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1// SPDX-License-Identifier: GPL-2.0+
2// Expose the Chromebook Pixel lightbar to userspace
3//
4// Copyright (C) 2014 Google, Inc.
5
6#include <linux/ctype.h>
7#include <linux/delay.h>
8#include <linux/device.h>
9#include <linux/fs.h>
10#include <linux/kobject.h>
11#include <linux/kstrtox.h>
12#include <linux/mod_devicetable.h>
13#include <linux/module.h>
14#include <linux/platform_data/cros_ec_commands.h>
15#include <linux/platform_data/cros_ec_proto.h>
16#include <linux/platform_device.h>
17#include <linux/sched.h>
18#include <linux/types.h>
19#include <linux/uaccess.h>
20#include <linux/slab.h>
21
22#define DRV_NAME "cros-ec-lightbar"
23
24/* Rate-limit the lightbar interface to prevent DoS. */
25static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
26
27/*
28 * Whether or not we have given userspace control of the lightbar.
29 * If this is true, we won't do anything during suspend/resume.
30 */
31static bool userspace_control;
32
33static ssize_t interval_msec_show(struct device *dev,
34 struct device_attribute *attr, char *buf)
35{
36 unsigned long msec = lb_interval_jiffies * 1000 / HZ;
37
38 return sysfs_emit(buf, "%lu\n", msec);
39}
40
41static ssize_t interval_msec_store(struct device *dev,
42 struct device_attribute *attr,
43 const char *buf, size_t count)
44{
45 unsigned long msec;
46
47 if (kstrtoul(buf, 0, &msec))
48 return -EINVAL;
49
50 lb_interval_jiffies = msec * HZ / 1000;
51
52 return count;
53}
54
55static DEFINE_MUTEX(lb_mutex);
56/* Return 0 if able to throttle correctly, error otherwise */
57static int lb_throttle(void)
58{
59 static unsigned long last_access;
60 unsigned long now, next_timeslot;
61 long delay;
62 int ret = 0;
63
64 mutex_lock(&lb_mutex);
65
66 now = jiffies;
67 next_timeslot = last_access + lb_interval_jiffies;
68
69 if (time_before(now, next_timeslot)) {
70 delay = (long)(next_timeslot) - (long)now;
71 set_current_state(TASK_INTERRUPTIBLE);
72 if (schedule_timeout(delay) > 0) {
73 /* interrupted - just abort */
74 ret = -EINTR;
75 goto out;
76 }
77 now = jiffies;
78 }
79
80 last_access = now;
81out:
82 mutex_unlock(&lb_mutex);
83
84 return ret;
85}
86
87static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
88{
89 struct cros_ec_command *msg;
90 int len;
91
92 len = max(sizeof(struct ec_params_lightbar),
93 sizeof(struct ec_response_lightbar));
94
95 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
96 if (!msg)
97 return NULL;
98
99 msg->version = 0;
100 msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
101 msg->outsize = sizeof(struct ec_params_lightbar);
102 msg->insize = sizeof(struct ec_response_lightbar);
103
104 return msg;
105}
106
107static int get_lightbar_version(struct cros_ec_dev *ec,
108 uint32_t *ver_ptr, uint32_t *flg_ptr)
109{
110 struct ec_params_lightbar *param;
111 struct ec_response_lightbar *resp;
112 struct cros_ec_command *msg;
113 int ret;
114
115 msg = alloc_lightbar_cmd_msg(ec);
116 if (!msg)
117 return 0;
118
119 param = (struct ec_params_lightbar *)msg->data;
120 param->cmd = LIGHTBAR_CMD_VERSION;
121 msg->outsize = sizeof(param->cmd);
122 msg->result = sizeof(resp->version);
123 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
124 if (ret < 0 && ret != -EINVAL) {
125 ret = 0;
126 goto exit;
127 }
128
129 switch (msg->result) {
130 case EC_RES_INVALID_PARAM:
131 /* Pixel had no version command. */
132 if (ver_ptr)
133 *ver_ptr = 0;
134 if (flg_ptr)
135 *flg_ptr = 0;
136 ret = 1;
137 goto exit;
138
139 case EC_RES_SUCCESS:
140 resp = (struct ec_response_lightbar *)msg->data;
141
142 /* Future devices w/lightbars should implement this command */
143 if (ver_ptr)
144 *ver_ptr = resp->version.num;
145 if (flg_ptr)
146 *flg_ptr = resp->version.flags;
147 ret = 1;
148 goto exit;
149 }
150
151 /* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
152 ret = 0;
153exit:
