Root/drivers/leds/leds-ns2.c

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 <linux/platform_data/leds-kirkwood-ns2.h>
33#include <linux/of_gpio.h>
34
35/*
36 * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
37 * relation with the SATA activity. This capability is exposed through the
38 * "sata" sysfs attribute.
39 *
40 * The following array detail the different LED registers and the combination
41 * of their possible values:
42 *
43 * cmd_led | slow_led | /SATA active | LED state
44 * | | |
45 * 1 | 0 | x | off
46 * - | 1 | x | on
47 * 0 | 0 | 1 | on
48 * 0 | 0 | 0 | blink (rate 300ms)
49 */
50
51enum ns2_led_modes {
52    NS_V2_LED_OFF,
53    NS_V2_LED_ON,
54    NS_V2_LED_SATA,
55};
56
57struct ns2_led_mode_value {
58    enum ns2_led_modes mode;
59    int cmd_level;
60    int slow_level;
61};
62
63static struct ns2_led_mode_value ns2_led_modval[] = {
64    { NS_V2_LED_OFF , 1, 0 },
65    { NS_V2_LED_ON , 0, 1 },
66    { NS_V2_LED_ON , 1, 1 },
67    { NS_V2_LED_SATA, 0, 0 },
68};
69
70struct ns2_led_data {
71    struct led_classdev cdev;
72    unsigned cmd;
73    unsigned slow;
74    unsigned char sata; /* True when SATA mode active. */
75    rwlock_t rw_lock; /* Lock GPIOs. */
76};
77
78static int ns2_led_get_mode(struct ns2_led_data *led_dat,
79                enum ns2_led_modes *mode)
80{
81    int i;
82    int ret = -EINVAL;
83    int cmd_level;
84    int slow_level;
85
86    read_lock_irq(&led_dat->rw_lock);
87
88    cmd_level = gpio_get_value(led_dat->cmd);
89    slow_level = gpio_get_value(led_dat->slow);
90
91    for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
92        if (cmd_level == ns2_led_modval[i].cmd_level &&
93            slow_level == ns2_led_modval[i].slow_level) {
94            *mode = ns2_led_modval[i].mode;
95            ret = 0;
96            break;
97        }
98    }
99
100    read_unlock_irq(&led_dat->rw_lock);
101
102    return ret;
103}
104
105static void ns2_led_set_mode(struct ns2_led_data *led_dat,
106                 enum ns2_led_modes mode)
107{
108    int i;
109    unsigned long flags;
110
111    write_lock_irqsave(&led_dat->rw_lock, flags);
112
113    for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
114        if (mode == ns2_led_modval[i].mode) {
115            gpio_set_value(led_dat->cmd,
116                       ns2_led_modval[i].cmd_level);
117            gpio_set_value(led_dat->slow,
118                       ns2_led_modval[i].slow_level);
119        }
120    }
121
122    write_unlock_irqrestore(&led_dat->rw_lock, flags);
123}
124
125static void ns2_led_set(struct led_classdev *led_cdev,
126            enum led_brightness value)
127{
128    struct ns2_led_data *led_dat =
129        container_of(led_cdev, struct ns2_led_data, cdev);
130    enum ns2_led_modes mode;
131
132    if (value == LED_OFF)
133        mode = NS_V2_LED_OFF;
134    else if (led_dat->sata)
135        mode = NS_V2_LED_SATA;
136    else
137        mode = NS_V2_LED_ON;
138
139    ns2_led_set_mode(led_dat, mode);
140}
141
142static ssize_t ns2_led_sata_store(struct device *dev,
143                  struct device_attribute *attr,
144                  const char *buff, size_t count)
145{
146    struct led_classdev *led_cdev = dev_get_drvdata(dev);
147    struct ns2_led_data *led_dat =
148        container_of(led_cdev, struct ns2_led_data, cdev);
149    int ret;
150    unsigned long enable;
151    enum ns2_led_modes mode;
152
153    ret = kstrtoul(buff, 10, &enable);
154    if (ret < 0)
155        return ret;
156
157    enable = !!enable;
158
159    if (led_dat->sata == enable)
160        return count;
161
162    ret = ns2_led_get_mode(led_dat, &mode);
163    if (ret < 0)
164        return ret;
165
166    if (enable && mode == NS_V2_LED_ON)
167        ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
168    if (!enable && mode == NS_V2_LED_SATA)
169        ns2_led_set_mode(led_dat, NS_V2_LED_ON);
170
171    led_dat->sata = enable;
172
173    return count;
174}
175
176static ssize_t ns2_led_sata_show(struct device *dev,
177                 struct device_attribute *attr, char *buf)
178{
179    struct led_classdev *led_cdev = dev_get_drvdata(dev);
180    struct ns2_led_data *led_dat =
181        container_of(led_cdev, struct ns2_led_data, cdev);
182
183    return sprintf(buf, "%d\n", led_dat->sata);
184}
185
186static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
187
188static int
189create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
190           const struct ns2_led *template)
191{
192    int ret;
193    enum ns2_led_modes mode;
194
195    ret = devm_gpio_request_one(&pdev->dev, template->cmd,
196            GPIOF_DIR_OUT | gpio_get_value(template->cmd),
197            template->name);
198    if (ret) {
199        dev_err(&pdev->dev, "%s: failed to setup command GPIO\n",
200            template->name);
201        return ret;
202    }
203
204    ret = devm_gpio_request_one(&pdev->dev, template->slow,
205            GPIOF_DIR_OUT | gpio_get_value(template->slow),
206            template->name);
207    if (ret) {
