1/*
2 * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
3 *
4 * Copyright (C) 2010 LaCie
5 *
6 * Author: Simon Guinot <sguinot@lacie.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 */
22
23#include <linux/module.h>
24#include <linux/irq.h>
25#include <linux/slab.h>
26#include <linux/spinlock.h>
27#include <linux/platform_device.h>
28#include <linux/gpio.h>
29#include <linux/of_gpio.h>
30#include <linux/leds.h>
31#include <linux/platform_data/leds-kirkwood-netxbig.h>
32
33/*
34 * GPIO extension bus.
35 */
36
37static DEFINE_SPINLOCK(gpio_ext_lock);
38
39static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
40{
41	int pin;
42
43	for (pin = 0; pin < gpio_ext->num_addr; pin++)
44		gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
45}
46
47static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
48{
49	int pin;
50
51	for (pin = 0; pin < gpio_ext->num_data; pin++)
52		gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
53}
54
55static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
56{
57	/* Enable select is done on the raising edge. */
58	gpio_set_value(gpio_ext->enable, 0);
59	gpio_set_value(gpio_ext->enable, 1);
60}
61
62static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
63			       int addr, int value)
64{
65	unsigned long flags;
66
67	spin_lock_irqsave(&gpio_ext_lock, flags);
68	gpio_ext_set_addr(gpio_ext, addr);
69	gpio_ext_set_data(gpio_ext, value);
70	gpio_ext_enable_select(gpio_ext);
71	spin_unlock_irqrestore(&gpio_ext_lock, flags);
72}
73
74static int gpio_ext_init(struct platform_device *pdev,
75			 struct netxbig_gpio_ext *gpio_ext)
76{
77	int err;
78	int i;
79
80	if (unlikely(!gpio_ext))
81		return -EINVAL;
82
83	/* Configure address GPIOs. */
84	for (i = 0; i < gpio_ext->num_addr; i++) {
85		err = devm_gpio_request_one(&pdev->dev, gpio_ext->addr[i],
86					    GPIOF_OUT_INIT_LOW,
87					    "GPIO extension addr");
88		if (err)
89			return err;
90	}
91	/* Configure data GPIOs. */
92	for (i = 0; i < gpio_ext->num_data; i++) {
93		err = devm_gpio_request_one(&pdev->dev, gpio_ext->data[i],
94					    GPIOF_OUT_INIT_LOW,
95					    "GPIO extension data");
96		if (err)
97			return err;
98	}
99	/* Configure "enable select" GPIO. */
100	err = devm_gpio_request_one(&pdev->dev, gpio_ext->enable,
101				    GPIOF_OUT_INIT_LOW,
102				    "GPIO extension enable");
103	if (err)
104		return err;
105
106	return 0;
107}
108
109/*
110 * Class LED driver.
111 */
112
113struct netxbig_led_data {
114	struct netxbig_gpio_ext	*gpio_ext;
115	struct led_classdev	cdev;
116	int			mode_addr;
117	int			*mode_val;
118	int			bright_addr;
119	struct			netxbig_led_timer *timer;
120	int			num_timer;
121	enum netxbig_led_mode	mode;
122	int			sata;
123	spinlock_t		lock;
124};
125
126static int netxbig_led_get_timer_mode(enum netxbig_led_mode *mode,
127				      unsigned long delay_on,
128				      unsigned long delay_off,
129				      struct netxbig_led_timer *timer,
130				      int num_timer)
131{
132	int i;
133
134	for (i = 0; i < num_timer; i++) {
135		if (timer[i].delay_on == delay_on &&
136		    timer[i].delay_off == delay_off) {
137			*mode = timer[i].mode;
138			return 0;
139		}
140	}
141	return -EINVAL;
142}
143
144static int netxbig_led_blink_set(struct led_classdev *led_cdev,
145				 unsigned long *delay_on,
146				 unsigned long *delay_off)
147{
148	struct netxbig_led_data *led_dat =
149		container_of(led_cdev, struct netxbig_led_data, cdev);
150	enum netxbig_led_mode mode;
151	int mode_val;
152	int ret;
153
154	/* Look for a LED mode with the requested timer frequency. */
155	ret = netxbig_led_get_timer_mode(&mode, *delay_on, *delay_off,
156					 led_dat->timer, led_dat->num_timer);
157	if (ret < 0)
158		return ret;
159
160	mode_val = led_dat->mode_val[mode];
161	if (mode_val == NETXBIG_LED_INVALID_MODE)
162		return -EINVAL;
163
164	spin_lock_irq(&led_dat->lock);
165
166	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
167	led_dat->mode = mode;
168
169	spin_unlock_irq(&led_dat->lock);
170
171	return 0;
172}
173
174static void netxbig_led_set(struct led_classdev *led_cdev,
175			    enum led_brightness value)
176{
177	struct netxbig_led_data *led_dat =
178		container_of(led_cdev, struct netxbig_led_data, cdev);
179	enum netxbig_led_mode mode;
180	int mode_val;
181	int set_brightness = 1;
182	unsigned long flags;
183
184	spin_lock_irqsave(&led_dat->lock, flags);
185
186	if (value == LED_OFF) {
187		mode = NETXBIG_LED_OFF;
188		set_brightness = 0;
189	} else {
190		if (led_dat->sata)
191			mode = NETXBIG_LED_SATA;
192		else if (led_dat->mode == NETXBIG_LED_OFF)
193			mode = NETXBIG_LED_ON;
194		else /* Keep 'timer' mode. */
195			mode = led_dat->mode;
196	}
197	mode_val = led_dat->mode_val[mode];
198
199	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
200	led_dat->mode = mode;
201	/*
202	 * Note that the brightness register is shared between all the
203	 * SATA LEDs. So, change the brightness setting for a single
204	 * SATA LED will affect all the others.
