Commit | Line | Data |
---|---|---|
1cbb4a1c CB |
1 | /* |
2 | * OPAL PNOR flash MTD abstraction | |
3 | * | |
4 | * Copyright IBM 2015 | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/of_address.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/mtd/mtd.h> | |
26 | #include <linux/mtd/partitions.h> | |
27 | ||
28 | #include <linux/debugfs.h> | |
29 | #include <linux/seq_file.h> | |
30 | ||
31 | #include <asm/opal.h> | |
32 | ||
33 | ||
34 | /* | |
35 | * This driver creates the a Linux MTD abstraction for platform PNOR flash | |
36 | * backed by OPAL calls | |
37 | */ | |
38 | ||
39 | struct powernv_flash { | |
40 | struct mtd_info mtd; | |
41 | u32 id; | |
42 | }; | |
43 | ||
44 | enum flash_op { | |
45 | FLASH_OP_READ, | |
46 | FLASH_OP_WRITE, | |
47 | FLASH_OP_ERASE, | |
48 | }; | |
49 | ||
50 | static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, | |
51 | loff_t offset, size_t len, size_t *retlen, u_char *buf) | |
52 | { | |
53 | struct powernv_flash *info = (struct powernv_flash *)mtd->priv; | |
54 | struct device *dev = &mtd->dev; | |
55 | int token; | |
56 | struct opal_msg msg; | |
57 | int rc; | |
58 | ||
59 | dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n", | |
60 | __func__, op, offset, len); | |
61 | ||
62 | token = opal_async_get_token_interruptible(); | |
63 | if (token < 0) { | |
64 | if (token != -ERESTARTSYS) | |
65 | dev_err(dev, "Failed to get an async token\n"); | |
66 | ||
67 | return token; | |
68 | } | |
69 | ||
70 | switch (op) { | |
71 | case FLASH_OP_READ: | |
72 | rc = opal_flash_read(info->id, offset, __pa(buf), len, token); | |
73 | break; | |
74 | case FLASH_OP_WRITE: | |
75 | rc = opal_flash_write(info->id, offset, __pa(buf), len, token); | |
76 | break; | |
77 | case FLASH_OP_ERASE: | |
78 | rc = opal_flash_erase(info->id, offset, len, token); | |
79 | break; | |
80 | default: | |
81 | BUG_ON(1); | |
82 | } | |
83 | ||
84 | if (rc != OPAL_ASYNC_COMPLETION) { | |
85 | dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", | |
86 | op, rc); | |
87 | opal_async_release_token(token); | |
88 | return -EIO; | |
89 | } | |
90 | ||
91 | rc = opal_async_wait_response(token, &msg); | |
92 | opal_async_release_token(token); | |
93 | if (rc) { | |
94 | dev_err(dev, "opal async wait failed (rc %d)\n", rc); | |
95 | return -EIO; | |
96 | } | |
97 | ||
d0226d31 | 98 | rc = opal_get_async_rc(msg); |
1cbb4a1c CB |
99 | if (rc == OPAL_SUCCESS) { |
100 | rc = 0; | |
101 | if (retlen) | |
102 | *retlen = len; | |
103 | } else { | |
104 | rc = -EIO; | |
105 | } | |
106 | ||
107 | return rc; | |
108 | } | |
109 | ||
110 | /** | |
111 | * @mtd: the device | |
112 | * @from: the offset to read from | |
113 | * @len: the number of bytes to read | |
114 | * @retlen: the number of bytes actually read | |
115 | * @buf: the filled in buffer | |
116 | * | |
117 | * Returns 0 if read successful, or -ERRNO if an error occurred | |
118 | */ | |
119 | static int powernv_flash_read(struct mtd_info *mtd, loff_t from, size_t len, | |
120 | size_t *retlen, u_char *buf) | |
121 | { | |
122 | return powernv_flash_async_op(mtd, FLASH_OP_READ, from, | |
123 | len, retlen, buf); | |
124 | } | |
125 | ||
126 | /** | |
127 | * @mtd: the device | |
128 | * @to: the offset to write to | |
129 | * @len: the number of bytes to write | |
130 | * @retlen: the number of bytes actually written | |
131 | * @buf: the buffer to get bytes from | |
132 | * | |
133 | * Returns 0 if write successful, -ERRNO if error occurred | |
134 | */ | |
135 | static int powernv_flash_write(struct mtd_info *mtd, loff_t to, size_t len, | |
136 | size_t *retlen, const u_char *buf) | |
137 | { | |
138 | return powernv_flash_async_op(mtd, FLASH_OP_WRITE, to, | |
139 | len, retlen, (u_char *)buf); | |
140 | } | |
141 | ||
142 | /** | |
143 | * @mtd: the device | |
144 | * @erase: the erase info | |
145 | * Returns 0 if erase successful or -ERRNO if an error occurred | |
146 | */ | |
147 | static int powernv_flash_erase(struct mtd_info *mtd, struct erase_info *erase) | |
148 | { | |
149 | int rc; | |
150 | ||
151 | erase->state = MTD_ERASING; | |
152 | ||
153 | /* todo: register our own notifier to do a true async implementation */ | |