154 kfree(msg);
155 return ret;
156}
157
158static ssize_t version_show(struct device *dev,
159 struct device_attribute *attr, char *buf)
160{
161 uint32_t version = 0, flags = 0;
162 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
163 int ret;
164
165 ret = lb_throttle();
166 if (ret)
167 return ret;
168
169 /* This should always succeed, because we check during init. */
170 if (!get_lightbar_version(ec, &version, &flags))
171 return -EIO;
172
173 return sysfs_emit(buf, "%d %d\n", version, flags);
174}
175
176static ssize_t brightness_store(struct device *dev,
177 struct device_attribute *attr,
178 const char *buf, size_t count)
179{
180 struct ec_params_lightbar *param;
181 struct cros_ec_command *msg;
182 int ret;
183 unsigned int val;
184 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
185
186 if (kstrtouint(buf, 0, &val))
187 return -EINVAL;
188
189 msg = alloc_lightbar_cmd_msg(ec);
190 if (!msg)
191 return -ENOMEM;
192
193 param = (struct ec_params_lightbar *)msg->data;
194 param->cmd = LIGHTBAR_CMD_SET_BRIGHTNESS;
195 param->set_brightness.num = val;
196 ret = lb_throttle();
197 if (ret)
198 goto exit;
199
200 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
201 if (ret < 0)
202 goto exit;
203
204 ret = count;
205exit:
206 kfree(msg);
207 return ret;
208}
209
210
211/*
212 * We expect numbers, and we'll keep reading until we find them, skipping over
213 * any whitespace (sysfs guarantees that the input is null-terminated). Every
214 * four numbers are sent to the lightbar as <LED,R,G,B>. We fail at the first
215 * parsing error, if we don't parse any numbers, or if we have numbers left
216 * over.
217 */
218static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
219 const char *buf, size_t count)
220{
221 struct ec_params_lightbar *param;
222 struct cros_ec_command *msg;
223 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
224 unsigned int val[4];
225 int ret, i = 0, j = 0, ok = 0;
226
227 msg = alloc_lightbar_cmd_msg(ec);
228 if (!msg)
229 return -ENOMEM;
230
231 do {
232 /* Skip any whitespace */
233 while (*buf && isspace(*buf))
234 buf++;
235
236 if (!*buf)
237 break;
238
239 ret = sscanf(buf, "%i", &val[i++]);
240 if (ret == 0)
241 goto exit;
242
243 if (i == 4) {
244 param = (struct ec_params_lightbar *)msg->data;
245 param->cmd = LIGHTBAR_CMD_SET_RGB;
246 param->set_rgb.led = val[0];
247 param->set_rgb.red = val[1];
248 param->set_rgb.green = val[2];
249 param->set_rgb.blue = val[3];
250 /*
251 * Throttle only the first of every four transactions,
252 * so that the user can update all four LEDs at once.
253 */
254 if ((j++ % 4) == 0) {
255 ret = lb_throttle();
256 if (ret)
257 goto exit;
258 }
259
260 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
261 if (ret < 0)
262 goto exit;
263
264 i = 0;
265 ok = 1;
266 }
267
268 /* Skip over the number we just read */
269 while (*buf && !isspace(*buf))
270 buf++;
271
272 } while (*buf);
273
274exit:
275 kfree(msg);
276 return (ok && i == 0) ? count : -EINVAL;
277}
278
279static char const *seqname[] = {
280 "ERROR", "S5", "S3", "S0", "S5S3", "S3S0",
281 "S0S3", "S3S5", "STOP", "RUN", "KONAMI",
282 "TAP", "PROGRAM",
283};
284
285static ssize_t sequence_show(struct device *dev,
286 struct device_attribute *attr, char *buf)
287{
288 struct ec_params_lightbar *param;
289 struct ec_response_lightbar *resp;
290 struct cros_ec_command *msg;
291 int ret;
292 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
293
294 msg = alloc_lightbar_cmd_msg(ec);
295 if (!msg)
296 return -ENOMEM;
297
298 param = (struct ec_params_lightbar *)msg->data;
299 param->cmd = LIGHTBAR_CMD_GET_SEQ;
300 ret = lb_throttle();
301 if (ret)
302 goto exit;
303
304 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
305 if (ret < 0) {
306 ret = sysfs_emit(buf, "XFER / EC ERROR %d / %d\n", ret, msg->result);
307 goto exit;
308 }
309
310 resp = (struct ec_response_lightbar *)msg->data;