205	 */
206	if (set_brightness)
207		gpio_ext_set_value(led_dat->gpio_ext,
208				   led_dat->bright_addr, value);
209
210	spin_unlock_irqrestore(&led_dat->lock, flags);
211}
212
213static ssize_t netxbig_led_sata_store(struct device *dev,
214				      struct device_attribute *attr,
215				      const char *buff, size_t count)
216{
217	struct led_classdev *led_cdev = dev_get_drvdata(dev);
218	struct netxbig_led_data *led_dat =
219		container_of(led_cdev, struct netxbig_led_data, cdev);
220	unsigned long enable;
221	enum netxbig_led_mode mode;
222	int mode_val;
223	int ret;
224
225	ret = kstrtoul(buff, 10, &enable);
226	if (ret < 0)
227		return ret;
228
229	enable = !!enable;
230
231	spin_lock_irq(&led_dat->lock);
232
233	if (led_dat->sata == enable) {
234		ret = count;
235		goto exit_unlock;
236	}
237
238	if (led_dat->mode != NETXBIG_LED_ON &&
239	    led_dat->mode != NETXBIG_LED_SATA)
240		mode = led_dat->mode; /* Keep modes 'off' and 'timer'. */
241	else if (enable)
242		mode = NETXBIG_LED_SATA;
243	else
244		mode = NETXBIG_LED_ON;
245
246	mode_val = led_dat->mode_val[mode];
247	if (mode_val == NETXBIG_LED_INVALID_MODE) {
248		ret = -EINVAL;
249		goto exit_unlock;
250	}
251
252	gpio_ext_set_value(led_dat->gpio_ext, led_dat->mode_addr, mode_val);
253	led_dat->mode = mode;
254	led_dat->sata = enable;
255
256	ret = count;
257
258exit_unlock:
259	spin_unlock_irq(&led_dat->lock);
260
261	return ret;
262}
263
264static ssize_t netxbig_led_sata_show(struct device *dev,
265				     struct device_attribute *attr, char *buf)
266{
267	struct led_classdev *led_cdev = dev_get_drvdata(dev);
268	struct netxbig_led_data *led_dat =
269		container_of(led_cdev, struct netxbig_led_data, cdev);
270
271	return sprintf(buf, "%d\n", led_dat->sata);
272}
273
274static DEVICE_ATTR(sata, 0644, netxbig_led_sata_show, netxbig_led_sata_store);
275
276static struct attribute *netxbig_led_attrs[] = {
277	&dev_attr_sata.attr,
278	NULL
279};
280ATTRIBUTE_GROUPS(netxbig_led);
281
282static int create_netxbig_led(struct platform_device *pdev,
283			      struct netxbig_led_platform_data *pdata,
284			      struct netxbig_led_data *led_dat,
285			      const struct netxbig_led *template)
286{
287	spin_lock_init(&led_dat->lock);
288	led_dat->gpio_ext = pdata->gpio_ext;
289	led_dat->cdev.name = template->name;
290	led_dat->cdev.default_trigger = template->default_trigger;
291	led_dat->cdev.blink_set = netxbig_led_blink_set;
292	led_dat->cdev.brightness_set = netxbig_led_set;
293	/*
294	 * Because the GPIO extension bus don't allow to read registers
295	 * value, there is no way to probe the LED initial state.
296	 * So, the initial sysfs LED value for the "brightness" and "sata"
297	 * attributes are inconsistent.
298	 *
299	 * Note that the initial LED state can't be reconfigured.
300	 * The reason is that the LED behaviour must stay uniform during
301	 * the whole boot process (bootloader+linux).
