/*
 * Samsung Laptop driver
 *
 * Copyright (C) 2009,2011 Greg Kroah-Hartman (gregkh@suse.de)
 * 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/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 <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;

        /* 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 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,

                        .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,

                        .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;

        bool handle_backlight;
        bool has_stepping_quirk;

        char sdiag[64];
};

struct samsung_quirks {
        bool broken_acpi_video;
};

static struct samsung_quirks samsung_unknown = {};

static struct samsung_quirks samsung_broken_acpi_video = {
        .broken_acpi_video = 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, S_IRUGO | S_IWUSR);
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 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 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, S_IWUSR | S_IRUGO,
                   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 || sscanf(buf, "%i", &value) != 1)
                return -EINVAL;

        ret = write_battery_life_extender(samsung, !!value);
        if (ret < 0)
                return ret;

        return count;
}

static DEVICE_ATTR(battery_life_extender, S_IWUSR | S_IRUGO,
                   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 || sscanf(buf, "%i", &value) != 1)
                return -EINVAL;

        ret = write_usb_charge(samsung, !!value);
        if (ret < 0)
                return ret;

        return count;
}

static DEVICE_ATTR(usb_charge, S_IWUSR | S_IRUGO,
                   get_usb_charge, set_usb_charge);

static struct attribute *platform_attributes[] = {
        &dev_attr_performance_level.attr,
        &dev_attr_battery_life_extender.attr,
        &dev_attr_usb_charge.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 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;
        else if (value < 0)
                value = 0;

        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)
{
        if (!IS_ERR_OR_NULL(samsung->kbd_led.dev))
                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;

                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 platform_device *pdev = to_platform_device(dev);
        struct samsung_laptop *samsung = platform_get_drvdata(pdev);
        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);

        return ok ? attr->mode : 0;
}

static 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 show_call(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;
}

static int samsung_debugfs_open(struct inode *inode, struct file *file)
{
        return single_open(file, show_call, inode->i_private);
}

static const struct file_operations samsung_laptop_call_io_ops = {
        .owner = THIS_MODULE,
        .open = samsung_debugfs_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = single_release,
};

static void samsung_debugfs_exit(struct samsung_laptop *samsung)
{
        debugfs_remove_recursive(samsung->debug.root);
}

static int samsung_debugfs_init(struct samsung_laptop *samsung)
{
        struct dentry *dent;

        samsung->debug.root = debugfs_create_dir("samsung-laptop", NULL);
        if (!samsung->debug.root) {
                pr_err("failed to create debugfs directory");
                goto error_debugfs;
        }

        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);

        dent = debugfs_create_u16("command", S_IRUGO | S_IWUSR,
                                  samsung->debug.root, &samsung->debug.command);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_u32("d0", S_IRUGO | S_IWUSR, samsung->debug.root,
                                  &samsung->debug.data.d0);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_u32("d1", S_IRUGO | S_IWUSR, samsung->debug.root,
                                  &samsung->debug.data.d1);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_u16("d2", S_IRUGO | S_IWUSR, samsung->debug.root,
                                  &samsung->debug.data.d2);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_u8("d3", S_IRUGO | S_IWUSR, samsung->debug.root,
                                 &samsung->debug.data.d3);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_blob("data", S_IRUGO | S_IWUSR,
                                   samsung->debug.root,
                                   &samsung->debug.data_wrapper);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_blob("f0000_segment", S_IRUSR | S_IWUSR,
                                   samsung->debug.root,
                                   &samsung->debug.f0000_wrapper);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_file("call", S_IFREG | S_IRUGO,
                                   samsung->debug.root, samsung,
                                   &samsung_laptop_call_io_ops);
        if (!dent)
                goto error_debugfs;

        dent = debugfs_create_blob("sdiag", S_IRUGO | S_IWUSR,
                                   samsung->debug.root,
                                   &samsung->debug.sdiag_wrapper);
        if (!dent)
                goto error_debugfs;

        return 0;

error_debugfs:
        samsung_debugfs_exit(samsung);
        return -ENOMEM;
}

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 ret = 0;
        int i;
        int loca;

        samsung->f0000_segment = ioremap_nocache(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 != 0; ++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_nocache(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 __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 struct dmi_system_id __initdata samsung_dmi_table[] = {
        {
                .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_broken_acpi_video,
        },
        {
         .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_broken_acpi_video,
        },
        {
         .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_broken_acpi_video,
        },
        { },
};
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_dmi_promote_vendor();

        /* Don't handle backlight here if the acpi video already handle it */
        if (acpi_video_backlight_support()) {
                samsung->handle_backlight = false;
        } else if (samsung->quirks->broken_acpi_video) {
                pr_info("Disabling ACPI video driver\n");
                acpi_video_unregister();
        }
#endif

        ret = samsung_platform_init(samsung);
        if (ret)
                goto error_platform;

        ret = samsung_sabi_init(samsung);
        if (ret)
                goto error_sabi;

#ifdef CONFIG_ACPI
        /* Only log that if we are really on a sabi platform */
        if (acpi_video_backlight_support())
                pr_info("Backlight controlled by ACPI video driver\n");
#endif

        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_debugfs_init(samsung);
        if (ret)
                goto error_debugfs;

        samsung_platform_device = samsung->platform_device;
        return ret;

error_debugfs:
        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);

        samsung_debugfs_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");