Commit | Line | Data |
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06b4501e AG |
1 | /* |
2 | * Driver for 93xx46 EEPROMs | |
3 | * | |
4 | * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> | |
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 version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/delay.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/spi/spi.h> | |
19 | #include <linux/sysfs.h> | |
20 | #include <linux/eeprom_93xx46.h> | |
21 | ||
22 | #define OP_START 0x4 | |
23 | #define OP_WRITE (OP_START | 0x1) | |
24 | #define OP_READ (OP_START | 0x2) | |
25 | #define ADDR_EWDS 0x00 | |
26 | #define ADDR_ERAL 0x20 | |
27 | #define ADDR_EWEN 0x30 | |
28 | ||
29 | struct eeprom_93xx46_dev { | |
30 | struct spi_device *spi; | |
31 | struct eeprom_93xx46_platform_data *pdata; | |
32 | struct bin_attribute bin; | |
33 | struct mutex lock; | |
34 | int addrlen; | |
35 | }; | |
36 | ||
37 | static ssize_t | |
38 | eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj, | |
39 | struct bin_attribute *bin_attr, | |
40 | char *buf, loff_t off, size_t count) | |
41 | { | |
42 | struct eeprom_93xx46_dev *edev; | |
43 | struct device *dev; | |
44 | struct spi_message m; | |
45 | struct spi_transfer t[2]; | |
46 | int bits, ret; | |
47 | u16 cmd_addr; | |
48 | ||
49 | dev = container_of(kobj, struct device, kobj); | |
50 | edev = dev_get_drvdata(dev); | |
51 | ||
52 | if (unlikely(off >= edev->bin.size)) | |
53 | return 0; | |
54 | if ((off + count) > edev->bin.size) | |
55 | count = edev->bin.size - off; | |
56 | if (unlikely(!count)) | |
57 | return count; | |
58 | ||
59 | cmd_addr = OP_READ << edev->addrlen; | |
60 | ||
61 | if (edev->addrlen == 7) { | |
62 | cmd_addr |= off & 0x7f; | |
63 | bits = 10; | |
64 | } else { | |
65 | cmd_addr |= off & 0x3f; | |
66 | bits = 9; | |
67 | } | |
68 | ||
69 | dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n", | |
70 | cmd_addr, edev->spi->max_speed_hz); | |
71 | ||
72 | spi_message_init(&m); | |
73 | memset(t, 0, sizeof(t)); | |
74 | ||
75 | t[0].tx_buf = (char *)&cmd_addr; | |
76 | t[0].len = 2; | |
77 | t[0].bits_per_word = bits; | |
78 | spi_message_add_tail(&t[0], &m); | |
79 | ||
80 | t[1].rx_buf = buf; | |
81 | t[1].len = count; | |
82 | t[1].bits_per_word = 8; | |
83 | spi_message_add_tail(&t[1], &m); | |
84 | ||
85 | mutex_lock(&edev->lock); | |
86 | ||
87 | if (edev->pdata->prepare) | |
88 | edev->pdata->prepare(edev); | |
89 | ||
90 | ret = spi_sync(edev->spi, &m); | |
91 | /* have to wait at least Tcsl ns */ | |
92 | ndelay(250); | |
93 | if (ret) { | |
94 | dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n", | |
95 | count, (int)off, ret); | |
96 | } | |
97 | ||
98 | if (edev->pdata->finish) | |
99 | edev->pdata->finish(edev); | |
100 | ||
101 | mutex_unlock(&edev->lock); | |
102 | return ret ? : count; | |
103 | } | |
104 | ||
105 | static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) | |
