1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
4 *
5 * Copyright (C) 2010 LaCie
6 *
7 * Author: Simon Guinot <sguinot@lacie.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/irq.h>
12 #include <linux/slab.h>
13 #include <linux/spinlock.h>
14 #include <linux/platform_device.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/leds.h>
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19
20 struct netxbig_gpio_ext {
21 struct gpio_desc **addr;
22 int num_addr;
23 struct gpio_desc **data;
24 int num_data;
25 struct gpio_desc *enable;
26 };
27
28 enum netxbig_led_mode {
29 NETXBIG_LED_OFF,
30 NETXBIG_LED_ON,
31 NETXBIG_LED_SATA,
32 NETXBIG_LED_TIMER1,
33 NETXBIG_LED_TIMER2,
34 NETXBIG_LED_MODE_NUM,
35 };
36
37 #define NETXBIG_LED_INVALID_MODE NETXBIG_LED_MODE_NUM
38
39 struct netxbig_led_timer {
40 unsigned long delay_on;
41 unsigned long delay_off;
42 enum netxbig_led_mode mode;
43 };
44
45 struct netxbig_led {
46 const char *name;
47 const char *default_trigger;
48 int mode_addr;
49 int *mode_val;
50 int bright_addr;
51 int bright_max;
52 };
53
54 struct netxbig_led_platform_data {
55 struct netxbig_gpio_ext *gpio_ext;
56 struct netxbig_led_timer *timer;
57 int num_timer;
58 struct netxbig_led *leds;
59 int num_leds;
60 };
61
62 /*
63 * GPIO extension bus.
64 */
65
66 static DEFINE_SPINLOCK(gpio_ext_lock);
67
gpio_ext_set_addr(struct netxbig_gpio_ext * gpio_ext,int addr)68 static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
69 {
70 int pin;
71
72 for (pin = 0; pin < gpio_ext->num_addr; pin++)
73 gpiod_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
74 }
75
gpio_ext_set_data(struct netxbig_gpio_ext * gpio_ext,int data)76 static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
77 {
78 int pin;
79
80 for (pin = 0; pin < gpio_ext->num_data; pin++)
81 gpiod_set_value(gpio_ext->data[pin], (data >> pin) & 1);
82 }
83
gpio_ext_enable_select(struct netxbig_gpio_ext * gpio_ext)84 static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
85 {
86 /* Enable select is done on the raising edge. */
87 gpiod_set_value(gpio_ext->enable, 0);
88 gpiod_set_value(gpio_ext->enable, 1);
89 }
90
gpio_ext_set_value(struct netxbig_gpio_ext * gpio_ext,int addr,int value)91 static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
92 int addr, int value)
93 {
94 unsigned long flags;
95
96 spin_lock_irqsave(&gpio_ext_lock, flags);
97 gpio_ext_set_addr(gpio_ext, addr);
98 gpio_ext_set_data(gpio_ext, value);
99 gpio_ext_enable_select(gpio_ext);
100 spin_unlock_irqrestore(&gpio_ext_lock, flags);
101 }
102
103 /*
104 * Class LED driver.
