linux/drivers/platform/x86/samsung-laptop.c
Jiapeng Chong 0284d4d1be platform/x86: samsung-laptop: Fix an unsigned comparison which can never be negative
Eliminate the follow smatch warnings:

drivers/platform/x86/samsung-laptop.c:1124 kbd_led_set() warn: unsigned
'value' is never less than zero.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220322061830.105579-1-jiapeng.chong@linux.alibaba.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-04-04 15:49:37 +02:00

1746 lines
42 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Samsung Laptop driver
*
* Copyright (C) 2009,2011 Greg Kroah-Hartman (gregkh@suse.de)
* Copyright (C) 2009,2011 Novell Inc.
*/
#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/leds.h>
#include <linux/fb.h>
#include <linux/dmi.h>
#include <linux/platform_device.h>
#include <linux/rfkill.h>
#include <linux/acpi.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/efi.h>
#include <linux/suspend.h>
#include <acpi/video.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
#define WL_STATUS_WLAN 0x0
#define WL_STATUS_BT 0x2
/* Structure get/set data using sabi */
struct sabi_data {
union {
struct {
u32 d0;
u32 d1;
u16 d2;
u8 d3;
};
u8 data[11];
};
};
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
*/
u16 get_brightness;
u16 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...
*/
u16 get_wireless_button;
u16 set_wireless_button;
/* 0 is off, 1 is on */
u16 get_backlight;
u16 set_backlight;
/*
* 0x80 or 0x00 - no action
* 0x81 - recovery key pressed
*/
u16 get_recovery_mode;
u16 set_recovery_mode;
/*
* on seclinux: 0 is low, 1 is high,
* on swsmi: 0 is normal, 1 is silent, 2 is turbo
*/
u16 get_performance_level;
u16 set_performance_level;
/* 0x80 is off, 0x81 is on */
u16 get_battery_life_extender;
u16 set_battery_life_extender;
/* 0x80 is off, 0x81 is on */
u16 get_usb_charge;
u16 set_usb_charge;
/* the first byte is for bluetooth and the third one is for wlan */
u16 get_wireless_status;
u16 set_wireless_status;
/* 0x80 is off, 0x81 is on */
u16 get_lid_handling;
u16 set_lid_handling;
/* 0x81 to read, (0x82 | level << 8) to set, 0xaabb to enable */
u16 kbd_backlight;
/*
* Tell the BIOS that Linux is running on this machine.
* 81 is on, 80 is off
*/
u16 set_linux;
};
struct sabi_performance_level {
const char *name;
u16 value;
};
struct sabi_config {
int sabi_version;
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[] = {
{
/* I don't know if it is really 2, but it is
* less than 3 anyway */
.sabi_version = 2,
.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,
.get_battery_life_extender = 0xFFFF,
.set_battery_life_extender = 0xFFFF,
.get_usb_charge = 0xFFFF,
.set_usb_charge = 0xFFFF,
.get_wireless_status = 0xFFFF,
.set_wireless_status = 0xFFFF,
.get_lid_handling = 0xFFFF,
.set_lid_handling = 0xFFFF,
.kbd_backlight = 0xFFFF,
.set_linux = 0x0a,
},
.performance_levels = {
{
.name = "silent",
.value = 0,
},
{
.name = "normal",
.value = 1,
},
{ },
},
.min_brightness = 1,
.max_brightness = 8,
},
{
.sabi_version = 3,
.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,
.get_battery_life_extender = 0x65,
.set_battery_life_extender = 0x66,
.get_usb_charge = 0x67,
.set_usb_charge = 0x68,
.get_wireless_status = 0x69,
.set_wireless_status = 0x6a,
.get_lid_handling = 0x6d,
.set_lid_handling = 0x6e,
.kbd_backlight = 0x78,
.set_linux = 0xff,
},
.performance_levels = {
{
.name = "normal",
.value = 0,
},
{
.name = "silent",
.value = 1,
},
{
.name = "overclock",
.value = 2,
},
{ },
},
.min_brightness = 0,
.max_brightness = 8,
},
{ },
};
/*
* samsung-laptop/ - debugfs root directory
* f0000_segment - dump f0000 segment
* command - current command
* data - current data
* d0, d1, d2, d3 - data fields
* call - call SABI using command and data
*
* This allow to call arbitrary sabi commands wihout
* modifying the driver at all.