106 | { | |
107 | struct spi_message m; | |
108 | struct spi_transfer t; | |
109 | int bits, ret; | |
110 | u16 cmd_addr; | |
111 | ||
112 | cmd_addr = OP_START << edev->addrlen; | |
113 | if (edev->addrlen == 7) { | |
114 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << 1; | |
115 | bits = 10; | |
116 | } else { | |
117 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS); | |
118 | bits = 9; | |
119 | } | |
120 | ||
121 | dev_dbg(&edev->spi->dev, "ew cmd 0x%04x\n", cmd_addr); | |
122 | ||
123 | spi_message_init(&m); | |
124 | memset(&t, 0, sizeof(t)); | |
125 | ||
126 | t.tx_buf = &cmd_addr; | |
127 | t.len = 2; | |
128 | t.bits_per_word = bits; | |
129 | spi_message_add_tail(&t, &m); | |
130 | ||
131 | mutex_lock(&edev->lock); | |
132 | ||
133 | if (edev->pdata->prepare) | |
134 | edev->pdata->prepare(edev); | |
135 | ||
136 | ret = spi_sync(edev->spi, &m); | |
137 | /* have to wait at least Tcsl ns */ | |
138 | ndelay(250); | |
139 | if (ret) | |
140 | dev_err(&edev->spi->dev, "erase/write %sable error %d\n", | |
141 | is_on ? "en" : "dis", ret); | |
142 | ||
143 | if (edev->pdata->finish) | |
144 | edev->pdata->finish(edev); | |
145 | ||
146 | mutex_unlock(&edev->lock); | |
147 | return ret; | |
148 | } | |
149 | ||
150 | static ssize_t | |
151 | eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, | |
152 | const char *buf, unsigned off) | |
153 | { | |
154 | struct spi_message m; | |
155 | struct spi_transfer t[2]; | |
156 | int bits, data_len, ret; | |
157 | u16 cmd_addr; | |
158 | ||
159 | cmd_addr = OP_WRITE << edev->addrlen; | |
160 | ||
161 | if (edev->addrlen == 7) { | |
162 | cmd_addr |= off & 0x7f; | |
163 | bits = 10; | |
164 | data_len = 1; | |
165 | } else { | |
166 | cmd_addr |= off & 0x3f; | |
167 | bits = 9; | |
168 | data_len = 2; | |
169 | } | |
170 | ||
171 | dev_dbg(&edev->spi->dev, "write cmd 0x%x\n", cmd_addr); | |
172 | ||
173 | spi_message_init(&m); | |
174 | memset(t, 0, sizeof(t)); | |
175 | ||
176 | t[0].tx_buf = (char *)&cmd_addr; | |
177 | t[0].len = 2; | |
178 | t[0].bits_per_word = bits; | |
179 | spi_message_add_tail(&t[0], &m); | |
180 | ||
181 | t[1].tx_buf = buf; | |
182 | t[1].len = data_len; | |
183 | t[1].bits_per_word = 8; | |
184 | spi_message_add_tail(&t[1], &m); | |
185 | ||
186 | ret = spi_sync(edev->spi, &m); | |
187 | /* have to wait program cycle time Twc ms */ | |
188 | mdelay(6); | |
189 | return ret; | |
190 | } | |
191 | ||
192 | static ssize_t | |
193 | eeprom_93xx46_bin_write(struct file *filp, struct kobject *kobj, | |
194 | struct bin_attribute *bin_attr, | |
195 | char *buf, loff_t off, size_t count) | |
196 | { | |
197 | struct eeprom_93xx46_dev *edev; | |
198 | struct device *dev; | |
199 | int i, ret, step = 1; | |
200 | ||
201 | dev = container_of(kobj, struct device, kobj); | |
202 | edev = dev_get_drvdata(dev); | |
203 | ||
204 | if (unlikely(off >= edev->bin.size)) | |
205 | return 0; | |
