xref: /linux/drivers/leds/leds-ns2.c (revision cdb138080b78146d1cdadba9f5dadbeb97445b91) 
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/init.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 #include <linux/gpio.h>
30 #include <linux/leds.h>
31 #include <mach/leds-ns2.h>
32 
33 /*
34  * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
35  * relation with the SATA activity. This capability is exposed through the
36  * "sata" sysfs attribute.
37  *
38  * The following array detail the different LED registers and the combination
39  * of their possible values:
40  *
41  *  cmd_led   |  slow_led  | /SATA active | LED state
42  *            |            |              |
43  *     1      |     0      |      x       |  off
44  *     -      |     1      |      x       |  on
45  *     0      |     0      |      1       |  on
46  *     0      |     0      |      0       |  blink (rate 300ms)
47  */
48 
49 enum ns2_led_modes {
50 	NS_V2_LED_OFF,
51 	NS_V2_LED_ON,
52 	NS_V2_LED_SATA,
53 };
54 
55 struct ns2_led_mode_value {
56 	enum ns2_led_modes	mode;
57 	int			cmd_level;
58 	int			slow_level;
59 };
60 
61 static struct ns2_led_mode_value ns2_led_modval[] = {
62 	{ NS_V2_LED_OFF	, 1, 0 },
63 	{ NS_V2_LED_ON	, 0, 1 },
64 	{ NS_V2_LED_ON	, 1, 1 },
65 	{ NS_V2_LED_SATA, 0, 0 },
66 };
67 
68 struct ns2_led_data {
69 	struct led_classdev	cdev;
70 	unsigned		cmd;
71 	unsigned		slow;
72 	unsigned char		sata; /* True when SATA mode active. */
73 	rwlock_t		rw_lock; /* Lock GPIOs. */
74 };
75 
76 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
77 			    enum ns2_led_modes *mode)
78 {
79 	int i;
80 	int ret = -EINVAL;
81 	int cmd_level;
82 	int slow_level;
83 
84 	read_lock_irq(&led_dat->rw_lock);
85 
86 	cmd_level = gpio_get_value(led_dat->cmd);
87 	slow_level = gpio_get_value(led_dat->slow);
88 
89 	for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
90 		if (cmd_level == ns2_led_modval[i].cmd_level &&
91 		    slow_level == ns2_led_modval[i].slow_level) {
92 			*mode = ns2_led_modval[i].mode;
93 			ret = 0;
94 			break;
95 		}
96 	}
97 
98 	read_unlock_irq(&led_dat->rw_lock);
99 
100 	return ret;
101 }
102 
103 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
104 			     enum ns2_led_modes mode)
105 {
106 	int i;
107 	unsigned long flags;
108 
109 	write_lock_irqsave(&led_dat->rw_lock, flags);
110 
111 	for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
112 		if (mode == ns2_led_modval[i].mode) {
113 			gpio_set_value(led_dat->cmd,
114 				       ns2_led_modval[i].cmd_level);
115 			gpio_set_value(led_dat->slow,
116 				       ns2_led_modval[i].slow_level);
117 		}
118 	}
119 
120 	write_unlock_irqrestore(&led_dat->rw_lock, flags);
121 }
122 
123 static void ns2_led_set(struct led_classdev *led_cdev,
124 			enum led_brightness value)
125 {
126 	struct ns2_led_data *led_dat =
127 		container_of(led_cdev, struct ns2_led_data, cdev);
128 	enum ns2_led_modes mode;
129 
130 	if (value == LED_OFF)
131 		mode = NS_V2_LED_OFF;
132 	else if (led_dat->sata)
133 		mode = NS_V2_LED_SATA;
134 	else
135 		mode = NS_V2_LED_ON;
136 
137 	ns2_led_set_mode(led_dat, mode);
138 }
139 
140 static ssize_t ns2_led_sata_store(struct device *dev,
141 				  struct device_attribute *attr,
142 				  const char *buff, size_t count)
143 {
144 	int ret;
145 	unsigned long enable;
146 	enum ns2_led_modes mode;
147 	struct ns2_led_data *led_dat = dev_get_drvdata(dev);
148 
149 	ret = strict_strtoul(buff, 10, &enable);
150 	if (ret < 0)
151 		return ret;
152 
153 	enable = !!enable;
154 
155 	if (led_dat->sata == enable)
156 		return count;
157 
158 	ret = ns2_led_get_mode(led_dat, &mode);
159 	if (ret < 0)
160 		return ret;
161 
162 	if (enable && mode == NS_V2_LED_ON)
163 		ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
164 	if (!enable && mode == NS_V2_LED_SATA)
165 		ns2_led_set_mode(led_dat, NS_V2_LED_ON);
166 
167 	led_dat->sata = enable;
168 
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 ns2_led_data *led_dat = dev_get_drvdata(dev);
176 
177 	return sprintf(buf, "%d\n", led_dat->sata);
178 }
179 
180 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
181 
