1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright 2008
4*4882a593Smuzhiyun * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * LED driver for the DAC124S085 SPI DAC
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/leds.h>
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/mutex.h>
12*4882a593Smuzhiyun #include <linux/slab.h>
13*4882a593Smuzhiyun #include <linux/spi/spi.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun struct dac124s085_led {
16*4882a593Smuzhiyun struct led_classdev ldev;
17*4882a593Smuzhiyun struct spi_device *spi;
18*4882a593Smuzhiyun int id;
19*4882a593Smuzhiyun char name[sizeof("dac124s085-3")];
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun struct mutex mutex;
22*4882a593Smuzhiyun };
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun struct dac124s085 {
25*4882a593Smuzhiyun struct dac124s085_led leds[4];
26*4882a593Smuzhiyun };
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun #define REG_WRITE (0 << 12)
29*4882a593Smuzhiyun #define REG_WRITE_UPDATE (1 << 12)
30*4882a593Smuzhiyun #define ALL_WRITE_UPDATE (2 << 12)
31*4882a593Smuzhiyun #define POWER_DOWN_OUTPUT (3 << 12)
32*4882a593Smuzhiyun
dac124s085_set_brightness(struct led_classdev * ldev,enum led_brightness brightness)33*4882a593Smuzhiyun static int dac124s085_set_brightness(struct led_classdev *ldev,
34*4882a593Smuzhiyun enum led_brightness brightness)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun struct dac124s085_led *led = container_of(ldev, struct dac124s085_led,
37*4882a593Smuzhiyun ldev);
38*4882a593Smuzhiyun u16 word;
39*4882a593Smuzhiyun int ret;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun mutex_lock(&led->mutex);
42*4882a593Smuzhiyun word = cpu_to_le16(((led->id) << 14) | REG_WRITE_UPDATE |
43*4882a593Smuzhiyun (brightness & 0xfff));
44*4882a593Smuzhiyun ret = spi_write(led->spi, (const u8 *)&word, sizeof(word));
45*4882a593Smuzhiyun mutex_unlock(&led->mutex);
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun return ret;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun
dac124s085_probe(struct spi_device * spi)50*4882a593Smuzhiyun static int dac124s085_probe(struct spi_device *spi)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun struct dac124s085 *dac;
53*4882a593Smuzhiyun struct dac124s085_led *led;
54*4882a593Smuzhiyun int i, ret;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun dac = devm_kzalloc(&spi->dev, sizeof(*dac), GFP_KERNEL);
57*4882a593Smuzhiyun if (!dac)
58*4882a593Smuzhiyun return -ENOMEM;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun spi->bits_per_word = 16;
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(dac->leds); i++) {
63*4882a593Smuzhiyun led = dac->leds + i;
64*4882a593Smuzhiyun led->id = i;
65*4882a593Smuzhiyun led->spi = spi;
66*4882a593Smuzhiyun snprintf(led->name, sizeof(led->name), "dac124s085-%d", i);
67*4882a593Smuzhiyun mutex_init(&led->mutex);
68*4882a593Smuzhiyun led->ldev.name = led->name;
69*4882a593Smuzhiyun led->ldev.brightness = LED_OFF;
70*4882a593Smuzhiyun led->ldev.max_brightness = 0xfff;
71*4882a593Smuzhiyun led->ldev.brightness_set_blocking = dac124s085_set_brightness;
72*4882a593Smuzhiyun ret = led_classdev_register(&spi->dev, &led->ldev);
73*4882a593Smuzhiyun if (ret < 0)
74*4882a593Smuzhiyun goto eledcr;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun spi_set_drvdata(spi, dac);
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun return 0;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun eledcr:
82*4882a593Smuzhiyun while (i--)
83*4882a593Smuzhiyun led_classdev_unregister(&dac->leds[i].ldev);
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun return ret;
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun
dac124s085_remove(struct spi_device * spi)88*4882a593Smuzhiyun static int dac124s085_remove(struct spi_device *spi)
89*4882a593Smuzhiyun {
90*4882a593Smuzhiyun struct dac124s085 *dac = spi_get_drvdata(spi);
91*4882a593Smuzhiyun int i;
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(dac->leds); i++)
94*4882a593Smuzhiyun led_classdev_unregister(&dac->leds[i].ldev);
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun return 0;
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun static struct spi_driver dac124s085_driver = {
100*4882a593Smuzhiyun .probe = dac124s085_probe,
101*4882a593Smuzhiyun .remove = dac124s085_remove,
102*4882a593Smuzhiyun .driver = {
103*4882a593Smuzhiyun .name = "dac124s085",
104*4882a593Smuzhiyun },
105*4882a593Smuzhiyun };
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun module_spi_driver(dac124s085_driver);
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
110*4882a593Smuzhiyun MODULE_DESCRIPTION("DAC124S085 LED driver");
111*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
112*4882a593Smuzhiyun MODULE_ALIAS("spi:dac124s085");
113