* For example, setting the keyboard backlight brightness to 5
*
* echo 0x78 > command
* echo 0x0582 > d0
* echo 0 > d1
* echo 0 > d2
* echo 0 > d3
* cat call
*/
struct samsung_laptop_debug {
struct dentry *root;
struct sabi_data data;
u16 command;
struct debugfs_blob_wrapper f0000_wrapper;
struct debugfs_blob_wrapper data_wrapper;
struct debugfs_blob_wrapper sdiag_wrapper;
};
struct samsung_laptop;
struct samsung_rfkill {
struct samsung_laptop *samsung;
struct rfkill *rfkill;
enum rfkill_type type;
};
struct samsung_laptop {
const struct sabi_config *config;
void __iomem *sabi;
void __iomem *sabi_iface;
void __iomem *f0000_segment;
struct mutex sabi_mutex;
struct platform_device *platform_device;
struct backlight_device *backlight_device;
struct samsung_rfkill wlan;
struct samsung_rfkill bluetooth;
struct led_classdev kbd_led;
int kbd_led_wk;
struct workqueue_struct *led_workqueue;
struct work_struct kbd_led_work;
struct samsung_laptop_debug debug;
struct samsung_quirks *quirks;
struct notifier_block pm_nb;
bool handle_backlight;
bool has_stepping_quirk;
char sdiag[64];
};
struct samsung_quirks {
bool broken_acpi_video;
bool four_kbd_backlight_levels;
bool enable_kbd_backlight;
bool use_native_backlight;
bool lid_handling;
};
static struct samsung_quirks samsung_unknown = {};
static struct samsung_quirks samsung_broken_acpi_video = {
.broken_acpi_video = true,
};
static struct samsung_quirks samsung_use_native_backlight = {
.use_native_backlight = true,
};
static struct samsung_quirks samsung_np740u3e = {
.four_kbd_backlight_levels = true,
.enable_kbd_backlight = true,
};
static struct samsung_quirks samsung_lid_handling = {
.lid_handling = true,
};
static bool force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force,
"Disable the DMI check and forces the driver to be loaded");
static bool debug;
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Debug enabled or not");
static int sabi_command(struct samsung_laptop *samsung, u16 command,
struct sabi_data *in,
struct sabi_data *out)
{
const struct sabi_config *config = samsung->config;
int ret = 0;
u16 port = readw(samsung->sabi + config->header_offsets.port);
u8 complete, iface_data;
mutex_lock(&samsung->sabi_mutex);
if (debug) {
if (in)
pr_info("SABI command:0x%04x "
"data:{0x%08x, 0x%08x, 0x%04x, 0x%02x}",
command, in->d0, in->d1, in->d2, in->d3);
else
pr_info("SABI command:0x%04x", command);
}
/* enable memory to be able to write to it */
outb(readb(samsung->sabi + config->header_offsets.en_mem), port);
/* write out the command */
writew(config->main_function, samsung->sabi_iface + SABI_IFACE_MAIN);
writew(command, samsung->sabi_iface + SABI_IFACE_SUB);
writeb(0, samsung->sabi_iface + SABI_IFACE_COMPLETE);
if (in) {
writel(in->d0, samsung->sabi_iface + SABI_IFACE_DATA);
writel(in->d1, samsung->sabi_iface + SABI_IFACE_DATA + 4);
writew(in->d2, samsung->sabi_iface + SABI_IFACE_DATA + 8);
writeb(in->d3, samsung->sabi_iface + SABI_IFACE_DATA + 10);
}
outb(readb(samsung->sabi + config->header_offsets.iface_func), port);
/* write protect memory to make it safe */
outb(readb(samsung->sabi + config->header_offsets.re_mem), port);
/* see if the command actually succeeded */
complete = readb(samsung->sabi_iface + SABI_IFACE_COMPLETE);
iface_data = readb(samsung->sabi_iface + SABI_IFACE_DATA);
/* iface_data = 0xFF happens when a command is not known
* so we only add a warning in debug mode since we will
* probably issue some unknown command at startup to find
* out which features are supported */
if (complete != 0xaa || (iface_data == 0xff && debug))
pr_warn("SABI command 0x%04x failed with"
" completion flag 0x%02x and interface data 0x%02x",
command, complete, iface_data);
if (complete != 0xaa || iface_data == 0xff) {
ret = -EINVAL;
goto exit;
}
if (out) {
out->d0 = readl(samsung->sabi_iface + SABI_IFACE_DATA);
out->d1 = readl(samsung->sabi_iface + SABI_IFACE_DATA + 4);
out->d2 = readw(samsung->sabi_iface + SABI_IFACE_DATA + 2);
out->d3 = readb(samsung->sabi_iface + SABI_IFACE_DATA + 1);
}
if (debug && out) {
pr_info("SABI return data:{0x%08x, 0x%08x, 0x%04x, 0x%02x}",
out->d0, out->d1, out->d2, out->d3);
}
exit:
mutex_unlock(&samsung->sabi_mutex);
return ret;
}
/* simple wrappers usable with most commands */
static int sabi_set_commandb(struct samsung_laptop *samsung,
u16 command, u8 data)
{
struct sabi_data in = { { { .d0 = 0, .d1 = 0, .d2 = 0, .d3 = 0 } } };
in.data[0] = data;
return sabi_command(samsung, command, &in, NULL);
}
static int read_brightness(struct samsung_laptop *samsung)
{
const struct sabi_config *config = samsung->config;
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data sretval;
int user_brightness = 0;
int retval;
retval = sabi_command(samsung, commands->get_brightness,
NULL, &sretval);
if (retval)
return retval;
user_brightness = sretval.data[0];
if (user_brightness > config->min_brightness)
user_brightness -= config->min_brightness;
else
user_brightness = 0;
return user_brightness;
}
static void set_brightness(struct samsung_laptop *samsung, u8 user_brightness)
{
const struct sabi_config *config = samsung->config;
const struct sabi_commands *commands = &samsung->config->commands;
u8 user_level = user_brightness + config->min_brightness;
if (samsung->has_stepping_quirk && user_level != 0) {
/*
* short circuit if the specified level is what's already set
* to prevent the screen from flickering needlessly
*/
if (user_brightness == read_brightness(samsung))
return;
sabi_set_commandb(samsung, commands->set_brightness, 0);
}
sabi_set_commandb(samsung, commands->set_brightness, user_level);
}
static int get_brightness(struct backlight_device *bd)
{
struct samsung_laptop *samsung = bl_get_data(bd);
return read_brightness(samsung);
}
static void check_for_stepping_quirk(struct samsung_laptop *samsung)
{
int initial_level;
int check_level;
int orig_level = read_brightness(samsung);
/*
* Some laptops exhibit the strange behaviour of stepping toward
* (rather than setting) the brightness except when changing to/from
* brightness level 0. This behaviour is checked for here and worked
* around in set_brightness.
