panel.c

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/*
 * Front panel driver for Linux
 * Copyright (C) 2000-2008, Willy Tarreau <[email protected]>
 *
 * 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 code drives an LCD module (/dev/lcd), and a keypad (/dev/keypad)
 * connected to a parallel printer port.
 *
 * The LCD module may either be an HD44780-like 8-bit parallel LCD, or a 1-bit
 * serial module compatible with Samsung's KS0074. The pins may be connected in
 * any combination, everything is programmable.
 *
 * The keypad consists in a matrix of push buttons connecting input pins to
 * data output pins or to the ground. The combinations have to be hard-coded
 * in the driver, though several profiles exist and adding new ones is easy.
 *
 * Several profiles are provided for commonly found LCD+keypad modules on the
 * market, such as those found in Nexcom's appliances.
 *
 * FIXME:
 *      - the initialization/deinitialization process is very dirty and should
 *        be rewritten. It may even be buggy.
 *
 * TODO:
 *  - document 24 keys keyboard (3 rows of 8 cols, 32 diodes + 2 inputs)
 *      - make the LCD a part of a virtual screen of Vx*Vy
 *  - make the inputs list smp-safe
 *      - change the keyboard to a double mapping : signals -> key_id -> values
 *        so that applications can change values without knowing signals
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/parport.h>
#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <generated/utsrelease.h>

#include <linux/io.h>
#include <linux/uaccess.h>

#define LCD_MINOR       156
#define KEYPAD_MINOR        185

#define PANEL_VERSION       "0.9.5"

#define LCD_MAXBYTES        256 /* max burst write */

#define KEYPAD_BUFFER       64

/* poll the keyboard this every second */
#define INPUT_POLL_TIME     (HZ/50)
/* a key starts to repeat after this times INPUT_POLL_TIME */
#define KEYPAD_REP_START    (10)
/* a key repeats this times INPUT_POLL_TIME */
#define KEYPAD_REP_DELAY    (2)

/* keep the light on this times INPUT_POLL_TIME for each flash */
#define FLASH_LIGHT_TEMPO   (200)

/* converts an r_str() input to an active high, bits string : 000BAOSE */
#define PNL_PINPUT(a)       ((((unsigned char)(a)) ^ 0x7F) >> 3)

#define PNL_PBUSY       0x80    /* inverted input, active low */
#define PNL_PACK        0x40    /* direct input, active low */
#define PNL_POUTPA      0x20    /* direct input, active high */
#define PNL_PSELECD     0x10    /* direct input, active high */
#define PNL_PERRORP     0x08    /* direct input, active low */

#define PNL_PBIDIR      0x20    /* bi-directional ports */
/* high to read data in or-ed with data out */
#define PNL_PINTEN      0x10
#define PNL_PSELECP     0x08    /* inverted output, active low */
#define PNL_PINITP      0x04    /* direct output, active low */
#define PNL_PAUTOLF     0x02    /* inverted output, active low */
#define PNL_PSTROBE     0x01    /* inverted output */

#define PNL_PD0         0x01
#define PNL_PD1         0x02
#define PNL_PD2         0x04
#define PNL_PD3         0x08
#define PNL_PD4         0x10
#define PNL_PD5         0x20
#define PNL_PD6         0x40
#define PNL_PD7         0x80

#define PIN_NONE        0
#define PIN_STROBE      1
#define PIN_D0          2
#define PIN_D1          3
#define PIN_D2          4
#define PIN_D3          5
#define PIN_D4          6
#define PIN_D5          7
#define PIN_D6          8
#define PIN_D7          9
#define PIN_AUTOLF      14
#define PIN_INITP       16
#define PIN_SELECP      17
#define PIN_NOT_SET     127

#define LCD_FLAG_S      0x0001
#define LCD_FLAG_ID     0x0002
#define LCD_FLAG_B      0x0004  /* blink on */
#define LCD_FLAG_C      0x0008  /* cursor on */
#define LCD_FLAG_D      0x0010  /* display on */
#define LCD_FLAG_F      0x0020  /* large font mode */
#define LCD_FLAG_N      0x0040  /* 2-rows mode */
#define LCD_FLAG_L      0x0080  /* backlight enabled */

#define LCD_ESCAPE_LEN      24  /* max chars for LCD escape command */
#define LCD_ESCAPE_CHAR 27  /* use char 27 for escape command */

/* macros to simplify use of the parallel port */
#define r_ctr(x)        (parport_read_control((x)->port))
#define r_dtr(x)        (parport_read_data((x)->port))
#define r_str(x)        (parport_read_status((x)->port))
#define w_ctr(x, y)     (parport_write_control((x)->port, (y)))
#define w_dtr(x, y)     (parport_write_data((x)->port, (y)))

/* this defines which bits are to be used and which ones to be ignored */
/* logical or of the output bits involved in the scan matrix */
static __u8 scan_mask_o;
/* logical or of the input bits involved in the scan matrix */
static __u8 scan_mask_i;

typedef __u64 pmask_t;

enum input_type {
    INPUT_TYPE_STD,
    INPUT_TYPE_KBD,
};

enum input_state {
    INPUT_ST_LOW,
    INPUT_ST_RISING,
    INPUT_ST_HIGH,
    INPUT_ST_FALLING,
};

struct logical_input {
    struct list_head list;
    pmask_t mask;
    pmask_t value;
    enum input_type type;
    enum input_state state;
    __u8 rise_time, fall_time;
    __u8 rise_timer, fall_timer, high_timer;

    union {
        struct {    /* valid when type == INPUT_TYPE_STD */
            void (*press_fct) (int);
            void (*release_fct) (int);
            int press_data;
            int release_data;
        } std;
        struct {    /* valid when type == INPUT_TYPE_KBD */
            /* strings can be non null-terminated */
            char press_str[sizeof(void *) + sizeof(int)];
            char repeat_str[sizeof(void *) + sizeof(int)];
            char release_str[sizeof(void *) + sizeof(int)];
        } kbd;
    } u;
};

LIST_HEAD(logical_inputs);  /* list of all defined logical inputs */

/* physical contacts history
 * Physical contacts are a 45 bits string of 9 groups of 5 bits each.
 * The 8 lower groups correspond to output bits 0 to 7, and the 9th group
 * corresponds to the ground.
 * Within each group, bits are stored in the same order as read on the port :
 * BAPSE (busy=4, ack=3, paper empty=2, select=1, error=0).
 * So, each __u64 (or pmask_t) is represented like this :
 * 0000000000000000000BAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSE
 * <-----unused------><gnd><d07><d06><d05><d04><d03><d02><d01><d00>
 */

/* what has just been read from the I/O ports */
static pmask_t phys_read;
/* previous phys_read */
static pmask_t phys_read_prev;
/* stabilized phys_read (phys_read|phys_read_prev) */
static pmask_t phys_curr;
/* previous phys_curr */
static pmask_t phys_prev;
/* 0 means that at least one logical signal needs be computed */
static char inputs_stable;

/* these variables are specific to the keypad */
static char keypad_buffer[KEYPAD_BUFFER];
static int keypad_buflen;
static int keypad_start;
static char keypressed;
static wait_queue_head_t keypad_read_wait;

/* lcd-specific variables */

/* contains the LCD config state */
static unsigned long int lcd_flags;
/* contains the LCD X offset */
static unsigned long int lcd_addr_x;
/* contains the LCD Y offset */
static unsigned long int lcd_addr_y;
/* current escape sequence, 0 terminated */
static char lcd_escape[LCD_ESCAPE_LEN + 1];
/* not in escape state. >=0 = escape cmd len */
static int lcd_escape_len = -1;

/*
 * Bit masks to convert LCD signals to parallel port outputs.
 * _d_ are values for data port, _c_ are for control port.
 * [0] = signal OFF, [1] = signal ON, [2] = mask
 */
#define BIT_CLR     0
#define BIT_SET     1
#define BIT_MSK     2
#define BIT_STATES  3
/*
 * one entry for each bit on the LCD
 */
#define LCD_BIT_E   0
#define LCD_BIT_RS  1
#define LCD_BIT_RW  2
#define LCD_BIT_BL  3
#define LCD_BIT_CL  4
#define LCD_BIT_DA  5
#define LCD_BITS    6

/*
 * each bit can be either connected to a DATA or CTRL port
 */
#define LCD_PORT_C  0
#define LCD_PORT_D  1
#define LCD_PORTS   2

static unsigned char lcd_bits[LCD_PORTS][LCD_BITS][BIT_STATES];

/*
 * LCD protocols
 */
#define LCD_PROTO_PARALLEL      0
#define LCD_PROTO_SERIAL        1
#define LCD_PROTO_TI_DA8XX_LCD  2

/*
 * LCD character sets
 */
#define LCD_CHARSET_NORMAL      0
#define LCD_CHARSET_KS0074      1

/*
 * LCD types
 */
#define LCD_TYPE_NONE       0
#define LCD_TYPE_OLD        1
#define LCD_TYPE_KS0074     2
#define LCD_TYPE_HANTRONIX  3
#define LCD_TYPE_NEXCOM     4
#define LCD_TYPE_CUSTOM     5

/*
 * keypad types
 */
#define KEYPAD_TYPE_NONE    0
#define KEYPAD_TYPE_OLD     1
#define KEYPAD_TYPE_NEW     2
#define KEYPAD_TYPE_NEXCOM  3

/*
 * panel profiles
 */
#define PANEL_PROFILE_CUSTOM    0
#define PANEL_PROFILE_OLD   1
#define PANEL_PROFILE_NEW   2
#define PANEL_PROFILE_HANTRONIX 3
#define PANEL_PROFILE_NEXCOM    4
#define PANEL_PROFILE_LARGE 5

