Staging: add Samsung Laptop driver

This is a drive for the Samsung N128 laptop to control the wireless LED
and backlight.

Many thanks to Joey Lee for his help in testing and finding all of my
bugs in the development of this driver, it has been invaluable.

Cc: Joey Lee <jlee@novell.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -131,6 +131,8 @@ source "drivers/staging/wlags49_h25/Kconfig"
 
 source "drivers/staging/batman-adv/Kconfig"
 
+source "drivers/staging/samsung-laptop/Kconfig"
+
 source "drivers/staging/strip/Kconfig"
 
 source "drivers/staging/arlan/Kconfig"

drivers/staging/Makefile

@@ -47,6 +47,7 @@ obj-$(CONFIG_RAMZSWAP)		+= ramzswap/
 obj-$(CONFIG_WLAGS49_H2)	+= wlags49_h2/
 obj-$(CONFIG_WLAGS49_H25)	+= wlags49_h25/
 obj-$(CONFIG_BATMAN_ADV)	+= batman-adv/
+obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop/
 obj-$(CONFIG_STRIP)		+= strip/
 obj-$(CONFIG_ARLAN)		+= arlan/
 obj-$(CONFIG_WAVELAN)		+= wavelan/

drivers/staging/samsung-laptop/Kconfig

+config SAMSUNG_LAPTOP
+	tristate "Samsung Laptop driver"
+	default n
+	depends on RFKILL && BACKLIGHT_CLASS_DEVICE && X86
+	help
+	  This module implements a driver for the N128 Samsung Laptop
+	  providing control over the Wireless LED and the LCD backlight
+
+	  To compile this driver as a module, choose
+	  M here: the module will be called samsung-laptop.