105 */
106
107 struct netxbig_led_data {
108 struct netxbig_gpio_ext *gpio_ext;
109 struct led_classdev cdev;
110 int mode_addr;
111 int *mode_val;
112 int bright_addr;
113 struct netxbig_led_timer *timer;
114 int num_timer;
115 enum netxbig_led_mode mode;
116 int sata;
117 spinlock_t lock;
118 };
119
netxbig_led_get_timer_mode(enum netxbig_led_mode * mode,unsigned long delay_on,unsigned long delay_off,struct netxbig_led_timer * timer,int num_timer)120 static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
121 unsigned long delay_on,
122 unsigned long delay_off,
123 struct netxbig_led_timer *timer,
124 int num_timer)
125 {
126 int i;
127
128 for (i = 0; i < num_timer; i++) {
129 if (timer[i].delay_on == delay_on &&
130 timer[i].delay_off == delay_off) {
131 *mode = timer[i].mode;
132 return 0;
133 }
134 }
135 return -EINVAL;
136 }
137
netxbig_led_blink_set(struct led_classdev * led_cdev,unsigned long * delay_on,unsigned long * delay_off)138 static int netxbig_led_blink_set(struct led_classdev *led_cdev,
139 unsigned long *delay_on,
140 unsigned long *delay_off)
141 {
142 struct netxbig_led_data *led_dat =
143 container_of(led_cdev, struct netxbig_led_data, cdev);
144 enum netxbig_led_mode mode;
145 int mode_val;
146 int ret;
147
148 /* Look for a LED mode with the requested timer frequency. */
149 ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
150 led_dat->timer, led_dat->num_timer);
151 if (ret < 0)
152 return ret;
153
154 mode_val = led_dat->mode_val[mode];
155 if (mode_val == NETXBIG_LED_INVALID_MODE)
156 return -EINVAL;
157
158 spin_lock_irq(&led_dat->lock);
159
160 gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
161 led_dat->mode = mode;
162
163 spin_unlock_irq(&led_dat->lock);
164
165 return 0;
166 }
167
netxbig_led_set(struct led_classdev * led_cdev,enum led_brightness value)168 static void netxbig_led_set(struct led_classdev *led_cdev,
169 enum led_brightness value)
170 {
171 struct netxbig_led_data *led_dat =
172 container_of(led_cdev, struct netxbig_led_data, cdev);
173 enum netxbig_led_mode mode;
174 int mode_val;
175 int set_brightness = 1;
176 unsigned long flags;
177
178 spin_lock_irqsave(&led_dat->lock, flags);
179
180 if (value == LED_OFF) {
181 mode = NETXBIG_LED_OFF;
182 set_brightness = 0;
183 } else {
184 if (led_dat->sata)
185 mode = NETXBIG_LED_SATA;
186 else if (led_dat->mode == NETXBIG_LED_OFF)
187 mode = NETXBIG_LED_ON;
188 else /* Keep 'timer' mode. */
189 mode = led_dat->mode;
190 }
191 mode_val = led_dat->mode_val[mode];
192
193 gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
194 led_dat->mode = mode;
195 /*
196 * Note that the brightness register is shared between all the
197 * SATA LEDs. So, change the brightness setting for a single
198 * SATA LED will affect all the others.
199 */
200 if (set_brightness)
201 gpio_ext_set_value(led_dat->gpio_ext,
202 led_dat->bright_addr, value);
203
204 spin_unlock_irqrestore(&led_dat->lock, flags);
205 }
206
sata_store(struct device * dev,struct device_attribute * attr,const char * buff,size_t count)207 static ssize_t sata_store(struct device *dev,
208 struct device_attribute *attr,
209 const char *buff, size_t count)
210 {
211 struct led_classdev *led_cdev = dev_get_drvdata(dev);
212 struct netxbig_led_data *led_dat =
213 container_of(led_cdev, struct netxbig_led_data, cdev);
214 unsigned long enable;
215 enum netxbig_led_mode mode;
216 int mode_val;
217 int ret;
218
219 ret = kstrtoul(buff, 10, &enable);
220 if (ret < 0)
221 return ret;
222
223 enable = !!enable;
224
225 spin_lock_irq(&led_dat->lock);
226
227 if (led_dat->sata == enable) {
228 ret = count;
229 goto exit_unlock;
230 }
231
232 if (led_dat->mode != NETXBIG_LED_ON &&
233 led_dat->mode != NETXBIG_LED_SATA)
234 mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
235 else if (enable)
236 mode = NETXBIG_LED_SATA;
237 else
238 mode = NETXBIG_LED_ON;
239
240 mode_val = led_dat->mode_val[mode];
241 if (mode_val == NETXBIG_LED_INVALID_MODE) {
242 ret = -EINVAL;
243 goto exit_unlock;
244 }
245
246 gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
247 led_dat->mode = mode;
248 led_dat->sata = enable;
249
250 ret = count;
251
252 exit_unlock:
253 spin_unlock_irq(&led_dat->lock);
254
255 return ret;
256 }
257
sata_show(struct device * dev,struct device_attribute * attr,char * buf)258 static ssize_t sata_show(struct device *dev,
259 struct device_attribute *attr, char *buf)
260 {
261 struct led_classdev *led_cdev = dev_get_drvdata(dev);
262 struct netxbig_led_data *led_dat =
263 container_of(led_cdev, struct netxbig_led_data, cdev);
264
265 return sprintf(buf, "%d\n", led_dat->sata);
266 }
267
268 static DEVICE_ATTR_RW(sata);
269
270 static struct attribute *netxbig_led_attrs[] = {
271 &dev_attr_sata.attr,
272 NULL
273 };
274 ATTRIBUTE_GROUPS(netxbig_led);
275
create_netxbig_led(struct platform_device * pdev,struct netxbig_led_platform_data * pdata,struct netxbig_led_data * led_dat,const struct netxbig_led * template)276 static int create_netxbig_led(struct platform_device *pdev,
277 struct netxbig_led_platform_data *pdata,
278 struct netxbig_led_data *led_dat,
279 const struct netxbig_led *template)
280 {
281 spin_lock_init(&led_dat->lock);
282 led_dat->gpio_ext = pdata->gpio_ext;
283 led_dat->cdev.name = template->name;
284 led_dat->cdev.default_trigger = template->default_trigger;
285 led_dat->cdev.blink_set = netxbig_led_blink_set;
286 led_dat->cdev.brightness_set = netxbig_led_set;
287 /*
288 * Because the GPIO extension bus don't allow to read registers
289 * value, there is no way to probe the LED initial state.
