leds: Add clevo notebook LED driver

The driver supports the mail LED commonly found on different Clevo notebooks.
The driver access the LED through the i8042 hardware which is handled by
the input subsystem.

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

drivers/leds/Kconfig

@@ -114,6 +114,30 @@ config LEDS_CM_X270
 	help
 	  This option enables support for the CM-X270 LEDs.
 
+config LEDS_CLEVO_MAIL
+	tristate "Mail LED on Clevo notebook (EXPERIMENTAL)"
+	depends on LEDS_CLASS && X86 && SERIO_I8042 && DMI && EXPERIMENTAL
+	help
+	  This driver makes the mail LED accessible from userspace
+	  programs through the leds subsystem. This LED have three
+	  known mode: off, blink at 0.5Hz and blink at 1Hz.
+
+	  As this LED cannot change it's brightness it blinks instead.
+	  The brightness value 0 means off, 1..127 means blink at 0.5Hz
+	  and 128..255 means blink at 1Hz.
+
+	  This module can drive the mail LED for the following notebooks:
+
+	  	Clevo D410J
+	  	Clevo D410V
+	  	Clevo D400V/D470V (not tested, but might work)
+	  	Clevo M540N
+	  	Clevo M5x0N (not tested, but might work)
+	  	Positivo Mobile (Clevo M5x0V)
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called leds-clevo-mail.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS

drivers/leds/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_LEDS_COBALT_QUBE)		+= leds-cobalt-qube.o
 obj-$(CONFIG_LEDS_COBALT_RAQ)		+= leds-cobalt-raq.o
 obj-$(CONFIG_LEDS_GPIO)			+= leds-gpio.o
 obj-$(CONFIG_LEDS_CM_X270)              += leds-cm-x270.o
+obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
 
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o

drivers/leds/leds-clevo-mail.c

@@ -0,0 +1,182 @@
+
+#include <linux/module.h>
+
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/leds.h>
+
+#include <linux/io.h>
+#include <linux/dmi.h>
+
+#include <linux/i8042.h>
+
+#define CLEVO_MAIL_LED_OFF		0x0084
+#define CLEVO_MAIL_LED_BLINK_1HZ	0x008A
+#define CLEVO_MAIL_LED_BLINK_0_5HZ	0x0083
+
+MODULE_AUTHOR("Márton Németh <nm127@freemail.hu>");
+MODULE_DESCRIPTION("Clevo mail LED driver");
+MODULE_LICENSE("GPL");
+
+static unsigned int __initdata nodetect;
+module_param_named(nodetect, nodetect, bool, 0);
+MODULE_PARM_DESC(nodetect, "Skip DMI hardware detection");
+
+static struct platform_device *pdev;
+
+static int __init clevo_mail_led_dmi_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": '%s' found\n", id->ident);
+	return 1;
+}
+
+/*
+ * struct mail_led_whitelist - List of known good models
+ *
+ * Contains the known good models this driver is compatible with.
+ * When adding a new model try to be as strict as possible. This
+ * makes it possible to keep the false positives (the model is
+ * detected as working, but in reality it is not) as low as
+ * possible.
+ */
+static struct dmi_system_id __initdata mail_led_whitelist[] = {
+	{
+		.callback = clevo_mail_led_dmi_callback,
+		.ident = "Clevo D410J",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "VIA"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "K8N800"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "VT8204B")
+		}
+	},
+	{
+		.callback = clevo_mail_led_dmi_callback,
+		.ident = "Clevo M5x0N",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "M5x0N")
+		}
+	},
+	{
+		.callback = clevo_mail_led_dmi_callback,
+		.ident = "Positivo Mobile",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "CLEVO Co. "),
+			DMI_MATCH(DMI_BOARD_NAME, "M5X0V "),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Positivo Mobile"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "VT6198")
+		}
+	},
+	{
+		.callback = clevo_mail_led_dmi_callback,
+		.ident = "Clevo D410V",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Clevo, Co."),
+			DMI_MATCH(DMI_BOARD_NAME, "D400V/D470V"),
+			DMI_MATCH(DMI_BOARD_VERSION, "SS78B"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "Rev. A1")
+		}
+	},
+	{ }
+};
+
+static void clevo_mail_led_set(struct led_classdev *led_cdev,
+				enum led_brightness value)
+{
+	if (value == LED_OFF)
+		i8042_command(NULL, CLEVO_MAIL_LED_OFF);
+	else if (value <= LED_HALF)
+		i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
+	else
+		i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ);
+
+}
+
+static struct led_classdev clevo_mail_led = {
+	.name			= "clevo",
+	.brightness_set		= clevo_mail_led_set,
+};
+
+static int __init clevo_mail_led_probe(struct platform_device *pdev)
+{
+	return led_classdev_register(&pdev->dev, &clevo_mail_led);
+}
+
+static int clevo_mail_led_remove(struct platform_device *pdev)
+{
+	led_classdev_unregister(&clevo_mail_led);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int clevo_mail_led_suspend(struct platform_device *dev,
+				  pm_message_t state)
+{
+	led_classdev_suspend(&clevo_mail_led);
+	return 0;
+}
+
+static int clevo_mail_led_resume(struct platform_device *dev)
+{
+	led_classdev_resume(&clevo_mail_led);
+	return 0;
+}
+#else
+#define clevo_mail_led_suspend    NULL
+#define clevo_mail_led_resume     NULL
+#endif
+
+static struct platform_driver clevo_mail_led_driver = {
+	.probe		= clevo_mail_led_probe,
+	.remove		= clevo_mail_led_remove,
+	.suspend	= clevo_mail_led_suspend,
+	.resume		= clevo_mail_led_resume,
+	.driver		= {
+		.name		= KBUILD_MODNAME,
+	},
+};
+
+static int __init clevo_mail_led_init(void)
+{
+	int error = 0;
+	int count = 0;
+
+	/* Check with the help of DMI if we are running on supported hardware */
+	if (!nodetect) {
+		count = dmi_check_system(mail_led_whitelist);
+	} else {
+		count = 1;
+		printk(KERN_ERR KBUILD_MODNAME ": Skipping DMI detection. "
+		       "If the driver works on your hardware please "
+		       "report model and the output of dmidecode in tracker "
+		       "at http://sourceforge.net/projects/clevo-mailled/\n");
+	}
+
+	if (!count)
+		return -ENODEV;
+
+	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
+	if (!IS_ERR(pdev)) {
+		error = platform_driver_probe(&clevo_mail_led_driver,
+					      clevo_mail_led_probe);
+		if (error) {
+			printk(KERN_ERR KBUILD_MODNAME
+			       ": Can't probe platform driver\n");
+			platform_device_unregister(pdev);
+		}
+	} else
+		error = PTR_ERR(pdev);
+
+	return error;
+}
+
+static void __exit clevo_mail_led_exit(void)
+{
+	platform_device_unregister(pdev);
+	platform_driver_unregister(&clevo_mail_led_driver);
+
+	clevo_mail_led_set(NULL, LED_OFF);
+}
+
+module_init(clevo_mail_led_init);
+module_exit(clevo_mail_led_exit);