drivers/staging/samsung-laptop/Makefile

+obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop.o

drivers/staging/samsung-laptop/samsung-laptop.c

+/*
+ * Samsung N130 Laptop driver
+ *
+ * Copyright (C) 2009 Greg Kroah-Hartman (gregkh@suse.de)
+ * Copyright (C) 2009 Novell Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ */
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
+#include <linux/dmi.h>
+#include <linux/platform_device.h>
+#include <linux/rfkill.h>
+
+/*
+ * This driver is needed because a number of Samsung laptops do not hook
+ * their control settings through ACPI.  So we have to poke around in the
+ * BIOS to do things like brightness values, and "special" key controls.
+ */
+
+/*
+ * We have 0 - 8 as valid brightness levels.  The specs say that level 0 should
+ * be reserved by the BIOS (which really doesn't make much sense), we tell
+ * userspace that the value is 0 - 7 and then just tell the hardware 1 - 8
+ */
+#define MAX_BRIGHT	0x07
+
+/* Brightness is 0 - 8, as described above.  Value 0 is for the BIOS to use */
+#define GET_BRIGHTNESS			0x00
+#define SET_BRIGHTNESS			0x01
+
+/* first byte:
+ * 0x00 - wireless is off
+ * 0x01 - wireless is on
+ * second byte:
+ * 0x02 - 3G is off
+ * 0x03 - 3G is on
+ * TODO, verify 3G is correct, that doesn't seem right...
+ */
+#define GET_WIRELESS_BUTTON		0x02
+#define SET_WIRELESS_BUTTON		0x03
+
+/* 0 is off, 1 is on */
+#define GET_BACKLIGHT			0x04
+#define SET_BACKLIGHT			0x05
+
+/*
+ * 0x80 or 0x00 - no action
+ * 0x81 - recovery key pressed
+ */
+#define GET_RECOVERY_METHOD		0x06
+#define SET_RECOVERY_METHOD		0x07
+
+/* 0 is low, 1 is high */
+#define GET_PERFORMANCE_LEVEL		0x08
+#define SET_PERFORMANCE_LEVEL		0x09
+
+/*
+ * Tell the BIOS that Linux is running on this machine.
+ * 81 is on, 80 is off
+ */
+#define SET_LINUX			0x0a
+
+
+#define MAIN_FUNCTION			0x4c49
+
+#define SABI_HEADER_PORT		0x00
+#define SABI_HEADER_RE_MEM		0x02
+#define SABI_HEADER_IFACEFUNC		0x03
+#define SABI_HEADER_EN_MEM		0x04
+#define SABI_HEADER_DATA_OFFSET		0x05
+#define SABI_HEADER_DATA_SEGMENT	0x07
+
+#define SABI_IFACE_MAIN			0x00
+#define SABI_IFACE_SUB			0x02
+#define SABI_IFACE_COMPLETE		0x04
+#define SABI_IFACE_DATA			0x05
+
+/* Structure to get data back to the calling function */
+struct sabi_retval {
+	u8 retval[20];
+};
+
+static void __iomem *sabi;
+static void __iomem *sabi_iface;
+static void __iomem *f0000_segment;
+static struct backlight_device *backlight_device;
+static struct mutex sabi_mutex;
+static struct platform_device *sdev;
+static struct rfkill *rfk;
+
+static int force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Disable the DMI check and forces the driver to be loaded");
+
+static int debug;
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+
+static int sabi_get_command(u8 command, struct sabi_retval *sretval)
+{
+	int retval = 0;
+	u16 port = readw(sabi + SABI_HEADER_PORT);
+
+	mutex_lock(&sabi_mutex);
+
+	/* enable memory to be able to write to it */
+	outb(readb(sabi + SABI_HEADER_EN_MEM), port);
+
+	/* write out the command */
+	writew(MAIN_FUNCTION, sabi_iface + SABI_IFACE_MAIN);
+	writew(command, sabi_iface + SABI_IFACE_SUB);
+	writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
+	outb(readb(sabi + SABI_HEADER_IFACEFUNC), port);
+
+	/* write protect memory to make it safe */
+	outb(readb(sabi + SABI_HEADER_RE_MEM), port);
+
+	/* see if the command actually succeeded */
+	if (readb(sabi_iface + SABI_IFACE_COMPLETE) == 0xaa &&
+	    readb(sabi_iface + SABI_IFACE_DATA) != 0xff) {
+		/*
+		 * It did!
+		 * Save off the data into a structure so the caller use it.
+		 * Right now we only care about the first 4 bytes,
