xref: /openbmc/linux/drivers/leds/leds-ns2.c (revision 3821a065)
1 /*
2  * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
3  *
4  * Copyright (C) 2010 LaCie
5  *
6  * Author: Simon Guinot <sguinot@lacie.com>
7  *
8  * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23  */
24 
25 #include <linux/kernel.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/gpio.h>
29 #include <linux/leds.h>
30 #include <linux/module.h>
31 #include <linux/platform_data/leds-kirkwood-ns2.h>
32 #include <linux/of.h>
33 #include <linux/of_gpio.h>
34 #include "leds.h"
35 
36 /*
37  * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
38  * modes are available: off, on and SATA activity blinking. The LED modes are
39  * controlled through two GPIOs (command and slow): each combination of values
40  * for the command/slow GPIOs corresponds to a LED mode.
41  */
42 
43 struct ns2_led_data {
44 	struct led_classdev	cdev;
45 	unsigned		cmd;
46 	unsigned		slow;
47 	bool			can_sleep;
48 	int			mode_index;
49 	unsigned char		sata; /* True when SATA mode active. */
50 	rwlock_t		rw_lock; /* Lock GPIOs. */
51 	struct work_struct	work;
52 	int			num_modes;
53 	struct ns2_led_modval	*modval;
54 };
55 
56 static void ns2_led_work(struct work_struct *work)
57 {
58 	struct ns2_led_data *led_dat =
59 		container_of(work, struct ns2_led_data, work);
60 	int i = led_dat->mode_index;
61 
62 	gpio_set_value_cansleep(led_dat->cmd, led_dat->modval[i].cmd_level);
63 	gpio_set_value_cansleep(led_dat->slow, led_dat->modval[i].slow_level);
64 }
65 
66 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
67 			    enum ns2_led_modes *mode)
68 {
69 	int i;
70 	int ret = -EINVAL;
71 	int cmd_level;
72 	int slow_level;
73 
74 	cmd_level = gpio_get_value_cansleep(led_dat->cmd);
75 	slow_level = gpio_get_value_cansleep(led_dat->slow);
76 
77 	for (i = 0; i < led_dat->num_modes; i++) {
78 		if (cmd_level == led_dat->modval[i].cmd_level &&
79 		    slow_level == led_dat->modval[i].slow_level) {
80 			*mode = led_dat->modval[i].mode;
81 			ret = 0;
82 			break;
83 		}
84 	}
85 
86 	return ret;
87 }
88 
89 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
90 			     enum ns2_led_modes mode)
91 {
92 	int i;
93 	bool found = false;
94 	unsigned long flags;
95 
96 	for (i = 0; i < led_dat->num_modes; i++)
97 		if (mode == led_dat->modval[i].mode) {
98 			found = true;
99 			break;
100 		}
101 
102 	if (!found)
103 		return;
104 
105 	write_lock_irqsave(&led_dat->rw_lock, flags);
106 
107 	if (!led_dat->can_sleep) {
108 		gpio_set_value(led_dat->cmd,
109 			       led_dat->modval[i].cmd_level);
110 		gpio_set_value(led_dat->slow,
111 			       led_dat->modval[i].slow_level);
112 		goto exit_unlock;
113 	}
114 
115 	led_dat->mode_index = i;
116 	schedule_work(&led_dat->work);
117 
118 exit_unlock:
119 	write_unlock_irqrestore(&led_dat->rw_lock, flags);
120 }
121 
122 static void ns2_led_set(struct led_classdev *led_cdev,
123 			enum led_brightness value)
124 {
125 	struct ns2_led_data *led_dat =
126 		container_of(led_cdev, struct ns2_led_data, cdev);
127 	enum ns2_led_modes mode;
128 
129 	if (value == LED_OFF)
130 		mode = NS_V2_LED_OFF;
131 	else if (led_dat->sata)
132 		mode = NS_V2_LED_SATA;
133 	else
134 		mode = NS_V2_LED_ON;
135 
136 	ns2_led_set_mode(led_dat, mode);
137 }
138 
139 static ssize_t ns2_led_sata_store(struct device *dev,
