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 | |
15 | struct 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 | |
24 | struct 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 | |
33 | static 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(spi: led->spi, buf: (const u8 *)&word, len: sizeof(word)); |
45 | mutex_unlock(lock: &led->mutex); |
46 | |
47 | return ret; |
48 | } |
49 | |
50 | static 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(dev: &spi->dev, size: 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(buf: led->name, size: sizeof(led->name), fmt: "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(parent: &spi->dev, led_cdev: &led->ldev); |
73 | if (ret < 0) |
74 | goto eledcr; |
75 | } |
76 | |
77 | spi_set_drvdata(spi, data: dac); |
78 | |
79 | return 0; |
80 | |
81 | eledcr: |
82 | while (i--) |
83 | led_classdev_unregister(led_cdev: &dac->leds[i].ldev); |
84 | |
85 | return ret; |
86 | } |
87 | |
88 | static 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(led_cdev: &dac->leds[i].ldev); |
95 | } |
96 | |
97 | static struct spi_driver dac124s085_driver = { |
98 | .probe = dac124s085_probe, |
99 | .remove = dac124s085_remove, |
100 | .driver = { |
101 | .name = "dac124s085" , |
102 | }, |
103 | }; |
104 | |
105 | module_spi_driver(dac124s085_driver); |
106 | |
107 | MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>" ); |
108 | MODULE_DESCRIPTION("DAC124S085 LED driver" ); |
109 | MODULE_LICENSE("GPL v2" ); |
110 | MODULE_ALIAS("spi:dac124s085" ); |
111 | |