drv_BWCT.c

/* $Id$
 * $URL$
 *
 * new style driver for BWCT USB LCD displays
 *
 * Copyright (C) 2003 Michael Reinelt <michael@reinelt.co.at>
 * Copyright (C) 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux 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, or (at your option)
 * any later version.
 *
 * LCD4Linux 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/* 
 *
 * exported fuctions:
 *
 * struct DRIVER drv_BWCT
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/time.h>

#include <usb.h>

#include "debug.h"
#include "cfg.h"
#include "qprintf.h"
#include "plugin.h"
#include "widget.h"
#include "widget_text.h"
#include "widget_icon.h"
#include "widget_bar.h"
#include "drv.h"
#include "drv_generic_text.h"


#define LCD_USB_VENDOR 0x03da
#define LCD_USB_DEVICE 0x0002

#define LCD_RESET    1
#define LCD_CMD      2
#define LCD_DATA     3
#define LCD_CONTRAST 4


static char Name[] = "BWCT";

static usb_dev_handle *lcd;
static int interface;

extern int got_signal;


/****************************************/
/***  hardware dependant functions    ***/
/****************************************/

static int drv_BW_open(void)
{
    struct usb_bus *busses, *bus;
    struct usb_device *dev;

    lcd = NULL;

    info("%s: scanning USB for BWCT LCD...", Name);

    usb_set_debug(0);

    usb_init();
    usb_find_busses();
    usb_find_devices();
    busses = usb_get_busses();

    for (bus = busses; bus; bus = bus->next) {
        for (dev = bus->devices; dev; dev = dev->next) {
            int c;
            if (dev->descriptor.idVendor != LCD_USB_VENDOR)
                continue;
            /* Loop through all of the configurations */
            for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
                int i;
                for (i = 0; i < dev->config[c].bNumInterfaces; i++) {
                    int a;
                    for (a = 0; a < dev->config[c].interface[i].num_altsetting; a++) {
                        if ((dev->descriptor.idProduct == LCD_USB_DEVICE) ||
                            ((dev->config[c].interface[i].altsetting[a].bInterfaceClass == 0xff) &&
                             (dev->config[c].interface[i].altsetting[a].bInterfaceSubClass == 0x01))) {
                            info("%s: found BWCT USB LCD on bus %s device %s", Name, bus->dirname, dev->filename);
                            interface = i;
                            lcd = usb_open(dev);
                            if (usb_claim_interface(lcd, interface) < 0) {
                                error("%s: usb_claim_interface() failed!", Name);
                                return -1;
                            }
                            return 0;
                        }
                    }
                }
            }
        }
    }
    return -1;
}


static int drv_BW_close(void)
{
    usb_release_interface(lcd, interface);
    usb_close(lcd);

    return 0;
}


static int drv_BW_send(int request, int value)
{
    static int errors = 0;

    if (errors > 20)
        return -1;

    if (usb_control_msg(lcd, USB_TYPE_VENDOR, request, value, interface, NULL, 0, 1000) < 0) {
        error("%s: USB request failed!", Name);
        if (++errors > 20) {
            error("%s: too many USB errors, aborting.", Name);
            got_signal = -1;
        }
        return -1;
    }
    errors = 0;
    return 0;
}


static void drv_BW_command(const unsigned char cmd)
{
    drv_BW_send(LCD_CMD, cmd);
}


static void drv_BW_clear(void)
{
    drv_BW_command(0x01);       /* clear display */
    drv_BW_command(0x03);       /* return home */
}


static void drv_BW_write(const int row, const int col, const char *data, int len)
{
    int pos;

    /* 16x4 Displays use a slightly different layout */
    if (DCOLS == 16 && DROWS == 4) {
        pos = (row % 2) * 64 + (row / 2) * 16 + col;
    } else {
        pos = (row % 2) * 64 + (row / 2) * 20 + col;
    }

    drv_BW_command(0x80 | pos);

    while (len--) {
        drv_BW_send(LCD_DATA, *data++);
    }
}

static void drv_BW_defchar(const int ascii, const unsigned char *matrix)
{
    int i;

    drv_BW_command(0x40 | 8 * ascii);

    for (i = 0; i < 8; i++) {
        drv_BW_send(LCD_DATA, *matrix++ & 0x1f);
    }
}


static int drv_BW_contrast(int contrast)
{
    if (contrast < 0)
        contrast = 0;
    if (contrast > 255)
        contrast = 255;

    drv_BW_send(LCD_CONTRAST, contrast);

    return contrast;
}


static int drv_BW_start(const char *section, const int quiet)
{
    int contrast;
    int rows = -1, cols = -1;
    char *s;

    s = cfg_get(section, "Size", NULL);
    if (s == NULL || *s == '\0') {
        error("%s: no '%s.Size' entry from %s", Name, section, cfg_source());
        return -1;
    }
    if (sscanf(s, "%dx%d", &cols, &rows) != 2 || rows < 1 || cols < 1) {
        error("%s: bad %s.Size '%s' from %s", Name, section, s, cfg_source());
        free(s);
        return -1;
    }

