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8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/types.h>
12#include <linux/delay.h>
13
14#include <linux/w1.h>
15
16#define W1_FAMILY_DS2438 0x26
17
18#define W1_DS2438_RETRIES 3
19
20
21#define W1_DS2438_READ_SCRATCH 0xBE
22#define W1_DS2438_WRITE_SCRATCH 0x4E
23#define W1_DS2438_COPY_SCRATCH 0x48
24#define W1_DS2438_RECALL_MEMORY 0xB8
25
26#define W1_DS2438_CONVERT_TEMP 0x44
27#define W1_DS2438_CONVERT_VOLTAGE 0xB4
28
29#define DS2438_PAGE_SIZE 8
30#define DS2438_ADC_INPUT_VAD 0
31#define DS2438_ADC_INPUT_VDD 1
32#define DS2438_MAX_CONVERSION_TIME 10
33
34
35#define DS2438_STATUS_REG 0x00
36#define DS2438_STATUS_IAD (1 << 0)
37#define DS2438_STATUS_CA (1 << 1)
38#define DS2438_STATUS_EE (1 << 2)
39#define DS2438_STATUS_AD (1 << 3)
40#define DS2438_STATUS_TB (1 << 4)
41#define DS2438_STATUS_NVB (1 << 5)
42#define DS2438_STATUS_ADB (1 << 6)
43
44#define DS2438_TEMP_LSB 0x01
45#define DS2438_TEMP_MSB 0x02
46#define DS2438_VOLTAGE_LSB 0x03
47#define DS2438_VOLTAGE_MSB 0x04
48#define DS2438_CURRENT_LSB 0x05
49#define DS2438_CURRENT_MSB 0x06
50#define DS2438_THRESHOLD 0x07
51
52
53#define DS2438_ETM_0 0x00
54#define DS2438_ETM_1 0x01
55#define DS2438_ETM_2 0x02
56#define DS2438_ETM_3 0x03
57#define DS2438_ICA 0x04
58#define DS2438_OFFSET_LSB 0x05
59#define DS2438_OFFSET_MSB 0x06
60
61static int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
62{
63 unsigned int retries = W1_DS2438_RETRIES;
64 u8 w1_buf[2];
65 u8 crc;
66 size_t count;
67
68 while (retries--) {
69 crc = 0;
70
71 if (w1_reset_select_slave(sl))
72 continue;
73 w1_buf[0] = W1_DS2438_RECALL_MEMORY;
74 w1_buf[1] = (u8)pageno;
75 w1_write_block(sl->master, w1_buf, 2);
76
77 if (w1_reset_select_slave(sl))
78 continue;
79 w1_buf[0] = W1_DS2438_READ_SCRATCH;
80 w1_buf[1] = (u8)pageno;
81 w1_write_block(sl->master, w1_buf, 2);
82
83 count = w1_read_block(sl->master, buf, DS2438_PAGE_SIZE + 1);
84 if (count == DS2438_PAGE_SIZE + 1) {
85 crc = w1_calc_crc8(buf, DS2438_PAGE_SIZE);
86
87
88 if ((u8)buf[DS2438_PAGE_SIZE] == crc)
89 return 0;
90 }
91 }
92 return -1;
93}
94
95static int w1_ds2438_get_temperature(struct w1_slave *sl, int16_t *temperature)
96{
97 unsigned int retries = W1_DS2438_RETRIES;
98 u8 w1_buf[DS2438_PAGE_SIZE + 1 ];
99 unsigned int tm = DS2438_MAX_CONVERSION_TIME;
100 unsigned long sleep_rem;
101 int ret;
102
103 mutex_lock(&sl->master->bus_mutex);
104
105 while (retries--) {
106 if (w1_reset_select_slave(sl))
107 continue;
108 w1_write_8(sl->master, W1_DS2438_CONVERT_TEMP);
109
110 mutex_unlock(&sl->master->bus_mutex);
111 sleep_rem = msleep_interruptible(tm);
112 if (sleep_rem != 0) {
113 ret = -1;
114 goto post_unlock;
115 }
116
117 if (mutex_lock_interruptible(&sl->master->bus_mutex) != 0) {
118 ret = -1;
119 goto post_unlock;
120 }
121
122 break;
123 }
124
125 if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) {
126 *temperature = (((int16_t) w1_buf[DS2438_TEMP_MSB]) << 8) | ((uint16_t) w1_buf[DS2438_TEMP_LSB]);
127 ret = 0;
