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 <linux/module.h>
32 #include <mach/leds-ns2.h>
33
34 /*
35 * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
36 * relation with the SATA activity. This capability is exposed through the
37 * "sata" sysfs attribute.
38 *
39 * The following array detail the different LED registers and the combination
40 * of their possible values:
41 *
42 * cmd_led | slow_led | /SATA active | LED state
43 * | | |
44 * 1 | 0 | x | off
45 * - | 1 | x | on
46 * 0 | 0 | 1 | on
47 * 0 | 0 | 0 | blink (rate 300ms)
48 */
49
50 enum ns2_led_modes {
51 NS_V2_LED_OFF,
52 NS_V2_LED_ON,
53 NS_V2_LED_SATA,
54 };
55
56 struct ns2_led_mode_value {
57 enum ns2_led_modes mode;
58 int cmd_level;
59 int slow_level;
60 };
61
62 static struct ns2_led_mode_value ns2_led_modval[] = {
63 { NS_V2_LED_OFF , 1, 0 },
64 { NS_V2_LED_ON , 0, 1 },
65 { NS_V2_LED_ON , 1, 1 },
66 { NS_V2_LED_SATA, 0, 0 },
67 };
68
69 struct ns2_led_data {
70 struct led_classdev cdev;
71 unsigned cmd;
72 unsigned slow;
73 unsigned char sata; /* True when SATA mode active. */
74 rwlock_t rw_lock; /* Lock GPIOs. */
75 };
76
ns2_led_get_mode(struct ns2_led_data * led_dat,enum ns2_led_modes * mode)77 static int ns2_led_get_mode(struct ns2_led_data *led_dat,
78 enum ns2_led_modes *mode)
79 {
80 int i;
81 int ret = -EINVAL;
82 int cmd_level;
83 int slow_level;
84
85 read_lock_irq(&led_dat->rw_lock);
86
87 cmd_level = gpio_get_value(led_dat->cmd);
88 slow_level = gpio_get_value(led_dat->slow);
89
90 for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
91 if (cmd_level == ns2_led_modval[i].cmd_level &&
92 slow_level == ns2_led_modval[i].slow_level) {
93 *mode = ns2_led_modval[i].mode;
94 ret = 0;
95 break;
96 }
97 }
98
99 read_unlock_irq(&led_dat->rw_lock);
100
101 return ret;
102 }
103
ns2_led_set_mode(struct ns2_led_data * led_dat,enum ns2_led_modes mode)104 static void ns2_led_set_mode(struct ns2_led_data *led_dat,
105 enum ns2_led_modes mode)
106 {
107 int i;
108 unsigned long flags;
109
110 write_lock_irqsave(&led_dat->rw_lock, flags);
111
112 for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
113 if (mode == ns2_led_modval[i].mode) {
114 gpio_set_value(led_dat->cmd,
115 ns2_led_modval[i].cmd_level);
116 gpio_set_value(led_dat->slow,
117 ns2_led_modval[i].slow_level);
118 }
119 }
120
121 write_unlock_irqrestore(&led_dat->rw_lock, flags);
122 }
123
ns2_led_set(struct led_classdev * led_cdev,enum led_brightness value)124 static void ns2_led_set(struct led_classdev *led_cdev,
125 enum led_brightness value)
126 {
127 struct ns2_led_data *led_dat =
128 container_of(led_cdev, struct ns2_led_data, cdev);
129 enum ns2_led_modes mode;
130
131 if (value == LED_OFF)
132 mode = NS_V2_LED_OFF;
133 else if (led_dat->sata)
134 mode = NS_V2_LED_SATA;
135 else
136 mode = NS_V2_LED_ON;
137
138 ns2_led_set_mode(led_dat, mode);
139 }
140
ns2_led_sata_store(struct device * dev,struct device_attribute * attr,const char * buff,size_t count)141 static ssize_t ns2_led_sata_store(struct device *dev,
142 struct device_attribute *attr,
143 const char *buff, size_t count)
144 {
145 struct led_classdev *led_cdev = dev_get_drvdata(dev);
146 struct ns2_led_data *led_dat =
147 container_of(led_cdev, struct ns2_led_data, cdev);
148 int ret;
149 unsigned long enable;
150 enum ns2_led_modes mode;
151
152 ret = strict_strtoul(buff, 10, &enable);
153 if (ret < 0)
154 return ret;
155
156 enable = !!enable;
157
158 if (led_dat->sata == enable)
159 return count;
160
161 ret = ns2_led_get_mode(led_dat, &mode);
162 if (ret < 0)
163 return ret;
164
165 if (enable && mode == NS_V2_LED_ON)
166 ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
167 if (!enable && mode == NS_V2_LED_SATA)
168 ns2_led_set_mode(led_dat, NS_V2_LED_ON);
169
170 led_dat->sata = enable;
171
172 return count;
173 }
174
ns2_led_sata_show(struct device * dev,struct device_attribute * attr,char * buf)175 static ssize_t ns2_led_sata_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177 {
178 struct led_classdev *led_cdev = dev_get_drvdata(dev);
179 struct ns2_led_data *led_dat =
