1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
4 *
5 *  This is the core LED driver of the MEN 14F021P00 BMC.
6 *  There are four LEDs available which can be switched on and off.
7 *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
8 *
9 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/platform_device.h>
15#include <linux/leds.h>
16#include <linux/i2c.h>
17
18#define BMC_CMD_LED_GET_SET	0xA0
19#define BMC_BIT_LED_STATUS	BIT(0)
20#define BMC_BIT_LED_HOTSWAP	BIT(1)
21#define BMC_BIT_LED_USER1	BIT(2)
22#define BMC_BIT_LED_USER2	BIT(3)
23
24struct menf21bmc_led {
25	struct led_classdev cdev;
26	u8 led_bit;
27	const char *name;
28	struct i2c_client *i2c_client;
29};
30
31static struct menf21bmc_led leds[] = {
32	{
33		.name = "menf21bmc:led_status",
34		.led_bit = BMC_BIT_LED_STATUS,
35	},
36	{
37		.name = "menf21bmc:led_hotswap",
38		.led_bit = BMC_BIT_LED_HOTSWAP,
39	},
40	{
41		.name = "menf21bmc:led_user1",
42		.led_bit = BMC_BIT_LED_USER1,
43	},
44	{
45		.name = "menf21bmc:led_user2",
46		.led_bit = BMC_BIT_LED_USER2,
47	}
48};
49
50static DEFINE_MUTEX(led_lock);
51
52static void
53menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
54{
55	int led_val;
56	struct menf21bmc_led *led = container_of(led_cdev,
57					struct menf21bmc_led, cdev);
58
59	mutex_lock(&led_lock);
60	led_val = i2c_smbus_read_byte_data(led->i2c_client,
61					   BMC_CMD_LED_GET_SET);
62	if (led_val < 0)
63		goto err_out;
64
65	if (value == LED_OFF)
66		led_val &= ~led->led_bit;
67	else
68		led_val |= led->led_bit;
69
70	i2c_smbus_write_byte_data(led->i2c_client,
71				  BMC_CMD_LED_GET_SET, led_val);
72err_out:
73	mutex_unlock(&led_lock);
74}
75
76static int menf21bmc_led_probe(struct platform_device *pdev)
77{
78	int i;
79	int ret;
80	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
81
82	for (i = 0; i < ARRAY_SIZE(leds); i++) {
83		leds[i].cdev.name = leds[i].name;
84		leds[i].cdev.brightness_set = menf21bmc_led_set;
85		leds[i].i2c_client = i2c_client;
86		ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
87		if (ret < 0) {
88			dev_err(&pdev->dev, "failed to register LED device\n");
89			return ret;
90		}
91	}
92	dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
93
94	return 0;
95
96}
97
98static struct platform_driver menf21bmc_led = {
99	.probe		= menf21bmc_led_probe,
100	.driver		= {
101		.name		= "menf21bmc_led",
102	},
103};
104
105module_platform_driver(menf21bmc_led);
106
107MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
108MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
109MODULE_LICENSE("GPL v2");
110MODULE_ALIAS("platform:menf21bmc_led");
111