1 /* 2 * Bachmann ot200 leds driver. 3 * 4 * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> 5 * Christian Gmeiner <christian.gmeiner@gmail.com> 6 * 7 * License: GPL as published by the FSF. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/platform_device.h> 13 #include <linux/slab.h> 14 #include <linux/leds.h> 15 #include <linux/io.h> 16 #include <linux/module.h> 17 18 19 struct ot200_led { 20 struct led_classdev cdev; 21 const char *name; 22 unsigned long port; 23 u8 mask; 24 }; 25 26 /* 27 * The device has three leds on the back panel (led_err, led_init and led_run) 28 * and can handle up to seven leds on the front panel. 29 */ 30 31 static struct ot200_led leds[] = { 32 { 33 .name = "led_run", 34 .port = 0x5a, 35 .mask = BIT(0), 36 }, 37 { 38 .name = "led_init", 39 .port = 0x5a, 40 .mask = BIT(1), 41 }, 42 { 43 .name = "led_err", 44 .port = 0x5a, 45 .mask = BIT(2), 46 }, 47 { 48 .name = "led_1", 49 .port = 0x49, 50 .mask = BIT(6), 51 }, 52 { 53 .name = "led_2", 54 .port = 0x49, 55 .mask = BIT(5), 56 }, 57 { 58 .name = "led_3", 59 .port = 0x49, 60 .mask = BIT(4), 61 }, 62 { 63 .name = "led_4", 64 .port = 0x49, 65 .mask = BIT(3), 66 }, 67 { 68 .name = "led_5", 69 .port = 0x49, 70 .mask = BIT(2), 71 }, 72 { 73 .name = "led_6", 74 .port = 0x49, 75 .mask = BIT(1), 76 }, 77 { 78 .name = "led_7", 79 .port = 0x49, 80 .mask = BIT(0), 81 } 82 }; 83 84 static DEFINE_SPINLOCK(value_lock); 85 86 /* 87 * we need to store the current led states, as it is not 88 * possible to read the current led state via inb(). 89 */ 90 static u8 leds_back; 91 static u8 leds_front; 92 93 static void ot200_led_brightness_set(struct led_classdev *led_cdev, 94 enum led_brightness value) 95 { 96 struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev); 97 u8 *val; 98 unsigned long flags; 99 100 spin_lock_irqsave(&value_lock, flags); 101 102 if (led->port == 0x49) 103 val = &leds_front; 104 else if (led->port == 0x5a) 105 val = &leds_back; 106 else 107 BUG(); 108 109 if (value == LED_OFF) 110 *val &= ~led->mask; 111 else 112 *val |= led->mask; 113 114 outb(*val, led->port); 115 spin_unlock_irqrestore(&value_lock, flags); 116 } 117 118 static int ot200_led_probe(struct platform_device *pdev) 119 { 120 int i; 121 int ret; 122 123 for (i = 0; i < ARRAY_SIZE(leds); i++) { 124 125 leds[i].cdev.name = leds[i].name; 126 leds[i].cdev.brightness_set = ot200_led_brightness_set; 127 128 ret = led_classdev_register(&pdev->dev, &leds[i].cdev); 129 if (ret < 0) 130 goto err; 131 } 132 133 leds_front = 0; /* turn off all front leds */ 134 leds_back = BIT(1); /* turn on init led */ 135 outb(leds_front, 0x49); 136 outb(leds_back, 0x5a); 137 138 return 0; 139 140 err: 141 for (i = i - 1; i >= 0; i--) 142 led_classdev_unregister(&leds[i].cdev); 143 144 return ret; 145 } 146 147 static int ot200_led_remove(struct platform_device *pdev) 148 { 149 int i; 150 151 for (i = 0; i < ARRAY_SIZE(leds); i++) 152 led_classdev_unregister(&leds[i].cdev); 153 154 return 0; 155 } 156 157 static struct platform_driver ot200_led_driver = { 158 .probe = ot200_led_probe, 159 .remove = ot200_led_remove, 160 .driver = { 161 .name = "leds-ot200", 162 .owner = THIS_MODULE, 163 }, 164 }; 165 166 module_platform_driver(ot200_led_driver); 167 168 MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>"); 169 MODULE_DESCRIPTION("ot200 LED driver"); 170 MODULE_LICENSE("GPL"); 171 MODULE_ALIAS("platform:leds-ot200"); 172