/*
 * Construct custom config from the kernel's configuration
 */
#define DEFAULT_PROFILE         PANEL_PROFILE_LARGE
#define DEFAULT_PARPORT         0
#define DEFAULT_LCD             LCD_TYPE_OLD
#define DEFAULT_KEYPAD          KEYPAD_TYPE_OLD
#define DEFAULT_LCD_WIDTH       40
#define DEFAULT_LCD_BWIDTH      40
#define DEFAULT_LCD_HWIDTH      64
#define DEFAULT_LCD_HEIGHT      2
#define DEFAULT_LCD_PROTO       LCD_PROTO_PARALLEL

#define DEFAULT_LCD_PIN_E       PIN_AUTOLF
#define DEFAULT_LCD_PIN_RS      PIN_SELECP
#define DEFAULT_LCD_PIN_RW      PIN_INITP
#define DEFAULT_LCD_PIN_SCL     PIN_STROBE
#define DEFAULT_LCD_PIN_SDA     PIN_D0
#define DEFAULT_LCD_PIN_BL      PIN_NOT_SET
#define DEFAULT_LCD_CHARSET     LCD_CHARSET_NORMAL

#ifdef CONFIG_PANEL_PROFILE
#undef DEFAULT_PROFILE
#define DEFAULT_PROFILE CONFIG_PANEL_PROFILE
#endif

#ifdef CONFIG_PANEL_PARPORT
#undef DEFAULT_PARPORT
#define DEFAULT_PARPORT CONFIG_PANEL_PARPORT
#endif

#if DEFAULT_PROFILE == 0    /* custom */
#ifdef CONFIG_PANEL_KEYPAD
#undef DEFAULT_KEYPAD
#define DEFAULT_KEYPAD CONFIG_PANEL_KEYPAD
#endif

#ifdef CONFIG_PANEL_LCD
#undef DEFAULT_LCD
#define DEFAULT_LCD CONFIG_PANEL_LCD
#endif

#ifdef CONFIG_PANEL_LCD_WIDTH
#undef DEFAULT_LCD_WIDTH
#define DEFAULT_LCD_WIDTH CONFIG_PANEL_LCD_WIDTH
#endif

#ifdef CONFIG_PANEL_LCD_BWIDTH
#undef DEFAULT_LCD_BWIDTH
#define DEFAULT_LCD_BWIDTH CONFIG_PANEL_LCD_BWIDTH
#endif

#ifdef CONFIG_PANEL_LCD_HWIDTH
#undef DEFAULT_LCD_HWIDTH
#define DEFAULT_LCD_HWIDTH CONFIG_PANEL_LCD_HWIDTH
#endif

#ifdef CONFIG_PANEL_LCD_HEIGHT
#undef DEFAULT_LCD_HEIGHT
#define DEFAULT_LCD_HEIGHT CONFIG_PANEL_LCD_HEIGHT
#endif

#ifdef CONFIG_PANEL_LCD_PROTO
#undef DEFAULT_LCD_PROTO
#define DEFAULT_LCD_PROTO CONFIG_PANEL_LCD_PROTO
#endif

#ifdef CONFIG_PANEL_LCD_PIN_E
#undef DEFAULT_LCD_PIN_E
#define DEFAULT_LCD_PIN_E CONFIG_PANEL_LCD_PIN_E
#endif

#ifdef CONFIG_PANEL_LCD_PIN_RS
#undef DEFAULT_LCD_PIN_RS
#define DEFAULT_LCD_PIN_RS CONFIG_PANEL_LCD_PIN_RS
#endif

#ifdef CONFIG_PANEL_LCD_PIN_RW
#undef DEFAULT_LCD_PIN_RW
#define DEFAULT_LCD_PIN_RW CONFIG_PANEL_LCD_PIN_RW
#endif

#ifdef CONFIG_PANEL_LCD_PIN_SCL
#undef DEFAULT_LCD_PIN_SCL
#define DEFAULT_LCD_PIN_SCL CONFIG_PANEL_LCD_PIN_SCL
#endif

#ifdef CONFIG_PANEL_LCD_PIN_SDA
#undef DEFAULT_LCD_PIN_SDA
#define DEFAULT_LCD_PIN_SDA CONFIG_PANEL_LCD_PIN_SDA
#endif

#ifdef CONFIG_PANEL_LCD_PIN_BL
#undef DEFAULT_LCD_PIN_BL
#define DEFAULT_LCD_PIN_BL CONFIG_PANEL_LCD_PIN_BL
#endif

#ifdef CONFIG_PANEL_LCD_CHARSET
#undef DEFAULT_LCD_CHARSET
#define DEFAULT_LCD_CHARSET CONFIG_PANEL_LCD_CHARSET
#endif

#endif /* DEFAULT_PROFILE == 0 */

/* global variables */
static int keypad_open_cnt; /* #times opened */
static int lcd_open_cnt;    /* #times opened */
static struct pardevice *pprt;

static int lcd_initialized;
static int keypad_initialized;

static int light_tempo;

static char lcd_must_clear;
static char lcd_left_shift;
static char init_in_progress;

static void (*lcd_write_cmd) (int);
static void (*lcd_write_data) (int);
static void (*lcd_clear_fast) (void);

static DEFINE_SPINLOCK(pprt_lock);
static struct timer_list scan_timer;

MODULE_DESCRIPTION("Generic parallel port LCD/Keypad driver");

static int parport = -1;
module_param(parport, int, 0000);
MODULE_PARM_DESC(parport, "Parallel port index (0=lpt1, 1=lpt2, ...)");

static int lcd_height = -1;
module_param(lcd_height, int, 0000);
MODULE_PARM_DESC(lcd_height, "Number of lines on the LCD");

static int lcd_width = -1;
module_param(lcd_width, int, 0000);
MODULE_PARM_DESC(lcd_width, "Number of columns on the LCD");

static int lcd_bwidth = -1; /* internal buffer width (usually 40) */
module_param(lcd_bwidth, int, 0000);
MODULE_PARM_DESC(lcd_bwidth, "Internal LCD line width (40)");

static int lcd_hwidth = -1; /* hardware buffer width (usually 64) */
module_param(lcd_hwidth, int, 0000);
MODULE_PARM_DESC(lcd_hwidth, "LCD line hardware address (64)");

static int lcd_enabled = -1;
module_param(lcd_enabled, int, 0000);
MODULE_PARM_DESC(lcd_enabled, "Deprecated option, use lcd_type instead");

static int keypad_enabled = -1;
module_param(keypad_enabled, int, 0000);
MODULE_PARM_DESC(keypad_enabled, "Deprecated option, use keypad_type instead");

static int lcd_type = -1;
module_param(lcd_type, int, 0000);
MODULE_PARM_DESC(lcd_type,
         "LCD type: 0=none, 1=old //, 2=serial ks0074, "
         "3=hantronix //, 4=nexcom //, 5=compiled-in");

static int lcd_proto = -1;
module_param(lcd_proto, int, 0000);
MODULE_PARM_DESC(lcd_proto,
        "LCD communication: 0=parallel (//), 1=serial,"
        "2=TI LCD Interface");

static int lcd_charset = -1;
module_param(lcd_charset, int, 0000);
MODULE_PARM_DESC(lcd_charset, "LCD character set: 0=standard, 1=KS0074");

static int keypad_type = -1;
module_param(keypad_type, int, 0000);
MODULE_PARM_DESC(keypad_type,
         "Keypad type: 0=none, 1=old 6 keys, 2=new 6+1 keys, "
         "3=nexcom 4 keys");

static int profile = DEFAULT_PROFILE;
module_param(profile, int, 0000);
MODULE_PARM_DESC(profile,
         "1=16x2 old kp; 2=serial 16x2, new kp; 3=16x2 hantronix; "
         "4=16x2 nexcom; default=40x2, old kp");

/*
 * These are the parallel port pins the LCD control signals are connected to.
 * Set this to 0 if the signal is not used. Set it to its opposite value
 * (negative) if the signal is negated. -MAXINT is used to indicate that the
 * pin has not been explicitly specified.
 *
 * WARNING! no check will be performed about collisions with keypad !
 */

static int lcd_e_pin  = PIN_NOT_SET;
module_param(lcd_e_pin, int, 0000);
MODULE_PARM_DESC(lcd_e_pin,
         "# of the // port pin connected to LCD 'E' signal, "
         "with polarity (-17..17)");

static int lcd_rs_pin = PIN_NOT_SET;
module_param(lcd_rs_pin, int, 0000);
MODULE_PARM_DESC(lcd_rs_pin,
         "# of the // port pin connected to LCD 'RS' signal, "
         "with polarity (-17..17)");

static int lcd_rw_pin = PIN_NOT_SET;
module_param(lcd_rw_pin, int, 0000);
MODULE_PARM_DESC(lcd_rw_pin,
         "# of the // port pin connected to LCD 'RW' signal, "
         "with polarity (-17..17)");

static int lcd_bl_pin = PIN_NOT_SET;
module_param(lcd_bl_pin, int, 0000);
MODULE_PARM_DESC(lcd_bl_pin,
         "# of the // port pin connected to LCD backlight, "
         "with polarity (-17..17)");

static int lcd_da_pin = PIN_NOT_SET;
module_param(lcd_da_pin, int, 0000);
MODULE_PARM_DESC(lcd_da_pin,
         "# of the // port pin connected to serial LCD 'SDA' "
         "signal, with polarity (-17..17)");

static int lcd_cl_pin = PIN_NOT_SET;
module_param(lcd_cl_pin, int, 0000);
MODULE_PARM_DESC(lcd_cl_pin,
         "# of the // port pin connected to serial LCD 'SCL' "
         "signal, with polarity (-17..17)");

static unsigned char *lcd_char_conv;