182 static int __devinit
183 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
184 	       const struct ns2_led *template)
185 {
186 	int ret;
187 	enum ns2_led_modes mode;
188 
189 	ret = gpio_request(template->cmd, template->name);
190 	if (ret == 0) {
191 		ret = gpio_direction_output(template->cmd,
192 					    gpio_get_value(template->cmd));
193 		if (ret)
194 			gpio_free(template->cmd);
195 	}
196 	if (ret) {
197 		dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
198 			template->name);
199 	}
200 
201 	ret = gpio_request(template->slow, template->name);
202 	if (ret == 0) {
203 		ret = gpio_direction_output(template->slow,
204 					    gpio_get_value(template->slow));
205 		if (ret)
206 			gpio_free(template->slow);
207 	}
208 	if (ret) {
209 		dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
210 			template->name);
211 		goto err_free_cmd;
212 	}
213 
214 	rwlock_init(&led_dat->rw_lock);
215 
216 	led_dat->cdev.name = template->name;
217 	led_dat->cdev.default_trigger = template->default_trigger;
218 	led_dat->cdev.blink_set = NULL;
219 	led_dat->cdev.brightness_set = ns2_led_set;
220 	led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
221 	led_dat->cmd = template->cmd;
222 	led_dat->slow = template->slow;
223 
224 	ret = ns2_led_get_mode(led_dat, &mode);
225 	if (ret < 0)
226 		goto err_free_slow;
227 
228 	/* Set LED initial state. */
229 	led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
230 	led_dat->cdev.brightness =
231 		(mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
232 
233 	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
234 	if (ret < 0)
235 		goto err_free_slow;
236 
237 	dev_set_drvdata(led_dat->cdev.dev, led_dat);
238 	ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
239 	if (ret < 0)
240 		goto err_free_cdev;
241 
242 	return 0;
243 
244 err_free_cdev:
245 	led_classdev_unregister(&led_dat->cdev);
246 err_free_slow:
247 	gpio_free(led_dat->slow);
248 err_free_cmd:
249 	gpio_free(led_dat->cmd);
250 
251 	return ret;
252 }
253 
254 static void __devexit delete_ns2_led(struct ns2_led_data *led_dat)
255 {
256 	device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
257 	led_classdev_unregister(&led_dat->cdev);
258 	gpio_free(led_dat->cmd);
259 	gpio_free(led_dat->slow);
260 }
261 
262 static int __devinit ns2_led_probe(struct platform_device *pdev)
263 {
264 	struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
265 	struct ns2_led_data *leds_data;
266 	int i;
267 	int ret;
268 
269 	if (!pdata)
270 		return -EINVAL;
271 
272 	leds_data = kzalloc(sizeof(struct ns2_led_data) *
273 			    pdata->num_leds, GFP_KERNEL);
274 	if (!leds_data)
275 		return -ENOMEM;
276 
277 	for (i = 0; i < pdata->num_leds; i++) {
278 		ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
279 		if (ret < 0)
280 			goto err;
281 
282 	}
283 
284 	platform_set_drvdata(pdev, leds_data);
285 
286 	return 0;
287 
288 err:
289 	for (i = i - 1; i >= 0; i--)
290 		delete_ns2_led(&leds_data[i]);
291 
292 	kfree(leds_data);
293 
294 	return ret;
295 }
296 
297 static int __devexit ns2_led_remove(struct platform_device *pdev)
298 {
299 	int i;
300 	struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
301 	struct ns2_led_data *leds_data;
302 
303 	leds_data = platform_get_drvdata(pdev);
304 
305 	for (i = 0; i < pdata->num_leds; i++)
306 		delete_ns2_led(&leds_data[i]);
307 
308 	kfree(leds_data);
309 	platform_set_drvdata(pdev, NULL);
310 
311 	return 0;
312 }
313 
314 static struct platform_driver ns2_led_driver = {
315 	.probe		= ns2_led_probe,
316 	.remove		= __devexit_p(ns2_led_remove),
317 	.driver		= {
318 		.name	= "leds-ns2",
319 		.owner	= THIS_MODULE,
320 	},
321 };
322 MODULE_ALIAS("platform:leds-ns2");
323 
324 static int __init ns2_led_init(void)
325 {
326 	return platform_driver_register(&ns2_led_driver);
327 }
328 
329 static void __exit ns2_led_exit(void)
330 {
331 	platform_driver_unregister(&ns2_led_driver);
332 }
333 
334 module_init(ns2_led_init);
335 module_exit(ns2_led_exit);
336 
337 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
338 MODULE_DESCRIPTION("Network Space v2 LED driver");
339 MODULE_LICENSE("GPL");
340