290 * So, the initial sysfs LED value for the "brightness" and "sata"
291 * attributes are inconsistent.
292 *
293 * Note that the initial LED state can't be reconfigured.
294 * The reason is that the LED behaviour must stay uniform during
295 * the whole boot process (bootloader+linux).
296 */
297 led_dat->sata = 0;
298 led_dat->cdev.brightness = LED_OFF;
299 led_dat->cdev.max_brightness = template->bright_max;
300 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
301 led_dat->mode_addr = template->mode_addr;
302 led_dat->mode_val = template->mode_val;
303 led_dat->bright_addr = template->bright_addr;
304 led_dat->timer = pdata->timer;
305 led_dat->num_timer = pdata->num_timer;
306 /*
307 * If available, expose the SATA activity blink capability through
308 * a "sata" sysfs attribute.
309 */
310 if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
311 led_dat->cdev.groups = netxbig_led_groups;
312
313 return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
314 }
315
316 /**
317 * netxbig_gpio_ext_remove() - Clean up GPIO extension data
318 * @data: managed resource data to clean up
319 *
320 * Since we pick GPIO descriptors from another device than the device our
321 * driver is probing to, we need to register a specific callback to free
322 * these up using managed resources.
323 */
netxbig_gpio_ext_remove(void * data)324 static void netxbig_gpio_ext_remove(void *data)
325 {
326 struct netxbig_gpio_ext *gpio_ext = data;
327 int i;
328
329 for (i = 0; i < gpio_ext->num_addr; i++)
330 gpiod_put(gpio_ext->addr[i]);
331 for (i = 0; i < gpio_ext->num_data; i++)
332 gpiod_put(gpio_ext->data[i]);
333 gpiod_put(gpio_ext->enable);
334 }
335
336 /**
337 * netxbig_gpio_ext_get() - Obtain GPIO extension device data
338 * @dev: main LED device
339 * @gpio_ext_dev: the GPIO extension device
340 * @gpio_ext: the data structure holding the GPIO extension data
341 *
342 * This function walks the subdevice that only contain GPIO line
343 * handles in the device tree and obtains the GPIO descriptors from that
344 * device.
345 */
netxbig_gpio_ext_get(struct device * dev,struct device * gpio_ext_dev,struct netxbig_gpio_ext * gpio_ext)346 static int netxbig_gpio_ext_get(struct device *dev,
347 struct device *gpio_ext_dev,
348 struct netxbig_gpio_ext *gpio_ext)
349 {
350 struct gpio_desc **addr, **data;
351 int num_addr, num_data;
352 struct gpio_desc *gpiod;
353 int ret;
354 int i;
355
356 ret = gpiod_count(gpio_ext_dev, "addr");
357 if (ret < 0) {
358 dev_err(dev,
359 "Failed to count GPIOs in DT property addr-gpios\n");
360 return ret;
361 }
362 num_addr = ret;
363 addr = devm_kcalloc(dev, num_addr, sizeof(*addr), GFP_KERNEL);
364 if (!addr)
365 return -ENOMEM;
366
367 /*
368 * We cannot use devm_ managed resources with these GPIO descriptors
369 * since they are associated with the "GPIO extension device" which
370 * does not probe any driver. The device tree parser will however
371 * populate a platform device for it so we can anyway obtain the
372 * GPIO descriptors from the device.