/* for some LCD drivers (ks0074) we need a charset conversion table. */
static unsigned char lcd_char_conv_ks0074[256] = {
    /*          0|8   1|9   2|A   3|B   4|C   5|D   6|E   7|F */
    /* 0x00 */ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    /* 0x08 */ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
    /* 0x10 */ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
    /* 0x18 */ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
    /* 0x20 */ 0x20, 0x21, 0x22, 0x23, 0xa2, 0x25, 0x26, 0x27,
    /* 0x28 */ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
    /* 0x30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
    /* 0x38 */ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
    /* 0x40 */ 0xa0, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
    /* 0x48 */ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
    /* 0x50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
    /* 0x58 */ 0x58, 0x59, 0x5a, 0xfa, 0xfb, 0xfc, 0x1d, 0xc4,
    /* 0x60 */ 0x96, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
    /* 0x68 */ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
    /* 0x70 */ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
    /* 0x78 */ 0x78, 0x79, 0x7a, 0xfd, 0xfe, 0xff, 0xce, 0x20,
    /* 0x80 */ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
    /* 0x88 */ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
    /* 0x90 */ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
    /* 0x98 */ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
    /* 0xA0 */ 0x20, 0x40, 0xb1, 0xa1, 0x24, 0xa3, 0xfe, 0x5f,
    /* 0xA8 */ 0x22, 0xc8, 0x61, 0x14, 0x97, 0x2d, 0xad, 0x96,
    /* 0xB0 */ 0x80, 0x8c, 0x82, 0x83, 0x27, 0x8f, 0x86, 0xdd,
    /* 0xB8 */ 0x2c, 0x81, 0x6f, 0x15, 0x8b, 0x8a, 0x84, 0x60,
    /* 0xC0 */ 0xe2, 0xe2, 0xe2, 0x5b, 0x5b, 0xae, 0xbc, 0xa9,
    /* 0xC8 */ 0xc5, 0xbf, 0xc6, 0xf1, 0xe3, 0xe3, 0xe3, 0xe3,
    /* 0xD0 */ 0x44, 0x5d, 0xa8, 0xe4, 0xec, 0xec, 0x5c, 0x78,
    /* 0xD8 */ 0xab, 0xa6, 0xe5, 0x5e, 0x5e, 0xe6, 0xaa, 0xbe,
    /* 0xE0 */ 0x7f, 0xe7, 0xaf, 0x7b, 0x7b, 0xaf, 0xbd, 0xc8,
    /* 0xE8 */ 0xa4, 0xa5, 0xc7, 0xf6, 0xa7, 0xe8, 0x69, 0x69,
    /* 0xF0 */ 0xed, 0x7d, 0xa8, 0xe4, 0xec, 0x5c, 0x5c, 0x25,
    /* 0xF8 */ 0xac, 0xa6, 0xea, 0xef, 0x7e, 0xeb, 0xb2, 0x79,
};

char old_keypad_profile[][4][9] = {
    {"S0", "Left\n", "Left\n", ""},
    {"S1", "Down\n", "Down\n", ""},
    {"S2", "Up\n", "Up\n", ""},
    {"S3", "Right\n", "Right\n", ""},
    {"S4", "Esc\n", "Esc\n", ""},
    {"S5", "Ret\n", "Ret\n", ""},
    {"", "", "", ""}
};

/* signals, press, repeat, release */
char new_keypad_profile[][4][9] = {
    {"S0", "Left\n", "Left\n", ""},
    {"S1", "Down\n", "Down\n", ""},
    {"S2", "Up\n", "Up\n", ""},
    {"S3", "Right\n", "Right\n", ""},
    {"S4s5", "", "Esc\n", "Esc\n"},
    {"s4S5", "", "Ret\n", "Ret\n"},
    {"S4S5", "Help\n", "", ""},
    /* add new signals above this line */
    {"", "", "", ""}
};

/* signals, press, repeat, release */
char nexcom_keypad_profile[][4][9] = {
    {"a-p-e-", "Down\n", "Down\n", ""},
    {"a-p-E-", "Ret\n", "Ret\n", ""},
    {"a-P-E-", "Esc\n", "Esc\n", ""},
    {"a-P-e-", "Up\n", "Up\n", ""},
    /* add new signals above this line */
    {"", "", "", ""}
};

static char (*keypad_profile)[4][9] = old_keypad_profile;

/* FIXME: this should be converted to a bit array containing signals states */
static struct {
    unsigned char e;  /* parallel LCD E (data latch on falling edge) */
    unsigned char rs; /* parallel LCD RS  (0 = cmd, 1 = data) */
    unsigned char rw; /* parallel LCD R/W (0 = W, 1 = R) */
    unsigned char bl; /* parallel LCD backlight (0 = off, 1 = on) */
    unsigned char cl; /* serial LCD clock (latch on rising edge) */
    unsigned char da; /* serial LCD data */
} bits;

static void init_scan_timer(void);

/* sets data port bits according to current signals values */
static int set_data_bits(void)
{
    int val, bit;

    val = r_dtr(pprt);
    for (bit = 0; bit < LCD_BITS; bit++)
        val &= lcd_bits[LCD_PORT_D][bit][BIT_MSK];

    val |= lcd_bits[LCD_PORT_D][LCD_BIT_E][bits.e]
        | lcd_bits[LCD_PORT_D][LCD_BIT_RS][bits.rs]
        | lcd_bits[LCD_PORT_D][LCD_BIT_RW][bits.rw]
        | lcd_bits[LCD_PORT_D][LCD_BIT_BL][bits.bl]
        | lcd_bits[LCD_PORT_D][LCD_BIT_CL][bits.cl]
        | lcd_bits[LCD_PORT_D][LCD_BIT_DA][bits.da];

    w_dtr(pprt, val);
    return val;
}

/* sets ctrl port bits according to current signals values */
static int set_ctrl_bits(void)
{
    int val, bit;

    val = r_ctr(pprt);
    for (bit = 0; bit < LCD_BITS; bit++)
        val &= lcd_bits[LCD_PORT_C][bit][BIT_MSK];

    val |= lcd_bits[LCD_PORT_C][LCD_BIT_E][bits.e]
        | lcd_bits[LCD_PORT_C][LCD_BIT_RS][bits.rs]
        | lcd_bits[LCD_PORT_C][LCD_BIT_RW][bits.rw]
        | lcd_bits[LCD_PORT_C][LCD_BIT_BL][bits.bl]
        | lcd_bits[LCD_PORT_C][LCD_BIT_CL][bits.cl]
        | lcd_bits[LCD_PORT_C][LCD_BIT_DA][bits.da];

    w_ctr(pprt, val);
    return val;
}

/* sets ctrl & data port bits according to current signals values */
static void panel_set_bits(void)
{
    set_data_bits();
    set_ctrl_bits();
}

/*
 * Converts a parallel port pin (from -25 to 25) to data and control ports
 * masks, and data and control port bits. The signal will be considered
 * unconnected if it's on pin 0 or an invalid pin (<-25 or >25).
 *
 * Result will be used this way :
 *   out(dport, in(dport) & d_val[2] | d_val[signal_state])
 *   out(cport, in(cport) & c_val[2] | c_val[signal_state])
 */
void pin_to_bits(int pin, unsigned char *d_val, unsigned char *c_val)
{
    int d_bit, c_bit, inv;

    d_val[0] = c_val[0] = d_val[1] = c_val[1] = 0;
    d_val[2] = c_val[2] = 0xFF;

    if (pin == 0)
        return;

    inv = (pin < 0);
    if (inv)
        pin = -pin;

    d_bit = c_bit = 0;

    switch (pin) {
    case PIN_STROBE:    /* strobe, inverted */
        c_bit = PNL_PSTROBE;
        inv = !inv;
        break;
    case PIN_D0...PIN_D7:   /* D0 - D7 = 2 - 9 */
        d_bit = 1 << (pin - 2);
        break;
    case PIN_AUTOLF:    /* autofeed, inverted */
        c_bit = PNL_PAUTOLF;
        inv = !inv;
        break;
    case PIN_INITP:     /* init, direct */
        c_bit = PNL_PINITP;
        break;
    case PIN_SELECP:    /* select_in, inverted */
        c_bit = PNL_PSELECP;
        inv = !inv;
        break;
    default:        /* unknown pin, ignore */
        break;
    }

    if (c_bit) {
        c_val[2] &= ~c_bit;
        c_val[!inv] = c_bit;
    } else if (d_bit) {
        d_val[2] &= ~d_bit;
        d_val[!inv] = d_bit;
    }
}

/* sleeps that many milliseconds with a reschedule */
static void long_sleep(int ms)
{

    if (in_interrupt())
        mdelay(ms);
    else {
        current->state = TASK_INTERRUPTIBLE;
        schedule_timeout((ms * HZ + 999) / 1000);
    }
}

/* send a serial byte to the LCD panel. The caller is responsible for locking
   if needed. */
static void lcd_send_serial(int byte)
{
    int bit;

    /* the data bit is set on D0, and the clock on STROBE.
     * LCD reads D0 on STROBE's rising edge. */
    for (bit = 0; bit < 8; bit++) {
        bits.cl = BIT_CLR;  /* CLK low */
        panel_set_bits();
        bits.da = byte & 1;
        panel_set_bits();
        udelay(2);  /* maintain the data during 2 us before CLK up */
        bits.cl = BIT_SET;  /* CLK high */
        panel_set_bits();
        udelay(1);  /* maintain the strobe during 1 us */
        byte >>= 1;
    }
}

/* turn the backlight on or off */
static void lcd_backlight(int on)
{
    if (lcd_bl_pin == PIN_NONE)
        return;

    /* The backlight is activated by setting the AUTOFEED line to +5V  */
    spin_lock_irq(&pprt_lock);
    bits.bl = on;
    panel_set_bits();
    spin_unlock_irq(&pprt_lock);
}

/* send a command to the LCD panel in serial mode */
static void lcd_write_cmd_s(int cmd)
{
    spin_lock_irq(&pprt_lock);
    lcd_send_serial(0x1F);  /* R/W=W, RS=0 */
    lcd_send_serial(cmd & 0x0F);
    lcd_send_serial((cmd >> 4) & 0x0F);
    udelay(40);     /* the shortest command takes at least 40 us */
    spin_unlock_irq(&pprt_lock);
}

