?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ASoC: wm8940: Fix check on error code form snd_soc_codec_set_cache_io
[linux-2.6/mini2440.git] / drivers / macintosh / therm_adt746x.c
blobfde377c60cca753eafe9c358f7e562c6d538ad7b
1 /*
2 * Device driver for the i2c thermostat found on the iBook G4, Albook G4
3 *
4 * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
5 *
6 * Documentation from
7 * http://www.analog.com/UploadedFiles/Data_Sheets/115254175ADT7467_pra.pdf
8 * http://www.analog.com/UploadedFiles/Data_Sheets/3686221171167ADT7460_b.pdf
9 *
10 */
11
12 #include <linux/types.h>
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/delay.h>
17 #include <linux/sched.h>
18 #include <linux/i2c.h>
19 #include <linux/slab.h>
20 #include <linux/init.h>
21 #include <linux/spinlock.h>
22 #include <linux/wait.h>
23 #include <linux/suspend.h>
24 #include <linux/kthread.h>
25 #include <linux/moduleparam.h>
26 #include <linux/freezer.h>
27 #include <linux/of_platform.h>
28
29 #include <asm/prom.h>
30 #include <asm/machdep.h>
31 #include <asm/io.h>
32 #include <asm/system.h>
33 #include <asm/sections.h>
34
35 #undef DEBUG
36
37 #define CONFIG_REG 0x40
38 #define MANUAL_MASK 0xe0
39 #define AUTO_MASK 0x20
40 #define INVERT_MASK 0x10
41
42 static u8 TEMP_REG[3] = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
43 static u8 LIMIT_REG[3] = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
44 static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
45 static u8 REM_CONTROL[2] = {0x00, 0x40};
46 static u8 FAN_SPEED[2] = {0x28, 0x2a};
47 static u8 FAN_SPD_SET[2] = {0x30, 0x31};
48
49 static u8 default_limits_local[3] = {70, 50, 70}; /* local, sensor1, sensor2 */
50 static u8 default_limits_chip[3] = {80, 65, 80}; /* local, sensor1, sensor2 */
51 static const char *sensor_location[3];
52
53 static int limit_adjust;
54 static int fan_speed = -1;
55 static int verbose;
56
57 MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
58 MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
59 "Powerbook G4 Alu");
60 MODULE_LICENSE("GPL");
61
62 module_param(limit_adjust, int, 0644);
63 MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
64 "by N degrees.");
65
66 module_param(fan_speed, int, 0644);
67 MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
68 "(default 64)");
69
70 module_param(verbose, bool, 0);
71 MODULE_PARM_DESC(verbose,"Verbose log operations "
72 "(default 0)");
73
74 struct thermostat {
75 struct i2c_client *clt;
76 u8 temps[3];
77 u8 cached_temp[3];
78 u8 initial_limits[3];
79 u8 limits[3];
80 int last_speed[2];
81 int last_var[2];
82 };
83
84 static enum {ADT7460, ADT7467} therm_type;
85 static int therm_bus, therm_address;
86 static struct of_device * of_dev;
87 static struct thermostat* thermostat;
88 static struct task_struct *thread_therm = NULL;
89
90 static void write_both_fan_speed(struct thermostat *th, int speed);
91 static void write_fan_speed(struct thermostat *th, int speed, int fan);
92
93 static int
94 write_reg(struct thermostat* th, int reg, u8 data)
95 {
96 u8 tmp[2];
97 int rc;
98
99 tmp[0] = reg;
100 tmp[1] = data;
101 rc = i2c_master_send(th->clt, (const char *)tmp, 2);
102 if (rc < 0)
103 return rc;
104 if (rc != 2)
105 return -ENODEV;
106 return 0;
107 }
108
109 static int
110 read_reg(struct thermostat* th, int reg)
111 {
112 u8 reg_addr, data;
113 int rc;
114
115 reg_addr = (u8)reg;
116 rc = i2c_master_send(th->clt, &reg_addr, 1);
117 if (rc < 0)
118 return rc;
119 if (rc != 1)
120 return -ENODEV;
121 rc = i2c_master_recv(th->clt, (char *)&data, 1);
122 if (rc < 0)
123 return rc;
124 return data;
125 }
126
127 static int
128 attach_thermostat(struct i2c_adapter *adapter)
129 {
130 unsigned long bus_no;
131 struct i2c_board_info info;
132 struct i2c_client *client;
133
134 if (strncmp(adapter->name, "uni-n", 5))
135 return -ENODEV;
136 bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
137 if (bus_no != therm_bus)
138 return -ENODEV;
139
140 memset(&info, 0, sizeof(struct i2c_board_info));
141 strlcpy(info.type, "therm_adt746x", I2C_NAME_SIZE);
142 info.addr = therm_address;
143 client = i2c_new_device(adapter, &info);
144 if (!client)
145 return -ENODEV;
146
147 /*
148 * Let i2c-core delete that device on driver removal.
