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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/module.h>
12#include <linux/platform_data/cros_ec_commands.h>
13#include <linux/platform_data/cros_ec_proto.h>
14#include <linux/platform_device.h>
15#include <linux/sched.h>
16#include <linux/types.h>
17#include <linux/uaccess.h>
18#include <linux/slab.h>
19
20#define DRV_NAME "cros-ec-lightbar"
21
22/* Rate-limit the lightbar interface to prevent DoS. */
23static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
24
25/*
26 * Whether or not we have given userspace control of the lightbar.
27 * If this is true, we won't do anything during suspend/resume.
28 */
29static bool userspace_control;
30
31static ssize_t interval_msec_show(struct device *dev,
32 struct device_attribute *attr, char *buf)
33{
34 unsigned long msec = lb_interval_jiffies * 1000 / HZ;
35
36 return scnprintf(buf, PAGE_SIZE, "%lu\n", msec);
37}
38
39static ssize_t interval_msec_store(struct device *dev,
40 struct device_attribute *attr,
41 const char *buf, size_t count)
42{
43 unsigned long msec;
44
45 if (kstrtoul(buf, 0, &msec))
46 return -EINVAL;
47
48 lb_interval_jiffies = msec * HZ / 1000;
49
50 return count;
51}
52
53static DEFINE_MUTEX(lb_mutex);
54/* Return 0 if able to throttle correctly, error otherwise */
55static int lb_throttle(void)
56{
57 static unsigned long last_access;
58 unsigned long now, next_timeslot;
59 long delay;
60 int ret = 0;
61
62 mutex_lock(&lb_mutex);
63
64 now = jiffies;
65 next_timeslot = last_access + lb_interval_jiffies;
66
67 if (time_before(now, next_timeslot)) {
68 delay = (long)(next_timeslot) - (long)now;
69 set_current_state(TASK_INTERRUPTIBLE);
70 if (schedule_timeout(delay) > 0) {
71 /* interrupted - just abort */
72 ret = -EINTR;
73 goto out;
74 }
75 now = jiffies;
76 }
77
78 last_access = now;
79out:
80 mutex_unlock(&lb_mutex);
81
82 return ret;
83}
84
85static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
86{
87 struct cros_ec_command *msg;
88 int len;
89
90 len = max(sizeof(struct ec_params_lightbar),
91 sizeof(struct ec_response_lightbar));
92
93 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
94 if (!msg)
95 return NULL;
96
97 msg->version = 0;
98 msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
99 msg->outsize = sizeof(struct ec_params_lightbar);
100 msg->insize = sizeof(struct ec_response_lightbar);
101
102 return msg;
103}
104
105static int get_lightbar_version(struct cros_ec_dev *ec,
106 uint32_t *ver_ptr, uint32_t *flg_ptr)
107{
108 struct ec_params_lightbar *param;
109 struct ec_response_lightbar *resp;
110 struct cros_ec_command *msg;
111 int ret;
112
113 msg = alloc_lightbar_cmd_msg(ec);
114 if (!msg)
115 return 0;
116
117 param = (struct ec_params_lightbar *)msg->data;
118 param->cmd = LIGHTBAR_CMD_VERSION;
119 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
120 if (ret < 0) {
121 ret = 0;
122 goto exit;
123 }
124
125 switch (msg->result) {
126 case EC_RES_INVALID_PARAM:
127 /* Pixel had no version command. */
128 if (ver_ptr)
129 *ver_ptr = 0;
130 if (flg_ptr)
131 *flg_ptr = 0;
132 ret = 1;
133 goto exit;
134
135 case EC_RES_SUCCESS:
136 resp = (struct ec_response_lightbar *)msg->data;
137
138 /* Future devices w/lightbars should implement this command */
139 if (ver_ptr)
140 *ver_ptr = resp->version.num;
141 if (flg_ptr)
142 *flg_ptr = resp->version.flags;
143 ret = 1;
144 goto exit;
145 }
146
147 /* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
148 ret = 0;
149exit:
150 kfree(msg);
151 return ret;
152}
153
154static ssize_t version_show(struct device *dev,
155 struct device_attribute *attr, char *buf)
156{
157 uint32_t version = 0, flags = 0;
158 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
159 int ret;
160
161 ret = lb_throttle();
162 if (ret)
163 return ret;
164
165 /* This should always succeed, because we check during init. */
166 if (!get_lightbar_version(ec, &version, &flags))
167 return -EIO;
168
169 return scnprintf(buf, PAGE_SIZE, "%d %d\n", version, flags);
170}
171
172static ssize_t brightness_store(struct device *dev,
173 struct device_attribute *attr,
174 const char *buf, size_t count)
175{
176 struct ec_params_lightbar *param;
177 struct cros_ec_command *msg;
178 int ret;
179 unsigned int val;
180 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
181
182 if (kstrtouint(buf, 0, &val))
183 return -EINVAL;
184
185 msg = alloc_lightbar_cmd_msg(ec);
186 if (!msg)
187 return -ENOMEM;
188
189 param = (struct ec_params_lightbar *)msg->data;
190 param->cmd = LIGHTBAR_CMD_SET_BRIGHTNESS;
191 param->set_brightness.num = val;
192 ret = lb_throttle();
193 if (ret)
194 goto exit;
195
196 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
197 if (ret < 0)
198 goto exit;
199
200 ret = count;
201exit:
202 kfree(msg);
203 return ret;
204}
205
206
207/*
208 * We expect numbers, and we'll keep reading until we find them, skipping over
209 * any whitespace (sysfs guarantees that the input is null-terminated). Every
210 * four numbers are sent to the lightbar as <LED,R,G,B>. We fail at the first
211 * parsing error, if we don't parse any numbers, or if we have numbers left
212 * over.