*/
if (orig_level == 0)
set_brightness(samsung, 1);
initial_level = read_brightness(samsung);
if (initial_level <= 2)
check_level = initial_level + 2;
else
check_level = initial_level - 2;
samsung->has_stepping_quirk = false;
set_brightness(samsung, check_level);
if (read_brightness(samsung) != check_level) {
samsung->has_stepping_quirk = true;
pr_info("enabled workaround for brightness stepping quirk\n");
}
set_brightness(samsung, orig_level);
}
static int update_status(struct backlight_device *bd)
{
struct samsung_laptop *samsung = bl_get_data(bd);
const struct sabi_commands *commands = &samsung->config->commands;
set_brightness(samsung, bd->props.brightness);
if (bd->props.power == FB_BLANK_UNBLANK)
sabi_set_commandb(samsung, commands->set_backlight, 1);
else
sabi_set_commandb(samsung, commands->set_backlight, 0);
return 0;
}
static const struct backlight_ops backlight_ops = {
.get_brightness = get_brightness,
.update_status = update_status,
};
static int seclinux_rfkill_set(void *data, bool blocked)
{
struct samsung_rfkill *srfkill = data;
struct samsung_laptop *samsung = srfkill->samsung;
const struct sabi_commands *commands = &samsung->config->commands;
return sabi_set_commandb(samsung, commands->set_wireless_button,
!blocked);
}
static const struct rfkill_ops seclinux_rfkill_ops = {
.set_block = seclinux_rfkill_set,
};
static int swsmi_wireless_status(struct samsung_laptop *samsung,
struct sabi_data *data)
{
const struct sabi_commands *commands = &samsung->config->commands;
return sabi_command(samsung, commands->get_wireless_status,
NULL, data);
}
static int swsmi_rfkill_set(void *priv, bool blocked)
{
struct samsung_rfkill *srfkill = priv;
struct samsung_laptop *samsung = srfkill->samsung;
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int ret, i;
ret = swsmi_wireless_status(samsung, &data);
if (ret)
return ret;
/* Don't set the state for non-present devices */
for (i = 0; i < 4; i++)
if (data.data[i] == 0x02)
data.data[1] = 0;
if (srfkill->type == RFKILL_TYPE_WLAN)
data.data[WL_STATUS_WLAN] = !blocked;
else if (srfkill->type == RFKILL_TYPE_BLUETOOTH)
data.data[WL_STATUS_BT] = !blocked;
return sabi_command(samsung, commands->set_wireless_status,
&data, &data);
}
static void swsmi_rfkill_query(struct rfkill *rfkill, void *priv)
{
struct samsung_rfkill *srfkill = priv;
struct samsung_laptop *samsung = srfkill->samsung;
struct sabi_data data;
int ret;
ret = swsmi_wireless_status(samsung, &data);
if (ret)
return ;
if (srfkill->type == RFKILL_TYPE_WLAN)
ret = data.data[WL_STATUS_WLAN];
else if (srfkill->type == RFKILL_TYPE_BLUETOOTH)
ret = data.data[WL_STATUS_BT];
else
return ;
rfkill_set_sw_state(rfkill, !ret);
}
static const struct rfkill_ops swsmi_rfkill_ops = {
.set_block = swsmi_rfkill_set,
.query = swsmi_rfkill_query,
};
static ssize_t get_performance_level(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
const struct sabi_config *config = samsung->config;
const struct sabi_commands *commands = &config->commands;
struct sabi_data sretval;
int retval;
int i;
/* Read the state */
retval = sabi_command(samsung, commands->get_performance_level,
NULL, &sretval);
if (retval)
return retval;
/* The logic is backwards, yeah, lots of fun... */
for (i = 0; config->performance_levels[i].name; ++i) {
if (sretval.data[0] == config->performance_levels[i].value)
return sprintf(buf, "%s\n", 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)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
const struct sabi_config *config = samsung->config;
const struct sabi_commands *commands = &config->commands;
int i;
if (count < 1)
return count;
for (i = 0; config->performance_levels[i].name; ++i) {
const struct sabi_performance_level *level =
&config->performance_levels[i];
if (!strncasecmp(level->name, buf, strlen(level->name))) {
sabi_set_commandb(samsung,
commands->set_performance_level,
level->value);
break;
}
}
if (!config->performance_levels[i].name)
return -EINVAL;
return count;
}
static DEVICE_ATTR(performance_level, 0644,
get_performance_level, set_performance_level);
static int read_battery_life_extender(struct samsung_laptop *samsung)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int retval;
if (commands->get_battery_life_extender == 0xFFFF)
return -ENODEV;
memset(&data, 0, sizeof(data));
data.data[0] = 0x80;
retval = sabi_command(samsung, commands->get_battery_life_extender,
&data, &data);
if (retval)
return retval;