    DROWS = rows;
    DCOLS = cols;

    if (drv_BW_open() < 0) {
        error("%s: could not find a BWCT USB LCD", Name);
        return -1;
    }

    /* reset */
    drv_BW_send(LCD_RESET, 0);

    /* initialize display */
    drv_BW_command(0x29);       /* 8 Bit mode, 1/16 duty cycle, 5x8 font */
    drv_BW_command(0x08);       /* Display off, cursor off, blink off */
    drv_BW_command(0x0c);       /* Display on, cursor off, blink off */
    drv_BW_command(0x06);       /* curser moves to right, no shift */


    if (cfg_number(section, "Contrast", 0, 0, 255, &contrast) > 0) {
        drv_BW_contrast(contrast);
    }

    drv_BW_clear();             /* clear display */

    if (!quiet) {
        char buffer[40];
        qprintf(buffer, sizeof(buffer), "%s %dx%d", Name, DCOLS, DROWS);
        if (drv_generic_text_greet(buffer, "www.bwct.de")) {
            sleep(3);
            drv_BW_clear();
        }
    }

    return 0;
}


/****************************************/
/***            plugins               ***/
/****************************************/

static void plugin_contrast(RESULT * result, RESULT * arg1)
{
    double contrast;

    contrast = drv_BW_contrast(R2N(arg1));
    SetResult(&result, R_NUMBER, &contrast);
}


/****************************************/
/***        widget callbacks          ***/
/****************************************/


/* using drv_generic_text_draw(W) */
/* using drv_generic_text_icon_draw(W) */
/* using drv_generic_text_bar_draw(W) */


/****************************************/
/***        exported functions        ***/
/****************************************/


/* list models */
int drv_BW_list(void)
{
    printf("BWCT USB to HD44780 interface");
    return 0;
}


/* initialize driver & display */
int drv_BW_init(const char *section, const int quiet)
{
    WIDGET_CLASS wc;
    int asc255bug;
    int ret;

    info("%s: %s", Name, "$Rev$");

    /* display preferences */
    XRES = 5;                   /* pixel width of one char  */
    YRES = 8;                   /* pixel height of one char  */
    CHARS = 8;                  /* number of user-defineable characters */
    CHAR0 = 0;                  /* ASCII of first user-defineable char */
    GOTO_COST = 2;              /* number of bytes a goto command requires */

    /* real worker functions */
    drv_generic_text_real_write = drv_BW_write;
    drv_generic_text_real_defchar = drv_BW_defchar;


    /* start display */
    if ((ret = drv_BW_start(section, quiet)) != 0)
        return ret;

    /* initialize generic text driver */
    if ((ret = drv_generic_text_init(section, Name)) != 0)
        return ret;

    /* initialize generic icon driver */
    if ((ret = drv_generic_text_icon_init()) != 0)
        return ret;

    /* initialize generic bar driver */
    if ((ret = drv_generic_text_bar_init(0)) != 0)
        return ret;

    /* add fixed chars to the bar driver */
    /* most displays have a full block on ascii 255, but some have kind of  */
    /* an 'inverted P'. If you specify 'asc255bug 1 in the config, this */
    /* char will not be used, but rendered by the bar driver */
    cfg_number(section, "asc255bug", 0, 0, 1, &asc255bug);
    drv_generic_text_bar_add_segment(0, 0, 255, 32);    /* ASCII  32 = blank */
    if (!asc255bug)
        drv_generic_text_bar_add_segment(255, 255, 255, 255);   /* ASCII 255 = block */

    /* register text widget */
    wc = Widget_Text;
    wc.draw = drv_generic_text_draw;
    widget_register(&wc);

    /* register icon widget */
    wc = Widget_Icon;
    wc.draw = drv_generic_text_icon_draw;
    widget_register(&wc);

    /* register bar widget */
    wc = Widget_Bar;
    wc.draw = drv_generic_text_bar_draw;
    widget_register(&wc);

    /* register plugins */
    AddFunction("LCD::contrast", 1, plugin_contrast);

    return 0;
}


/* close driver & display */
int drv_BW_quit(const int quiet)
{

    info("%s: shutting down.", Name);

    drv_generic_text_quit();

    /* clear display */
    drv_BW_clear();

    /* say goodbye... */
    if (!quiet) {
        drv_generic_text_greet("goodbye!", NULL);
    }

    debug("closing USB connection");
    drv_BW_close();

    return (0);
}


DRIVER drv_BWCT = {
    .name = Name,
    .list = drv_BW_list,
    .init = drv_BW_init,
    .quit = drv_BW_quit,
};