/* send data to the LCD panel in serial mode */
static void lcd_write_data_s(int data)
{
    spin_lock_irq(&pprt_lock);
    lcd_send_serial(0x5F);  /* R/W=W, RS=1 */
    lcd_send_serial(data & 0x0F);
    lcd_send_serial((data >> 4) & 0x0F);
    udelay(40);     /* the shortest data takes at least 40 us */
    spin_unlock_irq(&pprt_lock);
}

/* send a command to the LCD panel in 8 bits parallel mode */
static void lcd_write_cmd_p8(int cmd)
{
    spin_lock_irq(&pprt_lock);
    /* present the data to the data port */
    w_dtr(pprt, cmd);
    udelay(20); /* maintain the data during 20 us before the strobe */

    bits.e = BIT_SET;
    bits.rs = BIT_CLR;
    bits.rw = BIT_CLR;
    set_ctrl_bits();

    udelay(40); /* maintain the strobe during 40 us */

    bits.e = BIT_CLR;
    set_ctrl_bits();

    udelay(120);    /* the shortest command takes at least 120 us */
    spin_unlock_irq(&pprt_lock);
}

/* send data to the LCD panel in 8 bits parallel mode */
static void lcd_write_data_p8(int data)
{
    spin_lock_irq(&pprt_lock);
    /* present the data to the data port */
    w_dtr(pprt, data);
    udelay(20); /* maintain the data during 20 us before the strobe */

    bits.e = BIT_SET;
    bits.rs = BIT_SET;
    bits.rw = BIT_CLR;
    set_ctrl_bits();

    udelay(40); /* maintain the strobe during 40 us */

    bits.e = BIT_CLR;
    set_ctrl_bits();

    udelay(45); /* the shortest data takes at least 45 us */
    spin_unlock_irq(&pprt_lock);
}

/* send a command to the TI LCD panel */
static void lcd_write_cmd_tilcd(int cmd)
{
    spin_lock_irq(&pprt_lock);
    /* present the data to the control port */
    w_ctr(pprt, cmd);
    udelay(60);
    spin_unlock_irq(&pprt_lock);
}

/* send data to the TI LCD panel */
static void lcd_write_data_tilcd(int data)
{
    spin_lock_irq(&pprt_lock);
    /* present the data to the data port */
    w_dtr(pprt, data);
    udelay(60);
    spin_unlock_irq(&pprt_lock);
}

static void lcd_gotoxy(void)
{
    lcd_write_cmd(0x80  /* set DDRAM address */
              | (lcd_addr_y ? lcd_hwidth : 0)
              /* we force the cursor to stay at the end of the
             line if it wants to go farther */
              | ((lcd_addr_x < lcd_bwidth) ? lcd_addr_x &
             (lcd_hwidth - 1) : lcd_bwidth - 1));
}

static void lcd_print(char c)
{
    if (lcd_addr_x < lcd_bwidth) {
        if (lcd_char_conv != NULL)
            c = lcd_char_conv[(unsigned char)c];
        lcd_write_data(c);
        lcd_addr_x++;
    }
    /* prevents the cursor from wrapping onto the next line */
    if (lcd_addr_x == lcd_bwidth)
        lcd_gotoxy();
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_s(void)
{
    int pos;
    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();

    spin_lock_irq(&pprt_lock);
    for (pos = 0; pos < lcd_height * lcd_hwidth; pos++) {
        lcd_send_serial(0x5F);  /* R/W=W, RS=1 */
        lcd_send_serial(' ' & 0x0F);
        lcd_send_serial((' ' >> 4) & 0x0F);
        udelay(40); /* the shortest data takes at least 40 us */
    }
    spin_unlock_irq(&pprt_lock);

    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_p8(void)
{
    int pos;
    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();

    spin_lock_irq(&pprt_lock);
    for (pos = 0; pos < lcd_height * lcd_hwidth; pos++) {
        /* present the data to the data port */
        w_dtr(pprt, ' ');

        /* maintain the data during 20 us before the strobe */
        udelay(20);

        bits.e = BIT_SET;
        bits.rs = BIT_SET;
        bits.rw = BIT_CLR;
        set_ctrl_bits();

        /* maintain the strobe during 40 us */
        udelay(40);

        bits.e = BIT_CLR;
        set_ctrl_bits();

        /* the shortest data takes at least 45 us */
        udelay(45);
    }
    spin_unlock_irq(&pprt_lock);

    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();
}

/* fills the display with spaces and resets X/Y */
static void lcd_clear_fast_tilcd(void)
{
    int pos;
    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();

    spin_lock_irq(&pprt_lock);
    for (pos = 0; pos < lcd_height * lcd_hwidth; pos++) {
        /* present the data to the data port */
        w_dtr(pprt, ' ');
        udelay(60);
    }

    spin_unlock_irq(&pprt_lock);

    lcd_addr_x = lcd_addr_y = 0;
    lcd_gotoxy();
}

/* clears the display and resets X/Y */
static void lcd_clear_display(void)
{
    lcd_write_cmd(0x01);    /* clear display */
    lcd_addr_x = lcd_addr_y = 0;
    /* we must wait a few milliseconds (15) */
    long_sleep(15);
}

static void lcd_init_display(void)
{

    lcd_flags = ((lcd_height > 1) ? LCD_FLAG_N : 0)
        | LCD_FLAG_D | LCD_FLAG_C | LCD_FLAG_B;

    long_sleep(20);     /* wait 20 ms after power-up for the paranoid */

    lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
    long_sleep(10);
    lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
    long_sleep(10);
    lcd_write_cmd(0x30);    /* 8bits, 1 line, small fonts */
    long_sleep(10);

    lcd_write_cmd(0x30  /* set font height and lines number */
              | ((lcd_flags & LCD_FLAG_F) ? 4 : 0)
              | ((lcd_flags & LCD_FLAG_N) ? 8 : 0)
        );
    long_sleep(10);

    lcd_write_cmd(0x08);    /* display off, cursor off, blink off */
    long_sleep(10);

    lcd_write_cmd(0x08  /* set display mode */
              | ((lcd_flags & LCD_FLAG_D) ? 4 : 0)
              | ((lcd_flags & LCD_FLAG_C) ? 2 : 0)
              | ((lcd_flags & LCD_FLAG_B) ? 1 : 0)
        );

    lcd_backlight((lcd_flags & LCD_FLAG_L) ? 1 : 0);

    long_sleep(10);

    /* entry mode set : increment, cursor shifting */
    lcd_write_cmd(0x06);

    lcd_clear_display();
}

/*
 * These are the file operation function for user access to /dev/lcd
 * This function can also be called from inside the kernel, by
 * setting file and ppos to NULL.
 *
 */

static inline int handle_lcd_special_code(void)
{
    /* LCD special codes */

    int processed = 0;

    char *esc = lcd_escape + 2;
    int oldflags = lcd_flags;

    /* check for display mode flags */
    switch (*esc) {
    case 'D':   /* Display ON */
        lcd_flags |= LCD_FLAG_D;
        processed = 1;
        break;
    case 'd':   /* Display OFF */
        lcd_flags &= ~LCD_FLAG_D;
        processed = 1;
        break;
    case 'C':   /* Cursor ON */
        lcd_flags |= LCD_FLAG_C;
        processed = 1;
        break;
    case 'c':   /* Cursor OFF */
        lcd_flags &= ~LCD_FLAG_C;
        processed = 1;
        break;
    case 'B':   /* Blink ON */
        lcd_flags |= LCD_FLAG_B;
        processed = 1;
        break;
    case 'b':   /* Blink OFF */
        lcd_flags &= ~LCD_FLAG_B;
        processed = 1;
        break;
    case '+':   /* Back light ON */
        lcd_flags |= LCD_FLAG_L;
        processed = 1;
        break;
    case '-':   /* Back light OFF */
        lcd_flags &= ~LCD_FLAG_L;
        processed = 1;
        break;
    case '*':
        /* flash back light using the keypad timer */
        if (scan_timer.function != NULL) {
            if (light_tempo == 0 && ((lcd_flags & LCD_FLAG_L) == 0))
                lcd_backlight(1);
            light_tempo = FLASH_LIGHT_TEMPO;
        }
        processed = 1;
        break;
    case 'f':   /* Small Font */
        lcd_flags &= ~LCD_FLAG_F;
        processed = 1;
        break;
    case 'F':   /* Large Font */
        lcd_flags |= LCD_FLAG_F;
        processed = 1;
        break;
    case 'n':   /* One Line */
        lcd_flags &= ~LCD_FLAG_N;
        processed = 1;
        break;
    case 'N':   /* Two Lines */
        lcd_flags |= LCD_FLAG_N;
        break;
    case 'l':   /* Shift Cursor Left */
        if (lcd_addr_x > 0) {
            /* back one char if not at end of line */
            if (lcd_addr_x < lcd_bwidth)
                lcd_write_cmd(0x10);
            lcd_addr_x--;
        }
        processed = 1;
        break;
    case 'r':   /* shift cursor right */
        if (lcd_addr_x < lcd_width) {
            /* allow the cursor to pass the end of the line */
            if (lcd_addr_x <
                (lcd_bwidth - 1))
                lcd_write_cmd(0x14);
            lcd_addr_x++;
        }
        processed = 1;
        break;
    case 'L':   /* shift display left */
        lcd_left_shift++;
        lcd_write_cmd(0x18);
        processed = 1;
        break;
    case 'R':   /* shift display right */
        lcd_left_shift--;
        lcd_write_cmd(0x1C);
        processed = 1;
        break;
    case 'k': { /* kill end of line */
        int x;
        for (x = lcd_addr_x; x < lcd_bwidth; x++)
            lcd_write_data(' ');