213 */
214static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
215 const char *buf, size_t count)
216{
217 struct ec_params_lightbar *param;
218 struct cros_ec_command *msg;
219 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
220 unsigned int val[4];
221 int ret, i = 0, j = 0, ok = 0;
222
223 msg = alloc_lightbar_cmd_msg(ec);
224 if (!msg)
225 return -ENOMEM;
226
227 do {
228 /* Skip any whitespace */
229 while (*buf && isspace(*buf))
230 buf++;
231
232 if (!*buf)
233 break;
234
235 ret = sscanf(buf, "%i", &val[i++]);
236 if (ret == 0)
237 goto exit;
238
239 if (i == 4) {
240 param = (struct ec_params_lightbar *)msg->data;
241 param->cmd = LIGHTBAR_CMD_SET_RGB;
242 param->set_rgb.led = val[0];
243 param->set_rgb.red = val[1];
244 param->set_rgb.green = val[2];
245 param->set_rgb.blue = val[3];
246 /*
247 * Throttle only the first of every four transactions,
248 * so that the user can update all four LEDs at once.
249 */
250 if ((j++ % 4) == 0) {
251 ret = lb_throttle();
252 if (ret)
253 goto exit;
254 }
255
256 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
257 if (ret < 0)
258 goto exit;
259
260 i = 0;
261 ok = 1;
262 }
263
264 /* Skip over the number we just read */
265 while (*buf && !isspace(*buf))
266 buf++;
267
268 } while (*buf);
269
270exit:
271 kfree(msg);
272 return (ok && i == 0) ? count : -EINVAL;
273}
274
275static char const *seqname[] = {
276 "ERROR", "S5", "S3", "S0", "S5S3", "S3S0",
277 "S0S3", "S3S5", "STOP", "RUN", "KONAMI",
278 "TAP", "PROGRAM",
279};
280
281static ssize_t sequence_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283{
284 struct ec_params_lightbar *param;
285 struct ec_response_lightbar *resp;
286 struct cros_ec_command *msg;
287 int ret;
288 struct cros_ec_dev *ec = to_cros_ec_dev(dev);
289
290 msg = alloc_lightbar_cmd_msg(ec);
291 if (!msg)
292 return -ENOMEM;
293
294 param = (struct ec_params_lightbar *)msg->data;
295 param->cmd = LIGHTBAR_CMD_GET_SEQ;
296 ret = lb_throttle();
297 if (ret)
298 goto exit;
299
300 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
301 if (ret == -EPROTO) {
302 ret = scnprintf(buf, PAGE_SIZE,
303 "ERROR: EC returned %d\n", msg->result);
304 goto exit;
305 } else if (ret < 0) {
306 goto exit;
307 }
308
309 resp = (struct ec_response_lightbar *)msg->data;
310 if (resp->get_seq.num >= ARRAY_SIZE(seqname))
311 ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->get_seq.num);
312 else
313 ret = scnprintf(buf, PAGE_SIZE, "%s\n",
314 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 scnprintf(buf, PAGE_SIZE, "%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 = strtobool(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 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 int 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 return 0;
575}
576
577static int __maybe_unused cros_ec_lightbar_resume(struct device *dev)
578{
579 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
580
581 if (userspace_control)
582 return 0;
583
584 return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_RESUME);
585}
586
587static int __maybe_unused cros_ec_lightbar_suspend(struct device *dev)
588{
589 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
590
591 if (userspace_control)
592 return 0;
593
594 return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_SUSPEND);
595}
596
597static SIMPLE_DEV_PM_OPS(cros_ec_lightbar_pm_ops,
598 cros_ec_lightbar_suspend, cros_ec_lightbar_resume);
599
600static struct platform_driver cros_ec_lightbar_driver = {
601 .driver = {
602 .name = DRV_NAME,
603 .pm = &cros_ec_lightbar_pm_ops,
604 },
605 .probe = cros_ec_lightbar_probe,
606 .remove = cros_ec_lightbar_remove,
607};
608
609module_platform_driver(cros_ec_lightbar_driver);
610
611MODULE_LICENSE("GPL");
612MODULE_DESCRIPTION("Expose the Chromebook Pixel's lightbar to userspace");
613MODULE_ALIAS("platform:" DRV_NAME);