1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * CZ.NIC's Turris Omnia LEDs driver |
4 | * |
5 | * 2020, 2023 by Marek BehĂșn <kabel@kernel.org> |
6 | */ |
7 | |
8 | #include <linux/i2c.h> |
9 | #include <linux/led-class-multicolor.h> |
10 | #include <linux/module.h> |
11 | #include <linux/mutex.h> |
12 | #include <linux/of.h> |
13 | #include "leds.h" |
14 | |
15 | #define OMNIA_BOARD_LEDS 12 |
16 | #define OMNIA_LED_NUM_CHANNELS 3 |
17 | |
18 | /* MCU controller commands at I2C address 0x2a */ |
19 | #define OMNIA_MCU_I2C_ADDR 0x2a |
20 | |
21 | #define CMD_GET_STATUS_WORD 0x01 |
22 | #define STS_FEATURES_SUPPORTED BIT(2) |
23 | |
24 | #define CMD_GET_FEATURES 0x10 |
25 | #define FEAT_LED_GAMMA_CORRECTION BIT(5) |
26 | |
27 | /* LED controller commands at I2C address 0x2b */ |
28 | #define CMD_LED_MODE 0x03 |
29 | #define CMD_LED_MODE_LED(l) ((l) & 0x0f) |
30 | #define CMD_LED_MODE_USER 0x10 |
31 | |
32 | #define CMD_LED_STATE 0x04 |
33 | #define CMD_LED_STATE_LED(l) ((l) & 0x0f) |
34 | #define CMD_LED_STATE_ON 0x10 |
35 | |
36 | #define CMD_LED_COLOR 0x05 |
37 | #define CMD_LED_SET_BRIGHTNESS 0x07 |
38 | #define CMD_LED_GET_BRIGHTNESS 0x08 |
39 | |
40 | #define CMD_SET_GAMMA_CORRECTION 0x30 |
41 | #define CMD_GET_GAMMA_CORRECTION 0x31 |
42 | |
43 | struct omnia_led { |
44 | struct led_classdev_mc mc_cdev; |
45 | struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS]; |
46 | u8 cached_channels[OMNIA_LED_NUM_CHANNELS]; |
47 | bool on, hwtrig; |
48 | int reg; |
49 | }; |
50 | |
51 | #define to_omnia_led(l) container_of(l, struct omnia_led, mc_cdev) |
52 | |
53 | struct omnia_leds { |
54 | struct i2c_client *client; |
55 | struct mutex lock; |
56 | bool has_gamma_correction; |
57 | struct omnia_led leds[]; |
58 | }; |
59 | |
60 | static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val) |
61 | { |
62 | u8 buf[2] = { cmd, val }; |
63 | int ret; |
64 | |
65 | ret = i2c_master_send(client, buf, count: sizeof(buf)); |
66 | |
67 | return ret < 0 ? ret : 0; |
68 | } |
69 | |
70 | static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd, |
71 | void *reply, size_t len) |
72 | { |
73 | struct i2c_msg msgs[2]; |
74 | int ret; |
75 | |
76 | msgs[0].addr = addr; |
77 | msgs[0].flags = 0; |
78 | msgs[0].len = 1; |
79 | msgs[0].buf = &cmd; |
80 | msgs[1].addr = addr; |
81 | msgs[1].flags = I2C_M_RD; |
82 | msgs[1].len = len; |
83 | msgs[1].buf = reply; |
84 | |
85 | ret = i2c_transfer(adap: adapter, msgs, ARRAY_SIZE(msgs)); |
86 | if (likely(ret == ARRAY_SIZE(msgs))) |
87 | return 0; |
88 | else if (ret < 0) |
89 | return ret; |
90 | else |
91 | return -EIO; |
92 | } |
93 | |
94 | static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd) |
95 | { |
96 | u8 reply; |
97 | int err; |
98 | |
99 | err = omnia_cmd_read_raw(adapter: client->adapter, addr: client->addr, cmd, reply: &reply, len: 1); |
100 | if (err) |
101 | return err; |
102 | |
103 | return reply; |
104 | } |
105 | |
106 | static int omnia_led_send_color_cmd(const struct i2c_client *client, |
107 | struct omnia_led *led) |
108 | { |
109 | char cmd[5]; |
110 | int ret; |
111 | |
112 | cmd[0] = CMD_LED_COLOR; |
113 | cmd[1] = led->reg; |
114 | cmd[2] = led->subled_info[0].brightness; |
115 | cmd[3] = led->subled_info[1].brightness; |
116 | cmd[4] = led->subled_info[2].brightness; |
117 | |
118 | /* Send the color change command */ |
119 | ret = i2c_master_send(client, buf: cmd, count: 5); |
120 | if (ret < 0) |
121 | return ret; |
122 | |
123 | /* Cache the RGB channel brightnesses */ |
124 | for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) |
125 | led->cached_channels[i] = led->subled_info[i].brightness; |
