/*
 *  toshiba_acpi.c - Toshiba Laptop ACPI Extras
 *
 *
 *  Copyright (C) 2002-2004 John Belmonte
 *  Copyright (C) 2008 Philip Langdale
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 *  The devolpment page for this driver is located at
 *  http://memebeam.org/toys/ToshibaAcpiDriver.
 *
 *  Credits:
 *      Jonathan A. Buzzard - Toshiba HCI info, and critical tips on reverse
 *              engineering the Windows drivers
 *      Yasushi Nagato - changes for linux kernel 2.4 -> 2.5
 *      Rob Miller - TV out and hotkeys help
 *
 *
 *  TODO
 *
 */

#define TOSHIBA_ACPI_VERSION    "0.19"
#define PROC_INTERFACE_VERSION  1

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <linux/platform_device.h>
#include <linux/rfkill.h>

#include <asm/uaccess.h>

#include <acpi/acpi_drivers.h>

MODULE_AUTHOR("John Belmonte");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Extras Driver");
MODULE_LICENSE("GPL");

#define MY_LOGPREFIX "toshiba_acpi: "
#define MY_ERR KERN_ERR MY_LOGPREFIX
#define MY_NOTICE KERN_NOTICE MY_LOGPREFIX
#define MY_INFO KERN_INFO MY_LOGPREFIX

/* Toshiba ACPI method paths */
#define METHOD_LCD_BRIGHTNESS   "\\_SB_.PCI0.VGA_.LCD_._BCM"
#define METHOD_HCI_1            "\\_SB_.VALD.GHCI"
#define METHOD_HCI_2            "\\_SB_.VALZ.GHCI"
#define METHOD_VIDEO_OUT        "\\_SB_.VALX.DSSX"

/* Toshiba HCI interface definitions
 *
 * HCI is Toshiba's "Hardware Control Interface" which is supposed to
 * be uniform across all their models.  Ideally we would just call
 * dedicated ACPI methods instead of using this primitive interface.
 * However the ACPI methods seem to be incomplete in some areas (for
 * example they allow setting, but not reading, the LCD brightness value),
 * so this is still useful.
 */

#define HCI_WORDS                       6

/* operations */
#define HCI_SET                         0xff00
#define HCI_GET                         0xfe00

/* return codes */
#define HCI_SUCCESS                     0x0000
#define HCI_FAILURE                     0x1000
#define HCI_NOT_SUPPORTED               0x8000
#define HCI_EMPTY                       0x8c00

/* registers */
#define HCI_FAN                         0x0004
#define HCI_SYSTEM_EVENT                0x0016
#define HCI_VIDEO_OUT                   0x001c
#define HCI_HOTKEY_EVENT                0x001e
#define HCI_LCD_BRIGHTNESS              0x002a
#define HCI_WIRELESS                    0x0056

/* field definitions */
#define HCI_LCD_BRIGHTNESS_BITS         3
#define HCI_LCD_BRIGHTNESS_SHIFT        (16-HCI_LCD_BRIGHTNESS_BITS)
#define HCI_LCD_BRIGHTNESS_LEVELS       (1 << HCI_LCD_BRIGHTNESS_BITS)
#define HCI_VIDEO_OUT_LCD               0x1
#define HCI_VIDEO_OUT_CRT               0x2
#define HCI_VIDEO_OUT_TV                0x4
#define HCI_WIRELESS_KILL_SWITCH        0x01
#define HCI_WIRELESS_BT_PRESENT         0x0f
#define HCI_WIRELESS_BT_ATTACH          0x40
#define HCI_WIRELESS_BT_POWER           0x80

static const struct acpi_device_id toshiba_device_ids[] = {
        {"TOS6200", 0},
        {"TOS6208", 0},
        {"TOS1900", 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, toshiba_device_ids);

/* utility
 */

static __inline__ void _set_bit(u32 * word, u32 mask, int value)
{
        *word = (*word & ~mask) | (mask * value);
}

/* acpi interface wrappers
 */

static int is_valid_acpi_path(const char *methodName)
{
        acpi_handle handle;
        acpi_status status;

        status = acpi_get_handle(NULL, (char *)methodName, &handle);
        return !ACPI_FAILURE(status);
}

static int write_acpi_int(const char *methodName, int val)
{
        struct acpi_object_list params;
        union acpi_object in_objs[1];
        acpi_status status;

        params.count = ARRAY_SIZE(in_objs);
        params.pointer = in_objs;
        in_objs[0].type = ACPI_TYPE_INTEGER;
        in_objs[0].integer.value = val;

        status = acpi_evaluate_object(NULL, (char *)methodName, &params, NULL);
        return (status == AE_OK);
}