311 if (resp->get_seq.num >= ARRAY_SIZE(seqname))
312 ret = sysfs_emit(buf, "%d\n", resp->get_seq.num);
313 else
314 ret = sysfs_emit(buf, "%s\n", seqname[resp->get_seq.num]);
315
316exit:
317 kfree(msg);
318 return ret;
319}
320
321static int lb_send_empty_cmd(struct cros_ec_dev *ec, uint8_t cmd)
322{
323 struct ec_params_lightbar *param;
324 struct cros_ec_command *msg;
325 int ret;
326
327 msg = alloc_lightbar_cmd_msg(ec);
328 if (!msg)
329 return -ENOMEM;
330
331 param = (struct ec_params_lightbar *)msg->data;
332 param->cmd = cmd;
333
334 ret = lb_throttle();
335 if (ret)
336 goto error;
337
338 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
339 if (ret < 0)
340 goto error;
341
342 ret = 0;
343error:
344 kfree(msg);
345
346 return ret;
347}
348
349static int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
350{
351 struct ec_params_lightbar *param;
352 struct cros_ec_command *msg;
353 int ret;
354
355 msg = alloc_lightbar_cmd_msg(ec);
356 if (!msg)
357 return -ENOMEM;
358
359 param = (struct ec_params_lightbar *)msg->data;
360
361 param->cmd = LIGHTBAR_CMD_MANUAL_SUSPEND_CTRL;
362 param->manual_suspend_ctrl.enable = enable;
363
364 ret = lb_throttle();
365 if (ret)
366 goto error;
367
368 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
369 if (ret < 0)
370 goto error;
371
372 ret = 0;
373error:
374 kfree(msg);
375
376 return ret;
377}
378
379static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
380 const char *buf, size_t count)
381{
382 struct ec_params_lightbar *param;
383 struct cros_ec_command *msg;
384 unsigned int num;
385 int ret, len;
386 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
387
388 for (len = 0; len < count; len++)
389 if (!isalnum(buf[len]))
390 break;
391
392 for (num = 0; num < ARRAY_SIZE(seqname); num++)
393 if (!strncasecmp(seqname[num], buf, len))
394 break;
395
396 if (num >= ARRAY_SIZE(seqname)) {
397 ret = kstrtouint(buf, 0, &num);
398 if (ret)
399 return ret;
400 }
401
402 msg = alloc_lightbar_cmd_msg(ec);
403 if (!msg)
404 return -ENOMEM;
405
406 param = (struct ec_params_lightbar *)msg->data;
407 param->cmd = LIGHTBAR_CMD_SEQ;
408 param->seq.num = num;
409 ret = lb_throttle();
410 if (ret)
411 goto exit;
412
413 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
414 if (ret < 0)
415 goto exit;
416
417 ret = count;
418exit:
419 kfree(msg);
420 return ret;
421}
422
423static ssize_t program_store(struct device *dev, struct device_attribute *attr,
424 const char *buf, size_t count)
425{
426 int extra_bytes, max_size, ret;
427 struct ec_params_lightbar *param;
428 struct cros_ec_command *msg;
429 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
430
431 /*
432 * We might need to reject the program for size reasons. The EC
433 * enforces a maximum program size, but we also don't want to try
434 * and send a program that is too big for the protocol. In order
435 * to ensure the latter, we also need to ensure we have extra bytes
436 * to represent the rest of the packet.
437 */
438 extra_bytes = sizeof(*param) - sizeof(param->set_program.data);
439 max_size = min(EC_LB_PROG_LEN, ec->ec_dev->max_request - extra_bytes);
440 if (count > max_size) {
441 dev_err(dev, "Program is %u bytes, too long to send (max: %u)",
442 (unsigned int)count, max_size);
443
444 return -EINVAL;
445 }
446
447 msg = alloc_lightbar_cmd_msg(ec);
448 if (!msg)
449 return -ENOMEM;
450
451 ret = lb_throttle();
452 if (ret)
453 goto exit;
454
455 dev_info(dev, "Copying %zu byte program to EC", count);
456
457 param = (struct ec_params_lightbar *)msg->data;
458 param->cmd = LIGHTBAR_CMD_SET_PROGRAM;
459
460 param->set_program.size = count;
461 memcpy(param->set_program.data, buf, count);
462
463 /*
464 * We need to set the message size manually or else it will use
465 * EC_LB_PROG_LEN. This might be too long, and the program
466 * is unlikely to use all of the space.
