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