#if 0
static int read_acpi_int(const char *methodName, int *pVal)
{
        struct acpi_buffer results;
        union acpi_object out_objs[1];
        acpi_status status;

        results.length = sizeof(out_objs);
        results.pointer = out_objs;

        status = acpi_evaluate_object(0, (char *)methodName, 0, &results);
        *pVal = out_objs[0].integer.value;

        return (status == AE_OK) && (out_objs[0].type == ACPI_TYPE_INTEGER);
}
#endif

static const char *method_hci /*= 0*/ ;

/* Perform a raw HCI call.  Here we don't care about input or output buffer
 * format.
 */
static acpi_status hci_raw(const u32 in[HCI_WORDS], u32 out[HCI_WORDS])
{
        struct acpi_object_list params;
        union acpi_object in_objs[HCI_WORDS];
        struct acpi_buffer results;
        union acpi_object out_objs[HCI_WORDS + 1];
        acpi_status status;
        int i;

        params.count = HCI_WORDS;
        params.pointer = in_objs;
        for (i = 0; i < HCI_WORDS; ++i) {
                in_objs[i].type = ACPI_TYPE_INTEGER;
                in_objs[i].integer.value = in[i];
        }

        results.length = sizeof(out_objs);
        results.pointer = out_objs;

        status = acpi_evaluate_object(NULL, (char *)method_hci, &params,
                                      &results);
        if ((status == AE_OK) && (out_objs->package.count <= HCI_WORDS)) {
                for (i = 0; i < out_objs->package.count; ++i) {
                        out[i] = out_objs->package.elements[i].integer.value;
                }
        }

        return status;
}

/* common hci tasks (get or set one or two value)
 *
 * In addition to the ACPI status, the HCI system returns a result which
 * may be useful (such as "not supported").
 */

static acpi_status hci_write1(u32 reg, u32 in1, u32 * result)
{
        u32 in[HCI_WORDS] = { HCI_SET, reg, in1, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(in, out);
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_read1(u32 reg, u32 * out1, u32 * result)
{
        u32 in[HCI_WORDS] = { HCI_GET, reg, 0, 0, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(in, out);
        *out1 = out[2];
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_write2(u32 reg, u32 in1, u32 in2, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_SET, reg, in1, in2, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(in, out);
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

static acpi_status hci_read2(u32 reg, u32 *out1, u32 *out2, u32 *result)
{
        u32 in[HCI_WORDS] = { HCI_GET, reg, *out1, *out2, 0, 0 };
        u32 out[HCI_WORDS];
        acpi_status status = hci_raw(in, out);
        *out1 = out[2];
        *out2 = out[3];
        *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
        return status;
}

struct toshiba_acpi_dev {
        struct platform_device *p_dev;
        struct rfkill *bt_rfk;

        const char *bt_name;

        struct mutex mutex;
};

static struct toshiba_acpi_dev toshiba_acpi = {
        .bt_name = "Toshiba Bluetooth",
};

/* Bluetooth rfkill handlers */

static u32 hci_get_bt_present(bool *present)
{
        u32 hci_result;
        u32 value, value2;

        value = 0;
        value2 = 0;
        hci_read2(HCI_WIRELESS, &value, &value2, &hci_result);
        if (hci_result == HCI_SUCCESS)
                *present = (value & HCI_WIRELESS_BT_PRESENT) ? true : false;

        return hci_result;
}

static u32 hci_get_radio_state(bool *radio_state)
{
        u32 hci_result;
        u32 value, value2;

        value = 0;
        value2 = 0x0001;
        hci_read2(HCI_WIRELESS, &value, &value2, &hci_result);

        *radio_state = value & HCI_WIRELESS_KILL_SWITCH;
        return hci_result;
}

static int bt_rfkill_set_block(void *data, bool blocked)
{
        struct toshiba_acpi_dev *dev = data;
        u32 result1, result2;
        u32 value;
        int err;
        bool radio_state;

        value = (blocked == false);

        mutex_lock(&dev->mutex);
        if (hci_get_radio_state(&radio_state) != HCI_SUCCESS) {
                err = -EBUSY;
                goto out;
        }

        if (!radio_state) {
                err = 0;
                goto out;
        }

        hci_write2(HCI_WIRELESS, value, HCI_WIRELESS_BT_POWER, &result1);
        hci_write2(HCI_WIRELESS, value, HCI_WIRELESS_BT_ATTACH, &result2);