128 } else
129 ret = -1;
130
131 mutex_unlock(&sl->master->bus_mutex);
132
133post_unlock:
134 return ret;
135}
136
137static int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value)
138{
139 unsigned int retries = W1_DS2438_RETRIES;
140 u8 w1_buf[3];
141 u8 status;
142 int perform_write = 0;
143
144 while (retries--) {
145 if (w1_reset_select_slave(sl))
146 continue;
147 w1_buf[0] = W1_DS2438_RECALL_MEMORY;
148 w1_buf[1] = 0x00;
149 w1_write_block(sl->master, w1_buf, 2);
150
151 if (w1_reset_select_slave(sl))
152 continue;
153 w1_buf[0] = W1_DS2438_READ_SCRATCH;
154 w1_buf[1] = 0x00;
155 w1_write_block(sl->master, w1_buf, 2);
156
157
158 status = w1_read_8(sl->master);
159
160
161 if (value)
162 value = mask;
163
164 if ((status & mask) == value)
165 return 0;
166
167
168 status ^= mask;
169 perform_write = 1;
170
171 break;
172 }
173
174 if (perform_write) {
175 retries = W1_DS2438_RETRIES;
176 while (retries--) {
177 if (w1_reset_select_slave(sl))
178 continue;
179 w1_buf[0] = W1_DS2438_WRITE_SCRATCH;
180 w1_buf[1] = 0x00;
181 w1_buf[2] = status;
182 w1_write_block(sl->master, w1_buf, 3);
183
184 if (w1_reset_select_slave(sl))
185 continue;
186 w1_buf[0] = W1_DS2438_COPY_SCRATCH;
187 w1_buf[1] = 0x00;
188 w1_write_block(sl->master, w1_buf, 2);
189
190 return 0;
191 }
192 }
193 return -1;
194}
195
196static int w1_ds2438_change_offset_register(struct w1_slave *sl, u8 *value)
197{
198 unsigned int retries = W1_DS2438_RETRIES;
199 u8 w1_buf[9];
200 u8 w1_page1_buf[DS2438_PAGE_SIZE + 1 ];
201
202 if (w1_ds2438_get_page(sl, 1, w1_page1_buf) == 0) {
203 memcpy(&w1_buf[2], w1_page1_buf, DS2438_PAGE_SIZE - 1);
204 w1_buf[7] = value[0];
205 w1_buf[8] = value[1];
206 while (retries--) {
207 if (w1_reset_select_slave(sl))
208 continue;
209 w1_buf[0] = W1_DS2438_WRITE_SCRATCH;
210 w1_buf[1] = 0x01;
211 w1_write_block(sl->master, w1_buf, 9);
212
213 if (w1_reset_select_slave(sl))
214 continue;
215 w1_buf[0] = W1_DS2438_COPY_SCRATCH;
216 w1_buf[1] = 0x01;
217 w1_write_block(sl->master, w1_buf, 2);
218 return 0;
219 }
220 }
221 return -1;
222}
223
224static int w1_ds2438_get_voltage(struct w1_slave *sl,
225 int adc_input, uint16_t *voltage)
226{
227 unsigned int retries = W1_DS2438_RETRIES;
228 u8 w1_buf[DS2438_PAGE_SIZE + 1 ];
229 unsigned int tm = DS2438_MAX_CONVERSION_TIME;
230 unsigned long sleep_rem;
231 int ret;
232
233 mutex_lock(&sl->master->bus_mutex);
234
235 if (w1_ds2438_change_config_bit(sl, DS2438_STATUS_AD, adc_input)) {
236 ret = -1;
237 goto pre_unlock;
238 }
239
240 while (retries--) {
241 if (w1_reset_select_slave(sl))
242 continue;
243 w1_write_8(sl->master, W1_DS2438_CONVERT_VOLTAGE);
244
245 mutex_unlock(&sl->master->bus_mutex);
246 sleep_rem = msleep_interruptible(tm);
247 if (sleep_rem != 0) {
248 ret = -1;
249 goto post_unlock;
250 }
251
252 if (mutex_lock_interruptible(&sl->master->bus_mutex) != 0) {
253 ret = -1;
254 goto post_unlock;
255 }
256
257 break;
258 }
259
260 if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) {