        /* restore cursor position */
        lcd_gotoxy();
        processed = 1;
        break;
    }
    case 'I':   /* reinitialize display */
        lcd_init_display();
        lcd_left_shift = 0;
        processed = 1;
        break;
    case 'G': {
        /* Generator : LGcxxxxx...xx; must have <c> between '0'
         * and '7', representing the numerical ASCII code of the
         * redefined character, and <xx...xx> a sequence of 16
         * hex digits representing 8 bytes for each character.
         * Most LCDs will only use 5 lower bits of the 7 first
         * bytes.
         */

        unsigned char cgbytes[8];
        unsigned char cgaddr;
        int cgoffset;
        int shift;
        char value;
        int addr;

        if (strchr(esc, ';') == NULL)
            break;

        esc++;

        cgaddr = *(esc++) - '0';
        if (cgaddr > 7) {
            processed = 1;
            break;
        }

        cgoffset = 0;
        shift = 0;
        value = 0;
        while (*esc && cgoffset < 8) {
            shift ^= 4;
            if (*esc >= '0' && *esc <= '9')
                value |= (*esc - '0') << shift;
            else if (*esc >= 'A' && *esc <= 'Z')
                value |= (*esc - 'A' + 10) << shift;
            else if (*esc >= 'a' && *esc <= 'z')
                value |= (*esc - 'a' + 10) << shift;
            else {
                esc++;
                continue;
            }

            if (shift == 0) {
                cgbytes[cgoffset++] = value;
                value = 0;
            }

            esc++;
        }

        lcd_write_cmd(0x40 | (cgaddr * 8));
        for (addr = 0; addr < cgoffset; addr++)
            lcd_write_data(cgbytes[addr]);

        /* ensures that we stop writing to CGRAM */
        lcd_gotoxy();
        processed = 1;
        break;
    }
    case 'x':   /* gotoxy : LxXXX[yYYY]; */
    case 'y':   /* gotoxy : LyYYY[xXXX]; */
        if (strchr(esc, ';') == NULL)
            break;

        while (*esc) {
            if (*esc == 'x') {
                esc++;
                if (kstrtoul(esc, 10, &lcd_addr_x) < 0)
                    break;
            } else if (*esc == 'y') {
                esc++;
                if (kstrtoul(esc, 10, &lcd_addr_y) < 0)
                    break;
            } else
                break;
        }

        lcd_gotoxy();
        processed = 1;
        break;
    }

    /* Check whether one flag was changed */
    if (oldflags != lcd_flags) {
        /* check whether one of B,C,D flags were changed */
        if ((oldflags ^ lcd_flags) &
            (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D))
            /* set display mode */
            lcd_write_cmd(0x08
                      | ((lcd_flags & LCD_FLAG_D) ? 4 : 0)
                      | ((lcd_flags & LCD_FLAG_C) ? 2 : 0)
                      | ((lcd_flags & LCD_FLAG_B) ? 1 : 0));
        /* check whether one of F,N flags was changed */
        else if ((oldflags ^ lcd_flags) & (LCD_FLAG_F | LCD_FLAG_N))
            lcd_write_cmd(0x30
                      | ((lcd_flags & LCD_FLAG_F) ? 4 : 0)
                      | ((lcd_flags & LCD_FLAG_N) ? 8 : 0));
        /* check whether L flag was changed */
        else if ((oldflags ^ lcd_flags) & (LCD_FLAG_L)) {
            if (lcd_flags & (LCD_FLAG_L))
                lcd_backlight(1);
            else if (light_tempo == 0)
                /* switch off the light only when the tempo
                   lighting is gone */
                lcd_backlight(0);
        }
    }

    return processed;
}

static ssize_t lcd_write(struct file *file,
             const char *buf, size_t count, loff_t *ppos)
{
    const char *tmp = buf;
    char c;

    for (; count-- > 0; (ppos ? (*ppos)++ : 0), ++tmp) {
        if (!in_interrupt() && (((count + 1) & 0x1f) == 0))
            /* let's be a little nice with other processes
               that need some CPU */
            schedule();

        if (ppos == NULL && file == NULL)
            /* let's not use get_user() from the kernel ! */
            c = *tmp;
        else if (get_user(c, tmp))
            return -EFAULT;

        /* first, we'll test if we're in escape mode */
        if ((c != '\n') && lcd_escape_len >= 0) {
            /* yes, let's add this char to the buffer */
            lcd_escape[lcd_escape_len++] = c;
            lcd_escape[lcd_escape_len] = 0;
        } else {
            /* aborts any previous escape sequence */
            lcd_escape_len = -1;

            switch (c) {
            case LCD_ESCAPE_CHAR:
                /* start of an escape sequence */
                lcd_escape_len = 0;
                lcd_escape[lcd_escape_len] = 0;
                break;
            case '\b':
                /* go back one char and clear it */
                if (lcd_addr_x > 0) {
                    /* check if we're not at the
                       end of the line */
                    if (lcd_addr_x < lcd_bwidth)
                        /* back one char */
                        lcd_write_cmd(0x10);
                    lcd_addr_x--;
                }
                /* replace with a space */
                lcd_write_data(' ');
                /* back one char again */
                lcd_write_cmd(0x10);
                break;
            case '\014':
                /* quickly clear the display */
                lcd_clear_fast();
                break;
            case '\n':
                /* flush the remainder of the current line and
                   go to the beginning of the next line */
                for (; lcd_addr_x < lcd_bwidth; lcd_addr_x++)
                    lcd_write_data(' ');
                lcd_addr_x = 0;
                lcd_addr_y = (lcd_addr_y + 1) % lcd_height;
                lcd_gotoxy();
                break;
            case '\r':
                /* go to the beginning of the same line */
                lcd_addr_x = 0;
                lcd_gotoxy();
                break;
            case '\t':
                /* print a space instead of the tab */
                lcd_print(' ');
                break;
            default:
                /* simply print this char */
                lcd_print(c);
                break;
            }
        }

        /* now we'll see if we're in an escape mode and if the current
           escape sequence can be understood. */
        if (lcd_escape_len >= 2) {
            int processed = 0;

            if (!strcmp(lcd_escape, "[2J")) {
                /* clear the display */
                lcd_clear_fast();
                processed = 1;
            } else if (!strcmp(lcd_escape, "[H")) {
                /* cursor to home */
                lcd_addr_x = lcd_addr_y = 0;
                lcd_gotoxy();
                processed = 1;
            }
            /* codes starting with ^[[L */
            else if ((lcd_escape_len >= 3) &&
                 (lcd_escape[0] == '[') &&
                 (lcd_escape[1] == 'L')) {
                processed = handle_lcd_special_code();
            }

            /* LCD special escape codes */
            /* flush the escape sequence if it's been processed
               or if it is getting too long. */
            if (processed || (lcd_escape_len >= LCD_ESCAPE_LEN))
                lcd_escape_len = -1;
        } /* escape codes */
    }

    return tmp - buf;
}

static int lcd_open(struct inode *inode, struct file *file)
{
    if (lcd_open_cnt)
        return -EBUSY;  /* open only once at a time */

    if (file->f_mode & FMODE_READ)  /* device is write-only */
        return -EPERM;

    if (lcd_must_clear) {
        lcd_clear_display();
        lcd_must_clear = 0;
    }
    lcd_open_cnt++;
    return nonseekable_open(inode, file);
}

static int lcd_release(struct inode *inode, struct file *file)
{
    lcd_open_cnt--;
    return 0;
}

static const struct file_operations lcd_fops = {
    .write   = lcd_write,
    .open    = lcd_open,
    .release = lcd_release,
    .llseek  = no_llseek,
};

static struct miscdevice lcd_dev = {
    LCD_MINOR,
    "lcd",
    &lcd_fops
};

/* public function usable from the kernel for any purpose */
void panel_lcd_print(char *s)
{
    if (lcd_enabled && lcd_initialized)
        lcd_write(NULL, s, strlen(s), NULL);
}

/* initialize the LCD driver */
void lcd_init(void)
{
    switch (lcd_type) {
    case LCD_TYPE_OLD:
        /* parallel mode, 8 bits */
        if (lcd_proto < 0)
            lcd_proto = LCD_PROTO_PARALLEL;
        if (lcd_charset < 0)
            lcd_charset = LCD_CHARSET_NORMAL;
        if (lcd_e_pin == PIN_NOT_SET)
            lcd_e_pin = PIN_STROBE;
        if (lcd_rs_pin == PIN_NOT_SET)
            lcd_rs_pin = PIN_AUTOLF;

        if (lcd_width < 0)
            lcd_width = 40;
        if (lcd_bwidth < 0)
            lcd_bwidth = 40;
        if (lcd_hwidth < 0)
            lcd_hwidth = 64;
        if (lcd_height < 0)
            lcd_height = 2;
        break;
    case LCD_TYPE_KS0074:
        /* serial mode, ks0074 */
        if (lcd_proto < 0)
            lcd_proto = LCD_PROTO_SERIAL;
        if (lcd_charset < 0)
            lcd_charset = LCD_CHARSET_KS0074;
        if (lcd_bl_pin == PIN_NOT_SET)
            lcd_bl_pin = PIN_AUTOLF;
        if (lcd_cl_pin == PIN_NOT_SET)
            lcd_cl_pin = PIN_STROBE;
        if (lcd_da_pin == PIN_NOT_SET)
            lcd_da_pin = PIN_D0;