+		 * I suppose there are commands that need more, but I don't
+		 * know about them.
+		 */
+		sretval->retval[0] = readb(sabi_iface + SABI_IFACE_DATA);
+		sretval->retval[1] = readb(sabi_iface + SABI_IFACE_DATA + 1);
+		sretval->retval[2] = readb(sabi_iface + SABI_IFACE_DATA + 2);
+		sretval->retval[3] = readb(sabi_iface + SABI_IFACE_DATA + 3);
+		goto exit;
+	}
+
+	/* Something bad happened, so report it and error out */
+	printk(KERN_WARNING "SABI command 0x%02x failed with completion flag 0x%02x and output 0x%02x\n",
+		command, readb(sabi_iface + SABI_IFACE_COMPLETE),
+		readb(sabi_iface + SABI_IFACE_DATA));
+	retval = -EINVAL;
+exit:
+	mutex_unlock(&sabi_mutex);
+	return retval;
+
+}
+
+static int sabi_set_command(u8 command, u8 data)
+{
+	int retval = 0;
+	u16 port = readw(sabi + SABI_HEADER_PORT);
+
+	mutex_lock(&sabi_mutex);
+
+	/* enable memory to be able to write to it */
+	outb(readb(sabi + SABI_HEADER_EN_MEM), port);
+
+	/* write out the command */
+	writew(MAIN_FUNCTION, sabi_iface + SABI_IFACE_MAIN);
+	writew(command, sabi_iface + SABI_IFACE_SUB);
+	writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
+	writeb(data, sabi_iface + SABI_IFACE_DATA);
+	outb(readb(sabi + SABI_HEADER_IFACEFUNC), port);
+
+	/* write protect memory to make it safe */
+	outb(readb(sabi + SABI_HEADER_RE_MEM), port);
+
+	/* see if the command actually succeeded */
+	if (readb(sabi_iface + SABI_IFACE_COMPLETE) == 0xaa &&
+	    readb(sabi_iface + SABI_IFACE_DATA) != 0xff) {
+		/* it did! */
+		goto exit;
+	}
+
+	/* Something bad happened, so report it and error out */
+	printk(KERN_WARNING "SABI command 0x%02x failed with completion flag 0x%02x and output 0x%02x\n",
+		command, readb(sabi_iface + SABI_IFACE_COMPLETE),
+		readb(sabi_iface + SABI_IFACE_DATA));
+	retval = -EINVAL;
+exit:
+	mutex_unlock(&sabi_mutex);
+	return retval;
+}
+
+static void test_backlight(void)
+{
+	struct sabi_retval sretval;
+
+	sabi_get_command(GET_BACKLIGHT, &sretval);
+	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
+
+	sabi_set_command(SET_BACKLIGHT, 0);
+	printk(KERN_DEBUG "backlight should be off\n");
+
+	sabi_get_command(GET_BACKLIGHT, &sretval);
+	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
+
+	msleep(1000);
+
+	sabi_set_command(SET_BACKLIGHT, 1);
+	printk(KERN_DEBUG "backlight should be on\n");
+
+	sabi_get_command(GET_BACKLIGHT, &sretval);
+	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
+}
+
+static void test_wireless(void)
+{
+	struct sabi_retval sretval;
+
+	sabi_get_command(GET_WIRELESS_BUTTON, &sretval);
+	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
+
+	sabi_set_command(SET_WIRELESS_BUTTON, 0);
+	printk(KERN_DEBUG "wireless led should be off\n");
+
+	sabi_get_command(GET_WIRELESS_BUTTON, &sretval);
+	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
+
+	msleep(1000);
+
+	sabi_set_command(SET_WIRELESS_BUTTON, 1);
+	printk(KERN_DEBUG "wireless led should be on\n");
+
+	sabi_get_command(GET_WIRELESS_BUTTON, &sretval);
+	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
+}
+
+static u8 read_brightness(void)
+{
+	struct sabi_retval sretval;
+	int user_brightness = 0;
+	int retval;
+
+	retval = sabi_get_command(GET_BRIGHTNESS, &sretval);
+	if (!retval)
+		user_brightness = sretval.retval[0];
+		if (user_brightness != 0)
+			--user_brightness;
+	return user_brightness;
+}
+
+static void set_brightness(u8 user_brightness)
+{
+	sabi_set_command(SET_BRIGHTNESS, user_brightness + 1);
+}
+
+static int get_brightness(struct backlight_device *bd)
+{
+	return (int)read_brightness();
+}
+
+static int update_status(struct backlight_device *bd)
+{
+	set_brightness(bd->props.brightness);
+
+	if (bd->props.power == FB_BLANK_UNBLANK)