373 */
374 for (i = 0; i < num_addr; i++) {
375 gpiod = gpiod_get_index(gpio_ext_dev, "addr", i,
376 GPIOD_OUT_LOW);
377 if (IS_ERR(gpiod))
378 return PTR_ERR(gpiod);
379 gpiod_set_consumer_name(gpiod, "GPIO extension addr");
380 addr[i] = gpiod;
381 }
382 gpio_ext->addr = addr;
383 gpio_ext->num_addr = num_addr;
384
385 ret = gpiod_count(gpio_ext_dev, "data");
386 if (ret < 0) {
387 dev_err(dev,
388 "Failed to count GPIOs in DT property data-gpios\n");
389 return ret;
390 }
391 num_data = ret;
392 data = devm_kcalloc(dev, num_data, sizeof(*data), GFP_KERNEL);
393 if (!data)
394 return -ENOMEM;
395
396 for (i = 0; i < num_data; i++) {
397 gpiod = gpiod_get_index(gpio_ext_dev, "data", i,
398 GPIOD_OUT_LOW);
399 if (IS_ERR(gpiod))
400 return PTR_ERR(gpiod);
401 gpiod_set_consumer_name(gpiod, "GPIO extension data");
402 data[i] = gpiod;
403 }
404 gpio_ext->data = data;
405 gpio_ext->num_data = num_data;
406
407 gpiod = gpiod_get(gpio_ext_dev, "enable", GPIOD_OUT_LOW);
408 if (IS_ERR(gpiod)) {
409 dev_err(dev,
410 "Failed to get GPIO from DT property enable-gpio\n");
411 return PTR_ERR(gpiod);
412 }
413 gpiod_set_consumer_name(gpiod, "GPIO extension enable");
414 gpio_ext->enable = gpiod;
415
416 return devm_add_action_or_reset(dev, netxbig_gpio_ext_remove, gpio_ext);
417 }
418
netxbig_leds_get_of_pdata(struct device * dev,struct netxbig_led_platform_data * pdata)419 static int netxbig_leds_get_of_pdata(struct device *dev,
420 struct netxbig_led_platform_data *pdata)
421 {
422 struct device_node *np = dev_of_node(dev);
423 struct device_node *gpio_ext_np;
424 struct platform_device *gpio_ext_pdev;
425 struct device *gpio_ext_dev;
426 struct netxbig_gpio_ext *gpio_ext;
427 struct netxbig_led_timer *timers;
428 struct netxbig_led *leds, *led;
429 int num_timers;
430 int num_leds = 0;
431 int ret;
432 int i;
433
434 /* GPIO extension */
435 gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
436 if (!gpio_ext_np) {
437 dev_err(dev, "Failed to get DT handle gpio-ext\n");
438 return -EINVAL;
439 }
440 gpio_ext_pdev = of_find_device_by_node(gpio_ext_np);
441 if (!gpio_ext_pdev) {
442 dev_err(dev, "Failed to find platform device for gpio-ext\n");
443 return -ENODEV;
444 }
445 gpio_ext_dev = &gpio_ext_pdev->dev;
446
447 gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
448 if (!gpio_ext) {
449 of_node_put(gpio_ext_np);
450 ret = -ENOMEM;
451 goto put_device;
452 }
453 ret = netxbig_gpio_ext_get(dev, gpio_ext_dev, gpio_ext);
454 of_node_put(gpio_ext_np);
455 if (ret)
456 goto put_device;
457 pdata->gpio_ext = gpio_ext;
458
459 /* Timers (optional) */
460 ret = of_property_count_u32_elems(np, "timers");
461 if (ret > 0) {
462 if (ret % 3) {
463 ret = -EINVAL;
464 goto put_device;
465 }
466
467 num_timers = ret / 3;
468 timers = devm_kcalloc(dev, num_timers, sizeof(*timers),
469 GFP_KERNEL);
470 if (!timers) {
471 ret = -ENOMEM;
472 goto put_device;
473 }
474 for (i = 0; i < num_timers; i++) {
475 u32 tmp;
476
477 of_property_read_u32_index(np, "timers", 3 * i,
478 &timers[i].mode);
479 if (timers[i].mode >= NETXBIG_LED_MODE_NUM) {
480 ret = -EINVAL;
481 goto put_device;
482 }
483 of_property_read_u32_index(np, "timers",
484 3 * i + 1, &tmp);
485 timers[i].delay_on = tmp;
486 of_property_read_u32_index(np, "timers",
487 3 * i + 2, &tmp);
488 timers[i].delay_off = tmp;
489 }
490 pdata->timer = timers;
491 pdata->num_timer = num_timers;
492 }
493
494 /* LEDs */
