/********************************************************************
* Description:  streamer.c
*               A HAL component that can be used to stream data
*               from a file onto HAL pins at a specific realtime
*               sample rate.
*
* Author: John Kasunich <jmkasunich at sourceforge dot net>
* License: GPL Version 2
*    
* Copyright (c) 2006 All rights reserved.
*
********************************************************************/
/** This file, 'streamer.c', is the realtime part of a HAL component
    that allows numbers stored in a file to be "streamed" onto HAL
    pins at a uniform realtime sample rate.  When the realtime module
    is loaded, it creates a fifo in shared memory.  Then, the user
    space program 'hal_streamer' is invoked.  'hal_streamer' takes 
    input from stdin and writes it to the fifo, and this component 
    transfers the data from the fifo to HAL pins.

    Loading:

    loadrt streamer depth=100 cfg=uffb


*/

/** Copyright (C) 2006 John Kasunich
 */

/** This program is free software; you can redistribute it and/or
    modify it under the terms of version 2 of the GNU General
    Public License as published by the Free Software Foundation.
    This library 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 library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111 USA

    THE AUTHORS OF THIS LIBRARY ACCEPT ABSOLUTELY NO LIABILITY FOR
    ANY HARM OR LOSS RESULTING FROM ITS USE.  IT IS _EXTREMELY_ UNWISE
    TO RELY ON SOFTWARE ALONE FOR SAFETY.  Any machinery capable of
    harming persons must have provisions for completely removing power
    from all motors, etc, before persons enter any danger area.  All
    machinery must be designed to comply with local and national safety
    codes, and the authors of this software can not, and do not, take
    any responsibility for such compliance.

    This code was written as part of the EMC HAL project.  For more
    information, go to www.linuxcnc.org.
*/

#include "rtapi.h"              /* RTAPI realtime OS API */
#include "rtapi_app.h"          /* RTAPI realtime module decls */
#include "hal.h"                /* HAL public API decls */
#include "streamer.h"		/* decls and such for fifos */
#include "rtapi_errno.h"
#include "rtapi_string.h"

/* module information */
MODULE_AUTHOR("John Kasunich");
MODULE_DESCRIPTION("Realtime File Streamer HAL");
MODULE_LICENSE("GPL");
static char *cfg[MAX_STREAMERS];	/* config string, no default */
RTAPI_MP_ARRAY_STRING(cfg,MAX_STREAMERS,"config string");
static int depth[MAX_STREAMERS];	/* depth of fifo, default 0 */
RTAPI_MP_ARRAY_INT(depth,MAX_STREAMERS,"fifo depth");

/***********************************************************************
*                STRUCTURES AND GLOBAL VARIABLES                       *
************************************************************************/

/* this structure contains the HAL shared memory data for one streamer */

typedef struct {
    fifo_t *fifo;		/* pointer to user/RT fifo */
    hal_s32_t *curr_depth;	/* pin: current fifo depth */
    hal_bit_t *empty;		/* pin: underrun flag */
    hal_bit_t *enable;		/* pin: enable streaming */
    hal_s32_t *underruns;	/* pin: number of underruns */
} streamer_t;

/* other globals */
static int comp_id;		/* component ID */
static int shmem_id[MAX_STREAMERS];

/***********************************************************************
*                  LOCAL FUNCTION DECLARATIONS                         *
************************************************************************/

static int parse_types(fifo_t *f, char *cfg);
static int init_streamer(int num, fifo_t *tmp_fifo);
static void update(void *arg, long period);

/***********************************************************************
*                       INIT AND EXIT CODE                             *
************************************************************************/

int rtapi_app_main(void)
{
    int n, numchan, max_depth, retval;
    fifo_t tmp_fifo[MAX_STREAMERS];

    /* validate config info */
    for ( n = 0 ; n < MAX_STREAMERS ; n++ ) {
	if (( cfg[n] == NULL ) || ( *cfg == '\0' ) || ( depth[n] <= 0 )) {
	    break;
	}
	tmp_fifo[n].num_pins = parse_types(&(tmp_fifo[n]), cfg[n]);
	if ( tmp_fifo[n].num_pins == 0 ) {
	    rtapi_print_msg(RTAPI_MSG_ERR,
		"STREAMER: ERROR: bad config string '%s'\n", cfg[n]);
	    return -EINVAL;
	}
	max_depth = MAX_SHMEM / (sizeof(shmem_data_t) * tmp_fifo[n].num_pins);
	if ( depth[n] > max_depth ) {
	    rtapi_print_msg(RTAPI_MSG_ERR,
		"STREAMER: ERROR: depth too large, max is %d\n", max_depth);
	    return -ENOMEM;
	}
	tmp_fifo[n].depth = depth[n];
    }
    if ( n == 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: no channels specified\n");
	return -EINVAL;
    }
    numchan = n;
    /* clear shmem IDs */
    for ( n = 0 ; n < MAX_STREAMERS ; n++ ) {
	shmem_id[n] = -1;
    }

    /* have good config info, connect to the HAL */
    comp_id = hal_init("streamer");
    if (comp_id < 0) {
	rtapi_print_msg(RTAPI_MSG_ERR, "STREAMER: ERROR: hal_init() failed\n");
	return -EINVAL;
    }

