1/*
2 * Normal mappings of chips in physical memory for OF devices
3 *
4 * Copyright (C) 2006 MontaVista Software Inc.
5 * Author: Vitaly Wool <vwool@ru.mvista.com>
6 *
7 * This program is free software; you can redistribute  it and/or modify it
8 * under  the terms of  the GNU General  Public License as published by the
9 * Free Software Foundation;  either version 2 of the  License, or (at your
10 * option) any later version.
11 */
12
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/device.h>
19#include <linux/mtd/mtd.h>
20#include <linux/mtd/map.h>
21#include <linux/mtd/partitions.h>
22#include <linux/mtd/physmap.h>
23#include <asm/io.h>
24#include <asm/prom.h>
25#include <asm/of_device.h>
26#include <asm/of_platform.h>
27
28struct physmap_flash_info {
29	struct mtd_info		*mtd;
30	struct map_info		map;
31	struct resource		*res;
32#ifdef CONFIG_MTD_PARTITIONS
33	int			nr_parts;
34	struct mtd_partition	*parts;
35#endif
36};
37
38static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", "map_rom", NULL };
39#ifdef CONFIG_MTD_PARTITIONS
40static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
41#endif
42
43#ifdef CONFIG_MTD_PARTITIONS
44static int parse_flash_partitions(struct device_node *node,
45		struct mtd_partition **parts)
46{
47	int i, plen, retval = -ENOMEM;
48	const  u32  *part;
49	const  char *name;
50
51	part = of_get_property(node, "partitions", &plen);
52	if (part == NULL)
53		goto err;
54
55	retval = plen / (2 * sizeof(u32));
56	*parts = kzalloc(retval * sizeof(struct mtd_partition), GFP_KERNEL);
57	if (*parts == NULL) {
58		printk(KERN_ERR "Can't allocate the flash partition data!\n");
59		goto err;
60	}
61
62	name = of_get_property(node, "partition-names", &plen);
63
64	for (i = 0; i < retval; i++) {
65		(*parts)[i].offset = *part++;
66		(*parts)[i].size   = *part & ~1;
67		if (*part++ & 1) /* bit 0 set signifies read only partition */
68			(*parts)[i].mask_flags = MTD_WRITEABLE;
69
70		if (name != NULL && plen > 0) {
71			int len = strlen(name) + 1;
72
73			(*parts)[i].name = (char *)name;
74			plen -= len;
75			name += len;
76		} else
77			(*parts)[i].name = "unnamed";
78	}
79err:
80	return retval;
81}
82#endif
83
84static int of_physmap_remove(struct of_device *dev)
85{
86	struct physmap_flash_info *info;
87
88	info = dev_get_drvdata(&dev->dev);
89	if (info == NULL)
90		return 0;
91	dev_set_drvdata(&dev->dev, NULL);
92
93	if (info->mtd != NULL) {
94#ifdef CONFIG_MTD_PARTITIONS
95		if (info->nr_parts) {
96			del_mtd_partitions(info->mtd);
97			kfree(info->parts);
98		} else {
99			del_mtd_device(info->mtd);
100		}
101#else
102		del_mtd_device(info->mtd);
103#endif
104		map_destroy(info->mtd);
105	}
106
107	if (info->map.virt != NULL)
108		iounmap(info->map.virt);
109
110	if (info->res != NULL) {
111		release_resource(info->res);
112		kfree(info->res);
113	}
114
115	return 0;
116}
117
118static int __devinit of_physmap_probe(struct of_device *dev, const struct of_device_id *match)
119{
120	struct device_node *dp = dev->node;
121	struct resource res;
122	struct physmap_flash_info *info;
123	const char **probe_type;
124	const char *of_probe;
125	const u32 *width;
126	int err;
127
128
129	if (of_address_to_resource(dp, 0, &res)) {
130		dev_err(&dev->dev, "Can't get the flash mapping!\n");
131		err = -EINVAL;
132		goto err_out;
133	}
134
135       	dev_dbg(&dev->dev, "physmap flash device: %.8llx at %.8llx\n",