        if (lcd_width < 0)
            lcd_width = 16;
        if (lcd_bwidth < 0)
            lcd_bwidth = 40;
        if (lcd_hwidth < 0)
            lcd_hwidth = 16;
        if (lcd_height < 0)
            lcd_height = 2;
        break;
    case LCD_TYPE_NEXCOM:
        /* parallel mode, 8 bits, generic */
        if (lcd_proto < 0)
            lcd_proto = LCD_PROTO_PARALLEL;
        if (lcd_charset < 0)
            lcd_charset = LCD_CHARSET_NORMAL;
        if (lcd_e_pin == PIN_NOT_SET)
            lcd_e_pin = PIN_AUTOLF;
        if (lcd_rs_pin == PIN_NOT_SET)
            lcd_rs_pin = PIN_SELECP;
        if (lcd_rw_pin == PIN_NOT_SET)
            lcd_rw_pin = PIN_INITP;

        if (lcd_width < 0)
            lcd_width = 16;
        if (lcd_bwidth < 0)
            lcd_bwidth = 40;
        if (lcd_hwidth < 0)
            lcd_hwidth = 64;
        if (lcd_height < 0)
            lcd_height = 2;
        break;
    case LCD_TYPE_CUSTOM:
        /* customer-defined */
        if (lcd_proto < 0)
            lcd_proto = DEFAULT_LCD_PROTO;
        if (lcd_charset < 0)
            lcd_charset = DEFAULT_LCD_CHARSET;
        /* default geometry will be set later */
        break;
    case LCD_TYPE_HANTRONIX:
        /* parallel mode, 8 bits, hantronix-like */
    default:
        if (lcd_proto < 0)
            lcd_proto = LCD_PROTO_PARALLEL;
        if (lcd_charset < 0)
            lcd_charset = LCD_CHARSET_NORMAL;
        if (lcd_e_pin == PIN_NOT_SET)
            lcd_e_pin = PIN_STROBE;
        if (lcd_rs_pin == PIN_NOT_SET)
            lcd_rs_pin = PIN_SELECP;

        if (lcd_width < 0)
            lcd_width = 16;
        if (lcd_bwidth < 0)
            lcd_bwidth = 40;
        if (lcd_hwidth < 0)
            lcd_hwidth = 64;
        if (lcd_height < 0)
            lcd_height = 2;
        break;
    }

    /* this is used to catch wrong and default values */
    if (lcd_width <= 0)
        lcd_width = DEFAULT_LCD_WIDTH;
    if (lcd_bwidth <= 0)
        lcd_bwidth = DEFAULT_LCD_BWIDTH;
    if (lcd_hwidth <= 0)
        lcd_hwidth = DEFAULT_LCD_HWIDTH;
    if (lcd_height <= 0)
        lcd_height = DEFAULT_LCD_HEIGHT;

    if (lcd_proto == LCD_PROTO_SERIAL) {    /* SERIAL */
        lcd_write_cmd = lcd_write_cmd_s;
        lcd_write_data = lcd_write_data_s;
        lcd_clear_fast = lcd_clear_fast_s;

        if (lcd_cl_pin == PIN_NOT_SET)
            lcd_cl_pin = DEFAULT_LCD_PIN_SCL;
        if (lcd_da_pin == PIN_NOT_SET)
            lcd_da_pin = DEFAULT_LCD_PIN_SDA;

    } else if (lcd_proto == LCD_PROTO_PARALLEL) {   /* PARALLEL */
        lcd_write_cmd = lcd_write_cmd_p8;
        lcd_write_data = lcd_write_data_p8;
        lcd_clear_fast = lcd_clear_fast_p8;

        if (lcd_e_pin == PIN_NOT_SET)
            lcd_e_pin = DEFAULT_LCD_PIN_E;
        if (lcd_rs_pin == PIN_NOT_SET)
            lcd_rs_pin = DEFAULT_LCD_PIN_RS;
        if (lcd_rw_pin == PIN_NOT_SET)
            lcd_rw_pin = DEFAULT_LCD_PIN_RW;
    } else {
        lcd_write_cmd = lcd_write_cmd_tilcd;
        lcd_write_data = lcd_write_data_tilcd;
        lcd_clear_fast = lcd_clear_fast_tilcd;
    }

    if (lcd_bl_pin == PIN_NOT_SET)
        lcd_bl_pin = DEFAULT_LCD_PIN_BL;

    if (lcd_e_pin == PIN_NOT_SET)
        lcd_e_pin = PIN_NONE;
    if (lcd_rs_pin == PIN_NOT_SET)
        lcd_rs_pin = PIN_NONE;
    if (lcd_rw_pin == PIN_NOT_SET)
        lcd_rw_pin = PIN_NONE;
    if (lcd_bl_pin == PIN_NOT_SET)
        lcd_bl_pin = PIN_NONE;
    if (lcd_cl_pin == PIN_NOT_SET)
        lcd_cl_pin = PIN_NONE;
    if (lcd_da_pin == PIN_NOT_SET)
        lcd_da_pin = PIN_NONE;

    if (lcd_charset < 0)
        lcd_charset = DEFAULT_LCD_CHARSET;

    if (lcd_charset == LCD_CHARSET_KS0074)
        lcd_char_conv = lcd_char_conv_ks0074;
    else
        lcd_char_conv = NULL;

    if (lcd_bl_pin != PIN_NONE)
        init_scan_timer();

    pin_to_bits(lcd_e_pin, lcd_bits[LCD_PORT_D][LCD_BIT_E],
            lcd_bits[LCD_PORT_C][LCD_BIT_E]);
    pin_to_bits(lcd_rs_pin, lcd_bits[LCD_PORT_D][LCD_BIT_RS],
            lcd_bits[LCD_PORT_C][LCD_BIT_RS]);
    pin_to_bits(lcd_rw_pin, lcd_bits[LCD_PORT_D][LCD_BIT_RW],
            lcd_bits[LCD_PORT_C][LCD_BIT_RW]);
    pin_to_bits(lcd_bl_pin, lcd_bits[LCD_PORT_D][LCD_BIT_BL],
            lcd_bits[LCD_PORT_C][LCD_BIT_BL]);
    pin_to_bits(lcd_cl_pin, lcd_bits[LCD_PORT_D][LCD_BIT_CL],
            lcd_bits[LCD_PORT_C][LCD_BIT_CL]);
    pin_to_bits(lcd_da_pin, lcd_bits[LCD_PORT_D][LCD_BIT_DA],
            lcd_bits[LCD_PORT_C][LCD_BIT_DA]);

    /* before this line, we must NOT send anything to the display.
     * Since lcd_init_display() needs to write data, we have to
     * enable mark the LCD initialized just before. */
    lcd_initialized = 1;
    lcd_init_display();

    /* display a short message */
#ifdef CONFIG_PANEL_CHANGE_MESSAGE
#ifdef CONFIG_PANEL_BOOT_MESSAGE
    panel_lcd_print("\x1b[Lc\x1b[Lb\x1b[L*" CONFIG_PANEL_BOOT_MESSAGE);
#endif
#else
    panel_lcd_print("\x1b[Lc\x1b[Lb\x1b[L*Linux-" UTS_RELEASE "\nPanel-"
            PANEL_VERSION);
#endif
    lcd_addr_x = lcd_addr_y = 0;
    /* clear the display on the next device opening */
    lcd_must_clear = 1;
    lcd_gotoxy();
}

/*
 * These are the file operation function for user access to /dev/keypad
 */

static ssize_t keypad_read(struct file *file,
               char *buf, size_t count, loff_t *ppos)
{

    unsigned i = *ppos;
    char *tmp = buf;

    if (keypad_buflen == 0) {
        if (file->f_flags & O_NONBLOCK)
            return -EAGAIN;

        interruptible_sleep_on(&keypad_read_wait);
        if (signal_pending(current))
            return -EINTR;
    }

    for (; count-- > 0 && (keypad_buflen > 0);
         ++i, ++tmp, --keypad_buflen) {
        put_user(keypad_buffer[keypad_start], tmp);
        keypad_start = (keypad_start + 1) % KEYPAD_BUFFER;
    }
    *ppos = i;

    return tmp - buf;
}

static int keypad_open(struct inode *inode, struct file *file)
{

    if (keypad_open_cnt)
        return -EBUSY;  /* open only once at a time */

    if (file->f_mode & FMODE_WRITE) /* device is read-only */
        return -EPERM;

    keypad_buflen = 0;  /* flush the buffer on opening */
    keypad_open_cnt++;
    return 0;
}

static int keypad_release(struct inode *inode, struct file *file)
{
    keypad_open_cnt--;
    return 0;
}

static const struct file_operations keypad_fops = {
    .read    = keypad_read,     /* read */
    .open    = keypad_open,     /* open */
    .release = keypad_release,  /* close */
    .llseek  = default_llseek,
};

static struct miscdevice keypad_dev = {
    KEYPAD_MINOR,
    "keypad",
    &keypad_fops
};

static void keypad_send_key(char *string, int max_len)
{
    if (init_in_progress)
        return;

    /* send the key to the device only if a process is attached to it. */
    if (keypad_open_cnt > 0) {
        while (max_len-- && keypad_buflen < KEYPAD_BUFFER && *string) {
            keypad_buffer[(keypad_start + keypad_buflen++) %
                      KEYPAD_BUFFER] = *string++;
        }
        wake_up_interruptible(&keypad_read_wait);
    }
}

/* this function scans all the bits involving at least one logical signal,
 * and puts the results in the bitfield "phys_read" (one bit per established
 * contact), and sets "phys_read_prev" to "phys_read".
 *
 * Note: to debounce input signals, we will only consider as switched a signal
 * which is stable across 2 measures. Signals which are different between two
 * reads will be kept as they previously were in their logical form (phys_prev).
 * A signal which has just switched will have a 1 in
 * (phys_read ^ phys_read_prev).
 */
static void phys_scan_contacts(void)
{
    int bit, bitval;
    char oldval;
    char bitmask;
    char gndmask;

    phys_prev = phys_curr;
    phys_read_prev = phys_read;
    phys_read = 0;      /* flush all signals */