495 num_leds = of_get_available_child_count(np);
496 if (!num_leds) {
497 dev_err(dev, "No LED subnodes found in DT\n");
498 ret = -ENODEV;
499 goto put_device;
500 }
501
502 leds = devm_kcalloc(dev, num_leds, sizeof(*leds), GFP_KERNEL);
503 if (!leds) {
504 ret = -ENOMEM;
505 goto put_device;
506 }
507
508 led = leds;
509 for_each_available_child_of_node_scoped(np, child) {
510 const char *string;
511 int *mode_val;
512 int num_modes;
513
514 ret = of_property_read_u32(child, "mode-addr",
515 &led->mode_addr);
516 if (ret)
517 goto put_device;
518
519 ret = of_property_read_u32(child, "bright-addr",
520 &led->bright_addr);
521 if (ret)
522 goto put_device;
523
524 ret = of_property_read_u32(child, "max-brightness",
525 &led->bright_max);
526 if (ret)
527 goto put_device;
528
529 mode_val =
530 devm_kcalloc(dev,
531 NETXBIG_LED_MODE_NUM, sizeof(*mode_val),
532 GFP_KERNEL);
533 if (!mode_val) {
534 ret = -ENOMEM;
535 goto put_device;
536 }
537
538 for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
539 mode_val[i] = NETXBIG_LED_INVALID_MODE;
540
541 ret = of_property_count_u32_elems(child, "mode-val");
542 if (ret < 0 || ret % 2) {
543 ret = -EINVAL;
544 goto put_device;
545 }
546 num_modes = ret / 2;
547 if (num_modes > NETXBIG_LED_MODE_NUM) {
548 ret = -EINVAL;
549 goto put_device;
550 }
551
552 for (i = 0; i < num_modes; i++) {
553 int mode;
554 int val;
555
556 of_property_read_u32_index(child,
557 "mode-val", 2 * i, &mode);
558 of_property_read_u32_index(child,
559 "mode-val", 2 * i + 1, &val);
560 if (mode >= NETXBIG_LED_MODE_NUM) {
561 ret = -EINVAL;
562 goto put_device;
563 }
564 mode_val[mode] = val;
565 }
566 led->mode_val = mode_val;
567
568 if (!of_property_read_string(child, "label", &string))
569 led->name = string;
570 else
571 led->name = child->name;
572
573 if (!of_property_read_string(child,
574 "linux,default-trigger", &string))
575 led->default_trigger = string;
576
577 led++;
578 }
579
580 pdata->leds = leds;
581 pdata->num_leds = num_leds;
582
583 return 0;
584
585 put_device:
586 put_device(gpio_ext_dev);
587 return ret;
588 }
589
590 static const struct of_device_id of_netxbig_leds_match[] = {
591 { .compatible = "lacie,netxbig-leds", },
592 {},
593 };
594 MODULE_DEVICE_TABLE(of, of_netxbig_leds_match);
595
netxbig_led_probe(struct platform_device * pdev)596 static int netxbig_led_probe(struct platform_device *pdev)
597 {
598 struct netxbig_led_platform_data *pdata;
599 struct netxbig_led_data *leds_data;
600 int i;
601 int ret;
602
603 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
604 if (!pdata)
605 return -ENOMEM;
606 ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
607 if (ret)
608 return ret;
609
610 leds_data = devm_kcalloc(&pdev->dev,
611 pdata->num_leds, sizeof(*leds_data),
612 GFP_KERNEL);
613 if (!leds_data)
614 return -ENOMEM;
615
616 for (i = 0; i < pdata->num_leds; i++) {
617 ret = create_netxbig_led(pdev, pdata,
618 &leds_data[i], &pdata->leds[i]);
619 if (ret < 0)
620 return ret;
621 }
622
623 return 0;
624 }
625
626 static struct platform_driver netxbig_led_driver = {
627 .probe = netxbig_led_probe,
628 .driver = {
629 .name = "leds-netxbig",
630 .of_match_table = of_netxbig_leds_match,
631 },
632 };
633
634 module_platform_driver(netxbig_led_driver);
635
636 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
637 MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
638 MODULE_LICENSE("GPL");
639 MODULE_ALIAS("platform:leds-netxbig");
640