time.h>
  25
  26 #include "cobalt-flash.h"
  27
  28 #define ADRS(offset) (COBALT_BUS_FLASH_BASE + offset)
  29
  30 static struct map_info cobalt_flash_map = {
  31         .name =         "cobalt-flash",
  32         .bankwidth =    2,         /* 16 bits */
  33         .size =         0x4000000, /* 64MB */
  34         .phys =         0,         /* offset  */
  35 };
  36
  37 static map_word flash_read16(struct map_info *map, unsigned long offset)
  38 {
  39         map_word r;
  40
  41         r.x[0] = cobalt_bus_read32(map->virt, ADRS(offset));
  42         if (offset & 0x2)
  43                 r.x[0] >>= 16;
  44         else
  45                 r.x[0] &= 0x0000ffff;
  46
  47         return r;
  48 }
  49
  50 static void flash_write16(struct map_info *map, const map_word datum,
  51                           unsigned long offset)
  52 {
  53         u16 data = (u16)datum.x[0];
  54
  55         cobalt_bus_write16(map->virt, ADRS(offset), data);
  56 }
  57
  58 static void flash_copy_from(struct map_info *map, void *to,
  59                             unsigned long from, ssize_t len)
  60 {
  61         u32 src = from;
  62         u8 *dest = to;
  63         u32 data;
  64
  65         while (len) {
  66                 data = cobalt_bus_read32(map->virt, ADRS(src));
  67                 do {
  68                         *dest = data >> (8 * (src & 3));
  69                         src++;
  70                         dest++;
  71                         len--;
  72                 } while (len && (src % 4));
  73         }
  74 }
  75
  76 static void flash_copy_to(struct map_info *map, unsigned long to,
  77                           const void *from, ssize_t len)
  78 {
  79         const u8 *src = from;
  80         u32 dest = to;
  81
  82         pr_info("%s: offset 0x%x: length %zu\n", __func__, dest, len);
  83         while (len) {
  84                 u16 data = 0xffff;
  85
  86                 do {
  87                         data = *src << (8 * (dest & 1));
  88                         src++;
  89                         dest++;
  90                         len--;
  91                 } while (len && (dest % 2));
  92
  93                 cobalt_bus_write16(map->virt, ADRS(dest - 2), data);
  94         }
  95 }
  96
  97 int cobalt_flash_probe(struct cobalt *cobalt)
  98 {
  99         struct map_info *map = &cobalt_flash_map;
 100         struct mtd_info *mtd;
 101
 102         BUG_ON(!map_bankwidth_supported(map->bankwidth));
 103         map->virt = cobalt->bar1;
 104         map->read = flash_read16;
 105         map->write = flash_write16;
 106         map->copy_from = flash_copy_from;
 107         map->copy_to = flash_copy_to;
 108
 109         mtd = do_map_probe("cfi_probe", map);
 110         cobalt->mtd = mtd;
 111         if (!mtd) {
 112                 cobalt_err("Probe CFI flash failed!\n");
 113                 return -1;
 114         }
 115
 116         mtd->owner = THIS_MODULE;
 117         mtd->dev.parent = &cobalt->pci_dev->dev;
 118         mtd_device_register(mtd, NULL, 0);
 119         return 0;
 120 }
 121
 122 void cobalt_flash_remove(struct cobalt *cobalt)
 123 {
 124         if (cobalt->mtd) {
 125                 mtd_device_unregister(cobalt->mtd);
 126                 map_destroy(cobalt->mtd);
 127         }
 128 }