    /* keep track of old value, with all outputs disabled */
    oldval = r_dtr(pprt) | scan_mask_o;
    /* activate all keyboard outputs (active low) */
    w_dtr(pprt, oldval & ~scan_mask_o);

    /* will have a 1 for each bit set to gnd */
    bitmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;
    /* disable all matrix signals */
    w_dtr(pprt, oldval);

    /* now that all outputs are cleared, the only active input bits are
     * directly connected to the ground
     */

    /* 1 for each grounded input */
    gndmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;

    /* grounded inputs are signals 40-44 */
    phys_read |= (pmask_t) gndmask << 40;

    if (bitmask != gndmask) {
        /* since clearing the outputs changed some inputs, we know
         * that some input signals are currently tied to some outputs.
         * So we'll scan them.
         */
        for (bit = 0; bit < 8; bit++) {
            bitval = 1 << bit;

            if (!(scan_mask_o & bitval))    /* skip unused bits */
                continue;

            w_dtr(pprt, oldval & ~bitval);  /* enable this output */
            bitmask = PNL_PINPUT(r_str(pprt)) & ~gndmask;
            phys_read |= (pmask_t) bitmask << (5 * bit);
        }
        w_dtr(pprt, oldval);    /* disable all outputs */
    }
    /* this is easy: use old bits when they are flapping,
     * use new ones when stable */
    phys_curr = (phys_prev & (phys_read ^ phys_read_prev)) |
            (phys_read & ~(phys_read ^ phys_read_prev));
}

static inline int input_state_high(struct logical_input *input)
{
#if 0
    /* FIXME:
     * this is an invalid test. It tries to catch
     * transitions from single-key to multiple-key, but
     * doesn't take into account the contacts polarity.
     * The only solution to the problem is to parse keys
     * from the most complex to the simplest combinations,
     * and mark them as 'caught' once a combination
     * matches, then unmatch it for all other ones.
     */

    /* try to catch dangerous transitions cases :
     * someone adds a bit, so this signal was a false
     * positive resulting from a transition. We should
     * invalidate the signal immediately and not call the
     * release function.
     * eg: 0 -(press A)-> A -(press B)-> AB : don't match A's release.
     */
    if (((phys_prev & input->mask) == input->value)
        && ((phys_curr & input->mask) > input->value)) {
        input->state = INPUT_ST_LOW; /* invalidate */
        return 1;
    }
#endif

    if ((phys_curr & input->mask) == input->value) {
        if ((input->type == INPUT_TYPE_STD) &&
            (input->high_timer == 0)) {
            input->high_timer++;
            if (input->u.std.press_fct != NULL)
                input->u.std.press_fct(input->u.std.press_data);
        } else if (input->type == INPUT_TYPE_KBD) {
            /* will turn on the light */
            keypressed = 1;

            if (input->high_timer == 0) {
                char *press_str = input->u.kbd.press_str;
                if (press_str[0])
                    keypad_send_key(press_str,
                            sizeof(press_str));
            }

            if (input->u.kbd.repeat_str[0]) {
                char *repeat_str = input->u.kbd.repeat_str;
                if (input->high_timer >= KEYPAD_REP_START) {
                    input->high_timer -= KEYPAD_REP_DELAY;
                    keypad_send_key(repeat_str,
                            sizeof(repeat_str));
                }
                /* we will need to come back here soon */
                inputs_stable = 0;
            }

            if (input->high_timer < 255)
                input->high_timer++;
        }
        return 1;
    } else {
        /* else signal falling down. Let's fall through. */
        input->state = INPUT_ST_FALLING;
        input->fall_timer = 0;
    }
    return 0;
}

static inline void input_state_falling(struct logical_input *input)
{
#if 0
    /* FIXME !!! same comment as in input_state_high */
    if (((phys_prev & input->mask) == input->value)
        && ((phys_curr & input->mask) > input->value)) {
        input->state = INPUT_ST_LOW;    /* invalidate */
        return;
    }
#endif

    if ((phys_curr & input->mask) == input->value) {
        if (input->type == INPUT_TYPE_KBD) {
            /* will turn on the light */
            keypressed = 1;

            if (input->u.kbd.repeat_str[0]) {
                char *repeat_str = input->u.kbd.repeat_str;
                if (input->high_timer >= KEYPAD_REP_START)
                    input->high_timer -= KEYPAD_REP_DELAY;
                    keypad_send_key(repeat_str,
                            sizeof(repeat_str));
                /* we will need to come back here soon */
                inputs_stable = 0;
            }

            if (input->high_timer < 255)
                input->high_timer++;
        }
        input->state = INPUT_ST_HIGH;
    } else if (input->fall_timer >= input->fall_time) {
        /* call release event */
        if (input->type == INPUT_TYPE_STD) {
            void (*release_fct)(int) = input->u.std.release_fct;
            if (release_fct != NULL)
                release_fct(input->u.std.release_data);
        } else if (input->type == INPUT_TYPE_KBD) {
            char *release_str = input->u.kbd.release_str;
            if (release_str[0])
                keypad_send_key(release_str,
                        sizeof(release_str));
        }

        input->state = INPUT_ST_LOW;
    } else {
        input->fall_timer++;
        inputs_stable = 0;
    }
}

static void panel_process_inputs(void)
{
    struct list_head *item;
    struct logical_input *input;

    keypressed = 0;
    inputs_stable = 1;
    list_for_each(item, &logical_inputs) {
        input = list_entry(item, struct logical_input, list);

        switch (input->state) {
        case INPUT_ST_LOW:
            if ((phys_curr & input->mask) != input->value)
                break;
            /* if all needed ones were already set previously,
             * this means that this logical signal has been
             * activated by the releasing of another combined
             * signal, so we don't want to match.
             * eg: AB -(release B)-> A -(release A)-> 0 :
             *     don't match A.
             */
            if ((phys_prev & input->mask) == input->value)
                break;
            input->rise_timer = 0;
            input->state = INPUT_ST_RISING;
            /* no break here, fall through */
        case INPUT_ST_RISING:
            if ((phys_curr & input->mask) != input->value) {
                input->state = INPUT_ST_LOW;
                break;
            }
            if (input->rise_timer < input->rise_time) {
                inputs_stable = 0;
                input->rise_timer++;
                break;
            }
            input->high_timer = 0;
            input->state = INPUT_ST_HIGH;
            /* no break here, fall through */
        case INPUT_ST_HIGH:
            if (input_state_high(input))
                break;
            /* no break here, fall through */
        case INPUT_ST_FALLING:
            input_state_falling(input);
        }
    }
}

static void panel_scan_timer(void)
{
    if (keypad_enabled && keypad_initialized) {
        if (spin_trylock_irq(&pprt_lock)) {
            phys_scan_contacts();

            /* no need for the parport anymore */
            spin_unlock_irq(&pprt_lock);
        }

        if (!inputs_stable || phys_curr != phys_prev)
            panel_process_inputs();
    }

    if (lcd_enabled && lcd_initialized) {
        if (keypressed) {
            if (light_tempo == 0 && ((lcd_flags & LCD_FLAG_L) == 0))
                lcd_backlight(1);
            light_tempo = FLASH_LIGHT_TEMPO;
        } else if (light_tempo > 0) {
            light_tempo--;
            if (light_tempo == 0 && ((lcd_flags & LCD_FLAG_L) == 0))
                lcd_backlight(0);
        }
    }

    mod_timer(&scan_timer, jiffies + INPUT_POLL_TIME);
}

static void init_scan_timer(void)
{
    if (scan_timer.function != NULL)
        return;     /* already started */

    init_timer(&scan_timer);
    scan_timer.expires = jiffies + INPUT_POLL_TIME;
    scan_timer.data = 0;
    scan_timer.function = (void *)&panel_scan_timer;
    add_timer(&scan_timer);
}

/* converts a name of the form "({BbAaPpSsEe}{01234567-})*" to a series of bits.
 * if <omask> or <imask> are non-null, they will be or'ed with the bits
 * corresponding to out and in bits respectively.
 * returns 1 if ok, 0 if error (in which case, nothing is written).
 */
static int input_name2mask(char *name, pmask_t *mask, pmask_t *value,
               char *imask, char *omask)
{
    static char sigtab[10] = "EeSsPpAaBb";
    char im, om;
    pmask_t m, v;

    om = im = m = v = 0ULL;
    while (*name) {
        int in, out, bit, neg;
        for (in = 0; (in < sizeof(sigtab)) &&
                 (sigtab[in] != *name); in++)
            ;
        if (in >= sizeof(sigtab))
            return 0;   /* input name not found */
        neg = (in & 1); /* odd (lower) names are negated */
        in >>= 1;
        im |= (1 << in);

        name++;
        if (isdigit(*name)) {
            out = *name - '0';
            om |= (1 << out);
        } else if (*name == '-')
            out = 8;
        else
            return 0;   /* unknown bit name */

        bit = (out * 5) + in;

        m |= 1ULL << bit;
        if (!neg)
            v |= 1ULL << bit;
        name++;
    }
    *mask = m;
    *value = v;
    if (imask)
        *imask |= im;
    if (omask)
        *omask |= om;
    return 1;
}

/* tries to bind a key to the signal name <name>. The key will send the
 * strings <press>, <repeat>, <release> for these respective events.
 * Returns the pointer to the new key if ok, NULL if the key could not be bound.
 */
static struct logical_input *panel_bind_key(char *name, char *press,
                        char *repeat, char *release)
{
    struct logical_input *key;

    key = kzalloc(sizeof(struct logical_input), GFP_KERNEL);
    if (!key)
        return NULL;

    if (!input_name2mask(name, &key->mask, &key->value, &scan_mask_i,
                 &scan_mask_o)) {
        kfree(key);
        return NULL;
    }

    key->type = INPUT_TYPE_KBD;
    key->state = INPUT_ST_LOW;
    key->rise_time = 1;
    key->fall_time = 1;

    strncpy(key->u.kbd.press_str, press, sizeof(key->u.kbd.press_str));
    strncpy(key->u.kbd.repeat_str, repeat, sizeof(key->u.kbd.repeat_str));
    strncpy(key->u.kbd.release_str, release,
        sizeof(key->u.kbd.release_str));
    list_add(&key->list, &logical_inputs);
    return key;
}