206 | if ((off + count) > edev->bin.size) | |
207 | count = edev->bin.size - off; | |
208 | if (unlikely(!count)) | |
209 | return count; | |
210 | ||
211 | /* only write even number of bytes on 16-bit devices */ | |
212 | if (edev->addrlen == 6) { | |
213 | step = 2; | |
214 | count &= ~1; | |
215 | } | |
216 | ||
217 | /* erase/write enable */ | |
218 | ret = eeprom_93xx46_ew(edev, 1); | |
219 | if (ret) | |
220 | return ret; | |
221 | ||
222 | mutex_lock(&edev->lock); | |
223 | ||
224 | if (edev->pdata->prepare) | |
225 | edev->pdata->prepare(edev); | |
226 | ||
227 | for (i = 0; i < count; i += step) { | |
228 | ret = eeprom_93xx46_write_word(edev, &buf[i], off + i); | |
229 | if (ret) { | |
230 | dev_err(&edev->spi->dev, "write failed at %d: %d\n", | |
231 | (int)off + i, ret); | |
232 | break; | |
233 | } | |
234 | } | |
235 | ||
236 | if (edev->pdata->finish) | |
237 | edev->pdata->finish(edev); | |
238 | ||
239 | mutex_unlock(&edev->lock); | |
240 | ||
241 | /* erase/write disable */ | |
242 | eeprom_93xx46_ew(edev, 0); | |
243 | return ret ? : count; | |
244 | } | |
245 | ||
246 | static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) | |
247 | { | |
248 | struct eeprom_93xx46_platform_data *pd = edev->pdata; | |
249 | struct spi_message m; | |
250 | struct spi_transfer t; | |
251 | int bits, ret; | |
252 | u16 cmd_addr; | |
253 | ||
254 | cmd_addr = OP_START << edev->addrlen; | |
255 | if (edev->addrlen == 7) { | |
256 | cmd_addr |= ADDR_ERAL << 1; | |
257 | bits = 10; | |
258 | } else { | |
259 | cmd_addr |= ADDR_ERAL; | |
260 | bits = 9; | |
261 | } | |
262 | ||
263 | spi_message_init(&m); | |
264 | memset(&t, 0, sizeof(t)); | |
265 | ||
266 | t.tx_buf = &cmd_addr; | |
267 | t.len = 2; | |
268 | t.bits_per_word = bits; | |
269 | spi_message_add_tail(&t, &m); | |
270 | ||
271 | mutex_lock(&edev->lock); | |
272 | ||
273 | if (edev->pdata->prepare) | |
274 | edev->pdata->prepare(edev); | |
275 | ||
276 | ret = spi_sync(edev->spi, &m); | |
277 | if (ret) | |
278 | dev_err(&edev->spi->dev, "erase error %d\n", ret); | |
279 | /* have to wait erase cycle time Tec ms */ | |
280 | mdelay(6); | |
281 | ||
282 | if (pd->finish) | |
283 | pd->finish(edev); | |
284 | ||
285 | mutex_unlock(&edev->lock); | |
286 | return ret; | |
287 | } | |
288 | ||
289 | static ssize_t eeprom_93xx46_store_erase(struct device *dev, | |
290 | struct device_attribute *attr, | |
291 | const char *buf, size_t count) | |
292 | { | |
293 | struct eeprom_93xx46_dev *edev = dev_get_drvdata(dev); | |
294 | int erase = 0, ret; | |
295 | ||
296 | sscanf(buf, "%d", &erase); | |
297 | if (erase) { | |
298 | ret = eeprom_93xx46_ew(edev, 1); | |
299 | if (ret) | |
300 | return ret; | |
301 | ret = eeprom_93xx46_eral(edev); | |
302 | if (ret) | |
303 | return ret; | |
304 | ret = eeprom_93xx46_ew(edev, 0); | |
305 | if (ret) | |
306 | return ret; | |
307 | } | |
308 | return count; | |
309 | } | |
