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