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
 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}