        if (result1 != HCI_SUCCESS || result2 != HCI_SUCCESS)
                err = -EBUSY;
        else
                err = 0;
 out:
        mutex_unlock(&dev->mutex);
        return err;
}

static void bt_rfkill_poll(struct rfkill *rfkill, void *data)
{
        bool new_rfk_state;
        bool value;
        u32 hci_result;
        struct toshiba_acpi_dev *dev = data;

        mutex_lock(&dev->mutex);

        hci_result = hci_get_radio_state(&value);
        if (hci_result != HCI_SUCCESS) {
                /* Can't do anything useful */
                mutex_unlock(&dev->mutex);
                return;
        }

        new_rfk_state = value;

        mutex_unlock(&dev->mutex);

        if (rfkill_set_hw_state(rfkill, !new_rfk_state))
                bt_rfkill_set_block(data, true);
}

static const struct rfkill_ops toshiba_rfk_ops = {
        .set_block = bt_rfkill_set_block,
        .poll = bt_rfkill_poll,
};

static struct proc_dir_entry *toshiba_proc_dir /*= 0*/ ;
static struct backlight_device *toshiba_backlight_device;
static int force_fan;
static int last_key_event;
static int key_event_valid;

typedef struct _ProcItem {
        const char *name;
        char *(*read_func) (char *);
        unsigned long (*write_func) (const char *, unsigned long);
} ProcItem;

/* proc file handlers
 */

static int
dispatch_read(char *page, char **start, off_t off, int count, int *eof,
              ProcItem * item)
{
        char *p = page;
        int len;

        if (off == 0)
                p = item->read_func(p);

        /* ISSUE: I don't understand this code */
        len = (p - page);
        if (len <= off + count)
                *eof = 1;
        *start = page + off;
        len -= off;
        if (len > count)
                len = count;
        if (len < 0)
                len = 0;
        return len;
}

static int
dispatch_write(struct file *file, const char __user * buffer,
               unsigned long count, ProcItem * item)
{
        int result;
        char *tmp_buffer;

        /* Arg buffer points to userspace memory, which can't be accessed
         * directly.  Since we're making a copy, zero-terminate the
         * destination so that sscanf can be used on it safely.
         */
        tmp_buffer = kmalloc(count + 1, GFP_KERNEL);
        if (!tmp_buffer)
                return -ENOMEM;

        if (copy_from_user(tmp_buffer, buffer, count)) {
                result = -EFAULT;
        } else {
                tmp_buffer[count] = 0;
                result = item->write_func(tmp_buffer, count);
        }
        kfree(tmp_buffer);
        return result;
}

static int get_lcd(struct backlight_device *bd)
{
        u32 hci_result;
        u32 value;

        hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                return (value >> HCI_LCD_BRIGHTNESS_SHIFT);
        } else
                return -EFAULT;
}

static char *read_lcd(char *p)
{
        int value = get_lcd(NULL);

        if (value >= 0) {
                p += sprintf(p, "brightness:              %d\n", value);
                p += sprintf(p, "brightness_levels:       %d\n",
                             HCI_LCD_BRIGHTNESS_LEVELS);
        } else {
                printk(MY_ERR "Error reading LCD brightness\n");
        }

        return p;
}

static int set_lcd(int value)
{
        u32 hci_result;

        value = value << HCI_LCD_BRIGHTNESS_SHIFT;
        hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
        if (hci_result != HCI_SUCCESS)
                return -EFAULT;

        return 0;
}

static int set_lcd_status(struct backlight_device *bd)
{
        return set_lcd(bd->props.brightness);
}

static unsigned long write_lcd(const char *buffer, unsigned long count)
{
        int value;
        int ret;

        if (sscanf(buffer, " brightness : %i", &value) == 1 &&
            value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS) {
                ret = set_lcd(value);
                if (ret == 0)
                        ret = count;
        } else {
                ret = -EINVAL;
        }
        return ret;
}

static char *read_video(char *p)
{
        u32 hci_result;
        u32 value;

        hci_read1(HCI_VIDEO_OUT, &value, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                int is_lcd = (value & HCI_VIDEO_OUT_LCD) ? 1 : 0;
                int is_crt = (value & HCI_VIDEO_OUT_CRT) ? 1 : 0;
                int is_tv = (value & HCI_VIDEO_OUT_TV) ? 1 : 0;
                p += sprintf(p, "lcd_out:                 %d\n", is_lcd);
                p += sprintf(p, "crt_out:                 %d\n", is_crt);
                p += sprintf(p, "tv_out:                  %d\n", is_tv);
        } else {
                printk(MY_ERR "Error reading video out status\n");
        }

        return p;
}

static unsigned long write_video(const char *buffer, unsigned long count)
{
        int value;
        int remain = count;
        int lcd_out = -1;
        int crt_out = -1;
        int tv_out = -1;
        u32 hci_result;
        u32 video_out;

