1 /*
2 * MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
3 *
4 * This is the core LED driver of the MEN 14F021P00 BMC.
5 * There are four LEDs available which can be switched on and off.
6 * STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
7 *
8 * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 */
15
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/platform_device.h>
19 #include <linux/leds.h>
20 #include <linux/i2c.h>
21
22 #define BMC_CMD_LED_GET_SET 0xA0
23 #define BMC_BIT_LED_STATUS BIT(0)
24 #define BMC_BIT_LED_HOTSWAP BIT(1)
25 #define BMC_BIT_LED_USER1 BIT(2)
26 #define BMC_BIT_LED_USER2 BIT(3)
27
28 struct menf21bmc_led {
29 struct led_classdev cdev;
30 u8 led_bit;
31 const char *name;
32 struct i2c_client *i2c_client;
33 };
34
35 static struct menf21bmc_led leds[] = {
36 {
37 .name = "menf21bmc:led_status",
38 .led_bit = BMC_BIT_LED_STATUS,
39 },
40 {
41 .name = "menf21bmc:led_hotswap",
42 .led_bit = BMC_BIT_LED_HOTSWAP,
43 },
44 {
45 .name = "menf21bmc:led_user1",
46 .led_bit = BMC_BIT_LED_USER1,
47 },
48 {
49 .name = "menf21bmc:led_user2",
50 .led_bit = BMC_BIT_LED_USER2,
51 }
52 };
53
54 static DEFINE_MUTEX(led_lock);
55
56 static void
menf21bmc_led_set(struct led_classdev * led_cdev,enum led_brightness value)57 menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
58 {
59 int led_val;
60 struct menf21bmc_led *led = container_of(led_cdev,
61 struct menf21bmc_led, cdev);
62
63 mutex_lock(&led_lock);
64 led_val = i2c_smbus_read_byte_data(led->i2c_client,
65 BMC_CMD_LED_GET_SET);
66 if (led_val < 0)
67 goto err_out;
68
69 if (value == LED_OFF)
70 led_val &= ~led->led_bit;
71 else
72 led_val |= led->led_bit;
73
74 i2c_smbus_write_byte_data(led->i2c_client,
75 BMC_CMD_LED_GET_SET, led_val);
76 err_out:
77 mutex_unlock(&led_lock);
78 }
79
menf21bmc_led_probe(struct platform_device * pdev)80 static int menf21bmc_led_probe(struct platform_device *pdev)
81 {
82 int i;
83 int ret;
84 struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
85
86 for (i = 0; i < ARRAY_SIZE(leds); i++) {
87 leds[i].cdev.name = leds[i].name;
88 leds[i].cdev.brightness_set = menf21bmc_led_set;
89 leds[i].i2c_client = i2c_client;
90 ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
91 if (ret < 0) {
92 dev_err(&pdev->dev, "failed to register LED device\n");
93 return ret;
94 }
95 }
96 dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
97
98 return 0;
99
100 }
101
102 static struct platform_driver menf21bmc_led = {
103 .probe = menf21bmc_led_probe,
104 .driver = {
105 .name = "menf21bmc_led",
106 },
107 };
108
109 module_platform_driver(menf21bmc_led);
110
111 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
112 MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
113 MODULE_LICENSE("GPL v2");
114 MODULE_ALIAS("platform:menf21bmc_led");
115