149 * This is safe because i2c-core holds the core_lock mutex for us.
150 */
151 list_add_tail(&client->detected, &client->driver->clients);
152 return 0;
153 }
154
155 static int
156 remove_thermostat(struct i2c_client *client)
157 {
158 struct thermostat *th = i2c_get_clientdata(client);
159 int i;
160
161 if (thread_therm != NULL) {
162 kthread_stop(thread_therm);
163 }
164
165 printk(KERN_INFO "adt746x: Putting max temperatures back from "
166 "%d, %d, %d to %d, %d, %d\n",
167 th->limits[0], th->limits[1], th->limits[2],
168 th->initial_limits[0], th->initial_limits[1],
169 th->initial_limits[2]);
170
171 for (i = 0; i < 3; i++)
172 write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
173
174 write_both_fan_speed(th, -1);
175
176 thermostat = NULL;
177
178 kfree(th);
179
180 return 0;
181 }
182
183 static int read_fan_speed(struct thermostat *th, u8 addr)
184 {
185 u8 tmp[2];
186 u16 res;
187
188 /* should start with low byte */
189 tmp[1] = read_reg(th, addr);
190 tmp[0] = read_reg(th, addr + 1);
191
192 res = tmp[1] + (tmp[0] << 8);
193 /* "a value of 0xffff means that the fan has stopped" */
194 return (res == 0xffff ? 0 : (90000*60)/res);
195 }
196
197 static void write_both_fan_speed(struct thermostat *th, int speed)
198 {
199 write_fan_speed(th, speed, 0);
200 if (therm_type == ADT7460)
201 write_fan_speed(th, speed, 1);
202 }
203
204 static void write_fan_speed(struct thermostat *th, int speed, int fan)
205 {
206 u8 manual;
207
208 if (speed > 0xff)
209 speed = 0xff;
210 else if (speed < -1)
211 speed = 0;
212
213 if (therm_type == ADT7467 && fan == 1)
214 return;
215
216 if (th->last_speed[fan] != speed) {
217 if (verbose) {
218 if (speed == -1)
219 printk(KERN_DEBUG "adt746x: Setting speed to automatic "
220 "for %s fan.\n", sensor_location[fan+1]);
221 else
222 printk(KERN_DEBUG "adt746x: Setting speed to %d "
223 "for %s fan.\n", speed, sensor_location[fan+1]);
224 }
225 } else
226 return;
227
228 if (speed >= 0) {
229 manual = read_reg(th, MANUAL_MODE[fan]);
230 write_reg(th, MANUAL_MODE[fan],
231 (manual|MANUAL_MASK) & (~INVERT_MASK));
232 write_reg(th, FAN_SPD_SET[fan], speed);
233 } else {
234 /* back to automatic */
235 if(therm_type == ADT7460) {
236 manual = read_reg(th,
237 MANUAL_MODE[fan]) & (~MANUAL_MASK);
238
239 write_reg(th,
240 MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
241 } else {
242 manual = read_reg(th, MANUAL_MODE[fan]);
243 write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
244 }
245 }
246
247 th->last_speed[fan] = speed;
248 }
249
250 static void read_sensors(struct thermostat *th)
251 {
252 int i = 0;
253
254 for (i = 0; i < 3; i++)
255 th->temps[i] = read_reg(th, TEMP_REG[i]);
256 }
257
258 #ifdef DEBUG
259 static void display_stats(struct thermostat *th)
260 {
261 if (th->temps[0] != th->cached_temp[0]
262 || th->temps[1] != th->cached_temp[1]
263 || th->temps[2] != th->cached_temp[2]) {
264 printk(KERN_INFO "adt746x: Temperature infos:"
265 " thermostats: %d,%d,%d;"
266 " limits: %d,%d,%d;"
267 " fan speed: %d RPM\n",
268 th->temps[0], th->temps[1], th->temps[2],
269 th->limits[0], th->limits[1], th->limits[2],
270 read_fan_speed(th, FAN_SPEED[0]));
271 }
272 th->cached_temp[0] = th->temps[0];
273 th->cached_temp[1] = th->temps[1];
274 th->cached_temp[2] = th->temps[2];
275 }
276 #endif
277
278 static void update_fans_speed (struct thermostat *th)
279 {
280 int lastvar = 0; /* last variation, for iBook */
281 int i = 0;
282
283 /* we don't care about local sensor, so we start at sensor 1 */
284 for (i = 1; i < 3; i++) {
285 int started = 0;
286 int fan_number = (therm_type == ADT7460 && i == 2);
287 int var = th->temps[i] - th->limits[i];
288
289 if (var > -1) {
290 int step = (255 - fan_speed) / 7;