208        dev_err(&pdev->dev, "%s: failed to setup slow GPIO\n",
209            template->name);
210        return ret;
211    }
212
213    rwlock_init(&led_dat->rw_lock);
214
215    led_dat->cdev.name = template->name;
216    led_dat->cdev.default_trigger = template->default_trigger;
217    led_dat->cdev.blink_set = NULL;
218    led_dat->cdev.brightness_set = ns2_led_set;
219    led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
220    led_dat->cmd = template->cmd;
221    led_dat->slow = template->slow;
222
223    ret = ns2_led_get_mode(led_dat, &mode);
224    if (ret < 0)
225        return ret;
226
227    /* Set LED initial state. */
228    led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
229    led_dat->cdev.brightness =
230        (mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
231
232    ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
233    if (ret < 0)
234        return ret;
235
236    ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
237    if (ret < 0)
238        goto err_free_cdev;
239
240    return 0;
241
242err_free_cdev:
243    led_classdev_unregister(&led_dat->cdev);
244    return ret;
245}
246
247static void delete_ns2_led(struct ns2_led_data *led_dat)
248{
249    device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
250    led_classdev_unregister(&led_dat->cdev);
251}
252
253#ifdef CONFIG_OF_GPIO
254/*
255 * Translate OpenFirmware node properties into platform_data.
256 */
257static int
258ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
259{
260    struct device_node *np = dev->of_node;
261    struct device_node *child;
262    struct ns2_led *leds;
263    int num_leds = 0;
264    int i = 0;
265
266    num_leds = of_get_child_count(np);
267    if (!num_leds)
268        return -ENODEV;
269
270    leds = devm_kzalloc(dev, num_leds * sizeof(struct ns2_led),
271                GFP_KERNEL);
272    if (!leds)
273        return -ENOMEM;
274
275    for_each_child_of_node(np, child) {
276        const char *string;
277        int ret;
278
279        ret = of_get_named_gpio(child, "cmd-gpio", 0);
280        if (ret < 0)
281            return ret;
282        leds[i].cmd = ret;
283        ret = of_get_named_gpio(child, "slow-gpio", 0);
284        if (ret < 0)
285            return ret;
286        leds[i].slow = ret;
287        ret = of_property_read_string(child, "label", &string);
288        leds[i].name = (ret == 0) ? string : child->name;
289        ret = of_property_read_string(child, "linux,default-trigger",
290                          &string);
291        if (ret == 0)
292            leds[i].default_trigger = string;
293
294        i++;
295    }
296
297    pdata->leds = leds;
298    pdata->num_leds = num_leds;
299
300    return 0;
301}
302
303static const struct of_device_id of_ns2_leds_match[] = {
304    { .compatible = "lacie,ns2-leds", },
305    {},
306};
307#endif /* CONFIG_OF_GPIO */
308
309static int ns2_led_probe(struct platform_device *pdev)
310{
311    struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
312    struct ns2_led_data *leds_data;
313    int i;
314    int ret;
315
316#ifdef CONFIG_OF_GPIO
317    if (!pdata) {
318        pdata = devm_kzalloc(&pdev->dev,
319                     sizeof(struct ns2_led_platform_data),
320                     GFP_KERNEL);
321        if (!pdata)
322            return -ENOMEM;
323
324        ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
325        if (ret)
326            return ret;
327    }
328#else
329    if (!pdata)
330        return -EINVAL;
331#endif /* CONFIG_OF_GPIO */
332
333    leds_data = devm_kzalloc(&pdev->dev, sizeof(struct ns2_led_data) *
334                 pdata->num_leds, GFP_KERNEL);
335    if (!leds_data)
336        return -ENOMEM;
337
338    for (i = 0; i < pdata->num_leds; i++) {
339        ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
340        if (ret < 0) {
341            for (i = i - 1; i >= 0; i--)
342                delete_ns2_led(&leds_data[i]);
343            return ret;
344        }
345    }
346
347    platform_set_drvdata(pdev, leds_data);
348
349    return 0;
350}
351
352static int ns2_led_remove(struct platform_device *pdev)
353{
354    int i;
355    struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
356    struct ns2_led_data *leds_data;
357
358    leds_data = platform_get_drvdata(pdev);
359
360    for (i = 0; i < pdata->num_leds; i++)
361        delete_ns2_led(&leds_data[i]);
362
363    platform_set_drvdata(pdev, NULL);
364
365    return 0;
366}
367
368static struct platform_driver ns2_led_driver = {
369    .probe = ns2_led_probe,
370    .remove = ns2_led_remove,
371    .driver = {
372        .name = "leds-ns2",
373        .owner = THIS_MODULE,
374        .of_match_table = of_match_ptr(of_ns2_leds_match),
375    },
376};
377
378module_platform_driver(ns2_led_driver);
379
380MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
381MODULE_DESCRIPTION("Network Space v2 LED driver");
382MODULE_LICENSE("GPL");
383MODULE_ALIAS("platform:leds-ns2");
384

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