136	    (unsigned long long)res.end - res.start + 1,
137	    (unsigned long long)res.start);
138
139	info = kzalloc(sizeof(struct physmap_flash_info), GFP_KERNEL);
140	if (info == NULL) {
141		err = -ENOMEM;
142		goto err_out;
143	}
144	memset(info, 0, sizeof(*info));
145
146	dev_set_drvdata(&dev->dev, info);
147
148	info->res = request_mem_region(res.start, res.end - res.start + 1,
149			dev->dev.bus_id);
150	if (info->res == NULL) {
151		dev_err(&dev->dev, "Could not reserve memory region\n");
152		err = -ENOMEM;
153		goto err_out;
154	}
155
156	width = of_get_property(dp, "bank-width", NULL);
157	if (width == NULL) {
158		dev_err(&dev->dev, "Can't get the flash bank width!\n");
159		err = -EINVAL;
160		goto err_out;
161	}
162
163	info->map.name = dev->dev.bus_id;
164	info->map.phys = res.start;
165	info->map.size = res.end - res.start + 1;
166	info->map.bankwidth = *width;
167
168	info->map.virt = ioremap(info->map.phys, info->map.size);
169	if (info->map.virt == NULL) {
170		dev_err(&dev->dev, "Failed to ioremap flash region\n");
171		err = EIO;
172		goto err_out;
173	}
174
175	simple_map_init(&info->map);
176
177	of_probe = of_get_property(dp, "probe-type", NULL);
178	if (of_probe == NULL) {
179		probe_type = rom_probe_types;
180		for (; info->mtd == NULL && *probe_type != NULL; probe_type++)
181			info->mtd = do_map_probe(*probe_type, &info->map);
182	} else if (!strcmp(of_probe, "CFI"))
183		info->mtd = do_map_probe("cfi_probe", &info->map);
184	else if (!strcmp(of_probe, "JEDEC"))
185		info->mtd = do_map_probe("jedec_probe", &info->map);
186	else {
187 		if (strcmp(of_probe, "ROM"))
188			dev_dbg(&dev->dev, "map_probe: don't know probe type "
189			"'%s', mapping as rom\n", of_probe);
190		info->mtd = do_map_probe("mtd_rom", &info->map);
191	}
192	if (info->mtd == NULL) {
193		dev_err(&dev->dev, "map_probe failed\n");
194		err = -ENXIO;
195		goto err_out;
196	}
197	info->mtd->owner = THIS_MODULE;
198
199#ifdef CONFIG_MTD_PARTITIONS
200	err = parse_mtd_partitions(info->mtd, part_probe_types, &info->parts, 0);
201	if (err > 0) {
202		add_mtd_partitions(info->mtd, info->parts, err);
203	} else if ((err = parse_flash_partitions(dp, &info->parts)) > 0) {
204		dev_info(&dev->dev, "Using OF partition information\n");
205		add_mtd_partitions(info->mtd, info->parts, err);
206		info->nr_parts = err;
207	} else
208#endif
209
210	add_mtd_device(info->mtd);
211	return 0;
212
213err_out:
214	of_physmap_remove(dev);
215	return err;
216
217	return 0;
218
219
220}
221
222static struct of_device_id of_physmap_match[] = {
223	{
224		.type		= "rom",
225		.compatible	= "direct-mapped"
226	},
227	{ },
228};
229
230MODULE_DEVICE_TABLE(of, of_physmap_match);
231
232
233static struct of_platform_driver of_physmap_flash_driver = {
234	.name		= "physmap-flash",
235	.match_table	= of_physmap_match,
236	.probe		= of_physmap_probe,
237	.remove		= of_physmap_remove,
238};
239
240static int __init of_physmap_init(void)
241{
242	return of_register_platform_driver(&of_physmap_flash_driver);
243}
244
245static void __exit of_physmap_exit(void)
246{
247	of_unregister_platform_driver(&of_physmap_flash_driver);
248}
249
250module_init(of_physmap_init);
251module_exit(of_physmap_exit);
252
253MODULE_LICENSE("GPL");
254MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
255MODULE_DESCRIPTION("Configurable MTD map driver for OF");
256