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
16 struct 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 */
26 static 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
versatile_led_set(struct led_classdev * cdev,enum led_brightness b)40 static 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
versatile_led_get(struct led_classdev * cdev)54 static 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
versatile_leds_probe(struct platform_device * dev)63 static 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
99 static struct platform_driver versatile_leds_driver = {
100 .driver = {
101 .name = "versatile-leds",
102 },
103 .probe = versatile_leds_probe,
104 };
105
106 module_platform_driver(versatile_leds_driver);
107
108 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
109 MODULE_DESCRIPTION("ARM Versatile LED driver");
110 MODULE_LICENSE("GPL v2");
111