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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
20struct 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
32struct 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
41static 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
54static 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
66static 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
100eledcr:
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
109static 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
125static 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
134module_spi_driver(dac124s085_driver);
135
136MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
137MODULE_DESCRIPTION("DAC124S085 LED driver");
138MODULE_LICENSE("GPL v2");
139MODULE_ALIAS("spi:dac124s085");
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/spi/spi.h>
17
18struct dac124s085_led {
19 struct led_classdev ldev;
20 struct spi_device *spi;
21 int id;
22 char name[sizeof("dac124s085-3")];
23
24 struct mutex mutex;
25};
26
27struct dac124s085 {
28 struct dac124s085_led leds[4];
29};
30
31#define REG_WRITE (0 << 12)
32#define REG_WRITE_UPDATE (1 << 12)
33#define ALL_WRITE_UPDATE (2 << 12)
34#define POWER_DOWN_OUTPUT (3 << 12)
35
36static int dac124s085_set_brightness(struct led_classdev *ldev,
37 enum led_brightness brightness)
38{
39 struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
40 ldev);
41 u16 word;
42 int ret;
43
44 mutex_lock(&led->mutex);
45 word = cpu_to_le16(((led->id) << 14) | REG_WRITE_UPDATE |
46 (brightness & 0xfff));
47 ret = spi_write(led->spi, (const u8 *)&word, sizeof(word));
48 mutex_unlock(&led->mutex);
49
50 return ret;
51}
52
53static int dac124s085_probe(struct spi_device *spi)
54{
55 struct dac124s085 *dac;
56 struct dac124s085_led *led;
57 int i, ret;
58
59 dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
60 if (!dac)
61 return -ENOMEM;
62
63 spi->bits_per_word = 16;
64
65 for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
66 led = dac->leds + i;
67 led->id = i;
68 led->spi = spi;
69 snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
70 mutex_init(&led->mutex);
71 led->ldev.name = led->name;
72 led->ldev.brightness = LED_OFF;
73 led->ldev.max_brightness = 0xfff;
74 led->ldev.brightness_set_blocking = dac124s085_set_brightness;
75 ret = led_classdev_register(&spi->dev, &led->ldev);
76 if (ret < 0)
77 goto eledcr;
78 }
79
80 spi_set_drvdata(spi, dac);
81
82 return 0;
83
84eledcr:
85 while (i--)
86 led_classdev_unregister(&dac->leds[i].ldev);
87
88 return ret;
89}
90
91static int dac124s085_remove(struct spi_device *spi)
92{
93 struct dac124s085 *dac = spi_get_drvdata(spi);
94 int i;
95
96 for (i = 0; i < ARRAY_SIZE(dac->leds); i++)
97 led_classdev_unregister(&dac->leds[i].ldev);
98
99 return 0;
100}
101
102static struct spi_driver dac124s085_driver = {
103 .probe = dac124s085_probe,
104 .remove = dac124s085_remove,
105 .driver = {
106 .name = "dac124s085",
107 },
108};
109
110module_spi_driver(dac124s085_driver);
111
112MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
113MODULE_DESCRIPTION("DAC124S085 LED driver");
114MODULE_LICENSE("GPL v2");
115MODULE_ALIAS("spi:dac124s085");