#if 0
/* tries to bind a callback function to the signal name <name>. The function
 * <press_fct> will be called with the <press_data> arg when the signal is
 * activated, and so on for <release_fct>/<release_data>
 * Returns the pointer to the new signal if ok, NULL if the signal could not
 * be bound.
 */
static struct logical_input *panel_bind_callback(char *name,
                         void (*press_fct) (int),
                         int press_data,
                         void (*release_fct) (int),
                         int release_data)
{
    struct logical_input *callback;

    callback = kmalloc(sizeof(struct logical_input), GFP_KERNEL);
    if (!callback)
        return NULL;

    memset(callback, 0, sizeof(struct logical_input));
    if (!input_name2mask(name, &callback->mask, &callback->value,
                 &scan_mask_i, &scan_mask_o))
        return NULL;

    callback->type = INPUT_TYPE_STD;
    callback->state = INPUT_ST_LOW;
    callback->rise_time = 1;
    callback->fall_time = 1;
    callback->u.std.press_fct = press_fct;
    callback->u.std.press_data = press_data;
    callback->u.std.release_fct = release_fct;
    callback->u.std.release_data = release_data;
    list_add(&callback->list, &logical_inputs);
    return callback;
}
#endif

static void keypad_init(void)
{
    int keynum;
    init_waitqueue_head(&keypad_read_wait);
    keypad_buflen = 0;  /* flushes any eventual noisy keystroke */

    /* Let's create all known keys */

    for (keynum = 0; keypad_profile[keynum][0][0]; keynum++) {
        panel_bind_key(keypad_profile[keynum][0],
                   keypad_profile[keynum][1],
                   keypad_profile[keynum][2],
                   keypad_profile[keynum][3]);
    }

    init_scan_timer();
    keypad_initialized = 1;
}

/**************************************************/
/* device initialization                          */
/**************************************************/

static int panel_notify_sys(struct notifier_block *this, unsigned long code,
                void *unused)
{
    if (lcd_enabled && lcd_initialized) {
        switch (code) {
        case SYS_DOWN:
            panel_lcd_print
                ("\x0cReloading\nSystem...\x1b[Lc\x1b[Lb\x1b[L+");
            break;
        case SYS_HALT:
            panel_lcd_print
                ("\x0cSystem Halted.\x1b[Lc\x1b[Lb\x1b[L+");
            break;
        case SYS_POWER_OFF:
            panel_lcd_print("\x0cPower off.\x1b[Lc\x1b[Lb\x1b[L+");
            break;
        default:
            break;
        }
    }
    return NOTIFY_DONE;
}

static struct notifier_block panel_notifier = {
    panel_notify_sys,
    NULL,
    0
};

static void panel_attach(struct parport *port)
{
    if (port->number != parport)
        return;

    if (pprt) {
        pr_err("%s: port->number=%d parport=%d, already registered!\n",
               __func__, port->number, parport);
        return;
    }

    pprt = parport_register_device(port, "panel", NULL, NULL,  /* pf, kf */
                       NULL,
                       /*PARPORT_DEV_EXCL */
                       0, (void *)&pprt);
    if (pprt == NULL) {
        pr_err("%s: port->number=%d parport=%d, parport_register_device() failed\n",
               __func__, port->number, parport);
        return;
    }

    if (parport_claim(pprt)) {
        pr_err("could not claim access to parport%d. Aborting.\n",
               parport);
        goto err_unreg_device;
    }

    /* must init LCD first, just in case an IRQ from the keypad is
     * generated at keypad init
     */
    if (lcd_enabled) {
        lcd_init();
        if (misc_register(&lcd_dev))
            goto err_unreg_device;
    }

    if (keypad_enabled) {
        keypad_init();
        if (misc_register(&keypad_dev))
            goto err_lcd_unreg;
    }
    return;

err_lcd_unreg:
    if (lcd_enabled)
        misc_deregister(&lcd_dev);
err_unreg_device:
    parport_unregister_device(pprt);
    pprt = NULL;
}

static void panel_detach(struct parport *port)
{
    if (port->number != parport)
        return;

    if (!pprt) {
        pr_err("%s: port->number=%d parport=%d, nothing to unregister.\n",
               __func__, port->number, parport);
        return;
    }

    if (keypad_enabled && keypad_initialized) {
        misc_deregister(&keypad_dev);
        keypad_initialized = 0;
    }

    if (lcd_enabled && lcd_initialized) {
        misc_deregister(&lcd_dev);
        lcd_initialized = 0;
    }

    parport_release(pprt);
    parport_unregister_device(pprt);
    pprt = NULL;
}

static struct parport_driver panel_driver = {
    .name = "panel",
    .attach = panel_attach,
    .detach = panel_detach,
};

/* init function */
int panel_init(void)
{
    /* for backwards compatibility */
    if (keypad_type < 0)
        keypad_type = keypad_enabled;

    if (lcd_type < 0)
        lcd_type = lcd_enabled;

    if (parport < 0)
        parport = DEFAULT_PARPORT;

    /* take care of an eventual profile */
    switch (profile) {
    case PANEL_PROFILE_CUSTOM:
        /* custom profile */
        if (keypad_type < 0)
            keypad_type = DEFAULT_KEYPAD;
        if (lcd_type < 0)
            lcd_type = DEFAULT_LCD;
        break;
    case PANEL_PROFILE_OLD:
        /* 8 bits, 2*16, old keypad */
        if (keypad_type < 0)
            keypad_type = KEYPAD_TYPE_OLD;
        if (lcd_type < 0)
            lcd_type = LCD_TYPE_OLD;
        if (lcd_width < 0)
            lcd_width = 16;
        if (lcd_hwidth < 0)
            lcd_hwidth = 16;
        break;
    case PANEL_PROFILE_NEW:
        /* serial, 2*16, new keypad */
        if (keypad_type < 0)
            keypad_type = KEYPAD_TYPE_NEW;
        if (lcd_type < 0)
            lcd_type = LCD_TYPE_KS0074;
        break;
    case PANEL_PROFILE_HANTRONIX:
        /* 8 bits, 2*16 hantronix-like, no keypad */
        if (keypad_type < 0)
            keypad_type = KEYPAD_TYPE_NONE;
        if (lcd_type < 0)
            lcd_type = LCD_TYPE_HANTRONIX;
        break;
    case PANEL_PROFILE_NEXCOM:
        /* generic 8 bits, 2*16, nexcom keypad, eg. Nexcom. */
        if (keypad_type < 0)
            keypad_type = KEYPAD_TYPE_NEXCOM;
        if (lcd_type < 0)
            lcd_type = LCD_TYPE_NEXCOM;
        break;
    case PANEL_PROFILE_LARGE:
        /* 8 bits, 2*40, old keypad */
        if (keypad_type < 0)
            keypad_type = KEYPAD_TYPE_OLD;
        if (lcd_type < 0)
            lcd_type = LCD_TYPE_OLD;
        break;
    }

    lcd_enabled = (lcd_type > 0);
    keypad_enabled = (keypad_type > 0);

    switch (keypad_type) {
    case KEYPAD_TYPE_OLD:
        keypad_profile = old_keypad_profile;
        break;
    case KEYPAD_TYPE_NEW:
        keypad_profile = new_keypad_profile;
        break;
    case KEYPAD_TYPE_NEXCOM:
        keypad_profile = nexcom_keypad_profile;
        break;
    default:
        keypad_profile = NULL;
        break;
    }

    /* tells various subsystems about the fact that we are initializing */
    init_in_progress = 1;

    if (parport_register_driver(&panel_driver)) {
        pr_err("could not register with parport. Aborting.\n");
        return -EIO;
    }

    if (!lcd_enabled && !keypad_enabled) {
        /* no device enabled, let's release the parport */
        if (pprt) {
            parport_release(pprt);
            parport_unregister_device(pprt);
            pprt = NULL;
        }
        parport_unregister_driver(&panel_driver);
        pr_err("driver version " PANEL_VERSION " disabled.\n");
        return -ENODEV;
    }

    register_reboot_notifier(&panel_notifier);

    if (pprt)
        pr_info("driver version " PANEL_VERSION
            " registered on parport%d (io=0x%lx).\n", parport,
            pprt->port->base);
    else
        pr_info("driver version " PANEL_VERSION
            " not yet registered\n");
    /* tells various subsystems about the fact that initialization
       is finished */
    init_in_progress = 0;
    return 0;
}

static int __init panel_init_module(void)
{
    return panel_init();
}

static void __exit panel_cleanup_module(void)
{
    unregister_reboot_notifier(&panel_notifier);

    if (scan_timer.function != NULL)
        del_timer(&scan_timer);

    if (pprt != NULL) {
        if (keypad_enabled) {
            misc_deregister(&keypad_dev);
            keypad_initialized = 0;
        }

        if (lcd_enabled) {
            panel_lcd_print("\x0cLCD driver " PANEL_VERSION
                    "\nunloaded.\x1b[Lc\x1b[Lb\x1b[L-");
            misc_deregister(&lcd_dev);
            lcd_initialized = 0;
        }

        /* TODO: free all input signals */
        parport_release(pprt);
        parport_unregister_device(pprt);
        pprt = NULL;
    }
    parport_unregister_driver(&panel_driver);
}

module_init(panel_init_module);
module_exit(panel_cleanup_module);
MODULE_AUTHOR("Willy Tarreau");
MODULE_LICENSE("GPL");

/*
 * Local variables:
 *  c-indent-level: 4
 *  tab-width: 8
 * End:
 */