302	 */
303	led_dat->sata = 0;
304	led_dat->cdev.brightness = LED_OFF;
305	led_dat->cdev.max_brightness = template->bright_max;
306	led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
307	led_dat->mode_addr = template->mode_addr;
308	led_dat->mode_val = template->mode_val;
309	led_dat->bright_addr = template->bright_addr;
310	led_dat->timer = pdata->timer;
311	led_dat->num_timer = pdata->num_timer;
312	/*
313	 * If available, expose the SATA activity blink capability through
314	 * a "sata" sysfs attribute.
315	 */
316	if (led_dat->mode_val[NETXBIG_LED_SATA] != NETXBIG_LED_INVALID_MODE)
317		led_dat->cdev.groups = netxbig_led_groups;
318
319	return devm_led_classdev_register(&pdev->dev, &led_dat->cdev);
320}
321
322#ifdef CONFIG_OF_GPIO
323static int gpio_ext_get_of_pdata(struct device *dev, struct device_node *np,
324				 struct netxbig_gpio_ext *gpio_ext)
325{
326	int *addr, *data;
327	int num_addr, num_data;
328	int ret;
329	int i;
330
331	ret = of_gpio_named_count(np, "addr-gpios");
332	if (ret < 0) {
333		dev_err(dev,
334			"Failed to count GPIOs in DT property addr-gpios\n");
335		return ret;
336	}
337	num_addr = ret;
338	addr = devm_kzalloc(dev, num_addr * sizeof(*addr), GFP_KERNEL);
339	if (!addr)
340		return -ENOMEM;
341
342	for (i = 0; i < num_addr; i++) {
343		ret = of_get_named_gpio(np, "addr-gpios", i);
344		if (ret < 0)
345			return ret;
346		addr[i] = ret;
347	}
348	gpio_ext->addr = addr;
349	gpio_ext->num_addr = num_addr;
350
351	ret = of_gpio_named_count(np, "data-gpios");
352	if (ret < 0) {
353		dev_err(dev,
354			"Failed to count GPIOs in DT property data-gpios\n");
355		return ret;
356	}
357	num_data = ret;
358	data = devm_kzalloc(dev, num_data * sizeof(*data), GFP_KERNEL);
359	if (!data)
360		return -ENOMEM;
361
362	for (i = 0; i < num_data; i++) {
363		ret = of_get_named_gpio(np, "data-gpios", i);
364		if (ret < 0)
365			return ret;
366		data[i] = ret;
367	}
368	gpio_ext->data = data;
369	gpio_ext->num_data = num_data;
370
371	ret = of_get_named_gpio(np, "enable-gpio", 0);
372	if (ret < 0) {
373		dev_err(dev,
374			"Failed to get GPIO from DT property enable-gpio\n");
375		return ret;
376	}
377	gpio_ext->enable = ret;
378
379	return 0;
380}
381
382static int netxbig_leds_get_of_pdata(struct device *dev,
383				     struct netxbig_led_platform_data *pdata)
384{
385	struct device_node *np = dev->of_node;
386	struct device_node *gpio_ext_np;
387	struct device_node *child;
388	struct netxbig_gpio_ext *gpio_ext;
389	struct netxbig_led_timer *timers;
390	struct netxbig_led *leds, *led;
391	int num_timers;
392	int num_leds = 0;
393	int ret;
394	int i;
395
396	/* GPIO extension */
397	gpio_ext_np = of_parse_phandle(np, "gpio-ext", 0);
398	if (!gpio_ext_np) {
399		dev_err(dev, "Failed to get DT handle gpio-ext\n");
400		return -EINVAL;
401	}
402
403	gpio_ext = devm_kzalloc(dev, sizeof(*gpio_ext), GFP_KERNEL);
404	if (!gpio_ext)
405		return -ENOMEM;
406	ret = gpio_ext_get_of_pdata(dev, gpio_ext_np, gpio_ext);
407	if (ret)
408		return ret;
409	of_node_put(gpio_ext_np);
410	pdata->gpio_ext = gpio_ext;
411
412	/* Timers (optional) */
413	ret = of_property_count_u32_elems(np, "timers");
414	if (ret > 0) {
415		if (ret % 3)
416			return -EINVAL;
417		num_timers = ret / 3;
418		timers = devm_kzalloc(dev, num_timers * sizeof(*timers),
419				      GFP_KERNEL);
420		if (!timers)
421			return -ENOMEM;
422		for (i = 0; i < num_timers; i++) {
423			u32 tmp;
424
425			of_property_read_u32_index(np, "timers", 3 * i,
426						   &timers[i].mode);
427			if (timers[i].mode >= NETXBIG_LED_MODE_NUM)
428				return -EINVAL;
429			of_property_read_u32_index(np, "timers",
430						   3 * i + 1, &tmp);
431			timers[i].delay_on = tmp;
432			of_property_read_u32_index(np, "timers",
433						   3 * i + 2, &tmp);
434			timers[i].delay_off = tmp;
435		}
436		pdata->timer = timers;
