include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-3.10.git] / drivers / leds / leds-dac124s085.c
1 /*
2  * Copyright 2008
3  * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
4  *
5  * This file is subject to the terms and conditions of version 2 of
6  * the GNU General Public License.  See the file COPYING in the main
7  * directory of this archive for more details.
8  *
9  * LED driver for the DAC124S085 SPI DAC
10  */
11
12 #include <linux/leds.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/workqueue.h>
18 #include <linux/spi/spi.h>
19
20 struct dac124s085_led {
21         struct led_classdev     ldev;
22         struct spi_device       *spi;
23         int                     id;
24         int                     brightness;
25         char                    name[sizeof("dac124s085-3")];
26
27         struct mutex            mutex;
28         struct work_struct      work;
29         spinlock_t              lock;
30 };
31
32 struct dac124s085 {
33         struct dac124s085_led leds[4];
34 };
35
36 #define REG_WRITE               (0 << 12)
37 #define REG_WRITE_UPDATE        (1 << 12)
38 #define ALL_WRITE_UPDATE        (2 << 12)
39 #define POWER_DOWN_OUTPUT       (3 << 12)
40
41 static void dac124s085_led_work(struct work_struct *work)
42 {
43         struct dac124s085_led *led = container_of(work, struct dac124s085_led,
44                                                   work);
45         u16 word;
46
47         mutex_lock(&led->mutex);
48         word = cpu_to_le16(((led->id) << 14) | REG_WRITE_UPDATE |
49                            (led->brightness & 0xfff));
50         spi_write(led->spi, (const u8 *)&word, sizeof(word));
51         mutex_unlock(&led->mutex);
52 }
53
54 static void dac124s085_set_brightness(struct led_classdev *ldev,
55                                       enum led_brightness brightness)
56 {
57         struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
58                                                   ldev);
59
60         spin_lock(&led->lock);
61         led->brightness = brightness;
62         schedule_work(&led->work);
63         spin_unlock(&led->lock);
64 }
65
66 static int dac124s085_probe(struct spi_device *spi)
67 {
68         struct dac124s085       *dac;
69         struct dac124s085_led   *led;
70         int i, ret;
71
72         dac = kzalloc(sizeof(*dac), GFP_KERNEL);
73         if (!dac)
74                 return -ENOMEM;
75
76         spi->bits_per_word = 16;
77
78         for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
79                 led             = dac->leds + i;
80                 led->id         = i;
81                 led->brightness = LED_OFF;
82                 led->spi        = spi;
83                 snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
84                 spin_lock_init(&led->lock);
85                 INIT_WORK(&led->work, dac124s085_led_work);
86                 mutex_init(&led->mutex);
87                 led->ldev.name = led->name;
88                 led->ldev.brightness = LED_OFF;
89                 led->ldev.max_brightness = 0xfff;
90                 led->ldev.brightness_set = dac124s085_set_brightness;
91                 ret = led_classdev_register(&spi->dev, &led->ldev);
92                 if (ret < 0)
93                         goto eledcr;
94         }
95
96         spi_set_drvdata(spi, dac);
97
98         return 0;
99
100 eledcr:
101         while (i--)
102                 led_classdev_unregister(&dac->leds[i].ldev);
103
104         spi_set_drvdata(spi, NULL);
105         kfree(dac);
106         return ret;
107 }
108
109 static int dac124s085_remove(struct spi_device *spi)
110 {
111         struct dac124s085       *dac = spi_get_drvdata(spi);
112         int i;
113
114         for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
115                 led_classdev_unregister(&dac->leds[i].ldev);
116                 cancel_work_sync(&dac->leds[i].work);
117         }
118
119         spi_set_drvdata(spi, NULL);
120         kfree(dac);
121
122         return 0;
123 }
124
125 static struct spi_driver dac124s085_driver = {
126         .probe          = dac124s085_probe,
127         .remove         = dac124s085_remove,
128         .driver = {
129                 .name   = "dac124s085",
130                 .owner  = THIS_MODULE,
131         },
132 };
133
134 static int __init dac124s085_leds_init(void)
135 {
136         return spi_register_driver(&dac124s085_driver);
137 }
138
139 static void __exit dac124s085_leds_exit(void)
140 {
141         spi_unregister_driver(&dac124s085_driver);
142 }
143
144 module_init(dac124s085_leds_init);
145 module_exit(dac124s085_leds_exit);
146
147 MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
148 MODULE_DESCRIPTION("DAC124S085 LED driver");
149 MODULE_LICENSE("GPL v2");
150 MODULE_ALIAS("spi:dac124s085");