291 int new_speed = 0;
292
293 /* hysteresis : change fan speed only if variation is
294 * more than two degrees */
295 if (abs(var - th->last_var[fan_number]) < 2)
296 continue;
297
298 started = 1;
299 new_speed = fan_speed + ((var-1)*step);
300
301 if (new_speed < fan_speed)
302 new_speed = fan_speed;
303 if (new_speed > 255)
304 new_speed = 255;
305
306 if (verbose)
307 printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
308 "(limit exceeded by %d on %s) \n",
309 new_speed, var,
310 sensor_location[fan_number+1]);
311 write_both_fan_speed(th, new_speed);
312 th->last_var[fan_number] = var;
313 } else if (var < -2) {
314 /* don't stop fan if sensor2 is cold and sensor1 is not
315 * so cold (lastvar >= -1) */
316 if (i == 2 && lastvar < -1) {
317 if (th->last_speed[fan_number] != 0)
318 if (verbose)
319 printk(KERN_DEBUG "adt746x: Stopping "
320 "fans.\n");
321 write_both_fan_speed(th, 0);
322 }
323 }
324
325 lastvar = var;
326
327 if (started)
328 return; /* we don't want to re-stop the fan
329 * if sensor1 is heating and sensor2 is not */
330 }
331 }
332
333 static int monitor_task(void *arg)
334 {
335 struct thermostat* th = arg;
336
337 set_freezable();
338 while(!kthread_should_stop()) {
339 try_to_freeze();
340 msleep_interruptible(2000);
341
342 #ifndef DEBUG
343 if (fan_speed != -1)
344 read_sensors(th);
345 #else
346 read_sensors(th);
347 #endif
348
349 if (fan_speed != -1)
350 update_fans_speed(th);
351
352 #ifdef DEBUG
353 display_stats(th);
354 #endif
355
356 }
357
358 return 0;
359 }
360
361 static void set_limit(struct thermostat *th, int i)
362 {
363 /* Set sensor1 limit higher to avoid powerdowns */
364 th->limits[i] = default_limits_chip[i] + limit_adjust;
365 write_reg(th, LIMIT_REG[i], th->limits[i]);
366
367 /* set our limits to normal */
368 th->limits[i] = default_limits_local[i] + limit_adjust;
369 }
370
371 static int probe_thermostat(struct i2c_client *client,
372 const struct i2c_device_id *id)
373 {
374 struct thermostat* th;
375 int rc;
376 int i;
377
378 if (thermostat)
379 return 0;
380
381 th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
382 if (!th)
383 return -ENOMEM;
384
385 i2c_set_clientdata(client, th);
386 th->clt = client;
387
388 rc = read_reg(th, 0);
389 if (rc < 0) {
390 dev_err(&client->dev, "Thermostat failed to read config!\n");
391 kfree(th);
392 return -ENODEV;
393 }
394
395 /* force manual control to start the fan quieter */
396 if (fan_speed == -1)
397 fan_speed = 64;
398
399 if(therm_type == ADT7460) {
400 printk(KERN_INFO "adt746x: ADT7460 initializing\n");
401 /* The 7460 needs to be started explicitly */
402 write_reg(th, CONFIG_REG, 1);
403 } else
404 printk(KERN_INFO "adt746x: ADT7467 initializing\n");
405
406 for (i = 0; i < 3; i++) {
407 th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
408 set_limit(th, i);
409 }
410
411 printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
412 " to %d, %d, %d\n",
413 th->initial_limits[0], th->initial_limits[1],
414 th->initial_limits[2], th->limits[0], th->limits[1],
415 th->limits[2]);
416
417 thermostat = th;
418
419 /* be sure to really write fan speed the first time */
420 th->last_speed[0] = -2;
421 th->last_speed[1] = -2;
422 th->last_var[0] = -80;
423 th->last_var[1] = -80;
424
425 if (fan_speed != -1) {
426 /* manual mode, stop fans */
427 write_both_fan_speed(th, 0);
428 } else {
429 /* automatic mode */
430 write_both_fan_speed(th, -1);
431 }
432
433 thread_therm = kthread_run(monitor_task, th, "kfand");
434
435 if (thread_therm == ERR_PTR(-ENOMEM)) {
436 printk(KERN_INFO "adt746x: Kthread creation failed\n");
437 thread_therm = NULL;
438 return -ENOMEM;
439 }
440
441 return 0;
442 }
443