437		pdata->num_timer = num_timers;
438	}
439
440	/* LEDs */
441	num_leds = of_get_child_count(np);
442	if (!num_leds) {
443		dev_err(dev, "No LED subnodes found in DT\n");
444		return -ENODEV;
445	}
446
447	leds = devm_kzalloc(dev, num_leds * sizeof(*leds), GFP_KERNEL);
448	if (!leds)
449		return -ENOMEM;
450
451	led = leds;
452	for_each_child_of_node(np, child) {
453		const char *string;
454		int *mode_val;
455		int num_modes;
456
457		ret = of_property_read_u32(child, "mode-addr",
458					   &led->mode_addr);
459		if (ret)
460			goto err_node_put;
461
462		ret = of_property_read_u32(child, "bright-addr",
463					   &led->bright_addr);
464		if (ret)
465			goto err_node_put;
466
467		ret = of_property_read_u32(child, "max-brightness",
468					   &led->bright_max);
469		if (ret)
470			goto err_node_put;
471
472		mode_val =
473			devm_kzalloc(dev,
474				     NETXBIG_LED_MODE_NUM * sizeof(*mode_val),
475				     GFP_KERNEL);
476		if (!mode_val) {
477			ret = -ENOMEM;
478			goto err_node_put;
479		}
480
481		for (i = 0; i < NETXBIG_LED_MODE_NUM; i++)
482			mode_val[i] = NETXBIG_LED_INVALID_MODE;
483
484		ret = of_property_count_u32_elems(child, "mode-val");
485		if (ret < 0 || ret % 2) {
486			ret = -EINVAL;
487			goto err_node_put;
488		}
489		num_modes = ret / 2;
490		if (num_modes > NETXBIG_LED_MODE_NUM) {
491			ret = -EINVAL;
492			goto err_node_put;
493		}
494
495		for (i = 0; i < num_modes; i++) {
496			int mode;
497			int val;
498
499			of_property_read_u32_index(child,
500						   "mode-val", 2 * i, &mode);
501			of_property_read_u32_index(child,
502						   "mode-val", 2 * i + 1, &val);
503			if (mode >= NETXBIG_LED_MODE_NUM) {
504				ret = -EINVAL;
505				goto err_node_put;
506			}
507			mode_val[mode] = val;
508		}
509		led->mode_val = mode_val;
510
511		if (!of_property_read_string(child, "label", &string))
512			led->name = string;
513		else
514			led->name = child->name;
515
516		if (!of_property_read_string(child,
517					     "linux,default-trigger", &string))
518			led->default_trigger = string;
519
520		led++;
521	}
522
523	pdata->leds = leds;
524	pdata->num_leds = num_leds;
525
526	return 0;
527
528err_node_put:
529	of_node_put(child);
530	return ret;
531}
532
533static const struct of_device_id of_netxbig_leds_match[] = {
534	{ .compatible = "lacie,netxbig-leds", },
535	{},
536};
537#else
538static inline int
539netxbig_leds_get_of_pdata(struct device *dev,
540			  struct netxbig_led_platform_data *pdata)
541{
542	return -ENODEV;
543}
544#endif /* CONFIG_OF_GPIO */
545
546static int netxbig_led_probe(struct platform_device *pdev)
547{
548	struct netxbig_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
549	struct netxbig_led_data *leds_data;
550	int i;
551	int ret;
552
553	if (!pdata) {
554		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
555		if (!pdata)
556			return -ENOMEM;
557		ret = netxbig_leds_get_of_pdata(&pdev->dev, pdata);
558		if (ret)
559			return ret;
560	}
561
562	leds_data = devm_kzalloc(&pdev->dev,
563				 pdata->num_leds * sizeof(*leds_data),
564				 GFP_KERNEL);
565	if (!leds_data)
566		return -ENOMEM;
567
568	ret = gpio_ext_init(pdev, pdata->gpio_ext);
569	if (ret < 0)
570		return ret;
571
572	for (i = 0; i < pdata->num_leds; i++) {
573		ret = create_netxbig_led(pdev, pdata,
574					 &leds_data[i], &pdata->leds[i]);
575		if (ret < 0)
576			return ret;
577	}
578
579	return 0;
580}
581
582static struct platform_driver netxbig_led_driver = {
583	.probe		= netxbig_led_probe,
584	.driver		= {
585		.name		= "leds-netxbig",
586		.of_match_table	= of_match_ptr(of_netxbig_leds_match),
587	},
588};
589
590module_platform_driver(netxbig_led_driver);
591
592MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
593MODULE_DESCRIPTION("LED driver for LaCie xBig Network boards");
594MODULE_LICENSE("GPL");
595MODULE_ALIAS("platform:leds-netxbig");
596