140 				  struct device_attribute *attr,
141 				  const char *buff, size_t count)
142 {
143 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
144 	struct ns2_led_data *led_dat =
145 		container_of(led_cdev, struct ns2_led_data, cdev);
146 	int ret;
147 	unsigned long enable;
148 
149 	ret = kstrtoul(buff, 10, &enable);
150 	if (ret < 0)
151 		return ret;
152 
153 	enable = !!enable;
154 
155 	if (led_dat->sata == enable)
156 		goto exit;
157 
158 	led_dat->sata = enable;
159 
160 	if (!led_get_brightness(led_cdev))
161 		goto exit;
162 
163 	if (enable)
164 		ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
165 	else
166 		ns2_led_set_mode(led_dat, NS_V2_LED_ON);
167 
168 exit:
169 	return count;
170 }
171 
172 static ssize_t ns2_led_sata_show(struct device *dev,
173 				 struct device_attribute *attr, char *buf)
174 {
175 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
176 	struct ns2_led_data *led_dat =
177 		container_of(led_cdev, struct ns2_led_data, cdev);
178 
179 	return sprintf(buf, "%d\n", led_dat->sata);
180 }
181 
182 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
183 
184 static struct attribute *ns2_led_attrs[] = {
185 	&dev_attr_sata.attr,
186 	NULL
187 };
188 ATTRIBUTE_GROUPS(ns2_led);
189 
190 static int
191 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
192 	       const struct ns2_led *template)
193 {
194 	int ret;
195 	enum ns2_led_modes mode;
196 
197 	ret = devm_gpio_request_one(&pdev->dev, template->cmd,
198 			gpio_get_value_cansleep(template->cmd) ?
199 			GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
200 			template->name);
201 	if (ret) {
202 		dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
203 			template->name);
204 		return ret;
205 	}
206 
207 	ret = devm_gpio_request_one(&pdev->dev, template->slow,
208 			gpio_get_value_cansleep(template->slow) ?
209 			GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
210 			template->name);
211 	if (ret) {
212 		dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
213 			template->name);
214 		return ret;
215 	}
216 
217 	rwlock_init(&led_dat->rw_lock);
218 
219 	led_dat->cdev.name = template->name;
220 	led_dat->cdev.default_trigger = template->default_trigger;
221 	led_dat->cdev.blink_set = NULL;
222 	led_dat->cdev.brightness_set = ns2_led_set;
223 	led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
224 	led_dat->cdev.groups = ns2_led_groups;
225 	led_dat->cmd = template->cmd;
226 	led_dat->slow = template->slow;
227 	led_dat->can_sleep = gpio_cansleep(led_dat->cmd) |
228 				gpio_cansleep(led_dat->slow);
229 	led_dat->modval = template->modval;
230 	led_dat->num_modes = template->num_modes;
231 
232 	ret = ns2_led_get_mode(led_dat, &mode);
233 	if (ret < 0)
234 		return ret;
235 
236 	/* Set LED initial state. */
237 	led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
238 	led_dat->cdev.brightness =
239 		(mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
240 
241 	INIT_WORK(&led_dat->work, ns2_led_work);
242 
243 	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
244 	if (ret < 0)
245 		return ret;
246 
247 	return 0;
248 }
249 
250 static void delete_ns2_led(struct ns2_led_data *led_dat)
251 {
252 	led_classdev_unregister(&led_dat->cdev);
253 	cancel_work_sync(&led_dat->work);
254 }
255 
256 #ifdef CONFIG_OF_GPIO
257 /*
258  * Translate OpenFirmware node properties into platform_data.
