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 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 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 = led_classdev_register(&pdev->dev, &leds[i].cdev); 91 if (ret < 0) 92 goto err_free_leds; 93 } 94 dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n"); 95 96 return 0; 97 98 err_free_leds: 99 dev_err(&pdev->dev, "failed to register LED device\n"); 100 101 for (i = i - 1; i >= 0; i--) 102 led_classdev_unregister(&leds[i].cdev); 103 104 return ret; 105 } 106 107 static int menf21bmc_led_remove(struct platform_device *pdev) 108 { 109 int i; 110 111 for (i = 0; i < ARRAY_SIZE(leds); i++) 112 led_classdev_unregister(&leds[i].cdev); 113 114 return 0; 115 } 116 117 static struct platform_driver menf21bmc_led = { 118 .probe = menf21bmc_led_probe, 119 .remove = menf21bmc_led_remove, 120 .driver = { 121 .name = "menf21bmc_led", 122 }, 123 }; 124 125 module_platform_driver(menf21bmc_led); 126 127 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); 128 MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver"); 129 MODULE_LICENSE("GPL v2"); 130 MODULE_ALIAS("platform:menf21bmc_led"); 131