467 */
468 msg->outsize = count + extra_bytes;
469
470 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
471 if (ret < 0)
472 goto exit;
473
474 ret = count;
475exit:
476 kfree(msg);
477
478 return ret;
479}
480
481static ssize_t userspace_control_show(struct device *dev,
482 struct device_attribute *attr,
483 char *buf)
484{
485 return sysfs_emit(buf, "%d\n", userspace_control);
486}
487
488static ssize_t userspace_control_store(struct device *dev,
489 struct device_attribute *attr,
490 const char *buf,
491 size_t count)
492{
493 bool enable;
494 int ret;
495
496 ret = kstrtobool(buf, &enable);
497 if (ret < 0)
498 return ret;
499
500 userspace_control = enable;
501
502 return count;
503}
504
505/* Module initialization */
506
507static DEVICE_ATTR_RW(interval_msec);
508static DEVICE_ATTR_RO(version);
509static DEVICE_ATTR_WO(brightness);
510static DEVICE_ATTR_WO(led_rgb);
511static DEVICE_ATTR_RW(sequence);
512static DEVICE_ATTR_WO(program);
513static DEVICE_ATTR_RW(userspace_control);
514
515static struct attribute *__lb_cmds_attrs[] = {
516 &dev_attr_interval_msec.attr,
517 &dev_attr_version.attr,
518 &dev_attr_brightness.attr,
519 &dev_attr_led_rgb.attr,
520 &dev_attr_sequence.attr,
521 &dev_attr_program.attr,
522 &dev_attr_userspace_control.attr,
523 NULL,
524};
525
526static const struct attribute_group cros_ec_lightbar_attr_group = {
527 .name = "lightbar",
528 .attrs = __lb_cmds_attrs,
529};
530
531static int cros_ec_lightbar_probe(struct platform_device *pd)
532{
533 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
534 struct cros_ec_platform *pdata = dev_get_platdata(ec_dev->dev);
535 struct device *dev = &pd->dev;
536 int ret;
537
538 /*
539 * Only instantiate the lightbar if the EC name is 'cros_ec'. Other EC
540 * devices like 'cros_pd' doesn't have a lightbar.
541 */
542 if (strcmp(pdata->ec_name, CROS_EC_DEV_NAME) != 0)
543 return -ENODEV;
544
545 /*
546 * Ask then for the lightbar version, if it's 0 then the 'cros_ec'
547 * doesn't have a lightbar.
548 */
549 if (!get_lightbar_version(ec_dev, NULL, NULL))
550 return -ENODEV;
551
552 /* Take control of the lightbar from the EC. */
553 lb_manual_suspend_ctrl(ec_dev, 1);
554
555 ret = sysfs_create_group(&ec_dev->class_dev.kobj,
556 &cros_ec_lightbar_attr_group);
557 if (ret < 0)
558 dev_err(dev, "failed to create %s attributes. err=%d\n",
559 cros_ec_lightbar_attr_group.name, ret);
560
561 return ret;
562}
563
564static void cros_ec_lightbar_remove(struct platform_device *pd)
565{
566 struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
567
568 sysfs_remove_group(&ec_dev->class_dev.kobj,
569 &cros_ec_lightbar_attr_group);
570
571 /* Let the EC take over the lightbar again. */
572 lb_manual_suspend_ctrl(ec_dev, 0);
573}
574
575static int __maybe_unused cros_ec_lightbar_resume(struct device *dev)
576{
577 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
578
579 if (userspace_control)
580 return 0;
581
582 return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_RESUME);
583}
584
585static int __maybe_unused cros_ec_lightbar_suspend(struct device *dev)
586{
587 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
588
589 if (userspace_control)
590 return 0;
591
592 return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_SUSPEND);
593}
594
595static SIMPLE_DEV_PM_OPS(cros_ec_lightbar_pm_ops,
596 cros_ec_lightbar_suspend, cros_ec_lightbar_resume);
597
598static const struct platform_device_id cros_ec_lightbar_id[] = {
599 { DRV_NAME, 0 },
600 {}
601};
602MODULE_DEVICE_TABLE(platform, cros_ec_lightbar_id);
603
604static struct platform_driver cros_ec_lightbar_driver = {
605 .driver = {
606 .name = DRV_NAME,
607 .pm = &cros_ec_lightbar_pm_ops,
608 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
609 },
610 .probe = cros_ec_lightbar_probe,
611 .remove = cros_ec_lightbar_remove,
612 .id_table = cros_ec_lightbar_id,
613};
614
615module_platform_driver(cros_ec_lightbar_driver);
616
617MODULE_LICENSE("GPL");
618MODULE_DESCRIPTION("Expose the Chromebook Pixel's lightbar to userspace");
1/*
2 * cros_ec_lightbar - expose the Chromebook Pixel lightbar to userspace
3 *
4 * Copyright (C) 2014 Google, Inc.
