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> | |
06b4501e AG |
14 | #include <linux/module.h> |
15 | #include <linux/mutex.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/spi/spi.h> | |
18 | #include <linux/sysfs.h> | |
19 | #include <linux/eeprom_93xx46.h> | |
20 | ||
21 | #define OP_START 0x4 | |
22 | #define OP_WRITE (OP_START | 0x1) | |
23 | #define OP_READ (OP_START | 0x2) | |
24 | #define ADDR_EWDS 0x00 | |
25 | #define ADDR_ERAL 0x20 | |
26 | #define ADDR_EWEN 0x30 | |
27 | ||
28 | struct eeprom_93xx46_dev { | |
29 | struct spi_device *spi; | |
30 | struct eeprom_93xx46_platform_data *pdata; | |
31 | struct bin_attribute bin; | |
32 | struct mutex lock; | |
33 | int addrlen; | |
34 | }; | |
35 | ||
36 | static ssize_t | |
37 | eeprom_93xx46_bin_read(struct file *filp, struct kobject *kobj, | |
38 | struct bin_attribute *bin_attr, | |
39 | char *buf, loff_t off, size_t count) | |
40 | { | |
41 | struct eeprom_93xx46_dev *edev; | |
42 | struct device *dev; | |
43 | struct spi_message m; | |
44 | struct spi_transfer t[2]; | |
45 | int bits, ret; | |
46 | u16 cmd_addr; | |
47 | ||
48 | dev = container_of(kobj, struct device, kobj); | |
49 | edev = dev_get_drvdata(dev); | |
50 | ||
06b4501e AG |
51 | cmd_addr = OP_READ << edev->addrlen; |
52 | ||
53 | if (edev->addrlen == 7) { | |
54 | cmd_addr |= off & 0x7f; | |
55 | bits = 10; | |
56 | } else { | |
57 | cmd_addr |= off & 0x3f; | |
58 | bits = 9; | |
59 | } | |
60 | ||
61 | dev_dbg(&edev->spi->dev, "read cmd 0x%x, %d Hz\n", | |
62 | cmd_addr, edev->spi->max_speed_hz); | |
63 | ||
64 | spi_message_init(&m); | |
65 | memset(t, 0, sizeof(t)); | |
66 | ||
67 | t[0].tx_buf = (char *)&cmd_addr; | |
68 | t[0].len = 2; | |
69 | t[0].bits_per_word = bits; | |
70 | spi_message_add_tail(&t[0], &m); | |
71 | ||
72 | t[1].rx_buf = buf; | |
73 | t[1].len = count; | |
74 | t[1].bits_per_word = 8; | |
75 | spi_message_add_tail(&t[1], &m); | |
76 | ||
77 | mutex_lock(&edev->lock); | |
78 | ||
79 | if (edev->pdata->prepare) | |
80 | edev->pdata->prepare(edev); | |
81 | ||
82 | ret = spi_sync(edev->spi, &m); | |
83 | /* have to wait at least Tcsl ns */ | |
84 | ndelay(250); | |
85 | if (ret) { | |
86 | dev_err(&edev->spi->dev, "read %zu bytes at %d: err. %d\n", | |
87 | count, (int)off, ret); | |
88 | } | |
89 | ||
90 | if (edev->pdata->finish) | |
91 | edev->pdata->finish(edev); | |
92 | ||
93 | mutex_unlock(&edev->lock); | |
94 | return ret ? : count; | |
95 | } | |
96 | ||
97 | static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) | |
98 | { | |
99 | struct spi_message m; | |
100 | struct spi_transfer t; | |
101 | int bits, ret; | |
102 | u16 cmd_addr; | |
103 | ||
104 | cmd_addr = OP_START << edev->addrlen; | |
105 | if (edev->addrlen == 7) { | |
106 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << 1; | |
107 | bits = 10; | |
108 | } else { | |
109 | cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS); | |
110 | bits = 9; | |
111 | } | |
112 | ||
113 | dev_dbg(&edev->spi->dev, "ew cmd 0x%04x\n", cmd_addr); | |
114 | ||
115 | spi_message_init(&m); | |
116 | memset(&t, 0, sizeof(t)); | |
117 | ||
118 | t.tx_buf = &cmd_addr; | |
119 | t.len = 2; | |
120 | t.bits_per_word = bits; | |
121 | spi_message_add_tail(&t, &m); | |
122 | ||
123 | mutex_lock(&edev->lock); | |
124 | ||
125 | if (edev->pdata->prepare) | |
126 | edev->pdata->prepare(edev); | |
127 | ||
128 | ret = spi_sync(edev->spi, &m); | |
129 | /* have to wait at least Tcsl ns */ | |
130 | ndelay(250); | |
131 | if (ret) | |
132 | dev_err(&edev->spi->dev, "erase/write %sable error %d\n", | |
133 | is_on ? "en" : "dis", ret); | |
134 | ||
135 | if (edev->pdata->finish) | |
136 | edev->pdata->finish(edev); | |
137 | ||