261 *voltage = (((uint16_t) w1_buf[DS2438_VOLTAGE_MSB]) << 8) | ((uint16_t) w1_buf[DS2438_VOLTAGE_LSB]);
262 ret = 0;
263 } else
264 ret = -1;
265
266pre_unlock:
267 mutex_unlock(&sl->master->bus_mutex);
268
269post_unlock:
270 return ret;
271}
272
273static int w1_ds2438_get_current(struct w1_slave *sl, int16_t *voltage)
274{
275 u8 w1_buf[DS2438_PAGE_SIZE + 1 ];
276 int ret;
277
278 mutex_lock(&sl->master->bus_mutex);
279
280 if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) {
281
282 *voltage = (((int16_t) w1_buf[DS2438_CURRENT_MSB]) << 8) | ((int16_t) w1_buf[DS2438_CURRENT_LSB]);
283 ret = 0;
284 } else
285 ret = -1;
286
287 mutex_unlock(&sl->master->bus_mutex);
288
289 return ret;
290}
291
292static ssize_t iad_write(struct file *filp, struct kobject *kobj,
293 struct bin_attribute *bin_attr, char *buf,
294 loff_t off, size_t count)
295{
296 struct w1_slave *sl = kobj_to_w1_slave(kobj);
297 int ret;
298
299 if (count != 1 || off != 0)
300 return -EFAULT;
301
302 mutex_lock(&sl->master->bus_mutex);
303
304 if (w1_ds2438_change_config_bit(sl, DS2438_STATUS_IAD, *buf & 0x01) == 0)
305 ret = 1;
306 else
307 ret = -EIO;
308
309 mutex_unlock(&sl->master->bus_mutex);
310
311 return ret;
312}
313
314static ssize_t iad_read(struct file *filp, struct kobject *kobj,
315 struct bin_attribute *bin_attr, char *buf,
316 loff_t off, size_t count)
317{
318 struct w1_slave *sl = kobj_to_w1_slave(kobj);
319 int ret;
320 int16_t voltage;
321
322 if (off != 0)
323 return 0;
324 if (!buf)
325 return -EINVAL;
326
327 if (w1_ds2438_get_current(sl, &voltage) == 0)
328 ret = snprintf(buf, count, "%i\n", voltage);
329 else
330 ret = -EIO;
331
332 return ret;
333}
334
335static ssize_t page0_read(struct file *filp, struct kobject *kobj,
336 struct bin_attribute *bin_attr, char *buf,
337 loff_t off, size_t count)
338{
339 struct w1_slave *sl = kobj_to_w1_slave(kobj);
340 int ret;
341 u8 w1_buf[DS2438_PAGE_SIZE + 1 ];
342
343 if (off != 0)
344 return 0;
345 if (!buf)
346 return -EINVAL;
347
348 mutex_lock(&sl->master->bus_mutex);
349
350
351 if (count > DS2438_PAGE_SIZE)
352 count = DS2438_PAGE_SIZE;
353
354 if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) {
355 memcpy(buf, &w1_buf, count);
356 ret = count;
357 } else
358 ret = -EIO;
359
360 mutex_unlock(&sl->master->bus_mutex);
361
362 return ret;
363}
364
365static ssize_t page1_read(struct file *filp, struct kobject *kobj,
366 struct bin_attribute *bin_attr, char *buf,
367 loff_t off, size_t count)
368{
369 struct w1_slave *sl = kobj_to_w1_slave(kobj);
370 int ret;
371 u8 w1_buf[DS2438_PAGE_SIZE + 1 ];
372
373 if (off != 0)
374 return 0;
375 if (!buf)
376 return -EINVAL;
377
378 mutex_lock(&sl->master->bus_mutex);
379
380
381 if (count > DS2438_PAGE_SIZE)
382 count = DS2438_PAGE_SIZE;
383
384 if (w1_ds2438_get_page(sl, 1, w1_buf) == 0) {
385 memcpy(buf, &w1_buf, count);
386 ret = count;
387 } else
388 ret = -EIO;
389
390 mutex_unlock(&sl->master->bus_mutex);
391
392 return ret;
393}
394
395static ssize_t offset_write(struct file *filp, struct kobject *kobj,