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 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#define pr_fmt(fmt) "cros_ec_lightbar: " fmt
21
22#include <linux/ctype.h>
23#include <linux/delay.h>
24#include <linux/device.h>
25#include <linux/fs.h>
26#include <linux/kobject.h>
27#include <linux/mfd/cros_ec.h>
28#include <linux/mfd/cros_ec_commands.h>
29#include <linux/module.h>
30#include <linux/platform_device.h>
31#include <linux/sched.h>
32#include <linux/types.h>
33#include <linux/uaccess.h>
34#include <linux/slab.h>
35
36#include "cros_ec_dev.h"
37
38/* Rate-limit the lightbar interface to prevent DoS. */
39static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
40
41static ssize_t interval_msec_show(struct device *dev,
42 struct device_attribute *attr, char *buf)
43{
44 unsigned long msec = lb_interval_jiffies * 1000 / HZ;
45
46 return scnprintf(buf, PAGE_SIZE, "%lu\n", msec);
47}
48
49static ssize_t interval_msec_store(struct device *dev,
50 struct device_attribute *attr,
51 const char *buf, size_t count)
52{
53 unsigned long msec;
54
55 if (kstrtoul(buf, 0, &msec))
56 return -EINVAL;
57
58 lb_interval_jiffies = msec * HZ / 1000;
59
60 return count;
61}
62
63static DEFINE_MUTEX(lb_mutex);
64/* Return 0 if able to throttle correctly, error otherwise */
65static int lb_throttle(void)
66{
67 static unsigned long last_access;
68 unsigned long now, next_timeslot;
69 long delay;
70 int ret = 0;
71
72 mutex_lock(&lb_mutex);
73
74 now = jiffies;
75 next_timeslot = last_access + lb_interval_jiffies;
76
77 if (time_before(now, next_timeslot)) {
78 delay = (long)(next_timeslot) - (long)now;
79 set_current_state(TASK_INTERRUPTIBLE);
80 if (schedule_timeout(delay) > 0) {
81 /* interrupted - just abort */
82 ret = -EINTR;
83 goto out;
84 }
85 now = jiffies;
86 }
87
88 last_access = now;
89out:
90 mutex_unlock(&lb_mutex);
91
92 return ret;
93}
94
95static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
96{
97 struct cros_ec_command *msg;
98 int len;
99
100 len = max(sizeof(struct ec_params_lightbar),
101 sizeof(struct ec_response_lightbar));
102
103 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
104 if (!msg)
105 return NULL;
106
107 msg->version = 0;
108 msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
109 msg->outsize = sizeof(struct ec_params_lightbar);
110 msg->insize = sizeof(struct ec_response_lightbar);
111
112 return msg;
113}
114
115static int get_lightbar_version(struct cros_ec_dev *ec,
116 uint32_t *ver_ptr, uint32_t *flg_ptr)
117{
118 struct ec_params_lightbar *param;
119 struct ec_response_lightbar *resp;
120 struct cros_ec_command *msg;
121 int ret;
122
123 msg = alloc_lightbar_cmd_msg(ec);
124 if (!msg)
125 return 0;
126
127 param = (struct ec_params_lightbar *)msg->data;
128 param->cmd = LIGHTBAR_CMD_VERSION;
129 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
130 if (ret < 0) {
131 ret = 0;
132 goto exit;
133 }
134
135 switch (msg->result) {
136 case EC_RES_INVALID_PARAM:
137 /* Pixel had no version command. */
138 if (ver_ptr)
139 *ver_ptr = 0;
140 if (flg_ptr)
141 *flg_ptr = 0;
142 ret = 1;
143 goto exit;
144