126 | |
127 | return 0; |
128 | } |
129 | |
130 | /* Determine if the computed RGB channels are different from the cached ones */ |
131 | static bool omnia_led_channels_changed(struct omnia_led *led) |
132 | { |
133 | for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) |
134 | if (led->subled_info[i].brightness != led->cached_channels[i]) |
135 | return true; |
136 | |
137 | return false; |
138 | } |
139 | |
140 | static int omnia_led_brightness_set_blocking(struct led_classdev *cdev, |
141 | enum led_brightness brightness) |
142 | { |
143 | struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(led_cdev: cdev); |
144 | struct omnia_leds *leds = dev_get_drvdata(dev: cdev->dev->parent); |
145 | struct omnia_led *led = to_omnia_led(mc_cdev); |
146 | int err = 0; |
147 | |
148 | mutex_lock(&leds->lock); |
149 | |
150 | /* |
151 | * Only recalculate RGB brightnesses from intensities if brightness is |
152 | * non-zero (if it is zero and the LED is in HW blinking mode, we use |
153 | * max_brightness as brightness). Otherwise we won't be using them and |
154 | * we can save ourselves some software divisions (Omnia's CPU does not |
155 | * implement the division instruction). |
156 | */ |
157 | if (brightness || led->hwtrig) { |
158 | led_mc_calc_color_components(mcled_cdev: mc_cdev, brightness: brightness ?: |
159 | cdev->max_brightness); |
160 | |
161 | /* |
162 | * Send color command only if brightness is non-zero and the RGB |
163 | * channel brightnesses changed. |
164 | */ |
165 | if (omnia_led_channels_changed(led)) |
166 | err = omnia_led_send_color_cmd(client: leds->client, led); |
167 | } |
168 | |
169 | /* |
170 | * Send on/off state change only if (bool)brightness changed and the LED |
171 | * is not being blinked by HW. |
172 | */ |
173 | if (!err && !led->hwtrig && !brightness != !led->on) { |
174 | u8 state = CMD_LED_STATE_LED(led->reg); |
175 | |
176 | if (brightness) |
177 | state |= CMD_LED_STATE_ON; |
178 | |
179 | err = omnia_cmd_write_u8(client: leds->client, CMD_LED_STATE, val: state); |
180 | if (!err) |
181 | led->on = !!brightness; |
182 | } |
183 | |
184 | mutex_unlock(lock: &leds->lock); |
185 | |
186 | return err; |
187 | } |
188 | |
189 | static struct led_hw_trigger_type omnia_hw_trigger_type; |
190 | |
191 | static int omnia_hwtrig_activate(struct led_classdev *cdev) |
192 | { |
193 | struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(led_cdev: cdev); |
194 | struct omnia_leds *leds = dev_get_drvdata(dev: cdev->dev->parent); |
195 | struct omnia_led *led = to_omnia_led(mc_cdev); |
196 | int err = 0; |
197 | |
198 | mutex_lock(&leds->lock); |
199 | |
200 | if (!led->on) { |
201 | /* |
202 | * If the LED is off (brightness was set to 0), the last |
203 | * configured color was not necessarily sent to the MCU. |
204 | * Recompute with max_brightness and send if needed. |
205 | */ |
206 | led_mc_calc_color_components(mcled_cdev: mc_cdev, brightness: cdev->max_brightness); |
207 | |
208 | if (omnia_led_channels_changed(led)) |
209 | err = omnia_led_send_color_cmd(client: leds->client, led); |
210 | } |
211 | |
212 | if (!err) { |
213 | /* Put the LED into MCU controlled mode */ |
214 | err = omnia_cmd_write_u8(client: leds->client, CMD_LED_MODE, |
215 | CMD_LED_MODE_LED(led->reg)); |
216 | if (!err) |
217 | led->hwtrig = true; |
218 | } |
219 | |
220 | mutex_unlock(lock: &leds->lock); |
221 | |
222 | return err; |
223 | } |
224 | |
225 | static void omnia_hwtrig_deactivate(struct led_classdev *cdev) |
226 | { |
227 | struct omnia_leds *leds = dev_get_drvdata(dev: cdev->dev->parent); |
