1/* 2 * Driver for the 8 user LEDs found on the RealViews and Versatiles 3 * Based on DaVinci's DM365 board code 4 * 5 * License terms: GNU General Public License (GPL) version 2 6 * Author: Linus Walleij <triad@df.lth.se> 7 */ 8#include <linux/kernel.h> 9#include <linux/init.h> 10#include <linux/module.h> 11#include <linux/io.h> 12#include <linux/slab.h> 13#include <linux/leds.h> 14#include <linux/platform_device.h> 15 16struct versatile_led { 17 void __iomem *base; 18 struct led_classdev cdev; 19 u8 mask; 20}; 21 22/* 23 * The triggers lines up below will only be used if the 24 * LED triggers are compiled in. 25 */ 26static const struct { 27 const char *name; 28 const char *trigger; 29} versatile_leds[] = { 30 { "versatile:0", "heartbeat", }, 31 { "versatile:1", "mmc0", }, 32 { "versatile:2", "cpu0" }, 33 { "versatile:3", "cpu1" }, 34 { "versatile:4", "cpu2" }, 35 { "versatile:5", "cpu3" }, 36 { "versatile:6", }, 37 { "versatile:7", }, 38}; 39 40static void versatile_led_set(struct led_classdev *cdev, 41 enum led_brightness b) 42{ 43 struct versatile_led *led = container_of(cdev, 44 struct versatile_led, cdev); 45 u32 reg = readl(led->base); 46 47 if (b != LED_OFF) 48 reg |= led->mask; 49 else 50 reg &= ~led->mask; 51 writel(reg, led->base); 52} 53 54static enum led_brightness versatile_led_get(struct led_classdev *cdev) 55{ 56 struct versatile_led *led = container_of(cdev, 57 struct versatile_led, cdev); 58 u32 reg = readl(led->base); 59 60 return (reg & led->mask) ? LED_FULL : LED_OFF; 61} 62 63static int versatile_leds_probe(struct platform_device *dev) 64{ 65 int i; 66 struct resource *res; 67 void __iomem *base; 68 69 res = platform_get_resource(dev, IORESOURCE_MEM, 0); 70 base = devm_ioremap_resource(&dev->dev, res); 71 if (IS_ERR(base)) 72 return PTR_ERR(base); 73 74 /* All off */ 75 writel(0, base); 76 for (i = 0; i < ARRAY_SIZE(versatile_leds); i++) { 77 struct versatile_led *led; 78 79 led = kzalloc(sizeof(*led), GFP_KERNEL); 80 if (!led) 81 break; 82 83 led->base = base; 84 led->cdev.name = versatile_leds[i].name; 85 led->cdev.brightness_set = versatile_led_set; 86 led->cdev.brightness_get = versatile_led_get; 87 led->cdev.default_trigger = versatile_leds[i].trigger; 88 led->mask = BIT(i); 89 90 if (led_classdev_register(NULL, &led->cdev) < 0) { 91 kfree(led); 92 break; 93 } 94 } 95 96 return 0; 97} 98 99static struct platform_driver versatile_leds_driver = { 100 .driver = { 101 .name = "versatile-leds", 102 }, 103 .probe = versatile_leds_probe, 104}; 105 106module_platform_driver(versatile_leds_driver); 107 108MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 109MODULE_DESCRIPTION("ARM Versatile LED driver"); 110MODULE_LICENSE("GPL v2"); 111