leds: ALIX.2 LEDs driver

Driver for PC Engines ALIX.2 and ALIX.3 LEDs.

Signed-off-by: Constantin Baranov <const@mimas.ru>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

1 files changed, 209 insertions, 0 deletions

diff --git a/drivers/leds/leds-alix2.c b/drivers/leds/leds-alix2.c
new file mode 100644
index 000000000000..d7666e6cb425
--- /dev/null
+++ b/drivers/leds/leds-alix2.c
@@ -0,0 +1,209 @@
+/*
+ * LEDs driver for PCEngines ALIX.2 and ALIX.3
+ *
+ * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+
+static int force = 0;
+module_param(force, bool, 0444);
+MODULE_PARM_DESC(force, "Assume system has ALIX.2 style LEDs");
+
+struct alix_led {
+        struct led_classdev cdev;
+        unsigned short port;
+        unsigned int on_value;
+        unsigned int off_value;
+};
+
+static void alix_led_set(struct led_classdev *led_cdev,
+                         enum led_brightness brightness)
+{
+        struct alix_led *led_dev =
+                container_of(led_cdev, struct alix_led, cdev);
+
+        if (brightness)
+                outl(led_dev->on_value, led_dev->port);
+        else
+                outl(led_dev->off_value, led_dev->port);
+}
+
+static struct alix_led alix_leds[] = {
+        {
+                .cdev = {
+                        .name = "alix:1",
+                        .brightness_set = alix_led_set,
+                },
+                .port = 0x6100,
+                .on_value = 1 << 22,
+                .off_value = 1 << 6,
+        },
+        {
+                .cdev = {
+                        .name = "alix:2",
+                        .brightness_set = alix_led_set,
+                },
+                .port = 0x6180,
+                .on_value = 1 << 25,
+                .off_value = 1 << 9,
+        },
+        {
+                .cdev = {
+                        .name = "alix:3",
+                        .brightness_set = alix_led_set,
+                },
+                .port = 0x6180,
+                .on_value = 1 << 27,
+                .off_value = 1 << 11,
+        },
+};
+
+#ifdef CONFIG_PM
+
+static int alix_led_suspend(struct platform_device *dev, pm_message_t state)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
+                led_classdev_suspend(&alix_leds[i].cdev);
+        return 0;
+}
+
+static int alix_led_resume(struct platform_device *dev)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
+                led_classdev_resume(&alix_leds[i].cdev);
+        return 0;
+}
+
+#else
+
+#define alix_led_suspend NULL
+#define alix_led_resume NULL
+
+#endif
+
+static int __init alix_led_probe(struct platform_device *pdev)
+{
+        int i;
+        int ret;
+
+        for (i = 0; i < ARRAY_SIZE(alix_leds); i++) {
+                ret = led_classdev_register(&pdev->dev, &alix_leds[i].cdev);
+                if (ret < 0)
+                        goto fail;
+        }
+        return 0;
+
+fail:
+        while (--i >= 0)
+                led_classdev_unregister(&alix_leds[i].cdev);
+        return ret;
+}
+
+static int alix_led_remove(struct platform_device *pdev)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
+                led_classdev_unregister(&alix_leds[i].cdev);
+        return 0;
+}
+
+static struct platform_driver alix_led_driver = {
+        .remove = alix_led_remove,
+        .suspend = alix_led_suspend,
+        .resume = alix_led_resume,
+        .driver = {
+                .name = KBUILD_MODNAME,
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init alix_present(void)
+{
+        const unsigned long bios_phys = 0x000f0000;
+        const size_t bios_len = 0x00010000;
+        const char alix_sig[] = "PC Engines ALIX.";
+        const size_t alix_sig_len = sizeof(alix_sig) - 1;
+
+        const char *bios_virt;
+        const char *scan_end;
+        const char *p;
+        int ret = 0;
+
+        if (force) {
+                printk(KERN_NOTICE "%s: forced to skip BIOS test, "
+                       "assume system has ALIX.2 style LEDs\n",
+                       KBUILD_MODNAME);
+                ret = 1;
+                goto out;
+        }
+
+        bios_virt = phys_to_virt(bios_phys);
+        scan_end = bios_virt + bios_len - (alix_sig_len + 2);
+        for (p = bios_virt; p < scan_end; p++) {
+                const char *tail;
+
+                if (memcmp(p, alix_sig, alix_sig_len) != 0) {
+                        continue;
+                }
+
+                tail = p + alix_sig_len;
+                if ((tail[0] == '2' || tail[0] == '3') && tail[1] == '\0') {
+                        printk(KERN_INFO
+                               "%s: system is recognized as \"%s\"\n",
+                               KBUILD_MODNAME, p);
+                        ret = 1;
+                        break;
+                }
+        }
+
+out:
+        return ret;
+}
+
+static struct platform_device *pdev;
+
+static int __init alix_led_init(void)
+{
+        int ret;
+
+        if (!alix_present()) {
+                ret = -ENODEV;
+                goto out;
+        }
+
+        pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
+        if (!IS_ERR(pdev)) {
+                ret = platform_driver_probe(&alix_led_driver, alix_led_probe);
+                if (ret)
+                        platform_device_unregister(pdev);
+        } else
+                ret = PTR_ERR(pdev);
+
+out:
+        return ret;
+}
+
+static void __exit alix_led_exit(void)
+{
+        platform_device_unregister(pdev);
+        platform_driver_unregister(&alix_led_driver);
+}
+
+module_init(alix_led_init);
+module_exit(alix_led_exit);
+
+MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
+MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
+MODULE_LICENSE("GPL");