228 | struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev)); |
229 | int err; |
230 | |
231 | mutex_lock(&leds->lock); |
232 | |
233 | led->hwtrig = false; |
234 | |
235 | /* Put the LED into software mode */ |
236 | err = omnia_cmd_write_u8(client: leds->client, CMD_LED_MODE, |
237 | CMD_LED_MODE_LED(led->reg) | |
238 | CMD_LED_MODE_USER); |
239 | |
240 | mutex_unlock(lock: &leds->lock); |
241 | |
242 | if (err) |
243 | dev_err(cdev->dev, "Cannot put LED to software mode: %i\n" , |
244 | err); |
245 | } |
246 | |
247 | static struct led_trigger omnia_hw_trigger = { |
248 | .name = "omnia-mcu" , |
249 | .activate = omnia_hwtrig_activate, |
250 | .deactivate = omnia_hwtrig_deactivate, |
251 | .trigger_type = &omnia_hw_trigger_type, |
252 | }; |
253 | |
254 | static int omnia_led_register(struct i2c_client *client, struct omnia_led *led, |
255 | struct device_node *np) |
256 | { |
257 | struct led_init_data init_data = {}; |
258 | struct device *dev = &client->dev; |
259 | struct led_classdev *cdev; |
260 | int ret, color; |
261 | |
262 | ret = of_property_read_u32(np, propname: "reg" , out_value: &led->reg); |
263 | if (ret || led->reg >= OMNIA_BOARD_LEDS) { |
264 | dev_warn(dev, |
265 | "Node %pOF: must contain 'reg' property with values between 0 and %i\n" , |
266 | np, OMNIA_BOARD_LEDS - 1); |
267 | return 0; |
268 | } |
269 | |
270 | ret = of_property_read_u32(np, propname: "color" , out_value: &color); |
271 | if (ret || color != LED_COLOR_ID_RGB) { |
272 | dev_warn(dev, |
273 | "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n" , |
274 | np); |
275 | return 0; |
276 | } |
277 | |
278 | led->subled_info[0].color_index = LED_COLOR_ID_RED; |
279 | led->subled_info[1].color_index = LED_COLOR_ID_GREEN; |
280 | led->subled_info[2].color_index = LED_COLOR_ID_BLUE; |
281 | |
282 | /* Initial color is white */ |
283 | for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) { |
284 | led->subled_info[i].intensity = 255; |
285 | led->subled_info[i].brightness = 255; |
286 | led->subled_info[i].channel = i; |
287 | } |
288 | |
289 | led->mc_cdev.subled_info = led->subled_info; |
290 | led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS; |
291 | |
292 | init_data.fwnode = &np->fwnode; |
293 | |
294 | cdev = &led->mc_cdev.led_cdev; |
295 | cdev->max_brightness = 255; |
296 | cdev->brightness_set_blocking = omnia_led_brightness_set_blocking; |
297 | cdev->trigger_type = &omnia_hw_trigger_type; |
298 | /* |
299 | * Use the omnia-mcu trigger as the default trigger. It may be rewritten |
300 | * by LED class from the linux,default-trigger property. |
301 | */ |
302 | cdev->default_trigger = omnia_hw_trigger.name; |
303 | |
304 | /* put the LED into software mode */ |
305 | ret = omnia_cmd_write_u8(client, CMD_LED_MODE, |
306 | CMD_LED_MODE_LED(led->reg) | |
307 | CMD_LED_MODE_USER); |
308 | if (ret) { |
309 | dev_err(dev, "Cannot set LED %pOF to software mode: %i\n" , np, |
310 | ret); |
311 | return ret; |
312 | } |
313 | |
314 | /* disable the LED */ |
315 | ret = omnia_cmd_write_u8(client, CMD_LED_STATE, |
316 | CMD_LED_STATE_LED(led->reg)); |
317 | if (ret) { |
318 | dev_err(dev, "Cannot set LED %pOF brightness: %i\n" , np, ret); |
319 | return ret; |
320 | } |
321 | |
322 | /* Set initial color and cache it */ |
323 | ret = omnia_led_send_color_cmd(client, led); |
324 | if (ret < 0) { |
325 | dev_err(dev, "Cannot set LED %pOF initial color: %i\n" , np, |
326 | ret); |
327 | return ret; |
328 | } |
329 | |
330 | ret = devm_led_classdev_multicolor_register_ext(parent: dev, mcled_cdev: &led->mc_cdev, |
331 | init_data: &init_data); |
332 | if (ret < 0) { |