259  */
260 static int
261 ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
262 {
263 	struct device_node *np = dev->of_node;
264 	struct device_node *child;
265 	struct ns2_led *led, *leds;
266 	int num_leds = 0;
267 
268 	num_leds = of_get_child_count(np);
269 	if (!num_leds)
270 		return -ENODEV;
271 
272 	leds = devm_kzalloc(dev, num_leds * sizeof(struct ns2_led),
273 			    GFP_KERNEL);
274 	if (!leds)
275 		return -ENOMEM;
276 
277 	led = leds;
278 	for_each_child_of_node(np, child) {
279 		const char *string;
280 		int ret, i, num_modes;
281 		struct ns2_led_modval *modval;
282 
283 		ret = of_get_named_gpio(child, "cmd-gpio", 0);
284 		if (ret < 0)
285 			return ret;
286 		led->cmd = ret;
287 		ret = of_get_named_gpio(child, "slow-gpio", 0);
288 		if (ret < 0)
289 			return ret;
290 		led->slow = ret;
291 		ret = of_property_read_string(child, "label", &string);
292 		led->name = (ret == 0) ? string : child->name;
293 		ret = of_property_read_string(child, "linux,default-trigger",
294 					      &string);
295 		if (ret == 0)
296 			led->default_trigger = string;
297 
298 		ret = of_property_count_u32_elems(child, "modes-map");
299 		if (ret < 0 || ret % 3) {
300 			dev_err(dev,
301 				"Missing or malformed modes-map property\n");
302 			return -EINVAL;
303 		}
304 
305 		num_modes = ret / 3;
306 		modval = devm_kzalloc(dev,
307 				      num_modes * sizeof(struct ns2_led_modval),
308 				      GFP_KERNEL);
309 		if (!modval)
310 			return -ENOMEM;
311 
312 		for (i = 0; i < num_modes; i++) {
313 			of_property_read_u32_index(child,
314 						"modes-map", 3 * i,
315 						(u32 *) &modval[i].mode);
316 			of_property_read_u32_index(child,
317 						"modes-map", 3 * i + 1,
318 						(u32 *) &modval[i].cmd_level);
319 			of_property_read_u32_index(child,
320 						"modes-map", 3 * i + 2,
321 						(u32 *) &modval[i].slow_level);
322 		}
323 
324 		led->num_modes = num_modes;
325 		led->modval = modval;
326 
327 		led++;
328 	}
329 
330 	pdata->leds = leds;
331 	pdata->num_leds = num_leds;
332 
333 	return 0;
334 }
335 
336 static const struct of_device_id of_ns2_leds_match[] = {
337 	{ .compatible = "lacie,ns2-leds", },
338 	{},
339 };
340 #endif /* CONFIG_OF_GPIO */
341 
342 struct ns2_led_priv {
343 	int num_leds;
344 	struct ns2_led_data leds_data[];
345 };
346 
347 static inline int sizeof_ns2_led_priv(int num_leds)
348 {
349 	return sizeof(struct ns2_led_priv) +
350 		      (sizeof(struct ns2_led_data) * num_leds);
351 }
352 
353 static int ns2_led_probe(struct platform_device *pdev)
354 {
355 	struct ns2_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
356 	struct ns2_led_priv *priv;
357 	int i;
358 	int ret;
359 
360 #ifdef CONFIG_OF_GPIO
361 	if (!pdata) {
362 		pdata = devm_kzalloc(&pdev->dev,
363 				     sizeof(struct ns2_led_platform_data),
364 				     GFP_KERNEL);
365 		if (!pdata)
366 			return -ENOMEM;
367 
368 		ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
369 		if (ret)
370 			return ret;
371 	}
372 #else
373 	if (!pdata)
374 		return -EINVAL;
375 #endif /* CONFIG_OF_GPIO */
376 
377 	priv = devm_kzalloc(&pdev->dev,
378 			    sizeof_ns2_led_priv(pdata->num_leds), GFP_KERNEL);
379 	if (!priv)
380 		return -ENOMEM;
381 	priv->num_leds = pdata->num_leds;
382 
383 	for (i = 0; i < priv->num_leds; i++) {
384 		ret = create_ns2_led(pdev, &priv->leds_data[i],
385 				     &pdata->leds[i]);
386 		if (ret < 0) {
387 			for (i = i - 1; i >= 0; i--)
388 				delete_ns2_led(&priv->leds_data[i]);
389 			return ret;
390 		}
391 	}
392 
393 	platform_set_drvdata(pdev, priv);
394 
395 	return 0;
396 }
397 
398 static int ns2_led_remove(struct platform_device *pdev)
399 {
400 	int i;
401 	struct ns2_led_priv *priv;
402 
403 	priv = platform_get_drvdata(pdev);
404 
405 	for (i = 0; i < priv->num_leds; i++)
406 		delete_ns2_led(&priv->leds_data[i]);
407 
408 	return 0;
409 }
410 
411 static struct platform_driver ns2_led_driver = {
412 	.probe		= ns2_led_probe,
413 	.remove		= ns2_led_remove,
414 	.driver		= {
415 		.name		= "leds-ns2",
416 		.of_match_table	= of_match_ptr(of_ns2_leds_match),
417 	},
418 };
419 
420 module_platform_driver(ns2_led_driver);
421 
422 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
423 MODULE_DESCRIPTION("Network Space v2 LED driver");
424 MODULE_LICENSE("GPL");
425 MODULE_ALIAS("platform:leds-ns2");
426