1/*
  2 * Interface for NOR flash driver whose high address lines are latched
  3 *
  4 * Copyright © 2000 Nicolas Pitre <nico@cam.org>
  5 * Copyright © 2005-2008 Analog Devices Inc.
  6 * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>
  7 *
  8 * This file is licensed under the terms of the GNU General Public License
  9 * version 2. This program is licensed "as is" without any warranty of any
 10 * kind, whether express or implied.
 11 */
 12
 13#include <linux/init.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/mtd/mtd.h>
 17#include <linux/mtd/map.h>
 18#include <linux/mtd/partitions.h>
 19#include <linux/platform_device.h>
 20#include <linux/mtd/latch-addr-flash.h>
 21#include <linux/slab.h>
 22
 23#define DRIVER_NAME "latch-addr-flash"
 24
 25struct latch_addr_flash_info {
 26	struct mtd_info		*mtd;
 27	struct map_info		map;
 28	struct resource		*res;
 29
 30	void			(*set_window)(unsigned long offset, void *data);
 31	void			*data;
 32
 33	/* cache; could be found out of res */
 34	unsigned long		win_mask;
 35
 36	int			nr_parts;
 37	struct mtd_partition	*parts;
 38
 39	spinlock_t		lock;
 40};
 41
 42static map_word lf_read(struct map_info *map, unsigned long ofs)
 43{
 44	struct latch_addr_flash_info *info;
 45	map_word datum;
 46
 47	info = (struct latch_addr_flash_info *)map->map_priv_1;
 48
 49	spin_lock(&info->lock);
 50
 51	info->set_window(ofs, info->data);
 52	datum = inline_map_read(map, info->win_mask & ofs);
 53
 54	spin_unlock(&info->lock);
 55
 56	return datum;
 57}
 58
 59static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
 60{
 61	struct latch_addr_flash_info *info;
 62
 63	info = (struct latch_addr_flash_info *)map->map_priv_1;
 64
 65	spin_lock(&info->lock);
 66
 67	info->set_window(ofs, info->data);
 68	inline_map_write(map, datum, info->win_mask & ofs);
 69
 70	spin_unlock(&info->lock);
 71}
 72
 73static void lf_copy_from(struct map_info *map, void *to,
 74		unsigned long from, ssize_t len)
 75{
 76	struct latch_addr_flash_info *info =
 77		(struct latch_addr_flash_info *) map->map_priv_1;
 78	unsigned n;
 79
 80	while (len > 0) {
 81		n = info->win_mask + 1 - (from & info->win_mask);
 82		if (n > len)
 83			n = len;
 84
 85		spin_lock(&info->lock);
 86
 87		info->set_window(from, info->data);
 88		memcpy_fromio(to, map->virt + (from & info->win_mask), n);
 89
 90		spin_unlock(&info->lock);
 91
 92		to += n;
 93		from += n;
 94		len -= n;
 95	}
 96}
 97
 98static char *rom_probe_types[] = { "cfi_probe", NULL };
 99
100static char *part_probe_types[] = { "cmdlinepart", NULL };
101
102static int latch_addr_flash_remove(struct platform_device *dev)
103{
104	struct latch_addr_flash_info *info;
105	struct latch_addr_flash_data *latch_addr_data;
106
107	info = platform_get_drvdata(dev);
108	if (info == NULL)
109		return 0;
110	platform_set_drvdata(dev, NULL);
111
112	latch_addr_data = dev->dev.platform_data;
113
114	if (info->mtd != NULL) {
115		if (info->nr_parts)
116			kfree(info->parts);
117		mtd_device_unregister(info->mtd);
118		map_destroy(info->mtd);
119	}
120
121	if (info->map.virt != NULL)
122		iounmap(info->map.virt);
123
124	if (info->res != NULL)
125		release_mem_region(info->res->start, resource_size(info->res));
126
127	kfree(info);
128
129	if (latch_addr_data->done)
130		latch_addr_data->done(latch_addr_data->data);
131
132	return 0;
133}
134
135static int __devinit latch_addr_flash_probe(struct platform_device *dev)
136{
137	struct latch_addr_flash_data *latch_addr_data;