180 container_of(led_cdev, struct ns2_led_data, cdev);
181
182 return sprintf(buf, "%d\n", led_dat->sata);
183 }
184
185 static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
186
187 static int __devinit
create_ns2_led(struct platform_device * pdev,struct ns2_led_data * led_dat,const struct ns2_led * template)188 create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
189 const struct ns2_led *template)
190 {
191 int ret;
192 enum ns2_led_modes mode;
193
194 ret = gpio_request(template->cmd, template->name);
195 if (ret == 0) {
196 ret = gpio_direction_output(template->cmd,
197 gpio_get_value(template->cmd));
198 if (ret)
199 gpio_free(template->cmd);
200 }
201 if (ret) {
202 dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
203 template->name);
204 }
205
206 ret = gpio_request(template->slow, template->name);
207 if (ret == 0) {
208 ret = gpio_direction_output(template->slow,
209 gpio_get_value(template->slow));
210 if (ret)
211 gpio_free(template->slow);
212 }
213 if (ret) {
214 dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
215 template->name);
216 goto err_free_cmd;
217 }
218
219 rwlock_init(&led_dat->rw_lock);
220
221 led_dat->cdev.name = template->name;
222 led_dat->cdev.default_trigger = template->default_trigger;
223 led_dat->cdev.blink_set = NULL;
224 led_dat->cdev.brightness_set = ns2_led_set;
225 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
226 led_dat->cmd = template->cmd;
227 led_dat->slow = template->slow;
228
229 ret = ns2_led_get_mode(led_dat, &mode);
230 if (ret < 0)
231 goto err_free_slow;
232
233 /* Set LED initial state. */
234 led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
235 led_dat->cdev.brightness =
236 (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
237
238 ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
239 if (ret < 0)
240 goto err_free_slow;
241
242 ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
243 if (ret < 0)
244 goto err_free_cdev;
245
246 return 0;
247
248 err_free_cdev:
249 led_classdev_unregister(&led_dat->cdev);
250 err_free_slow:
251 gpio_free(led_dat->slow);
252 err_free_cmd:
253 gpio_free(led_dat->cmd);
254
255 return ret;
256 }
257
delete_ns2_led(struct ns2_led_data * led_dat)258 static void delete_ns2_led(struct ns2_led_data *led_dat)
259 {
260 device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
261 led_classdev_unregister(&led_dat->cdev);
262 gpio_free(led_dat->cmd);
263 gpio_free(led_dat->slow);
264 }
265
ns2_led_probe(struct platform_device * pdev)266 static int __devinit ns2_led_probe(struct platform_device *pdev)
267 {
268 struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
269 struct ns2_led_data *leds_data;
270 int i;
271 int ret;
272
273 if (!pdata)
274 return -EINVAL;
275
276 leds_data = kzalloc(sizeof(struct ns2_led_data) *
277 pdata->num_leds, GFP_KERNEL);
278 if (!leds_data)
279 return -ENOMEM;
280
281 for (i = 0; i < pdata->num_leds; i++) {
282 ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
283 if (ret < 0)
284 goto err;
285
286 }
287
288 platform_set_drvdata(pdev, leds_data);
289
290 return 0;
291
292 err:
293 for (i = i - 1; i >= 0; i--)
294 delete_ns2_led(&leds_data[i]);
295
296 kfree(leds_data);
297
298 return ret;
299 }
300
ns2_led_remove(struct platform_device * pdev)301 static int __devexit ns2_led_remove(struct platform_device *pdev)
302 {
303 int i;
304 struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
305 struct ns2_led_data *leds_data;
306
307 leds_data = platform_get_drvdata(pdev);
308
309 for (i = 0; i < pdata->num_leds; i++)
310 delete_ns2_led(&leds_data[i]);
311
312 kfree(leds_data);
313 platform_set_drvdata(pdev, NULL);
314
315 return 0;
316 }
317
318 static struct platform_driver ns2_led_driver = {
319 .probe = ns2_led_probe,
320 .remove = __devexit_p(ns2_led_remove),
321 .driver = {
322 .name = "leds-ns2",
323 .owner = THIS_MODULE,
324 },
325 };
326
327 module_platform_driver(ns2_led_driver);
328
329 MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
330 MODULE_DESCRIPTION("Network Space v2 LED driver");
331 MODULE_LICENSE("GPL");
332 MODULE_ALIAS("platform:leds-ns2");
333