138 | mutex_unlock(&edev->lock); | |
139 | return ret; | |
140 | } | |
141 | ||
142 | static ssize_t | |
143 | eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, | |
144 | const char *buf, unsigned off) | |
145 | { | |
146 | struct spi_message m; | |
147 | struct spi_transfer t[2]; | |
148 | int bits, data_len, ret; | |
149 | u16 cmd_addr; | |
150 | ||
151 | cmd_addr = OP_WRITE << edev->addrlen; | |
152 | ||
153 | if (edev->addrlen == 7) { | |
154 | cmd_addr |= off & 0x7f; | |
155 | bits = 10; | |
156 | data_len = 1; | |
157 | } else { | |
158 | cmd_addr |= off & 0x3f; | |
159 | bits = 9; | |
160 | data_len = 2; | |
161 | } | |
162 | ||
163 | dev_dbg(&edev->spi->dev, "write cmd 0x%x\n", cmd_addr); | |
164 | ||
165 | spi_message_init(&m); | |
166 | memset(t, 0, sizeof(t)); | |
167 | ||
168 | t[0].tx_buf = (char *)&cmd_addr; | |
169 | t[0].len = 2; | |
170 | t[0].bits_per_word = bits; | |
171 | spi_message_add_tail(&t[0], &m); | |
172 | ||
173 | t[1].tx_buf = buf; | |
174 | t[1].len = data_len; | |
175 | t[1].bits_per_word = 8; | |
176 | spi_message_add_tail(&t[1], &m); | |
177 | ||
178 | ret = spi_sync(edev->spi, &m); | |
179 | /* have to wait program cycle time Twc ms */ | |
180 | mdelay(6); | |
181 | return ret; | |
182 | } | |
183 | ||
184 | static ssize_t | |
185 | eeprom_93xx46_bin_write(struct file *filp, struct kobject *kobj, | |
186 | struct bin_attribute *bin_attr, | |
187 | char *buf, loff_t off, size_t count) | |
188 | { | |
189 | struct eeprom_93xx46_dev *edev; | |
190 | struct device *dev; | |
191 | int i, ret, step = 1; | |
192 | ||
193 | dev = container_of(kobj, struct device, kobj); | |
194 | edev = dev_get_drvdata(dev); | |
195 | ||
06b4501e AG |
196 | /* only write even number of bytes on 16-bit devices */ |
197 | if (edev->addrlen == 6) { | |
198 | step = 2; | |
199 | count &= ~1; | |
200 | } | |
201 | ||
202 | /* erase/write enable */ | |
203 | ret = eeprom_93xx46_ew(edev, 1); | |
204 | if (ret) | |
205 | return ret; | |
206 | ||
207 | mutex_lock(&edev->lock); | |
208 | ||
209 | if (edev->pdata->prepare) | |
210 | edev->pdata->prepare(edev); | |
211 | ||
212 | for (i = 0; i < count; i += step) { | |
213 | ret = eeprom_93xx46_write_word(edev, &buf[i], off + i); | |
214 | if (ret) { | |
215 | dev_err(&edev->spi->dev, "write failed at %d: %d\n", | |
216 | (int)off + i, ret); | |
217 | break; | |
218 | } | |
219 | } | |
220 | ||
221 | if (edev->pdata->finish) | |
222 | edev->pdata->finish(edev); | |
223 | ||
224 | mutex_unlock(&edev->lock); | |
225 | ||
226 | /* erase/write disable */ | |
227 | eeprom_93xx46_ew(edev, 0); | |
228 | return ret ? : count; | |
229 | } | |
230 | ||
231 | static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) | |
232 | { | |
233 | struct eeprom_93xx46_platform_data *pd = edev->pdata; | |
234 | struct spi_message m; | |
235 | struct spi_transfer t; | |
236 | int bits, ret; | |
237 | u16 cmd_addr; | |
238 | ||
239 | cmd_addr = OP_START << edev->addrlen; | |
240 | if (edev->addrlen == 7) { | |
241 | cmd_addr |= ADDR_ERAL << 1; | |
242 | bits = 10; | |
243 | } else { | |
244 | cmd_addr |= ADDR_ERAL; | |
245 | bits = 9; | |
246 | } | |
247 | ||
248 | spi_message_init(&m); | |
249 | memset(&t, 0, sizeof(t)); | |
250 | ||
251 | t.tx_buf = &cmd_addr; | |
252 | t.len = 2; | |
253 | t.bits_per_word = bits; | |
254 | spi_message_add_tail(&t, &m); | |
255 | ||
256 | mutex_lock(&edev->lock); | |
257 | ||
258 | if (edev->pdata->prepare) | |
259 | edev->pdata->prepare(edev); | |
260 | ||
261 | ret = spi_sync(edev->spi, &m); | |
262 | if (ret) | |
263 | dev_err(&edev->spi->dev, "erase error %d\n", ret); | |
264 | /* have to wait erase cycle time Tec ms */ | |
265 | mdelay(6); | |
266 | ||
267 | if (pd->finish) | |