if (data.data[0] != 0 && data.data[0] != 1)
return -ENODEV;
return data.data[0];
}
static int write_battery_life_extender(struct samsung_laptop *samsung,
int enabled)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
memset(&data, 0, sizeof(data));
data.data[0] = 0x80 | enabled;
return sabi_command(samsung, commands->set_battery_life_extender,
&data, NULL);
}
static ssize_t get_battery_life_extender(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret;
ret = read_battery_life_extender(samsung);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", ret);
}
static ssize_t set_battery_life_extender(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret, value;
if (!count || kstrtoint(buf, 0, &value) != 0)
return -EINVAL;
ret = write_battery_life_extender(samsung, !!value);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(battery_life_extender, 0644,
get_battery_life_extender, set_battery_life_extender);
static int read_usb_charge(struct samsung_laptop *samsung)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int retval;
if (commands->get_usb_charge == 0xFFFF)
return -ENODEV;
memset(&data, 0, sizeof(data));
data.data[0] = 0x80;
retval = sabi_command(samsung, commands->get_usb_charge,
&data, &data);
if (retval)
return retval;
if (data.data[0] != 0 && data.data[0] != 1)
return -ENODEV;
return data.data[0];
}
static int write_usb_charge(struct samsung_laptop *samsung,
int enabled)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
memset(&data, 0, sizeof(data));
data.data[0] = 0x80 | enabled;
return sabi_command(samsung, commands->set_usb_charge,
&data, NULL);
}
static ssize_t get_usb_charge(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret;
ret = read_usb_charge(samsung);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", ret);
}
static ssize_t set_usb_charge(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret, value;
if (!count || kstrtoint(buf, 0, &value) != 0)
return -EINVAL;
ret = write_usb_charge(samsung, !!value);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(usb_charge, 0644,
get_usb_charge, set_usb_charge);
static int read_lid_handling(struct samsung_laptop *samsung)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int retval;
if (commands->get_lid_handling == 0xFFFF)
return -ENODEV;
memset(&data, 0, sizeof(data));
retval = sabi_command(samsung, commands->get_lid_handling,
&data, &data);
if (retval)
return retval;
return data.data[0] & 0x1;
}
static int write_lid_handling(struct samsung_laptop *samsung,
int enabled)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
memset(&data, 0, sizeof(data));
data.data[0] = 0x80 | enabled;
return sabi_command(samsung, commands->set_lid_handling,
&data, NULL);
}
static ssize_t get_lid_handling(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret;
ret = read_lid_handling(samsung);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", ret);
}
static ssize_t set_lid_handling(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct samsung_laptop *samsung = dev_get_drvdata(dev);
int ret, value;
if (!count || kstrtoint(buf, 0, &value) != 0)
return -EINVAL;
ret = write_lid_handling(samsung, !!value);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(lid_handling, 0644,
get_lid_handling, set_lid_handling);
static struct attribute *platform_attributes[] = {
&dev_attr_performance_level.attr,
&dev_attr_battery_life_extender.attr,
&dev_attr_usb_charge.attr,
&dev_attr_lid_handling.attr,
NULL
};
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 void samsung_rfkill_exit(struct samsung_laptop *samsung)
{
if (samsung->wlan.rfkill) {
rfkill_unregister(samsung->wlan.rfkill);
rfkill_destroy(samsung->wlan.rfkill);
samsung->wlan.rfkill = NULL;
}
if (samsung->bluetooth.rfkill) {
rfkill_unregister(samsung->bluetooth.rfkill);
rfkill_destroy(samsung->bluetooth.rfkill);
samsung->bluetooth.rfkill = NULL;
}
}
static int samsung_new_rfkill(struct samsung_laptop *samsung,
struct samsung_rfkill *arfkill,
const char *name, enum rfkill_type type,
const struct rfkill_ops *ops,
int blocked)
{
struct rfkill **rfkill = &arfkill->rfkill;
int ret;
arfkill->type = type;
arfkill->samsung = samsung;
*rfkill = rfkill_alloc(name, &samsung->platform_device->dev,
type, ops, arfkill);
if (!*rfkill)
return -EINVAL;
if (blocked != -1)
rfkill_init_sw_state(*rfkill, blocked);
ret = rfkill_register(*rfkill);
if (ret) {
rfkill_destroy(*rfkill);
*rfkill = NULL;
return ret;
}
return 0;
