linux/drivers/media/pci/cobalt/cobalt-flash.c
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   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
  18static 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
  25static 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
  38static 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
  46static 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
  64static 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
  85int 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
 110void cobalt_flash_remove(struct cobalt *cobalt)
 111{
 112        if (cobalt->mtd) {
 113                mtd_device_unregister(cobalt->mtd);
 114                map_destroy(cobalt->mtd);
 115        }
 116}
 117
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