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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Cobalt NOR flash functions
   4  *
   5  *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
   6  *  All rights reserved.
   7  */
   8
   9 #include <linux/mtd/mtd.h>
  10 #include <linux/mtd/map.h>
  11 #include <linux/mtd/cfi.h>
  12 #include <linux/time.h>
  13
  14 #include "cobalt-flash.h"
  15
  16 #define ADRS(offset) (COBALT_BUS_FLASH_BASE + offset)
  17
  18 static struct map_info cobalt_flash_map = {
  19         .name =         "cobalt-flash",
  20         .bankwidth =    2,         /* 16 bits */
  21         .size =         0x4000000, /* 64MB */
  22         .phys =         0,         /* offset  */
  23 };
  24
  25 static map_word flash_read16(struct map_info *map, unsigned long offset)
  26 {
  27         map_word r;
  28
  29         r.x[0] = cobalt_bus_read32(map->virt, ADRS(offset));
  30         if (offset & 0x2)
  31                 r.x[0] >>= 16;
  32         else
  33                 r.x[0] &= 0x0000ffff;
  34
  35         return r;
  36 }
  37
  38 static void flash_write16(struct map_info *map, const map_word datum,
  39                           unsigned long offset)
  40 {
  41         u16 data = (u16)datum.x[0];
  42
  43         cobalt_bus_write16(map->virt, ADRS(offset), data);
  44 }
  45
  46 static void flash_copy_from(struct map_info *map, void *to,
  47                             unsigned long from, ssize_t len)
  48 {
  49         u32 src = from;
  50         u8 *dest = to;
  51         u32 data;
  52
  53         while (len) {
  54                 data = cobalt_bus_read32(map->virt, ADRS(src));
  55                 do {
  56                         *dest = data >> (8 * (src & 3));
  57                         src++;
  58                         dest++;
  59                         len--;
  60                 } while (len && (src % 4));
  61         }
  62 }
  63
  64 static void flash_copy_to(struct map_info *map, unsigned long to,
  65                           const void *from, ssize_t len)
  66 {
  67         const u8 *src = from;
  68         u32 dest = to;
  69
  70         pr_info("%s: offset 0x%x: length %zu\n", __func__, dest, len);
  71         while (len) {
  72                 u16 data;
  73
  74                 do {
  75                         data = *src << (8 * (dest & 1));
  76                         src++;
  77                         dest++;
  78                         len--;
  79                 } while (len && (dest % 2));
  80
  81                 cobalt_bus_write16(map->virt, ADRS(dest - 2), data);
  82         }
  83 }
  84
  85 int cobalt_flash_probe(struct cobalt *cobalt)
  86 {
  87         struct map_info *map = &cobalt_flash_map;
  88         struct mtd_info *mtd;
  89
  90         BUG_ON(!map_bankwidth_supported(map->bankwidth));
  91         map->virt = cobalt->bar1;
  92         map->read = flash_read16;
  93         map->write = flash_write16;
  94         map->copy_from = flash_copy_from;
  95         map->copy_to = flash_copy_to;
  96
  97         mtd = do_map_probe("cfi_probe", map);
  98         cobalt->mtd = mtd;
  99         if (!mtd) {
 100                 cobalt_err("Probe CFI flash failed!\n");
 101                 return -1;
 102         }
 103
 104         mtd->owner = THIS_MODULE;
 105         mtd->dev.parent = &cobalt->pci_dev->dev;
 106         mtd_device_register(mtd, NULL, 0);
 107         return 0;
 108 }
 109
 110 void cobalt_flash_remove(struct cobalt *cobalt)
 111 {
 112         if (cobalt->mtd) {
 113                 mtd_device_unregister(cobalt->mtd);
 114                 map_destroy(cobalt->mtd);
 115         }
 116 }