        /* scan expression.  Multiple expressions may be delimited with ;
         *
         *  NOTE: to keep scanning simple, invalid fields are ignored
         */
        while (remain) {
                if (sscanf(buffer, " lcd_out : %i", &value) == 1)
                        lcd_out = value & 1;
                else if (sscanf(buffer, " crt_out : %i", &value) == 1)
                        crt_out = value & 1;
                else if (sscanf(buffer, " tv_out : %i", &value) == 1)
                        tv_out = value & 1;
                /* advance to one character past the next ; */
                do {
                        ++buffer;
                        --remain;
                }
                while (remain && *(buffer - 1) != ';');
        }

        hci_read1(HCI_VIDEO_OUT, &video_out, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                unsigned int new_video_out = video_out;
                if (lcd_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_LCD, lcd_out);
                if (crt_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_CRT, crt_out);
                if (tv_out != -1)
                        _set_bit(&new_video_out, HCI_VIDEO_OUT_TV, tv_out);
                /* To avoid unnecessary video disruption, only write the new
                 * video setting if something changed. */
                if (new_video_out != video_out)
                        write_acpi_int(METHOD_VIDEO_OUT, new_video_out);
        } else {
                return -EFAULT;
        }

        return count;
}

static char *read_fan(char *p)
{
        u32 hci_result;
        u32 value;

        hci_read1(HCI_FAN, &value, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                p += sprintf(p, "running:                 %d\n", (value > 0));
                p += sprintf(p, "force_on:                %d\n", force_fan);
        } else {
                printk(MY_ERR "Error reading fan status\n");
        }

        return p;
}

static unsigned long write_fan(const char *buffer, unsigned long count)
{
        int value;
        u32 hci_result;

        if (sscanf(buffer, " force_on : %i", &value) == 1 &&
            value >= 0 && value <= 1) {
                hci_write1(HCI_FAN, value, &hci_result);
                if (hci_result != HCI_SUCCESS)
                        return -EFAULT;
                else
                        force_fan = value;
        } else {
                return -EINVAL;
        }

        return count;
}

static char *read_keys(char *p)
{
        u32 hci_result;
        u32 value;

        if (!key_event_valid) {
                hci_read1(HCI_SYSTEM_EVENT, &value, &hci_result);
                if (hci_result == HCI_SUCCESS) {
                        key_event_valid = 1;
                        last_key_event = value;
                } else if (hci_result == HCI_EMPTY) {
                        /* better luck next time */
                } else if (hci_result == HCI_NOT_SUPPORTED) {
                        /* This is a workaround for an unresolved issue on
                         * some machines where system events sporadically
                         * become disabled. */
                        hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);
                        printk(MY_NOTICE "Re-enabled hotkeys\n");
                } else {
                        printk(MY_ERR "Error reading hotkey status\n");
                        goto end;
                }
        }

        p += sprintf(p, "hotkey_ready:            %d\n", key_event_valid);
        p += sprintf(p, "hotkey:                  0x%04x\n", last_key_event);

      end:
        return p;
}

static unsigned long write_keys(const char *buffer, unsigned long count)
{
        int value;

        if (sscanf(buffer, " hotkey_ready : %i", &value) == 1 && value == 0) {
                key_event_valid = 0;
        } else {
                return -EINVAL;
        }

        return count;
}

static char *read_version(char *p)
{
        p += sprintf(p, "driver:                  %s\n", TOSHIBA_ACPI_VERSION);
        p += sprintf(p, "proc_interface:          %d\n",
                     PROC_INTERFACE_VERSION);
        return p;
}