138	struct latch_addr_flash_info *info;
139	resource_size_t win_base = dev->resource->start;
140	resource_size_t win_size = resource_size(dev->resource);
141	char **probe_type;
142	int chipsel;
143	int err;
144
145	latch_addr_data = dev->dev.platform_data;
146	if (latch_addr_data == NULL)
147		return -ENODEV;
148
149	pr_notice("latch-addr platform flash device: %#llx byte "
150		  "window at %#.8llx\n",
151		  (unsigned long long)win_size, (unsigned long long)win_base);
152
153	chipsel = dev->id;
154
155	if (latch_addr_data->init) {
156		err = latch_addr_data->init(latch_addr_data->data, chipsel);
157		if (err != 0)
158			return err;
159	}
160
161	info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
162	if (info == NULL) {
163		err = -ENOMEM;
164		goto done;
165	}
166
167	platform_set_drvdata(dev, info);
168
169	info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
170	if (info->res == NULL) {
171		dev_err(&dev->dev, "Could not reserve memory region\n");
172		err = -EBUSY;
173		goto free_info;
174	}
175
176	info->map.name		= DRIVER_NAME;
177	info->map.size		= latch_addr_data->size;
178	info->map.bankwidth	= latch_addr_data->width;
179
180	info->map.phys		= NO_XIP;
181	info->map.virt		= ioremap(win_base, win_size);
182	if (!info->map.virt) {
183		err = -ENOMEM;
184		goto free_res;
185	}
186
187	info->map.map_priv_1	= (unsigned long)info;
188
189	info->map.read		= lf_read;
190	info->map.copy_from	= lf_copy_from;
191	info->map.write		= lf_write;
192	info->set_window	= latch_addr_data->set_window;
193	info->data		= latch_addr_data->data;
194	info->win_mask		= win_size - 1;
195
196	spin_lock_init(&info->lock);
197
198	for (probe_type = rom_probe_types; !info->mtd && *probe_type;
199		probe_type++)
200		info->mtd = do_map_probe(*probe_type, &info->map);
201
202	if (info->mtd == NULL) {
203		dev_err(&dev->dev, "map_probe failed\n");
204		err = -ENODEV;
205		goto iounmap;
206	}
207	info->mtd->owner = THIS_MODULE;
208
209	err = parse_mtd_partitions(info->mtd, (const char **)part_probe_types,
210				   &info->parts, 0);
211	if (err > 0) {
212		mtd_device_register(info->mtd, info->parts, err);
213		return 0;
214	}
215	if (latch_addr_data->nr_parts) {
216		pr_notice("Using latch-addr-flash partition information\n");
217		mtd_device_register(info->mtd,
218				    latch_addr_data->parts,
219				    latch_addr_data->nr_parts);
220		return 0;
221	}
222
223	mtd_device_register(info->mtd, NULL, 0);
224	return 0;
225
226iounmap:
227	iounmap(info->map.virt);
228free_res:
229	release_mem_region(info->res->start, resource_size(info->res));
230free_info:
231	kfree(info);
232done:
233	if (latch_addr_data->done)
234		latch_addr_data->done(latch_addr_data->data);
235	return err;
236}
237
238static struct platform_driver latch_addr_flash_driver = {
239	.probe		= latch_addr_flash_probe,
240	.remove		= __devexit_p(latch_addr_flash_remove),
241	.driver		= {
242		.name	= DRIVER_NAME,
243	},
244};
245
246static int __init latch_addr_flash_init(void)
247{
248	return platform_driver_register(&latch_addr_flash_driver);
249}
250module_init(latch_addr_flash_init);
251
252static void __exit latch_addr_flash_exit(void)
253{
254	platform_driver_unregister(&latch_addr_flash_driver);
255}
256module_exit(latch_addr_flash_exit);
257
258MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
259MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
260		"address lines being set board specifically");
261MODULE_LICENSE("GPL v2");