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
20struct 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
28enum 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
39struct netxbig_led_timer {
40	unsigned long		delay_on;
41	unsigned long		delay_off;
42	enum netxbig_led_mode	mode;
43};
44
45struct 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
54struct 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
66static DEFINE_SPINLOCK(gpio_ext_lock);
67
68static 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
76static 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
84static 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
91static 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
107struct 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
120static 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
138static 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
168static 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
207static 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
252exit_unlock:
253	spin_unlock_irq(&led_dat->lock);
254
255	return ret;
256}
257
258static 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
268static DEVICE_ATTR_RW(sata);
269
270static struct attribute *netxbig_led_attrs[] = {
271	&dev_attr_sata.attr,
272	NULL
273};
274ATTRIBUTE_GROUPS(netxbig_led);
275
276static 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 */
324static 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 */
346static 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
419static 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 device_node *child;
427	struct netxbig_gpio_ext *gpio_ext;
428	struct netxbig_led_timer *timers;
429	struct netxbig_led *leds, *led;
430	int num_timers;
431	int num_leds = 0;
432	int ret;
433	int i;
434
435	/* GPIO extension */
436	gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
437	if (!gpio_ext_np) {
438		dev_err(dev, "Failed to get DT handle gpio-ext\n");
439		return -EINVAL;
440	}
441	gpio_ext_pdev = of_find_device_by_node(gpio_ext_np);
442	if (!gpio_ext_pdev) {
443		dev_err(dev, "Failed to find platform device for gpio-ext\n");
444		return -ENODEV;
445	}
446	gpio_ext_dev = &gpio_ext_pdev->dev;
447
448	gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
449	if (!gpio_ext) {
450		of_node_put(gpio_ext_np);
451		ret = -ENOMEM;
452		goto put_device;
453	}
454	ret = netxbig_gpio_ext_get(dev, gpio_ext_dev, gpio_ext);
455	of_node_put(gpio_ext_np);
456	if (ret)
457		goto put_device;
458	pdata->gpio_ext = gpio_ext;
459
460	/* Timers (optional) */
461	ret = of_property_count_u32_elems(np, "timers");
462	if (ret > 0) {
463		if (ret % 3) {
464			ret = -EINVAL;
465			goto put_device;
466		}
467
468		num_timers = ret / 3;
469		timers = devm_kcalloc(dev, num_timers, sizeof(*timers),
470				      GFP_KERNEL);
471		if (!timers) {
472			ret = -ENOMEM;
473			goto put_device;
474		}
475		for (i = 0; i < num_timers; i++) {
476			u32 tmp;
477
478			of_property_read_u32_index(np, "timers", 3 * i,
479						   &timers[i].mode);
480			if (timers[i].mode >= NETXBIG_LED_MODE_NUM) {
481				ret = -EINVAL;
482				goto put_device;
483			}
484			of_property_read_u32_index(np, "timers",
485						   3 * i + 1, &tmp);
486			timers[i].delay_on = tmp;
487			of_property_read_u32_index(np, "timers",
488						   3 * i + 2, &tmp);
489			timers[i].delay_off = tmp;
490		}
491		pdata->timer = timers;
492		pdata->num_timer = num_timers;
493	}
494
495	/* LEDs */
496	num_leds = of_get_available_child_count(np);
497	if (!num_leds) {
498		dev_err(dev, "No LED subnodes found in DT\n");
499		ret = -ENODEV;
500		goto put_device;
501	}
502
503	leds = devm_kcalloc(dev, num_leds, sizeof(*leds), GFP_KERNEL);
504	if (!leds) {
505		ret = -ENOMEM;
506		goto put_device;
507	}
508
509	led = leds;
510	for_each_available_child_of_node(np, child) {
511		const char *string;
512		int *mode_val;
513		int num_modes;
514
515		ret = of_property_read_u32(child, "mode-addr",
516					   &led->mode_addr);
517		if (ret)
518			goto err_node_put;
519
520		ret = of_property_read_u32(child, "bright-addr",
521					   &led->bright_addr);
522		if (ret)
523			goto err_node_put;
524
525		ret = of_property_read_u32(child, "max-brightness",
526					   &led->bright_max);
527		if (ret)
528			goto err_node_put;
529
530		mode_val =
531			devm_kcalloc(dev,
532				     NETXBIG_LED_MODE_NUM, sizeof(*mode_val),
533				     GFP_KERNEL);
534		if (!mode_val) {
535			ret = -ENOMEM;
536			goto err_node_put;
537		}
538
539		for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
540			mode_val[i] = NETXBIG_LED_INVALID_MODE;
541
542		ret = of_property_count_u32_elems(child, "mode-val");
543		if (ret < 0 || ret % 2) {
544			ret = -EINVAL;
545			goto err_node_put;
546		}
547		num_modes = ret / 2;
548		if (num_modes > NETXBIG_LED_MODE_NUM) {
549			ret = -EINVAL;
550			goto err_node_put;
551		}
552
553		for (i = 0; i < num_modes; i++) {
554			int mode;
555			int val;
556
557			of_property_read_u32_index(child,
558						   "mode-val", 2 * i, &mode);
559			of_property_read_u32_index(child,
560						   "mode-val", 2 * i + 1, &val);
561			if (mode >= NETXBIG_LED_MODE_NUM) {
562				ret = -EINVAL;
563				goto err_node_put;
564			}
565			mode_val[mode] = val;
566		}
567		led->mode_val = mode_val;
568
569		if (!of_property_read_string(child, "label", &string))
570			led->name = string;
571		else
572			led->name = child->name;
573
574		if (!of_property_read_string(child,
575					     "linux,default-trigger", &string))
576			led->default_trigger = string;
577
578		led++;
579	}
580
581	pdata->leds = leds;
582	pdata->num_leds = num_leds;
583
584	return 0;
585
586err_node_put:
587	of_node_put(child);
588put_device:
589	put_device(gpio_ext_dev);
590	return ret;
591}
592
593static const struct of_device_id of_netxbig_leds_match[] = {
594	{ .compatible = "lacie,netxbig-leds", },
595	{},
596};
597MODULE_DEVICE_TABLE(of, of_netxbig_leds_match);
598
599static int netxbig_led_probe(struct platform_device *pdev)
600{
601	struct netxbig_led_platform_data *pdata;
602	struct netxbig_led_data *leds_data;
603	int i;
604	int ret;
605
606	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
607	if (!pdata)
608		return -ENOMEM;
609	ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
610	if (ret)
611		return ret;
612
613	leds_data = devm_kcalloc(&pdev->dev,
614				 pdata->num_leds, sizeof(*leds_data),
615				 GFP_KERNEL);
616	if (!leds_data)
617		return -ENOMEM;
618
619	for (i = 0; i < pdata->num_leds; i++) {
620		ret = create_netxbig_led(pdev, pdata,
621					 &leds_data[i], &pdata->leds[i]);
622		if (ret < 0)
623			return ret;
624	}
625
626	return 0;
627}
628
629static struct platform_driver netxbig_led_driver = {
630	.probe		= netxbig_led_probe,
631	.driver		= {
632		.name		= "leds-netxbig",
633		.of_match_table	= of_netxbig_leds_match,
634	},
635};
636
637module_platform_driver(netxbig_led_driver);
638
639MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
640MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
641MODULE_LICENSE("GPL");
642MODULE_ALIAS("platform:leds-netxbig");
643