/* proc and module init
 */

#define PROC_TOSHIBA            "toshiba"

static ProcItem proc_items[] = {
        {"lcd", read_lcd, write_lcd},
        {"video", read_video, write_video},
        {"fan", read_fan, write_fan},
        {"keys", read_keys, write_keys},
        {"version", read_version, NULL},
        {NULL}
};

static acpi_status __init add_device(void)
{
        struct proc_dir_entry *proc;
        ProcItem *item;

        for (item = proc_items; item->name; ++item) {
                proc = create_proc_read_entry(item->name,
                                              S_IFREG | S_IRUGO | S_IWUSR,
                                              toshiba_proc_dir,
                                              (read_proc_t *) dispatch_read,
                                              item);
                if (proc && item->write_func)
                        proc->write_proc = (write_proc_t *) dispatch_write;
        }

        return AE_OK;
}

static acpi_status remove_device(void)
{
        ProcItem *item;

        for (item = proc_items; item->name; ++item)
                remove_proc_entry(item->name, toshiba_proc_dir);
        return AE_OK;
}

static struct backlight_ops toshiba_backlight_data = {
        .get_brightness = get_lcd,
        .update_status  = set_lcd_status,
};

static void toshiba_acpi_exit(void)
{
        if (toshiba_acpi.bt_rfk) {
                rfkill_unregister(toshiba_acpi.bt_rfk);
                rfkill_destroy(toshiba_acpi.bt_rfk);
        }

        if (toshiba_backlight_device)
                backlight_device_unregister(toshiba_backlight_device);

        remove_device();

        if (toshiba_proc_dir)
                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);

        platform_device_unregister(toshiba_acpi.p_dev);

        return;
}

static int __init toshiba_acpi_init(void)
{
        acpi_status status = AE_OK;
        u32 hci_result;
        bool bt_present;
        int ret = 0;

        if (acpi_disabled)
                return -ENODEV;

        /* simple device detection: look for HCI method */
        if (is_valid_acpi_path(METHOD_HCI_1))
                method_hci = METHOD_HCI_1;
        else if (is_valid_acpi_path(METHOD_HCI_2))
                method_hci = METHOD_HCI_2;
        else
                return -ENODEV;

        printk(MY_INFO "Toshiba Laptop ACPI Extras version %s\n",
               TOSHIBA_ACPI_VERSION);
        printk(MY_INFO "    HCI method: %s\n", method_hci);

        mutex_init(&toshiba_acpi.mutex);

        toshiba_acpi.p_dev = platform_device_register_simple("toshiba_acpi",
                                                              -1, NULL, 0);
        if (IS_ERR(toshiba_acpi.p_dev)) {
                ret = PTR_ERR(toshiba_acpi.p_dev);
                printk(MY_ERR "unable to register platform device\n");
                toshiba_acpi.p_dev = NULL;
                toshiba_acpi_exit();
                return ret;
        }

        force_fan = 0;
        key_event_valid = 0;

        /* enable event fifo */
        hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);

        toshiba_proc_dir = proc_mkdir(PROC_TOSHIBA, acpi_root_dir);
        if (!toshiba_proc_dir) {
                toshiba_acpi_exit();
                return -ENODEV;
        } else {
                status = add_device();
                if (ACPI_FAILURE(status)) {
                        toshiba_acpi_exit();
                        return -ENODEV;
                }
        }

        toshiba_backlight_device = backlight_device_register("toshiba",
                                                &toshiba_acpi.p_dev->dev,
                                                NULL,
                                                &toshiba_backlight_data);
        if (IS_ERR(toshiba_backlight_device)) {
                ret = PTR_ERR(toshiba_backlight_device);

                printk(KERN_ERR "Could not register toshiba backlight device\n");
                toshiba_backlight_device = NULL;
                toshiba_acpi_exit();
                return ret;
        }
        toshiba_backlight_device->props.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1;

        /* Register rfkill switch for Bluetooth */
        if (hci_get_bt_present(&bt_present) == HCI_SUCCESS && bt_present) {
                toshiba_acpi.bt_rfk = rfkill_alloc(toshiba_acpi.bt_name,
                                                   &toshiba_acpi.p_dev->dev,
                                                   RFKILL_TYPE_BLUETOOTH,
                                                   &toshiba_rfk_ops,
                                                   &toshiba_acpi);
                if (!toshiba_acpi.bt_rfk) {
                        printk(MY_ERR "unable to allocate rfkill device\n");
                        toshiba_acpi_exit();
                        return -ENOMEM;
                }

                ret = rfkill_register(toshiba_acpi.bt_rfk);
                if (ret) {
                        printk(MY_ERR "unable to register rfkill device\n");
                        rfkill_destroy(toshiba_acpi.bt_rfk);
                        toshiba_acpi_exit();
                        return ret;
                }
        }

        return 0;
}

module_init(toshiba_acpi_init);
module_exit(toshiba_acpi_exit);