}
static int __init samsung_rfkill_init_seclinux(struct samsung_laptop *samsung)
{
return samsung_new_rfkill(samsung, &samsung->wlan, "samsung-wlan",
RFKILL_TYPE_WLAN, &seclinux_rfkill_ops, -1);
}
static int __init samsung_rfkill_init_swsmi(struct samsung_laptop *samsung)
{
struct sabi_data data;
int ret;
ret = swsmi_wireless_status(samsung, &data);
if (ret) {
/* Some swsmi laptops use the old seclinux way to control
* wireless devices */
if (ret == -EINVAL)
ret = samsung_rfkill_init_seclinux(samsung);
return ret;
}
/* 0x02 seems to mean that the device is no present/available */
if (data.data[WL_STATUS_WLAN] != 0x02)
ret = samsung_new_rfkill(samsung, &samsung->wlan,
"samsung-wlan",
RFKILL_TYPE_WLAN,
&swsmi_rfkill_ops,
!data.data[WL_STATUS_WLAN]);
if (ret)
goto exit;
if (data.data[WL_STATUS_BT] != 0x02)
ret = samsung_new_rfkill(samsung, &samsung->bluetooth,
"samsung-bluetooth",
RFKILL_TYPE_BLUETOOTH,
&swsmi_rfkill_ops,
!data.data[WL_STATUS_BT]);
if (ret)
goto exit;
exit:
if (ret)
samsung_rfkill_exit(samsung);
return ret;
}
static int __init samsung_rfkill_init(struct samsung_laptop *samsung)
{
if (samsung->config->sabi_version == 2)
return samsung_rfkill_init_seclinux(samsung);
if (samsung->config->sabi_version == 3)
return samsung_rfkill_init_swsmi(samsung);
return 0;
}
static void samsung_lid_handling_exit(struct samsung_laptop *samsung)
{
if (samsung->quirks->lid_handling)
write_lid_handling(samsung, 0);
}
static int __init samsung_lid_handling_init(struct samsung_laptop *samsung)
{
int retval = 0;
if (samsung->quirks->lid_handling)
retval = write_lid_handling(samsung, 1);
return retval;
}
static int kbd_backlight_enable(struct samsung_laptop *samsung)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int retval;
if (commands->kbd_backlight == 0xFFFF)
return -ENODEV;
memset(&data, 0, sizeof(data));
data.d0 = 0xaabb;
retval = sabi_command(samsung, commands->kbd_backlight,
&data, &data);
if (retval)
return retval;
if (data.d0 != 0xccdd)
return -ENODEV;
return 0;
}
static int kbd_backlight_read(struct samsung_laptop *samsung)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
int retval;
memset(&data, 0, sizeof(data));
data.data[0] = 0x81;
retval = sabi_command(samsung, commands->kbd_backlight,
&data, &data);
if (retval)
return retval;
return data.data[0];
}
static int kbd_backlight_write(struct samsung_laptop *samsung, int brightness)
{
const struct sabi_commands *commands = &samsung->config->commands;
struct sabi_data data;
memset(&data, 0, sizeof(data));
data.d0 = 0x82 | ((brightness & 0xFF) << 8);
return sabi_command(samsung, commands->kbd_backlight,
&data, NULL);
}
static void kbd_led_update(struct work_struct *work)
{
struct samsung_laptop *samsung;
samsung = container_of(work, struct samsung_laptop, kbd_led_work);
kbd_backlight_write(samsung, samsung->kbd_led_wk);
}
static void kbd_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct samsung_laptop *samsung;
samsung = container_of(led_cdev, struct samsung_laptop, kbd_led);
if (value > samsung->kbd_led.max_brightness)
value = samsung->kbd_led.max_brightness;
samsung->kbd_led_wk = value;
queue_work(samsung->led_workqueue, &samsung->kbd_led_work);
}
static enum led_brightness kbd_led_get(struct led_classdev *led_cdev)
{
struct samsung_laptop *samsung;
samsung = container_of(led_cdev, struct samsung_laptop, kbd_led);
return kbd_backlight_read(samsung);
}
static void samsung_leds_exit(struct samsung_laptop *samsung)
{
led_classdev_unregister(&samsung->kbd_led);
if (samsung->led_workqueue)
destroy_workqueue(samsung->led_workqueue);
}
static int __init samsung_leds_init(struct samsung_laptop *samsung)
{
int ret = 0;
samsung->led_workqueue = create_singlethread_workqueue("led_workqueue");
if (!samsung->led_workqueue)
return -ENOMEM;
if (kbd_backlight_enable(samsung) >= 0) {
INIT_WORK(&samsung->kbd_led_work, kbd_led_update);
samsung->kbd_led.name = "samsung::kbd_backlight";
samsung->kbd_led.brightness_set = kbd_led_set;
samsung->kbd_led.brightness_get = kbd_led_get;
samsung->kbd_led.max_brightness = 8;
if (samsung->quirks->four_kbd_backlight_levels)
samsung->kbd_led.max_brightness = 4;
ret = led_classdev_register(&samsung->platform_device->dev,
&samsung->kbd_led);
}
if (ret)
samsung_leds_exit(samsung);
return ret;
}
static void samsung_backlight_exit(struct samsung_laptop *samsung)
{
if (samsung->backlight_device) {
backlight_device_unregister(samsung->backlight_device);
