Re: [PATCH] Platform: add Samsung Laptop platform driver

From: Greg KH
Date: Thu Mar 10 2011 - 13:10:18 EST


On Thu, Mar 10, 2011 at 07:28:00PM +0200, Nikolai Kondrashov wrote:
> On 03/10/2011 07:19 PM, Greg KH wrote:
> >Can you provide me the output of:
> > grep . /sys/class/dmi/id/*
> >so I can try to add support for this machine to the driver?
> Sure, here it is.

Great, here's a new version of the samsung-laptop.c file, can you
replace it whereever you were building the previous one, rebuild it and
test it for this machine to see if it works?

thanks,

greg k-h
/*
* Samsung Laptop driver
*
* Copyright (C) 2009,2011 Greg Kroah-Hartman (gregkh@xxxxxxx)
* Copyright (C) 2009,2011 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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


#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];
};

struct sabi_header_offsets {
u8 port;
u8 re_mem;
u8 iface_func;
u8 en_mem;
u8 data_offset;
u8 data_segment;
};

struct sabi_commands {
/*
* Brightness is 0 - 8, as described above.
* Value 0 is for the BIOS to use
*/
u8 get_brightness;
u8 set_brightness;

/*
* 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...
*/
u8 get_wireless_button;
u8 set_wireless_button;

/* 0 is off, 1 is on */
u8 get_backlight;
u8 set_backlight;

/*
* 0x80 or 0x00 - no action
* 0x81 - recovery key pressed
*/
u8 get_recovery_mode;
u8 set_recovery_mode;

/*
* on seclinux: 0 is low, 1 is high,
* on swsmi: 0 is normal, 1 is silent, 2 is turbo
*/
u8 get_performance_level;
u8 set_performance_level;

/*
* Tell the BIOS that Linux is running on this machine.
* 81 is on, 80 is off
*/
u8 set_linux;
};

struct sabi_performance_level {
const char *name;
u8 value;
};

struct sabi_config {
const char *test_string;
u16 main_function;
const struct sabi_header_offsets header_offsets;
const struct sabi_commands commands;
const struct sabi_performance_level performance_levels[4];
u8 min_brightness;
u8 max_brightness;
};

static const struct sabi_config sabi_configs[] = {
{
.test_string = "SECLINUX",

.main_function = 0x4c49,

.header_offsets = {
.port = 0x00,
.re_mem = 0x02,
.iface_func = 0x03,
.en_mem = 0x04,
.data_offset = 0x05,
.data_segment = 0x07,
},

.commands = {
.get_brightness = 0x00,
.set_brightness = 0x01,

.get_wireless_button = 0x02,
.set_wireless_button = 0x03,

.get_backlight = 0x04,
.set_backlight = 0x05,

.get_recovery_mode = 0x06,
.set_recovery_mode = 0x07,

.get_performance_level = 0x08,
.set_performance_level = 0x09,

.set_linux = 0x0a,
},

.performance_levels = {
{
.name = "silent",
.value = 0,
},
{
.name = "normal",
.value = 1,
},
{ },
},
.min_brightness = 1,
.max_brightness = 8,
},
{
.test_string = "SwSmi@",

.main_function = 0x5843,

.header_offsets = {
.port = 0x00,
.re_mem = 0x04,
.iface_func = 0x02,
.en_mem = 0x03,
.data_offset = 0x05,
.data_segment = 0x07,
},

.commands = {
.get_brightness = 0x10,
.set_brightness = 0x11,

.get_wireless_button = 0x12,
.set_wireless_button = 0x13,

.get_backlight = 0x2d,
.set_backlight = 0x2e,

.get_recovery_mode = 0xff,
.set_recovery_mode = 0xff,

.get_performance_level = 0x31,
.set_performance_level = 0x32,

.set_linux = 0xff,
},

.performance_levels = {
{
.name = "normal",
.value = 0,
},
{
.name = "silent",
.value = 1,
},
{
.name = "overclock",
.value = 2,
},
{ },
},
.min_brightness = 0,
.max_brightness = 8,
},
{ },
};

static const struct sabi_config *sabi_config;

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_config->header_offsets.port);
u8 complete, iface_data;

mutex_lock(&sabi_mutex);

/* enable memory to be able to write to it */
outb(readb(sabi + sabi_config->header_offsets.en_mem), port);

/* write out the command */
writew(sabi_config->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_config->header_offsets.iface_func), port);

/* write protect memory to make it safe */
outb(readb(sabi + sabi_config->header_offsets.re_mem), port);

/* see if the command actually succeeded */
complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
iface_data = readb(sabi_iface + SABI_IFACE_DATA);
if (complete != 0xaa || iface_data == 0xff) {
pr_warn("SABI get command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
command, complete, iface_data);
retval = -EINVAL;
goto exit;
}
/*
* Save off the data into a structure so the caller use it.
* Right now we only want the first 4 bytes,
* There are commands that need more, but not for the ones we
* currently care about.
*/
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);

exit:
mutex_unlock(&sabi_mutex);
return retval;