+		sabi_set_command(SET_BACKLIGHT, 1);
+	else
+		sabi_set_command(SET_BACKLIGHT, 0);
+	return 0;
+}
+
+static struct backlight_ops backlight_ops = {
+	.get_brightness	= get_brightness,
+	.update_status	= update_status,
+};
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,31)
+static int rfkill_set(void *data, bool blocked)
+{
+	/* Do something with blocked...*/
+	/*
+	 * blocked == false is on
+	 * blocked == true is off
+	 */
+	if (blocked)
+		sabi_set_command(SET_WIRELESS_BUTTON, 0);
+	else
+		sabi_set_command(SET_WIRELESS_BUTTON, 1);
+
+	return 0;
+}
+
+static struct rfkill_ops rfkill_ops = {
+	.set_block = rfkill_set,
+};
+
+static int init_wireless(struct platform_device *sdev)
+{
+	int retval;
+
+	rfk = rfkill_alloc("samsung-wifi", &sdev->dev, RFKILL_TYPE_WLAN,
+			   &rfkill_ops, NULL);
+	if (!rfk)
+		return -ENOMEM;
+
+	retval = rfkill_register(rfk);
+	if (retval) {
+		rfkill_destroy(rfk);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void destroy_wireless(void)
+{
+	rfkill_unregister(rfk);
+	rfkill_destroy(rfk);
+}
+
+#else
+
+static int rfkill_set(void *data, enum rfkill_state state)
+{
+	if (state ==  RFKILL_STATE_UNBLOCKED)
+		sabi_set_command(SET_WIRELESS_BUTTON, 1);
+	else
+		sabi_set_command(SET_WIRELESS_BUTTON, 0);
+
+	return 0;
+}
+
+static int init_wireless(struct platform_device *sdev)
+{
+	int retval;
+
+	rfk = rfkill_allocate(&sdev->dev, RFKILL_TYPE_WLAN);
+	if (!rfk)
+		return -ENOMEM;
+	rfk->toggle_radio = rfkill_set;
+	rfk->name = "samsung-wifi";
+
+	retval = rfkill_register(rfk);
+	if (retval) {
+		rfkill_free(rfk);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void destroy_wireless(void)
+{
+	rfkill_unregister(rfk);
+}
+
+#endif
+
+static ssize_t get_silent_state(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct sabi_retval sretval;
+	int retval;
+
+	/* Read the state */
+	retval = sabi_get_command(GET_PERFORMANCE_LEVEL, &sretval);
+	if (retval)
+		return retval;
+
+	/* The logic is backwards, yeah, lots of fun... */
+	if (sretval.retval[0] == 0)
+		retval = 1;
+	else
+		retval = 0;
+	return sprintf(buf, "%d\n", retval);
+}
+
+static ssize_t set_silent_state(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t count)
+{
+	char value;
+
+	if (count >= 1) {
+		value = buf[0];
+		if ((value == '0') || (value == 'n') || (value == 'N')) {
+			/* Turn speed up */
+			sabi_set_command(SET_PERFORMANCE_LEVEL, 0x01);
+		} else if ((value == '1') || (value == 'y') || (value == 'Y')) {
+			/* Turn speed down */
+			sabi_set_command(SET_PERFORMANCE_LEVEL, 0x00);
+		} else {
+			return -EINVAL;
+		}
+	}
+	return count;
+}
+static DEVICE_ATTR(silent, S_IWUGO | S_IRUGO,
+		   get_silent_state, set_silent_state);
+
+
+static int __init dmi_check_cb(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": found laptop model '%s'\n",
+		id->ident);
+	return 0;
+}
+
+static struct dmi_system_id __initdata samsung_dmi_table[] = {
+	{
+		.ident = "N128",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "N128"),
+			DMI_MATCH(DMI_BOARD_NAME, "N128"),
+		},
+		.callback = dmi_check_cb,
+	},
+	{
+		.ident = "N130",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "N130"),
+			DMI_MATCH(DMI_BOARD_NAME, "N130"),
+		},
+		.callback = dmi_check_cb,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
+
+static int __init samsung_init(void)
+{
+	struct sabi_retval sretval;
+	const char *testStr = "SECLINUX";
+	void __iomem *memcheck;
+	unsigned int ifaceP;
+	int pStr;
+	int loca;
+	int retval;
+
+	mutex_init(&sabi_mutex);
+
+	if (!force && !dmi_check_system(samsung_dmi_table))
+		return -ENODEV;
+
+	f0000_segment = ioremap(0xf0000, 0xffff);
+	if (!f0000_segment) {
+		printk(KERN_ERR "Can't map the segment at 0xf0000\n");