444 static const struct i2c_device_id therm_adt746x_id[] = {
445 { "therm_adt746x", 0 },
446 { }
447 };
448
449 static struct i2c_driver thermostat_driver = {
450 .driver = {
451 .name = "therm_adt746x",
452 },
453 .attach_adapter = attach_thermostat,
454 .probe = probe_thermostat,
455 .remove = remove_thermostat,
456 .id_table = therm_adt746x_id,
457 };
458
459 /*
460 * Now, unfortunately, sysfs doesn't give us a nice void * we could
461 * pass around to the attribute functions, so we don't really have
462 * choice but implement a bunch of them...
463 *
464 * FIXME, it does now...
465 */
466 #define BUILD_SHOW_FUNC_INT(name, data) \
467 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
468 { \
469 return sprintf(buf, "%d\n", data); \
470 }
471
472 #define BUILD_SHOW_FUNC_STR(name, data) \
473 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
474 { \
475 return sprintf(buf, "%s\n", data); \
476 }
477
478 #define BUILD_SHOW_FUNC_FAN(name, data) \
479 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
480 { \
481 return sprintf(buf, "%d (%d rpm)\n", \
482 thermostat->last_speed[data], \
483 read_fan_speed(thermostat, FAN_SPEED[data]) \
484 ); \
485 }
486
487 #define BUILD_STORE_FUNC_DEG(name, data) \
488 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
489 { \
490 int val; \
491 int i; \
492 val = simple_strtol(buf, NULL, 10); \
493 printk(KERN_INFO "Adjusting limits by %d degrees\n", val); \
494 limit_adjust = val; \
495 for (i=0; i < 3; i++) \
496 set_limit(thermostat, i); \
497 return n; \
498 }
499
500 #define BUILD_STORE_FUNC_INT(name, data) \
501 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
502 { \
503 int val; \
504 val = simple_strtol(buf, NULL, 10); \
505 if (val < 0 || val > 255) \
506 return -EINVAL; \
507 printk(KERN_INFO "Setting specified fan speed to %d\n", val); \
508 data = val; \
509 return n; \
510 }
511
512 BUILD_SHOW_FUNC_INT(sensor1_temperature, (read_reg(thermostat, TEMP_REG[1])))
513 BUILD_SHOW_FUNC_INT(sensor2_temperature, (read_reg(thermostat, TEMP_REG[2])))
514 BUILD_SHOW_FUNC_INT(sensor1_limit, thermostat->limits[1])
515 BUILD_SHOW_FUNC_INT(sensor2_limit, thermostat->limits[2])
516 BUILD_SHOW_FUNC_STR(sensor1_location, sensor_location[1])
517 BUILD_SHOW_FUNC_STR(sensor2_location, sensor_location[2])
518
519 BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
520 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed, 0)
521 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed, 1)
522
523 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
524 BUILD_SHOW_FUNC_INT(limit_adjust, limit_adjust)
525 BUILD_STORE_FUNC_DEG(limit_adjust, thermostat)
526
527 static DEVICE_ATTR(sensor1_temperature, S_IRUGO,
528 show_sensor1_temperature,NULL);
529 static DEVICE_ATTR(sensor2_temperature, S_IRUGO,
530 show_sensor2_temperature,NULL);
531 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
532 show_sensor1_limit, NULL);
533 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
534 show_sensor2_limit, NULL);
535 static DEVICE_ATTR(sensor1_location, S_IRUGO,
536 show_sensor1_location, NULL);
537 static DEVICE_ATTR(sensor2_location, S_IRUGO,
538 show_sensor2_location, NULL);
539
540 static DEVICE_ATTR(specified_fan_speed, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
541 show_specified_fan_speed,store_specified_fan_speed);
542
543 static DEVICE_ATTR(sensor1_fan_speed, S_IRUGO,
544 show_sensor1_fan_speed, NULL);
545 static DEVICE_ATTR(sensor2_fan_speed, S_IRUGO,
546 show_sensor2_fan_speed, NULL);
547
548 static DEVICE_ATTR(limit_adjust, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
549 show_limit_adjust, store_limit_adjust);
550
551
552 static int __init
553 thermostat_init(void)
554 {
555 struct device_node* np;
556 const u32 *prop;