}

static int sabi_set_command(u8 command, u8 data)
{
int retval = 0;
u16 port = readw(sabi + sabi_config->header_offsets.port);
u8 complete, iface_data;

mutex_lock(&sabi_mutex);

/* enable memory to be able to write to it */
outb(readb(sabi + sabi_config->header_offsets.en_mem), port);

/* write out the command */
writew(sabi_config->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_config->header_offsets.iface_func), port);

/* write protect memory to make it safe */
outb(readb(sabi + sabi_config->header_offsets.re_mem), port);

/* see if the command actually succeeded */
complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
iface_data = readb(sabi_iface + SABI_IFACE_DATA);
if (complete != 0xaa || iface_data == 0xff) {
pr_warn("SABI set command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
command, complete, iface_data);
retval = -EINVAL;
}

mutex_unlock(&sabi_mutex);
return retval;
}

static void test_backlight(void)
{
struct sabi_retval sretval;

sabi_get_command(sabi_config->commands.get_backlight, &sretval);
printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);

sabi_set_command(sabi_config->commands.set_backlight, 0);
printk(KERN_DEBUG "backlight should be off\n");

sabi_get_command(sabi_config->commands.get_backlight, &sretval);
printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);

msleep(1000);

sabi_set_command(sabi_config->commands.set_backlight, 1);
printk(KERN_DEBUG "backlight should be on\n");

sabi_get_command(sabi_config->commands.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(sabi_config->commands.get_wireless_button, &sretval);
printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);

sabi_set_command(sabi_config->commands.set_wireless_button, 0);
printk(KERN_DEBUG "wireless led should be off\n");

sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);

msleep(1000);

sabi_set_command(sabi_config->commands.set_wireless_button, 1);
printk(KERN_DEBUG "wireless led should be on\n");

sabi_get_command(sabi_config->commands.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(sabi_config->commands.get_brightness,
&sretval);
if (!retval) {
user_brightness = sretval.retval[0];
if (user_brightness != 0)
user_brightness -= sabi_config->min_brightness;
}
return user_brightness;
}

static void set_brightness(u8 user_brightness)
{
u8 user_level = user_brightness - sabi_config->min_brightness;

sabi_set_command(sabi_config->commands.set_brightness, user_level);
}

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(sabi_config->commands.set_backlight, 1);
else
sabi_set_command(sabi_config->commands.set_backlight, 0);
return 0;
}

static const struct backlight_ops backlight_ops = {
.get_brightness = get_brightness,
.update_status = update_status,
};

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(sabi_config->commands.set_wireless_button, 0);
else
sabi_set_command(sabi_config->commands.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);
}

static ssize_t get_performance_level(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sabi_retval sretval;
int retval;
int i;

/* Read the state */
retval = sabi_get_command(sabi_config->commands.get_performance_level,
&sretval);
if (retval)
return retval;

/* The logic is backwards, yeah, lots of fun... */
for (i = 0; sabi_config->performance_levels[i].name; ++i) {
if (sretval.retval[0] == sabi_config->performance_levels[i].value)
return sprintf(buf, "%s\n", sabi_config->performance_levels[i].name);
}
return sprintf(buf, "%s\n", "unknown");
}

static ssize_t set_performance_level(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
if (count >= 1) {
int i;
for (i = 0; sabi_config->performance_levels[i].name; ++i) {
const struct sabi_performance_level *level =
&sabi_config->performance_levels[i];
if (!strncasecmp(level->name, buf, strlen(level->name))) {
sabi_set_command(sabi_config->commands.set_performance_level,
level->value);
break;
}
}
if (!sabi_config->performance_levels[i].name)
return -EINVAL;
}
return count;
}
static DEVICE_ATTR(performance_level, S_IWUSR | S_IRUGO,
get_performance_level, set_performance_level);