+		return -EINVAL;
+	}
+
+	/* Try to find the signature "SECLINUX" in memory to find the header */
+	pStr = 0;
+	memcheck = f0000_segment;
+	for (loca = 0; loca < 0xffff; loca++) {
+		char temp = readb(memcheck + loca);
+
+		if (temp == testStr[pStr]) {
+			if (pStr == strlen(testStr)-1)
+				break;
+			++pStr;
+		} else {
+			pStr = 0;
+		}
+	}
+	if (loca == 0xffff) {
+		printk(KERN_ERR "This computer does not support SABI\n");
+		goto error_no_signature;
+		}
+
+	/* point to the SMI port Number */
+	loca += 1;
+	sabi = (memcheck + loca);
+
+	if (debug) {
+		printk(KERN_DEBUG "This computer supports SABI==%x\n",
+			loca + 0xf0000 - 6);
+		printk(KERN_DEBUG "SABI header:\n");
+		printk(KERN_DEBUG " SMI Port Number = 0x%04x\n",
+			readw(sabi + SABI_HEADER_PORT));
+		printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
+			readb(sabi + SABI_HEADER_IFACEFUNC));
+		printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
+			readb(sabi + SABI_HEADER_EN_MEM));
+		printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
+			readb(sabi + SABI_HEADER_RE_MEM));
+		printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
+			readw(sabi + SABI_HEADER_DATA_OFFSET));
+		printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
+			readw(sabi + SABI_HEADER_DATA_SEGMENT));
+	}
+
+	/* Get a pointer to the SABI Interface */
+	ifaceP = (readw(sabi + SABI_HEADER_DATA_SEGMENT) & 0x0ffff) << 4;
+	ifaceP += readw(sabi + SABI_HEADER_DATA_OFFSET) & 0x0ffff;
+	sabi_iface = ioremap(ifaceP, 16);
+	if (!sabi_iface) {
+		printk(KERN_ERR "Can't remap %x\n", ifaceP);
+		goto exit;
+	}
+	if (debug) {
+		printk(KERN_DEBUG "ifaceP = 0x%08x\n", ifaceP);
+		printk(KERN_DEBUG "sabi_iface = %p\n", sabi_iface);
+
+		test_backlight();
+		test_wireless();
+
+		retval = sabi_get_command(GET_BRIGHTNESS, &sretval);
+		printk(KERN_DEBUG "brightness = 0x%02x\n", sretval.retval[0]);
+	}
+
+	/* Turn on "Linux" mode in the BIOS */
+	retval = sabi_set_command(SET_LINUX, 0x81);
+	if (retval) {
+		printk(KERN_ERR KBUILD_MODNAME ": Linux mode was not set!\n");
+		goto error_no_platform;
+	}
+
+	/* knock up a platform device to hang stuff off of */
+	sdev = platform_device_register_simple("samsung", -1, NULL, 0);
+	if (IS_ERR(sdev))
+		goto error_no_platform;
+
+	/* create a backlight device to talk to this one */
+	backlight_device = backlight_device_register("samsung", &sdev->dev,
+						     NULL, &backlight_ops);
+	if (IS_ERR(backlight_device))
+		goto error_no_backlight;
+
+	backlight_device->props.max_brightness = MAX_BRIGHT;
+	backlight_device->props.brightness = read_brightness();
+	backlight_device->props.power = FB_BLANK_UNBLANK;
+	backlight_update_status(backlight_device);
+
+	retval = init_wireless(sdev);
+	if (retval)
+		goto error_no_rfk;
+
+	retval = device_create_file(&sdev->dev, &dev_attr_silent);
+	if (retval)
+		goto error_file_create;
+
+exit:
+	return 0;
+
+error_file_create:
+	destroy_wireless();
+
+error_no_rfk:
+	backlight_device_unregister(backlight_device);
+
+error_no_backlight:
+	platform_device_unregister(sdev);
+
+error_no_platform:
+	iounmap(sabi_iface);
+
+error_no_signature:
+	iounmap(f0000_segment);
+	return -EINVAL;
+}
+
+static void __exit samsung_exit(void)
+{
+	/* Turn off "Linux" mode in the BIOS */
+	sabi_set_command(SET_LINUX, 0x80);
+
+	device_remove_file(&sdev->dev, &dev_attr_silent);
+	backlight_device_unregister(backlight_device);
+	destroy_wireless();
+	iounmap(sabi_iface);
+	iounmap(f0000_segment);
+	platform_device_unregister(sdev);
+}
+
+module_init(samsung_init);
+module_exit(samsung_exit);
+
+MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@suse.de>");
+MODULE_DESCRIPTION("Samsung Backlight driver");
+MODULE_LICENSE("GPL");