samsung->backlight_device = NULL;
}
}
static int __init samsung_backlight_init(struct samsung_laptop *samsung)
{
struct backlight_device *bd;
struct backlight_properties props;
if (!samsung->handle_backlight)
return 0;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = samsung->config->max_brightness -
samsung->config->min_brightness;
bd = backlight_device_register("samsung",
&samsung->platform_device->dev,
samsung, &backlight_ops,
&props);
if (IS_ERR(bd))
return PTR_ERR(bd);
samsung->backlight_device = bd;
samsung->backlight_device->props.brightness = read_brightness(samsung);
samsung->backlight_device->props.power = FB_BLANK_UNBLANK;
backlight_update_status(samsung->backlight_device);
return 0;
}
static umode_t samsung_sysfs_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct samsung_laptop *samsung = dev_get_drvdata(dev);
bool ok = true;
if (attr == &dev_attr_performance_level.attr)
ok = !!samsung->config->performance_levels[0].name;
if (attr == &dev_attr_battery_life_extender.attr)
ok = !!(read_battery_life_extender(samsung) >= 0);
if (attr == &dev_attr_usb_charge.attr)
ok = !!(read_usb_charge(samsung) >= 0);
if (attr == &dev_attr_lid_handling.attr)
ok = !!(read_lid_handling(samsung) >= 0);
return ok ? attr->mode : 0;
}
static const struct attribute_group platform_attribute_group = {
.is_visible = samsung_sysfs_is_visible,
.attrs = platform_attributes
};
static void samsung_sysfs_exit(struct samsung_laptop *samsung)
{
struct platform_device *device = samsung->platform_device;
sysfs_remove_group(&device->dev.kobj, &platform_attribute_group);
}
static int __init samsung_sysfs_init(struct samsung_laptop *samsung)
{
struct platform_device *device = samsung->platform_device;
return sysfs_create_group(&device->dev.kobj, &platform_attribute_group);
}
static int samsung_laptop_call_show(struct seq_file *m, void *data)
{
struct samsung_laptop *samsung = m->private;
struct sabi_data *sdata = &samsung->debug.data;
int ret;
seq_printf(m, "SABI 0x%04x {0x%08x, 0x%08x, 0x%04x, 0x%02x}\n",
samsung->debug.command,
sdata->d0, sdata->d1, sdata->d2, sdata->d3);
ret = sabi_command(samsung, samsung->debug.command, sdata, sdata);
if (ret) {
seq_printf(m, "SABI command 0x%04x failed\n",
samsung->debug.command);
return ret;
}
seq_printf(m, "SABI {0x%08x, 0x%08x, 0x%04x, 0x%02x}\n",
sdata->d0, sdata->d1, sdata->d2, sdata->d3);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(samsung_laptop_call);
static void samsung_debugfs_exit(struct samsung_laptop *samsung)
{
debugfs_remove_recursive(samsung->debug.root);
}
static void samsung_debugfs_init(struct samsung_laptop *samsung)
{
struct dentry *root;
root = debugfs_create_dir("samsung-laptop", NULL);
samsung->debug.root = root;
samsung->debug.f0000_wrapper.data = samsung->f0000_segment;
samsung->debug.f0000_wrapper.size = 0xffff;
samsung->debug.data_wrapper.data = &samsung->debug.data;
samsung->debug.data_wrapper.size = sizeof(samsung->debug.data);
samsung->debug.sdiag_wrapper.data = samsung->sdiag;
samsung->debug.sdiag_wrapper.size = strlen(samsung->sdiag);
debugfs_create_u16("command", 0644, root, &samsung->debug.command);
debugfs_create_u32("d0", 0644, root, &samsung->debug.data.d0);
debugfs_create_u32("d1", 0644, root, &samsung->debug.data.d1);
debugfs_create_u16("d2", 0644, root, &samsung->debug.data.d2);
debugfs_create_u8("d3", 0644, root, &samsung->debug.data.d3);
debugfs_create_blob("data", 0444, root, &samsung->debug.data_wrapper);
debugfs_create_blob("f0000_segment", 0400, root,
&samsung->debug.f0000_wrapper);
debugfs_create_file("call", 0444, root, samsung,
&samsung_laptop_call_fops);
debugfs_create_blob("sdiag", 0444, root, &samsung->debug.sdiag_wrapper);
}
static void samsung_sabi_exit(struct samsung_laptop *samsung)
{
const struct sabi_config *config = samsung->config;
/* Turn off "Linux" mode in the BIOS */
if (config && config->commands.set_linux != 0xff)
sabi_set_commandb(samsung, config->commands.set_linux, 0x80);
if (samsung->sabi_iface) {
iounmap(samsung->sabi_iface);
samsung->sabi_iface = NULL;
}
if (samsung->f0000_segment) {
iounmap(samsung->f0000_segment);
samsung->f0000_segment = NULL;
}
samsung->config = NULL;
}
static __init void samsung_sabi_infos(struct samsung_laptop *samsung, int loca,
unsigned int ifaceP)
{
const struct sabi_config *config = samsung->config;
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(samsung->sabi + config->header_offsets.port));
printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
readb(samsung->sabi + config->header_offsets.iface_func));
printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
readb(samsung->sabi + config->header_offsets.en_mem));
printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
readb(samsung->sabi + config->header_offsets.re_mem));
printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
readw(samsung->sabi + config->header_offsets.data_offset));
printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
readw(samsung->sabi + config->header_offsets.data_segment));
printk(KERN_DEBUG " SABI pointer = 0x%08x\n", ifaceP);
}
static void __init samsung_sabi_diag(struct samsung_laptop *samsung)
{
int loca = find_signature(samsung->f0000_segment, "SDiaG@");
int i;
if (loca == 0xffff)
return ;
/* Example:
* Ident: @SDiaG@686XX-N90X3A/966-SEC-07HL-S90X3A
*
* Product name: 90X3A
* BIOS Version: 07HL
*/
loca += 1;
for (i = 0; loca < 0xffff && i < sizeof(samsung->sdiag) - 1; loca++) {
char temp = readb(samsung->f0000_segment + loca);
if (isalnum(temp) || temp == '/' || temp == '-')
samsung->sdiag[i++] = temp;
else
break ;
}
if (debug && samsung->sdiag[0])
pr_info("sdiag: %s", samsung->sdiag);
}
static int __init samsung_sabi_init(struct samsung_laptop *samsung)
{
const struct sabi_config *config = NULL;
const struct sabi_commands *commands;
unsigned int ifaceP;
int loca = 0xffff;
int ret = 0;
int i;
samsung->f0000_segment = ioremap(0xf0000, 0xffff);
if (!samsung->f0000_segment) {
if (debug || force)
pr_err("Can't map the segment at 0xf0000\n");
ret = -EINVAL;
goto exit;
}
samsung_sabi_diag(samsung);
/* Try to find one of the signatures in memory to find the header */
for (i = 0; sabi_configs[i].test_string != NULL; ++i) {
samsung->config = &sabi_configs[i];
loca = find_signature(samsung->f0000_segment,
samsung->config->test_string);
if (loca != 0xffff)
break;
}
if (loca == 0xffff) {
if (debug || force)
pr_err("This computer does not support SABI\n");
ret = -ENODEV;
goto exit;
}
config = samsung->config;
commands = &config->commands;
/* point to the SMI port Number */
loca += 1;
samsung->sabi = (samsung->f0000_segment + loca);
/* Get a pointer to the SABI Interface */
ifaceP = (readw(samsung->sabi + config->header_offsets.data_segment) & 0x0ffff) << 4;
ifaceP += readw(samsung->sabi + config->header_offsets.data_offset) & 0x0ffff;
if (debug)
samsung_sabi_infos(samsung, loca, ifaceP);
samsung->sabi_iface = ioremap(ifaceP, 16);
if (!samsung->sabi_iface) {
pr_err("Can't remap %x\n", ifaceP);
ret = -EINVAL;
goto exit;
}
/* Turn on "Linux" mode in the BIOS */
if (commands->set_linux != 0xff) {
int retval = sabi_set_commandb(samsung,
commands->set_linux, 0x81);
if (retval) {
pr_warn("Linux mode was not set!\n");
ret = -ENODEV;
goto exit;
}
}
/* Check for stepping quirk */
if (samsung->handle_backlight)
check_for_stepping_quirk(samsung);
pr_info("detected SABI interface: %s\n",
samsung->config->test_string);
exit:
if (ret)
samsung_sabi_exit(samsung);
return ret;
}
static void samsung_platform_exit(struct samsung_laptop *samsung)
{
if (samsung->platform_device) {
platform_device_unregister(samsung->platform_device);
samsung->platform_device = NULL;
}
}
static int samsung_pm_notification(struct notifier_block *nb,
unsigned long val, void *ptr)
{
struct samsung_laptop *samsung;
samsung = container_of(nb, struct samsung_laptop, pm_nb);
if (val == PM_POST_HIBERNATION &&
samsung->quirks->enable_kbd_backlight)
kbd_backlight_enable(samsung);
if (val == PM_POST_HIBERNATION && samsung->quirks->lid_handling)
write_lid_handling(samsung, 1);
return 0;
}
static int __init samsung_platform_init(struct samsung_laptop *samsung)
{
struct platform_device *pdev;
pdev = platform_device_register_simple("samsung", -1, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
samsung->platform_device = pdev;
platform_set_drvdata(samsung->platform_device, samsung);
return 0;
}
static struct samsung_quirks *quirks;
static int __init samsung_dmi_matched(const struct dmi_system_id *d)
{
quirks = d->driver_data;
return 0;
}
static const struct dmi_system_id samsung_dmi_table[] __initconst = {
{
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_CHASSIS_TYPE, "8"), /* Portable */
},
},
{
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_CHASSIS_TYPE, "9"), /* Laptop */
},
},
{
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_CHASSIS_TYPE, "10"), /* Notebook */
},
},
{
