Revert toshiba_acpi strlcpy'fication as per John Belmonte.

[linux-2.6/history.git] / drivers / acpi / toshiba_acpi.c

/*
 *  toshiba_acpi.c - Toshiba Laptop ACPI Extras
 *
 *
 *  Copyright (C) 2002-2003 John Belmonte
 *
 *  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    "0.15"
#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/version.h>

#include <acpi/acpi_drivers.h>

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

/* Toshiba ACPI method paths */
#define METHOD_LCD_BRIGHTNESS   "\\_SB_.PCI0.VGA_.LCD_._BCM"
#define METHOD_HCI              "\\_SB_.VALD.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

/* 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

/* utility
 */

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

/* an sscanf that takes explicit string length */
static int
snscanf(const char* str, int n, const char* format, ...)
{
        va_list args;
        int result;
        char* str2 = kmalloc(n + 1, GFP_KERNEL);
        if (str2 == 0) return 0;
        strncpy(str2, str, n);
        str2[n] = 0;
        va_start(args, format);
        result = vsscanf(str2, format, args);
        va_end(args);
        kfree(str2);
        return result;
}

/* acpi interface wrappers
 */

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

        status = acpi_evaluate_object(0, (char*)methodName, &params, 0);
        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

/* 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(0, 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 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 struct proc_dir_entry*   toshiba_proc_dir = NULL;
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* buffer, unsigned long count,
        ProcItem* item)
{
        return item->write_func(buffer, count);
}

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

        hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                value = value >> HCI_LCD_BRIGHTNESS_SHIFT;
                p += sprintf(p, "brightness:              %d\n", value);
                p += sprintf(p, "brightness_levels:       %d\n",
                        HCI_LCD_BRIGHTNESS_LEVELS);
        } else {
                p += sprintf(p, "ERROR\n");
        }

        return p;
}

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

        if (snscanf(buffer, count, " brightness : %i", &value) == 1 &&
                        value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS) {
                value = value << HCI_LCD_BRIGHTNESS_SHIFT;
                hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
                if (hci_result != HCI_SUCCESS)
                        return -EFAULT;
        } else {
                return -EINVAL;
        }

        return count;
}

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 {
                p += sprintf(p, "ERROR\n");
        }

        return p;
}

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

        /* scan expression.  Multiple expressions may be delimited with ; */
        do {
                if (snscanf(buffer, count, " lcd_out : %i", &value) == 1)
                        lcd_out = value & 1;
                else if (snscanf(buffer, count, " crt_out : %i", &value) == 1)
                        crt_out = value & 1;
                else if (snscanf(buffer, count, " tv_out : %i", &value) == 1)
                        tv_out = value & 1;
                /* advance to one character past the next ; */
                do ++buffer;
                while ((buffer < buffer_end) && (*(buffer-1) != ';'));
        } while (buffer < buffer_end);

        hci_read1(HCI_VIDEO_OUT, &video_out, &hci_result);
        if (hci_result == HCI_SUCCESS) {
                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);
        }

        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 {
                p += sprintf(p, "ERROR\n");
        }

        return p;
}

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

        if (snscanf(buffer, count, " 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);
                } else {
                        p += sprintf(p, "ERROR\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 (snscanf(buffer, count, " 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"

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  , 0             },
        { 0             , 0             , 0             },
};

static acpi_status
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 int __init
toshiba_acpi_init(void)
{
        acpi_status status = AE_OK;
        int value;
        u32 hci_result;

        /* simple device detection: try reading an HCI register */
        hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
        if (hci_result != HCI_SUCCESS)
                return -ENODEV;

        printk("Toshiba Laptop ACPI Extras version %s\n", TOSHIBA_ACPI_VERSION);

        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) {
                status = AE_ERROR;
        } else {
                status = add_device();
                if (ACPI_FAILURE(status))
                        remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
        }

        return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
}

static void __exit
toshiba_acpi_exit(void)
{
        remove_device();

        if (toshiba_proc_dir)
                remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);

        return;
}

module_init(toshiba_acpi_init);
module_exit(toshiba_acpi_exit);