268 | pd->finish(edev); | |
269 | ||
270 | mutex_unlock(&edev->lock); | |
271 | return ret; | |
272 | } | |
273 | ||
274 | static ssize_t eeprom_93xx46_store_erase(struct device *dev, | |
275 | struct device_attribute *attr, | |
276 | const char *buf, size_t count) | |
277 | { | |
278 | struct eeprom_93xx46_dev *edev = dev_get_drvdata(dev); | |
279 | int erase = 0, ret; | |
280 | ||
281 | sscanf(buf, "%d", &erase); | |
282 | if (erase) { | |
283 | ret = eeprom_93xx46_ew(edev, 1); | |
284 | if (ret) | |
285 | return ret; | |
286 | ret = eeprom_93xx46_eral(edev); | |
287 | if (ret) | |
288 | return ret; | |
289 | ret = eeprom_93xx46_ew(edev, 0); | |
290 | if (ret) | |
291 | return ret; | |
292 | } | |
293 | return count; | |
294 | } | |
295 | static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase); | |
296 | ||
80c8ae28 | 297 | static int eeprom_93xx46_probe(struct spi_device *spi) |
06b4501e AG |
298 | { |
299 | struct eeprom_93xx46_platform_data *pd; | |
300 | struct eeprom_93xx46_dev *edev; | |
301 | int err; | |
302 | ||
303 | pd = spi->dev.platform_data; | |
304 | if (!pd) { | |
305 | dev_err(&spi->dev, "missing platform data\n"); | |
306 | return -ENODEV; | |
307 | } | |
308 | ||
309 | edev = kzalloc(sizeof(*edev), GFP_KERNEL); | |
310 | if (!edev) | |
311 | return -ENOMEM; | |
312 | ||
313 | if (pd->flags & EE_ADDR8) | |
314 | edev->addrlen = 7; | |
315 | else if (pd->flags & EE_ADDR16) | |
316 | edev->addrlen = 6; | |
317 | else { | |
318 | dev_err(&spi->dev, "unspecified address type\n"); | |
319 | err = -EINVAL; | |
320 | goto fail; | |
321 | } | |
322 | ||
323 | mutex_init(&edev->lock); | |
324 | ||
325 | edev->spi = spi_dev_get(spi); | |
326 | edev->pdata = pd; | |
327 | ||
328 | sysfs_bin_attr_init(&edev->bin); | |
329 | edev->bin.attr.name = "eeprom"; | |
330 | edev->bin.attr.mode = S_IRUSR; | |
331 | edev->bin.read = eeprom_93xx46_bin_read; | |
332 | edev->bin.size = 128; | |
333 | if (!(pd->flags & EE_READONLY)) { | |
334 | edev->bin.write = eeprom_93xx46_bin_write; | |
335 | edev->bin.attr.mode |= S_IWUSR; | |
336 | } | |
337 | ||
338 | err = sysfs_create_bin_file(&spi->dev.kobj, &edev->bin); | |
339 | if (err) | |
340 | goto fail; | |
341 | ||
342 | dev_info(&spi->dev, "%d-bit eeprom %s\n", | |
343 | (pd->flags & EE_ADDR8) ? 8 : 16, | |
344 | (pd->flags & EE_READONLY) ? "(readonly)" : ""); | |
345 | ||
346 | if (!(pd->flags & EE_READONLY)) { | |
347 | if (device_create_file(&spi->dev, &dev_attr_erase)) | |
348 | dev_err(&spi->dev, "can't create erase interface\n"); | |
349 | } | |
350 | ||
5ba75b55 | 351 | spi_set_drvdata(spi, edev); |
06b4501e AG |
352 | return 0; |
353 | fail: | |
354 | kfree(edev); | |
355 | return err; | |
356 | } | |
357 | ||
486a5c28 | 358 | static int eeprom_93xx46_remove(struct spi_device *spi) |
06b4501e | 359 | { |
5ba75b55 | 360 | struct eeprom_93xx46_dev *edev = spi_get_drvdata(spi); |
06b4501e AG |
361 | |
362 | if (!(edev->pdata->flags & EE_READONLY)) | |
363 | device_remove_file(&spi->dev, &dev_attr_erase); | |
364 | ||
365 | sysfs_remove_bin_file(&spi->dev.kobj, &edev->bin); | |
06b4501e AG |
366 | kfree(edev); |
367 | return 0; | |
368 | } | |
369 | ||
370 | static struct spi_driver eeprom_93xx46_driver = { | |
371 | .driver = { | |
372 | .name = "93xx46", | |
06b4501e AG |
373 | }, |
374 | .probe = eeprom_93xx46_probe, | |
2d6bed9c | 375 | .remove = eeprom_93xx46_remove, |
06b4501e AG |
376 | }; |
377 | ||
a3dc3c9e | 378 | module_spi_driver(eeprom_93xx46_driver); |
06b4501e AG |
379 | |
380 | MODULE_LICENSE("GPL"); | |
381 | MODULE_DESCRIPTION("Driver for 93xx46 EEPROMs"); | |
382 | MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>"); | |
383 | MODULE_ALIAS("spi:93xx46"); |