.matches = {
DMI_MATCH(DMI_SYS_VENDOR,
"SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_CHASSIS_TYPE, "14"), /* Sub-Notebook */
},
},
/* DMI ids for laptops with bad Chassis Type */
{
.ident = "R40/R41",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "R40/R41"),
DMI_MATCH(DMI_BOARD_NAME, "R40/R41"),
},
},
/* Specific DMI ids for laptop with quirks */
{
.callback = samsung_dmi_matched,
.ident = "N150P",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
DMI_MATCH(DMI_BOARD_NAME, "N150P"),
},
.driver_data = &samsung_use_native_backlight,
},
{
.callback = samsung_dmi_matched,
.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"),
},
.driver_data = &samsung_use_native_backlight,
},
{
.callback = samsung_dmi_matched,
.ident = "N150/N210/N220",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
},
.driver_data = &samsung_broken_acpi_video,
},
{
.callback = samsung_dmi_matched,
.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"),
},
.driver_data = &samsung_broken_acpi_video,
},
{
.callback = samsung_dmi_matched,
.ident = "X360",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
DMI_MATCH(DMI_BOARD_NAME, "X360"),
},
.driver_data = &samsung_broken_acpi_video,
},
{
.callback = samsung_dmi_matched,
.ident = "N250P",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N250P"),
DMI_MATCH(DMI_BOARD_NAME, "N250P"),
},
.driver_data = &samsung_use_native_backlight,
},
{
.callback = samsung_dmi_matched,
.ident = "NC210",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "NC210/NC110"),
DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
},
.driver_data = &samsung_broken_acpi_video,
},
{
.callback = samsung_dmi_matched,
.ident = "730U3E/740U3E",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
},
.driver_data = &samsung_np740u3e,
},
{
.callback = samsung_dmi_matched,
.ident = "300V3Z/300V4Z/300V5Z",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "300V3Z/300V4Z/300V5Z"),
},
.driver_data = &samsung_lid_handling,
},
{ },
};
MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
static struct platform_device *samsung_platform_device;
static int __init samsung_init(void)
{
struct samsung_laptop *samsung;
int ret;
if (efi_enabled(EFI_BOOT))
return -ENODEV;
quirks = &samsung_unknown;
if (!force && !dmi_check_system(samsung_dmi_table))
return -ENODEV;
samsung = kzalloc(sizeof(*samsung), GFP_KERNEL);
if (!samsung)
return -ENOMEM;
mutex_init(&samsung->sabi_mutex);
samsung->handle_backlight = true;
samsung->quirks = quirks;
#ifdef CONFIG_ACPI
if (samsung->quirks->broken_acpi_video)
acpi_video_set_dmi_backlight_type(acpi_backlight_vendor);
if (samsung->quirks->use_native_backlight)
acpi_video_set_dmi_backlight_type(acpi_backlight_native);
if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
samsung->handle_backlight = false;
#endif
ret = samsung_platform_init(samsung);
if (ret)
goto error_platform;
ret = samsung_sabi_init(samsung);
if (ret)
goto error_sabi;
ret = samsung_sysfs_init(samsung);
if (ret)
goto error_sysfs;
ret = samsung_backlight_init(samsung);
if (ret)
goto error_backlight;
ret = samsung_rfkill_init(samsung);
if (ret)
goto error_rfkill;
ret = samsung_leds_init(samsung);
if (ret)
goto error_leds;
ret = samsung_lid_handling_init(samsung);
if (ret)
goto error_lid_handling;
samsung_debugfs_init(samsung);
samsung->pm_nb.notifier_call = samsung_pm_notification;
register_pm_notifier(&samsung->pm_nb);
samsung_platform_device = samsung->platform_device;
return ret;
error_lid_handling:
samsung_leds_exit(samsung);
error_leds:
samsung_rfkill_exit(samsung);
error_rfkill:
samsung_backlight_exit(samsung);
error_backlight:
samsung_sysfs_exit(samsung);
error_sysfs:
samsung_sabi_exit(samsung);
error_sabi:
samsung_platform_exit(samsung);
error_platform:
kfree(samsung);
return ret;
}
static void __exit samsung_exit(void)
{
struct samsung_laptop *samsung;
samsung = platform_get_drvdata(samsung_platform_device);
unregister_pm_notifier(&samsung->pm_nb);
samsung_debugfs_exit(samsung);
samsung_lid_handling_exit(samsung);
samsung_leds_exit(samsung);
samsung_rfkill_exit(samsung);
samsung_backlight_exit(samsung);
samsung_sysfs_exit(samsung);
samsung_sabi_exit(samsung);
samsung_platform_exit(samsung);
kfree(samsung);
samsung_platform_device = NULL;
}
module_init(samsung_init);
module_exit(samsung_exit);
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@suse.de>");
MODULE_DESCRIPTION("Samsung Backlight driver");
MODULE_LICENSE("GPL");