557 int i = 0, offset = 0;
558 int err;
559
560 np = of_find_node_by_name(NULL, "fan");
561 if (!np)
562 return -ENODEV;
563 if (of_device_is_compatible(np, "adt7460"))
564 therm_type = ADT7460;
565 else if (of_device_is_compatible(np, "adt7467"))
566 therm_type = ADT7467;
567 else {
568 of_node_put(np);
569 return -ENODEV;
570 }
571
572 prop = of_get_property(np, "hwsensor-params-version", NULL);
573 printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
574 (*prop == 1)?"":"un");
575 if (*prop != 1) {
576 of_node_put(np);
577 return -ENODEV;
578 }
579
580 prop = of_get_property(np, "reg", NULL);
581 if (!prop) {
582 of_node_put(np);
583 return -ENODEV;
584 }
585
586 /* look for bus either by path or using "reg" */
587 if (strstr(np->full_name, "/i2c-bus@") != NULL) {
588 const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
589 therm_bus = tmp_bus[0]-'0';
590 } else {
591 therm_bus = ((*prop) >> 8) & 0x0f;
592 }
593
594 therm_address = ((*prop) & 0xff) >> 1;
595
596 printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
597 "limit_adjust: %d, fan_speed: %d\n",
598 therm_bus, therm_address, limit_adjust, fan_speed);
599
600 if (of_get_property(np, "hwsensor-location", NULL)) {
601 for (i = 0; i < 3; i++) {
602 sensor_location[i] = of_get_property(np,
603 "hwsensor-location", NULL) + offset;
604
605 if (sensor_location[i] == NULL)
606 sensor_location[i] = "";
607
608 printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
609 offset += strlen(sensor_location[i]) + 1;
610 }
611 } else {
612 sensor_location[0] = "?";
613 sensor_location[1] = "?";
614 sensor_location[2] = "?";
615 }
616
617 of_dev = of_platform_device_create(np, "temperatures", NULL);
618 of_node_put(np);
619
620 if (of_dev == NULL) {
621 printk(KERN_ERR "Can't register temperatures device !\n");
622 return -ENODEV;
623 }
624
625 err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
626 err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
627 err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
628 err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
629 err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
630 err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
631 err |= device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
632 err |= device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
633 err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
634 if(therm_type == ADT7460)
635 err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
636 if (err)
637 printk(KERN_WARNING
638 "Failed to create tempertaure attribute file(s).\n");
639
640 #ifndef CONFIG_I2C_POWERMAC
641 request_module("i2c-powermac");
642 #endif
643
644 return i2c_add_driver(&thermostat_driver);
645 }
646
647 static void __exit
648 thermostat_exit(void)
649 {
650 if (of_dev) {
651 device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
652 device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
653 device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
654 device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
655 device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
656 device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
657 device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
658 device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
659 device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
660
661 if(therm_type == ADT7460)
662 device_remove_file(&of_dev->dev,
663 &dev_attr_sensor2_fan_speed);
664
665 of_device_unregister(of_dev);
666 }
667 i2c_del_driver(&thermostat_driver);
668 }
669
670 module_init(thermostat_init);
671 module_exit(thermostat_exit);
Support for the Chinese Samsung S3C2440 based development boards