333 | dev_err(dev, "Cannot register LED %pOF: %i\n" , np, ret); |
334 | return ret; |
335 | } |
336 | |
337 | return 1; |
338 | } |
339 | |
340 | /* |
341 | * On the front panel of the Turris Omnia router there is also a button which |
342 | * can be used to control the intensity of all the LEDs at once, so that if they |
343 | * are too bright, user can dim them. |
344 | * The microcontroller cycles between 8 levels of this global brightness (from |
345 | * 100% to 0%), but this setting can have any integer value between 0 and 100. |
346 | * It is therefore convenient to be able to change this setting from software. |
347 | * We expose this setting via a sysfs attribute file called "brightness". This |
348 | * file lives in the device directory of the LED controller, not an individual |
349 | * LED, so it should not confuse users. |
350 | */ |
351 | static ssize_t brightness_show(struct device *dev, struct device_attribute *a, |
352 | char *buf) |
353 | { |
354 | struct i2c_client *client = to_i2c_client(dev); |
355 | int ret; |
356 | |
357 | ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS); |
358 | |
359 | if (ret < 0) |
360 | return ret; |
361 | |
362 | return sysfs_emit(buf, fmt: "%d\n" , ret); |
363 | } |
364 | |
365 | static ssize_t brightness_store(struct device *dev, struct device_attribute *a, |
366 | const char *buf, size_t count) |
367 | { |
368 | struct i2c_client *client = to_i2c_client(dev); |
369 | unsigned long brightness; |
370 | int err; |
371 | |
372 | if (kstrtoul(s: buf, base: 10, res: &brightness)) |
373 | return -EINVAL; |
374 | |
375 | if (brightness > 100) |
376 | return -EINVAL; |
377 | |
378 | err = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, val: brightness); |
379 | |
380 | return err ?: count; |
381 | } |
382 | static DEVICE_ATTR_RW(brightness); |
383 | |
384 | static ssize_t gamma_correction_show(struct device *dev, |
385 | struct device_attribute *a, char *buf) |
386 | { |
387 | struct i2c_client *client = to_i2c_client(dev); |
388 | struct omnia_leds *leds = i2c_get_clientdata(client); |
389 | int ret; |
390 | |
391 | if (leds->has_gamma_correction) { |
392 | ret = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION); |
393 | if (ret < 0) |
394 | return ret; |
395 | } else { |
396 | ret = 0; |
397 | } |
398 | |
399 | return sysfs_emit(buf, fmt: "%d\n" , !!ret); |
400 | } |
401 | |
402 | static ssize_t gamma_correction_store(struct device *dev, |
403 | struct device_attribute *a, |
404 | const char *buf, size_t count) |
405 | { |
406 | struct i2c_client *client = to_i2c_client(dev); |
407 | struct omnia_leds *leds = i2c_get_clientdata(client); |
408 | bool val; |
409 | int err; |
410 | |
411 | if (!leds->has_gamma_correction) |
412 | return -EOPNOTSUPP; |
413 | |
414 | if (kstrtobool(s: buf, res: &val) < 0) |
415 | return -EINVAL; |
416 | |
417 | err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val); |
418 | |
419 | return err ?: count; |
420 | } |
421 | static DEVICE_ATTR_RW(gamma_correction); |
422 | |
423 | static struct attribute *omnia_led_controller_attrs[] = { |
424 | &dev_attr_brightness.attr, |
425 | &dev_attr_gamma_correction.attr, |
426 | NULL, |
427 | }; |
428 | ATTRIBUTE_GROUPS(omnia_led_controller); |
429 | |
430 | static int omnia_mcu_get_features(const struct i2c_client *client) |
431 | { |
432 | u16 reply; |
433 | int err; |
434 | |
435 | err = omnia_cmd_read_raw(adapter: client->adapter, OMNIA_MCU_I2C_ADDR, |
436 | CMD_GET_STATUS_WORD, reply: &reply, len: sizeof(reply)); |
437 | if (err) |
438 | return err; |
439 | |
440 | /* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */ |
441 | if (!(le16_to_cpu(reply) & STS_FEATURES_SUPPORTED)) |
442 | return 0; |
443 | |
444 | err = omnia_cmd_read_raw(adapter: client->adapter, OMNIA_MCU_I2C_ADDR, |
445 | CMD_GET_FEATURES, reply: &reply, len: sizeof(reply)); |
446 | if (err) |
447 | return err; |
448 | |
449 | return le16_to_cpu(reply); |
450 | } |
451 | |
452 | static int omnia_leds_probe(struct i2c_client *client) |
453 | { |
454 | struct device *dev = &client->dev; |
455 | struct device_node *np = dev_of_node(dev), *child; |
456 | struct omnia_leds *leds; |
457 | struct omnia_led *led; |
458 | int ret, count; |
459 | |
460 | count = of_get_available_child_count(np); |
461 | if (!count) { |
462 | dev_err(dev, "LEDs are not defined in device tree!\n" ); |
463 | return -ENODEV; |
464 | } else if (count > OMNIA_BOARD_LEDS) { |
465 | dev_err(dev, "Too many LEDs defined in device tree!\n" ); |
466 | return -EINVAL; |
467 | } |
468 | |
469 | leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL); |
470 | if (!leds) |
471 | return -ENOMEM; |
472 | |
473 | leds->client = client; |
474 | i2c_set_clientdata(client, data: leds); |
475 | |
476 | ret = omnia_mcu_get_features(client); |
477 | if (ret < 0) { |
478 | dev_err(dev, "Cannot determine MCU supported features: %d\n" , |
479 | ret); |
480 | return ret; |
481 | } |
482 | |
483 | leds->has_gamma_correction = ret & FEAT_LED_GAMMA_CORRECTION; |
484 | if (!leds->has_gamma_correction) { |
485 | dev_info(dev, |
486 | "Your board's MCU firmware does not support the LED gamma correction feature.\n" ); |
487 | dev_info(dev, |
488 | "Consider upgrading MCU firmware with the omnia-mcutool utility.\n" ); |
489 | } |
490 | |
491 | mutex_init(&leds->lock); |
492 | |
493 | ret = devm_led_trigger_register(dev, trigger: &omnia_hw_trigger); |
494 | if (ret < 0) { |
495 | dev_err(dev, "Cannot register private LED trigger: %d\n" , ret); |
496 | return ret; |
497 | } |
498 | |
499 | led = &leds->leds[0]; |
500 | for_each_available_child_of_node(np, child) { |
501 | ret = omnia_led_register(client, led, np: child); |
502 | if (ret < 0) { |
503 | of_node_put(node: child); |
504 | return ret; |
505 | } |
506 | |
507 | led += ret; |
508 | } |
509 | |
510 | return 0; |
511 | } |
512 | |
513 | static void omnia_leds_remove(struct i2c_client *client) |
514 | { |
515 | u8 buf[5]; |
516 | |
517 | /* put all LEDs into default (HW triggered) mode */ |
518 | omnia_cmd_write_u8(client, CMD_LED_MODE, |
519 | CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); |
520 | |
521 | /* set all LEDs color to [255, 255, 255] */ |
522 | buf[0] = CMD_LED_COLOR; |
523 | buf[1] = OMNIA_BOARD_LEDS; |
524 | buf[2] = 255; |
525 | buf[3] = 255; |
526 | buf[4] = 255; |
527 | |
528 | i2c_master_send(client, buf, count: 5); |
529 | } |
530 | |
531 | static const struct of_device_id of_omnia_leds_match[] = { |
532 | { .compatible = "cznic,turris-omnia-leds" , }, |
533 | {}, |
534 | }; |
535 | |
536 | static const struct i2c_device_id omnia_id[] = { |
537 | { "omnia" , 0 }, |
538 | { } |
539 | }; |
540 | MODULE_DEVICE_TABLE(i2c, omnia_id); |
541 | |
542 | static struct i2c_driver omnia_leds_driver = { |
543 | .probe = omnia_leds_probe, |
544 | .remove = omnia_leds_remove, |
545 | .id_table = omnia_id, |
546 | .driver = { |
547 | .name = "leds-turris-omnia" , |
548 | .of_match_table = of_omnia_leds_match, |
549 | .dev_groups = omnia_led_controller_groups, |
550 | }, |
551 | }; |
552 | |
553 | module_i2c_driver(omnia_leds_driver); |
554 | |
555 | MODULE_AUTHOR("Marek Behun <kabel@kernel.org>" ); |
556 | MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs" ); |
557 | MODULE_LICENSE("GPL v2" ); |
558 | |