145 case EC_RES_SUCCESS:
146 resp = (struct ec_response_lightbar *)msg->data;
147
148 /* Future devices w/lightbars should implement this command */
149 if (ver_ptr)
150 *ver_ptr = resp->version.num;
151 if (flg_ptr)
152 *flg_ptr = resp->version.flags;
153 ret = 1;
154 goto exit;
155 }
156
157 /* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
158 ret = 0;
159exit:
160 kfree(msg);
161 return ret;
162}
163
164static ssize_t version_show(struct device *dev,
165 struct device_attribute *attr, char *buf)
166{
167 uint32_t version = 0, flags = 0;
168 struct cros_ec_dev *ec = container_of(dev,
169 struct cros_ec_dev, class_dev);
170 int ret;
171
172 ret = lb_throttle();
173 if (ret)
174 return ret;
175
176 /* This should always succeed, because we check during init. */
177 if (!get_lightbar_version(ec, &version, &flags))
178 return -EIO;
179
180 return scnprintf(buf, PAGE_SIZE, "%d %d\n", version, flags);
181}
182
183static ssize_t brightness_store(struct device *dev,
184 struct device_attribute *attr,
185 const char *buf, size_t count)
186{
187 struct ec_params_lightbar *param;
188 struct cros_ec_command *msg;
189 int ret;
190 unsigned int val;
191 struct cros_ec_dev *ec = container_of(dev,
192 struct cros_ec_dev, class_dev);
193
194 if (kstrtouint(buf, 0, &val))
195 return -EINVAL;
196
197 msg = alloc_lightbar_cmd_msg(ec);
198 if (!msg)
199 return -ENOMEM;
200
201 param = (struct ec_params_lightbar *)msg->data;
202 param->cmd = LIGHTBAR_CMD_SET_BRIGHTNESS;
203 param->set_brightness.num = val;
204 ret = lb_throttle();
205 if (ret)
206 goto exit;
207
208 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
209 if (ret < 0)
210 goto exit;
211
212 if (msg->result != EC_RES_SUCCESS) {
213 ret = -EINVAL;
214 goto exit;
215 }
216
217 ret = count;
218exit:
219 kfree(msg);
220 return ret;
221}
222
223
224/*
225 * We expect numbers, and we'll keep reading until we find them, skipping over
226 * any whitespace (sysfs guarantees that the input is null-terminated). Every
227 * four numbers are sent to the lightbar as <LED,R,G,B>. We fail at the first
228 * parsing error, if we don't parse any numbers, or if we have numbers left
229 * over.
230 */
231static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
232 const char *buf, size_t count)
233{
234 struct ec_params_lightbar *param;
235 struct cros_ec_command *msg;
236 struct cros_ec_dev *ec = container_of(dev,
237 struct cros_ec_dev, class_dev);
238 unsigned int val[4];
239 int ret, i = 0, j = 0, ok = 0;
240
241 msg = alloc_lightbar_cmd_msg(ec);
242 if (!msg)
243 return -ENOMEM;
244
245 do {
246 /* Skip any whitespace */
247 while (*buf && isspace(*buf))
248 buf++;
249
250 if (!*buf)
251 break;
252
253 ret = sscanf(buf, "%i", &val[i++]);
254 if (ret == 0)
255 goto exit;
256
257 if (i == 4) {
258 param = (struct ec_params_lightbar *)msg->data;
259 param->cmd = LIGHTBAR_CMD_SET_RGB;
260 param->set_rgb.led = val[0];
261 param->set_rgb.red = val[1];
262 param->set_rgb.green = val[2];
263 param->set_rgb.blue = val[3];
264 /*
265 * Throttle only the first of every four transactions,
266 * so that the user can update all four LEDs at once.