154 | rc = powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr, | |
155 | erase->len, NULL, NULL); | |
156 | ||
157 | if (rc) { | |
158 | erase->fail_addr = erase->addr; | |
159 | erase->state = MTD_ERASE_FAILED; | |
160 | } else { | |
161 | erase->state = MTD_ERASE_DONE; | |
162 | } | |
163 | mtd_erase_callback(erase); | |
164 | return rc; | |
165 | } | |
166 | ||
167 | /** | |
168 | * powernv_flash_set_driver_info - Fill the mtd_info structure and docg3 | |
169 | * structure @pdev: The platform device | |
170 | * @mtd: The structure to fill | |
171 | */ | |
172 | static int powernv_flash_set_driver_info(struct device *dev, | |
173 | struct mtd_info *mtd) | |
174 | { | |
175 | u64 size; | |
176 | u32 erase_size; | |
177 | int rc; | |
178 | ||
179 | rc = of_property_read_u32(dev->of_node, "ibm,flash-block-size", | |
180 | &erase_size); | |
181 | if (rc) { | |
182 | dev_err(dev, "couldn't get resource block size information\n"); | |
183 | return rc; | |
184 | } | |
185 | ||
186 | rc = of_property_read_u64(dev->of_node, "reg", &size); | |
187 | if (rc) { | |
188 | dev_err(dev, "couldn't get resource size information\n"); | |
189 | return rc; | |
190 | } | |
191 | ||
192 | /* | |
193 | * Going to have to check what details I need to set and how to | |
194 | * get them | |
195 | */ | |
196 | mtd->name = of_get_property(dev->of_node, "name", NULL); | |
197 | mtd->type = MTD_NORFLASH; | |
198 | mtd->flags = MTD_WRITEABLE; | |
199 | mtd->size = size; | |
200 | mtd->erasesize = erase_size; | |
201 | mtd->writebufsize = mtd->writesize = 1; | |
202 | mtd->owner = THIS_MODULE; | |
203 | mtd->_erase = powernv_flash_erase; | |
204 | mtd->_read = powernv_flash_read; | |
205 | mtd->_write = powernv_flash_write; | |
206 | mtd->dev.parent = dev; | |
207 | return 0; | |
208 | } | |
209 | ||
210 | /** | |
211 | * powernv_flash_probe | |
212 | * @pdev: platform device | |
213 | * | |
214 | * Returns 0 on success, -ENOMEM, -ENXIO on error | |
215 | */ | |
216 | static int powernv_flash_probe(struct platform_device *pdev) | |
217 | { | |
218 | struct device *dev = &pdev->dev; | |
219 | struct powernv_flash *data; | |
220 | int ret; | |
221 | ||
222 | data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); | |
223 | if (!data) { | |
224 | ret = -ENOMEM; | |
225 | goto out; | |
226 | } | |
227 | data->mtd.priv = data; | |
228 | ||
229 | ret = of_property_read_u32(dev->of_node, "ibm,opal-id", &(data->id)); | |
230 | if (ret) { | |
231 | dev_err(dev, "no device property 'ibm,opal-id'\n"); | |
232 | goto out; | |
233 | } | |
234 | ||
235 | ret = powernv_flash_set_driver_info(dev, &data->mtd); | |
236 | if (ret) | |
237 | goto out; | |
238 | ||
239 | dev_set_drvdata(dev, data); | |
240 | ||
241 | /* | |
242 | * The current flash that skiboot exposes is one contiguous flash chip | |
243 | * with an ffs partition at the start, it should prove easier for users | |
244 | * to deal with partitions or not as they see fit | |
245 | */ | |
246 | ret = mtd_device_register(&data->mtd, NULL, 0); | |
247 | ||
248 | out: | |
249 | return ret; | |
250 | } | |
251 | ||
252 | /** | |
253 | * op_release - Release the driver | |
254 | * @pdev: the platform device | |
255 | * | |
256 | * Returns 0 | |
257 | */ | |
258 | static int powernv_flash_release(struct platform_device *pdev) | |
259 | { | |
260 | struct powernv_flash *data = dev_get_drvdata(&(pdev->dev)); | |
261 | ||
262 | /* All resources should be freed automatically */ | |
263 | return mtd_device_unregister(&(data->mtd)); | |
264 | } | |
265 | ||
266 | static const struct of_device_id powernv_flash_match[] = { | |
267 | { .compatible = "ibm,opal-flash" }, | |
268 | {} | |
269 | }; | |
270 | ||
271 | static struct platform_driver powernv_flash_driver = { | |
272 | .driver = { | |
273 | .name = "powernv_flash", | |
274 | .of_match_table = powernv_flash_match, | |
275 | }, | |
276 | .remove = powernv_flash_release, | |
277 | .probe = powernv_flash_probe, | |
278 | }; | |
279 | ||
280 | module_platform_driver(powernv_flash_driver); | |
281 | ||
282 | MODULE_DEVICE_TABLE(of, powernv_flash_match); | |
283 | MODULE_LICENSE("GPL"); | |
284 | MODULE_AUTHOR("Cyril Bur <cyril.bur@au1.ibm.com>"); | |
285 | MODULE_DESCRIPTION("MTD abstraction for OPAL flash"); |