396 struct bin_attribute *bin_attr, char *buf,
397 loff_t off, size_t count)
398{
399 struct w1_slave *sl = kobj_to_w1_slave(kobj);
400 int ret;
401
402 mutex_lock(&sl->master->bus_mutex);
403
404 if (w1_ds2438_change_offset_register(sl, buf) == 0)
405 ret = count;
406 else
407 ret = -EIO;
408
409 mutex_unlock(&sl->master->bus_mutex);
410
411 return ret;
412}
413
414static ssize_t temperature_read(struct file *filp, struct kobject *kobj,
415 struct bin_attribute *bin_attr, char *buf,
416 loff_t off, size_t count)
417{
418 struct w1_slave *sl = kobj_to_w1_slave(kobj);
419 int ret;
420 int16_t temp;
421
422 if (off != 0)
423 return 0;
424 if (!buf)
425 return -EINVAL;
426
427 if (w1_ds2438_get_temperature(sl, &temp) == 0)
428 ret = snprintf(buf, count, "%i\n", temp);
429 else
430 ret = -EIO;
431
432 return ret;
433}
434
435static ssize_t vad_read(struct file *filp, struct kobject *kobj,
436 struct bin_attribute *bin_attr, char *buf,
437 loff_t off, size_t count)
438{
439 struct w1_slave *sl = kobj_to_w1_slave(kobj);
440 int ret;
441 uint16_t voltage;
442
443 if (off != 0)
444 return 0;
445 if (!buf)
446 return -EINVAL;
447
448 if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VAD, &voltage) == 0)
449 ret = snprintf(buf, count, "%u\n", voltage);
450 else
451 ret = -EIO;
452
453 return ret;
454}
455
456static ssize_t vdd_read(struct file *filp, struct kobject *kobj,
457 struct bin_attribute *bin_attr, char *buf,
458 loff_t off, size_t count)
459{
460 struct w1_slave *sl = kobj_to_w1_slave(kobj);
461 int ret;
462 uint16_t voltage;
463
464 if (off != 0)
465 return 0;
466 if (!buf)
467 return -EINVAL;
468
469 if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VDD, &voltage) == 0)
470 ret = snprintf(buf, count, "%u\n", voltage);
471 else
472 ret = -EIO;
473
474 return ret;
475}
476
477static BIN_ATTR_RW(iad, 0);
478static BIN_ATTR_RO(page0, DS2438_PAGE_SIZE);
479static BIN_ATTR_RO(page1, DS2438_PAGE_SIZE);
480static BIN_ATTR_WO(offset, 2);
481static BIN_ATTR_RO(temperature, 0);
482static BIN_ATTR_RO(vad, 0);
483static BIN_ATTR_RO(vdd, 0);
484
485static struct bin_attribute *w1_ds2438_bin_attrs[] = {
486 &bin_attr_iad,
487 &bin_attr_page0,
488 &bin_attr_page1,
489 &bin_attr_offset,
490 &bin_attr_temperature,
491 &bin_attr_vad,
492 &bin_attr_vdd,
493 NULL,
494};
495
496static const struct attribute_group w1_ds2438_group = {
497 .bin_attrs = w1_ds2438_bin_attrs,
498};
499
500static const struct attribute_group *w1_ds2438_groups[] = {
501 &w1_ds2438_group,
502 NULL,
503};
504
505static const struct w1_family_ops w1_ds2438_fops = {
506 .groups = w1_ds2438_groups,
507};
508
509static struct w1_family w1_ds2438_family = {
510 .fid = W1_FAMILY_DS2438,
511 .fops = &w1_ds2438_fops,
512};
513module_w1_family(w1_ds2438_family);
514
515MODULE_LICENSE("GPL");
516MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
517MODULE_DESCRIPTION("1-wire driver for Maxim/Dallas DS2438 Smart Battery Monitor");
518MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2438));
519
