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/drivers/mtd/maps/ixp4xx.c

https://bitbucket.org/ndreys/linux-sunxi
C | 311 lines | 204 code | 52 blank | 55 comment | 23 complexity | 2cbed544c3a2401897ddbfc120b59207 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/*
  2 * drivers/mtd/maps/ixp4xx.c
  3 *
  4 * MTD Map file for IXP4XX based systems. Please do not make per-board
  5 * changes in here. If your board needs special setup, do it in your
  6 * platform level code in arch/arm/mach-ixp4xx/board-setup.c
  7 *
  8 * Original Author: Intel Corporation
  9 * Maintainer: Deepak Saxena <dsaxena@mvista.com>
 10 *
 11 * Copyright (C) 2002 Intel Corporation
 12 * Copyright (C) 2003-2004 MontaVista Software, Inc.
 13 *
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/types.h>
 18#include <linux/init.h>
 19#include <linux/kernel.h>
 20#include <linux/string.h>
 21#include <linux/slab.h>
 22#include <linux/ioport.h>
 23#include <linux/device.h>
 24#include <linux/platform_device.h>
 25
 26#include <linux/mtd/mtd.h>
 27#include <linux/mtd/map.h>
 28#include <linux/mtd/partitions.h>
 29
 30#include <asm/io.h>
 31#include <asm/mach/flash.h>
 32
 33#include <linux/reboot.h>
 34
 35/*
 36 * Read/write a 16 bit word from flash address 'addr'.
 37 *
 38 * When the cpu is in little-endian mode it swizzles the address lines
 39 * ('address coherency') so we need to undo the swizzling to ensure commands
 40 * and the like end up on the correct flash address.
 41 *
 42 * To further complicate matters, due to the way the expansion bus controller
 43 * handles 32 bit reads, the byte stream ABCD is stored on the flash as:
 44 *     D15    D0
 45 *     +---+---+
 46 *     | A | B | 0
 47 *     +---+---+
 48 *     | C | D | 2
 49 *     +---+---+
 50 * This means that on LE systems each 16 bit word must be swapped. Note that
 51 * this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
 52 * data and other flash commands which are always in D7-D0.
 53 */
 54#ifndef __ARMEB__
 55#ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
 56#  error CONFIG_MTD_CFI_BE_BYTE_SWAP required
 57#endif
 58
 59static inline u16 flash_read16(void __iomem *addr)
 60{
 61	return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
 62}
 63
 64static inline void flash_write16(u16 d, void __iomem *addr)
 65{
 66	__raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
 67}
 68
 69#define	BYTE0(h)	((h) & 0xFF)
 70#define	BYTE1(h)	(((h) >> 8) & 0xFF)
 71
 72#else
 73
 74static inline u16 flash_read16(const void __iomem *addr)
 75{
 76	return __raw_readw(addr);
 77}
 78
 79static inline void flash_write16(u16 d, void __iomem *addr)
 80{
 81	__raw_writew(d, addr);
 82}
 83
 84#define	BYTE0(h)	(((h) >> 8) & 0xFF)
 85#define	BYTE1(h)	((h) & 0xFF)
 86#endif
 87
 88static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
 89{
 90	map_word val;
 91	val.x[0] = flash_read16(map->virt + ofs);
 92	return val;
 93}
 94
 95/*
 96 * The IXP4xx expansion bus only allows 16-bit wide acceses
 97 * when attached to a 16-bit wide device (such as the 28F128J3A),
 98 * so we can't just memcpy_fromio().
 99 */
100static void ixp4xx_copy_from(struct map_info *map, void *to,
101			     unsigned long from, ssize_t len)
102{
103	u8 *dest = (u8 *) to;
104	void __iomem *src = map->virt + from;
105
106	if (len <= 0)
107		return;
108
109	if (from & 1) {
110		*dest++ = BYTE1(flash_read16(src-1));
111		src++;
112		--len;
113	}
114
115	while (len >= 2) {
116		u16 data = flash_read16(src);
117		*dest++ = BYTE0(data);
118		*dest++ = BYTE1(data);
119		src += 2;
120		len -= 2;
121	}
122
123	if (len > 0)
124		*dest++ = BYTE0(flash_read16(src));
125}
126
127/*
128 * Unaligned writes are ignored, causing the 8-bit
129 * probe to fail and proceed to the 16-bit probe (which succeeds).