310 | static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase); | |
311 | ||
312 | static int __devinit eeprom_93xx46_probe(struct spi_device *spi) | |
313 | { | |
314 | struct eeprom_93xx46_platform_data *pd; | |
315 | struct eeprom_93xx46_dev *edev; | |
316 | int err; | |
317 | ||
318 | pd = spi->dev.platform_data; | |
319 | if (!pd) { | |
320 | dev_err(&spi->dev, "missing platform data\n"); | |
321 | return -ENODEV; | |
322 | } | |
323 | ||
324 | edev = kzalloc(sizeof(*edev), GFP_KERNEL); | |
325 | if (!edev) | |
326 | return -ENOMEM; | |
327 | ||
328 | if (pd->flags & EE_ADDR8) | |
329 | edev->addrlen = 7; | |
330 | else if (pd->flags & EE_ADDR16) | |
331 | edev->addrlen = 6; | |
332 | else { | |
333 | dev_err(&spi->dev, "unspecified address type\n"); | |
334 | err = -EINVAL; | |
335 | goto fail; | |
336 | } | |
337 | ||
338 | mutex_init(&edev->lock); | |
339 | ||
340 | edev->spi = spi_dev_get(spi); | |
341 | edev->pdata = pd; | |
342 | ||
343 | sysfs_bin_attr_init(&edev->bin); | |
344 | edev->bin.attr.name = "eeprom"; | |
345 | edev->bin.attr.mode = S_IRUSR; | |
346 | edev->bin.read = eeprom_93xx46_bin_read; | |
347 | edev->bin.size = 128; | |
348 | if (!(pd->flags & EE_READONLY)) { | |
349 | edev->bin.write = eeprom_93xx46_bin_write; | |
350 | edev->bin.attr.mode |= S_IWUSR; | |
351 | } | |
352 | ||
353 | err = sysfs_create_bin_file(&spi->dev.kobj, &edev->bin); | |
354 | if (err) | |
355 | goto fail; | |
356 | ||
357 | dev_info(&spi->dev, "%d-bit eeprom %s\n", | |
358 | (pd->flags & EE_ADDR8) ? 8 : 16, | |
359 | (pd->flags & EE_READONLY) ? "(readonly)" : ""); | |
360 | ||
361 | if (!(pd->flags & EE_READONLY)) { | |
362 | if (device_create_file(&spi->dev, &dev_attr_erase)) | |
363 | dev_err(&spi->dev, "can't create erase interface\n"); | |
364 | } | |
365 | ||
366 | dev_set_drvdata(&spi->dev, edev); | |
367 | return 0; | |
368 | fail: | |
369 | kfree(edev); | |
370 | return err; | |
371 | } | |
372 | ||
373 | static int __devexit eeprom_93xx46_remove(struct spi_device *spi) | |
374 | { | |
375 | struct eeprom_93xx46_dev *edev = dev_get_drvdata(&spi->dev); | |
376 | ||
377 | if (!(edev->pdata->flags & EE_READONLY)) | |
378 | device_remove_file(&spi->dev, &dev_attr_erase); | |
379 | ||
380 | sysfs_remove_bin_file(&spi->dev.kobj, &edev->bin); | |
381 | dev_set_drvdata(&spi->dev, NULL); | |
382 | kfree(edev); | |
383 | return 0; | |
384 | } | |
385 | ||
386 | static struct spi_driver eeprom_93xx46_driver = { | |
387 | .driver = { | |
388 | .name = "93xx46", | |
389 | .owner = THIS_MODULE, | |
390 | }, | |
391 | .probe = eeprom_93xx46_probe, | |
392 | .remove = __devexit_p(eeprom_93xx46_remove), | |
393 | }; | |
394 | ||
a3dc3c9e | 395 | module_spi_driver(eeprom_93xx46_driver); |
06b4501e AG |
396 | |
397 | MODULE_LICENSE("GPL"); | |
398 | MODULE_DESCRIPTION("Driver for 93xx46 EEPROMs"); | |
399 | MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>"); | |
400 | MODULE_ALIAS("spi:93xx46"); |