267 */
268 if ((j++ % 4) == 0) {
269 ret = lb_throttle();
270 if (ret)
271 goto exit;
272 }
273
274 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
275 if (ret < 0)
276 goto exit;
277
278 if (msg->result != EC_RES_SUCCESS)
279 goto exit;
280
281 i = 0;
282 ok = 1;
283 }
284
285 /* Skip over the number we just read */
286 while (*buf && !isspace(*buf))
287 buf++;
288
289 } while (*buf);
290
291exit:
292 kfree(msg);
293 return (ok && i == 0) ? count : -EINVAL;
294}
295
296static char const *seqname[] = {
297 "ERROR", "S5", "S3", "S0", "S5S3", "S3S0",
298 "S0S3", "S3S5", "STOP", "RUN", "PULSE", "TEST", "KONAMI",
299};
300
301static ssize_t sequence_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
303{
304 struct ec_params_lightbar *param;
305 struct ec_response_lightbar *resp;
306 struct cros_ec_command *msg;
307 int ret;
308 struct cros_ec_dev *ec = container_of(dev,
309 struct cros_ec_dev, class_dev);
310
311 msg = alloc_lightbar_cmd_msg(ec);
312 if (!msg)
313 return -ENOMEM;
314
315 param = (struct ec_params_lightbar *)msg->data;
316 param->cmd = LIGHTBAR_CMD_GET_SEQ;
317 ret = lb_throttle();
318 if (ret)
319 goto exit;
320
321 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
322 if (ret < 0)
323 goto exit;
324
325 if (msg->result != EC_RES_SUCCESS) {
326 ret = scnprintf(buf, PAGE_SIZE,
327 "ERROR: EC returned %d\n", msg->result);
328 goto exit;
329 }
330
331 resp = (struct ec_response_lightbar *)msg->data;
332 if (resp->get_seq.num >= ARRAY_SIZE(seqname))
333 ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->get_seq.num);
334 else
335 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
336 seqname[resp->get_seq.num]);
337
338exit:
339 kfree(msg);
340 return ret;
341}
342
343static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
344 const char *buf, size_t count)
345{
346 struct ec_params_lightbar *param;
347 struct cros_ec_command *msg;
348 unsigned int num;
349 int ret, len;
350 struct cros_ec_dev *ec = container_of(dev,
351 struct cros_ec_dev, class_dev);
352
353 for (len = 0; len < count; len++)
354 if (!isalnum(buf[len]))
355 break;
356
357 for (num = 0; num < ARRAY_SIZE(seqname); num++)
358 if (!strncasecmp(seqname[num], buf, len))
359 break;
360
361 if (num >= ARRAY_SIZE(seqname)) {
362 ret = kstrtouint(buf, 0, &num);
363 if (ret)
364 return ret;
365 }
366
367 msg = alloc_lightbar_cmd_msg(ec);
368 if (!msg)
369 return -ENOMEM;
370
371 param = (struct ec_params_lightbar *)msg->data;
372 param->cmd = LIGHTBAR_CMD_SEQ;
373 param->seq.num = num;
374 ret = lb_throttle();
375 if (ret)
376 goto exit;
377
378 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
379 if (ret < 0)
380 goto exit;
381
382 if (msg->result != EC_RES_SUCCESS) {
383 ret = -EINVAL;
384 goto exit;
385 }
386
387 ret = count;
388exit:
389 kfree(msg);
390 return ret;
391}
392
393/* Module initialization */
394
395static DEVICE_ATTR_RW(interval_msec);
396static DEVICE_ATTR_RO(version);
397static DEVICE_ATTR_WO(brightness);
398static DEVICE_ATTR_WO(led_rgb);
399static DEVICE_ATTR_RW(sequence);
400static struct attribute *__lb_cmds_attrs[] = {
401 &dev_attr_interval_msec.attr,
402 &dev_attr_version.attr,
403 &dev_attr_brightness.attr,
404 &dev_attr_led_rgb.attr,
405 &dev_attr_sequence.attr,
406 NULL,
407};
408
409static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
410 struct attribute *a, int n)
411{
412 struct device *dev = container_of(kobj, struct device, kobj);
413 struct cros_ec_dev *ec = container_of(dev,
414 struct cros_ec_dev, class_dev);
415 struct platform_device *pdev = container_of(ec->dev,
416 struct platform_device, dev);
417 if (pdev->id != 0)
418 return 0;
419
420 /* Only instantiate this stuff if the EC has a lightbar */
421 if (get_lightbar_version(ec, NULL, NULL))
422 return a->mode;
423 else
424 return 0;
425}
426
427struct attribute_group cros_ec_lightbar_attr_group = {
428 .name = "lightbar",
429 .attrs = __lb_cmds_attrs,
430 .is_visible = cros_ec_lightbar_attrs_are_visible,
431};