static int __init dmi_check_cb(const struct dmi_system_id *id)
{
pr_info("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,
},
{
.ident = "X125",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "X125"),
DMI_MATCH(DMI_BOARD_NAME, "X125"),
},
.callback = dmi_check_cb,
},
{
.ident = "X120/X170",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "X120/X170"),
DMI_MATCH(DMI_BOARD_NAME, "X120/X170"),
},
.callback = dmi_check_cb,
},
{
.ident = "NC10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "NC10"),
DMI_MATCH(DMI_BOARD_NAME, "NC10"),
},
.callback = dmi_check_cb,
},
{
.ident = "NP-Q45",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "SQ45S70S"),
DMI_MATCH(DMI_BOARD_NAME, "SQ45S70S"),
},
.callback = dmi_check_cb,
},
{
.ident = "X360",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
DMI_MATCH(DMI_BOARD_NAME, "X360"),
},
.callback = dmi_check_cb,
},
{
.ident = "R410 Plus",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R410P"),
DMI_MATCH(DMI_BOARD_NAME, "R460"),
},
.callback = dmi_check_cb,
},
{
.ident = "R518",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R518"),
DMI_MATCH(DMI_BOARD_NAME, "R518"),
},
.callback = dmi_check_cb,
},
{
.ident = "R519/R719",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R519/R719"),
DMI_MATCH(DMI_BOARD_NAME, "R519/R719"),
},
.callback = dmi_check_cb,
},
{
.ident = "N150/N210/N220/N230",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220/N230"),
DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220/N230"),
},
.callback = dmi_check_cb,
},
{
.ident = "N150P/N210P/N220P",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150P/N210P/N220P"),
DMI_MATCH(DMI_BOARD_NAME, "N150P/N210P/N220P"),
},
.callback = dmi_check_cb,
},
{
.ident = "R530/R730",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R530/R730"),
DMI_MATCH(DMI_BOARD_NAME, "R530/R730"),
},
.callback = dmi_check_cb,
},
{
.ident = "NF110/NF210/NF310",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
},
.callback = dmi_check_cb,
},
{
.ident = "N145P/N250P/N260P",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
},
.callback = dmi_check_cb,
},
{
.ident = "R70/R71",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R70/R71"),
DMI_MATCH(DMI_BOARD_NAME, "R70/R71"),
},
.callback = dmi_check_cb,
},
{
.ident = "P460",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "P460"),
DMI_MATCH(DMI_BOARD_NAME, "P460"),
},
.callback = dmi_check_cb,
},
{ },
};
MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);

static int find_signature(void __iomem *memcheck, const char *testStr)
{
int i = 0;
int loca;

for (loca = 0; loca < 0xffff; loca++) {
char temp = readb(memcheck + loca);

if (temp == testStr[i]) {
if (i == strlen(testStr)-1)
break;
++i;
} else {
i = 0;
}
}
return loca;
}

static int __init samsung_init(void)
{
struct backlight_properties props;
struct sabi_retval sretval;
unsigned int ifaceP;
int i;
int loca;
int retval;

mutex_init(&sabi_mutex);

if (!force && !dmi_check_system(samsung_dmi_table))
return -ENODEV;

f0000_segment = ioremap_nocache(0xf0000, 0xffff);
if (!f0000_segment) {
pr_err("Can't map the segment at 0xf0000\n");
return -EINVAL;
}

/* Try to find one of the signatures in memory to find the header */
for (i = 0; sabi_configs[i].test_string != 0; ++i) {
sabi_config = &sabi_configs[i];
loca = find_signature(f0000_segment, sabi_config->test_string);
if (loca != 0xffff)
break;
}

if (loca == 0xffff) {
pr_err("This computer does not support SABI\n");
goto error_no_signature;
}

/* point to the SMI port Number */
loca += 1;
sabi = (f0000_segment + 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_config->header_offsets.port));
printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
readb(sabi + sabi_config->header_offsets.iface_func));
printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
readb(sabi + sabi_config->header_offsets.en_mem));
printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
readb(sabi + sabi_config->header_offsets.re_mem));
printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
readw(sabi + sabi_config->header_offsets.data_offset));
printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
readw(sabi + sabi_config->header_offsets.data_segment));
}

/* Get a pointer to the SABI Interface */
ifaceP = (readw(sabi + sabi_config->header_offsets.data_segment) & 0x0ffff) << 4;
ifaceP += readw(sabi + sabi_config->header_offsets.data_offset) & 0x0ffff;
sabi_iface = ioremap_nocache(ifaceP, 16);
if (!sabi_iface) {
pr_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(sabi_config->commands.get_brightness,
&sretval);
printk(KERN_DEBUG "brightness = 0x%02x\n", sretval.retval[0]);
}

/* Turn on "Linux" mode in the BIOS */
if (sabi_config->commands.set_linux != 0xff) {
retval = sabi_set_command(sabi_config->commands.set_linux,
0x81);
if (retval) {
pr_warn("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 */
memset(&props, 0, sizeof(struct backlight_properties));
props.max_brightness = sabi_config->max_brightness;
backlight_device = backlight_device_register("samsung", &sdev->dev,
NULL, &backlight_ops,
&props);
if (IS_ERR(backlight_device))
goto error_no_backlight;

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_performance_level);
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 */
if (sabi_config->commands.set_linux != 0xff)
sabi_set_command(sabi_config->commands.set_linux, 0x80);

device_remove_file(&sdev->dev, &dev_attr_performance_level);
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@xxxxxxx>");
MODULE_DESCRIPTION("Samsung Backlight driver");
MODULE_LICENSE("GPL");