130 */
131static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
132{
133	if (!(adr & 1))
134		flash_write16(d.x[0], map->virt + adr);
135}
136
137/*
138 * Fast write16 function without the probing check above
139 */
140static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
141{
142	flash_write16(d.x[0], map->virt + adr);
143}
144
145struct ixp4xx_flash_info {
146	struct mtd_info *mtd;
147	struct map_info map;
148	struct mtd_partition *partitions;
149	struct resource *res;
150};
151
152static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
153
154static int ixp4xx_flash_remove(struct platform_device *dev)
155{
156	struct flash_platform_data *plat = dev->dev.platform_data;
157	struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
158
159	platform_set_drvdata(dev, NULL);
160
161	if(!info)
162		return 0;
163
164	if (info->mtd) {
165		mtd_device_unregister(info->mtd);
166		map_destroy(info->mtd);
167	}
168	if (info->map.virt)
169		iounmap(info->map.virt);
170
171	kfree(info->partitions);
172
173	if (info->res) {
174		release_resource(info->res);
175		kfree(info->res);
176	}
177
178	if (plat->exit)
179		plat->exit();
180
181	return 0;
182}
183
184static int ixp4xx_flash_probe(struct platform_device *dev)
185{
186	struct flash_platform_data *plat = dev->dev.platform_data;
187	struct ixp4xx_flash_info *info;
188	const char *part_type = NULL;
189	int nr_parts = 0;
190	int err = -1;
191
192	if (!plat)
193		return -ENODEV;
194
195	if (plat->init) {
196		err = plat->init();
197		if (err)
198			return err;
199	}
200
201	info = kzalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
202	if(!info) {
203		err = -ENOMEM;
204		goto Error;
205	}
206
207	platform_set_drvdata(dev, info);
208
209	/*
210	 * Tell the MTD layer we're not 1:1 mapped so that it does
211	 * not attempt to do a direct access on us.
212	 */
213	info->map.phys = NO_XIP;
214	info->map.size = resource_size(dev->resource);
215
216	/*
217	 * We only support 16-bit accesses for now. If and when
218	 * any board use 8-bit access, we'll fixup the driver to
219	 * handle that.
220	 */
221	info->map.bankwidth = 2;
222	info->map.name = dev_name(&dev->dev);
223	info->map.read = ixp4xx_read16;
224	info->map.write = ixp4xx_probe_write16;
225	info->map.copy_from = ixp4xx_copy_from;
226
227	info->res = request_mem_region(dev->resource->start,
228			resource_size(dev->resource),
229			"IXP4XXFlash");
230	if (!info->res) {
231		printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
232		err = -ENOMEM;
233		goto Error;
234	}
235
236	info->map.virt = ioremap(dev->resource->start,
237				 resource_size(dev->resource));
238	if (!info->map.virt) {
239		printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
240		err = -EIO;
241		goto Error;
242	}
243
244	info->mtd = do_map_probe(plat->map_name, &info->map);
245	if (!info->mtd) {
246		printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
247		err = -ENXIO;
248		goto Error;
249	}
250	info->mtd->owner = THIS_MODULE;
251
252	/* Use the fast version */
253	info->map.write = ixp4xx_write16;
254
255	nr_parts = parse_mtd_partitions(info->mtd, probes, &info->partitions,
256					dev->resource->start);
257	if (nr_parts > 0) {
258		part_type = "dynamic";
259	} else {
260		info->partitions = plat->parts;
261		nr_parts = plat->nr_parts;
262		part_type = "static";
263	}
264	if (nr_parts == 0)
265		printk(KERN_NOTICE "IXP4xx flash: no partition info "
266			"available, registering whole flash\n");
267	else
268		printk(KERN_NOTICE "IXP4xx flash: using %s partition "
269			"definition\n", part_type);
270
271	err = mtd_device_register(info->mtd, info->partitions, nr_parts);
272	if (err)
273		printk(KERN_ERR "Could not parse partitions\n");
274
275	if (err)
276		goto Error;
277
278	return 0;
279
280Error:
281	ixp4xx_flash_remove(dev);
282	return err;
283}
284
285static struct platform_driver ixp4xx_flash_driver = {
286	.probe		= ixp4xx_flash_probe,
287	.remove		= ixp4xx_flash_remove,
288	.driver		= {
289		.name	= "IXP4XX-Flash",
290		.owner	= THIS_MODULE,
291	},
292};
293
294static int __init ixp4xx_flash_init(void)
295{
296	return platform_driver_register(&ixp4xx_flash_driver);
297}
298
299static void __exit ixp4xx_flash_exit(void)
300{
301	platform_driver_unregister(&ixp4xx_flash_driver);
302}
303
304
305module_init(ixp4xx_flash_init);
306module_exit(ixp4xx_flash_exit);
307
308MODULE_LICENSE("GPL");
309MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
310MODULE_AUTHOR("Deepak Saxena");
311MODULE_ALIAS("platform:IXP4XX-Flash");