    /* create the streamers - allocate memory, export pins, etc. */
    for (n = 0; n < numchan; n++) {
	retval = init_streamer(n, &(tmp_fifo[n]));
	if (retval != 0) {
	    rtapi_print_msg(RTAPI_MSG_ERR,
		"STREAMER: ERROR: streamer %d init failed\n", n);
	    hal_exit(comp_id);
	    return retval;
	}
    }
    rtapi_print_msg(RTAPI_MSG_INFO,
	"STREAMER: installed %d data streamers\n", numchan);
    hal_ready(comp_id);
    return 0;
}

void rtapi_app_exit(void)
{
    int n;

    /* free any shmem blocks */
    for ( n = 0 ; n < MAX_STREAMERS ; n++ ) {
	if ( shmem_id[n] > 0 ) {
	    rtapi_shmem_delete(shmem_id[n], comp_id);
	}
    }
    hal_exit(comp_id);
}

/***********************************************************************
*            REALTIME COUNTER COUNTING AND UPDATE FUNCTIONS            *
************************************************************************/

static void update(void *arg, long period)
{
    streamer_t *str;
    fifo_t *fifo;
    pin_data_t *pptr;
    shmem_data_t *dptr;
    int tmpin, tmpout, n;

    /* point at streamer struct in HAL shmem */
    str = arg;
    /* are we enabled? */
    if ( ! *(str->enable) ) {
	/* no, done */
	return;
    }
    /* HAL pins are right after the streamer_t struct in HAL shmem */
    pptr = (pin_data_t *)(str+1);
    /* point at user/RT fifo in other shmem */
    fifo = str->fifo;
    /* fifo data area is right after the fifo_t struct in shmem */
    dptr = (shmem_data_t *)(fifo+1);
    /* find the next block of data in the fifo */
    tmpin = fifo->in;
    tmpout = fifo->out;
    if ( tmpout == tmpin ) {
        /* fifo empty - log it */
	(*str->underruns)++;
	*(str->empty) = 1;
	*(str->curr_depth) = 0;
	/* done - output pins retain current values */
	return;
    }
    /* clear the "empty" pin */
    *(str->empty) = 0;
    /* calculate current depth */
    if ( tmpin < tmpout ) {
	tmpin += fifo->depth;
    }
    *(str->curr_depth) = tmpin - tmpout;
    /* make ptr to first data item of the current fifo record */
    dptr += tmpout * fifo->num_pins;
    /* copy data from fifo to HAL pins */
    for ( n = 0 ; n < fifo->num_pins ; n++ ) {
	switch ( fifo->type[n] ) {
	case HAL_FLOAT:
	    *(pptr->hfloat) = dptr->f;
	    break;
	case HAL_BIT:
	    if ( dptr->b ) {
		*(pptr->hbit) = 1;
	    } else {
		*(pptr->hbit) = 0;
	    }
	    break;
	case HAL_U32:
	    *(pptr->hu32) = dptr->u;
	    break;
	case HAL_S32:
	    *(pptr->hs32) = dptr->s;
	    break;
	default:
	    break;
	}
	dptr++;
	pptr++;
    }
    tmpout++;
    if ( tmpout >= fifo->depth ) {
        tmpout = 0;
    }
    /* store new value of out */
    fifo->out = tmpout;
}

/***********************************************************************
*                   LOCAL FUNCTION DEFINITIONS                         *
************************************************************************/

static int parse_types(fifo_t *f, char *cfg)
{
    char *c;
    int n;

    c = cfg;
    n = 0;
    while (( n < MAX_PINS ) && ( *c != '\0' )) {
	switch (*c) {
	case 'f':
	case 'F':
	    f->type[n++] = HAL_FLOAT;
	    c++;
	    break;
	case 'b':
	case 'B':
	    f->type[n++] = HAL_BIT;
	    c++;
	    break;
	case 'u':
	case 'U':
	    f->type[n++] = HAL_U32;
	    c++;
	    break;
	case 's':
	case 'S':
	    f->type[n++] = HAL_S32;
	    c++;
	    break;
	default:
	    rtapi_print_msg(RTAPI_MSG_ERR,
		"STREAMER: ERROR: unknown type '%c', must be F, B, U, or S\n", *c);
	    return 0;
	}
    }
    if ( *c != '\0' ) {
	/* didn't reach end of cfg string */
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: more than %d items\n", MAX_PINS);
	return 0;
    }
    return n;
}

static int init_streamer(int num, fifo_t *tmp_fifo)
{
    int size, retval, n, usefp;
    void *shmem_ptr;
    streamer_t *str;
    pin_data_t *pptr;
    fifo_t *fifo;
    char buf[HAL_NAME_LEN + 1];

    /* alloc shmem for base streamer data and user specified pins */
    size = sizeof(streamer_t) + tmp_fifo->num_pins*sizeof(pin_data_t);
    str = hal_malloc(size);

    if (str == 0) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: couldn't allocate HAL shared memory\n");
	return -ENOMEM;
    }
    /* export "standard" pins and params */
    retval = hal_pin_bit_newf(HAL_OUT, &(str->empty), comp_id,
	"streamer.%d.empty", num);
    if (retval != 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: 'empty' pin export failed\n");
	return -EIO;
    }
    retval = hal_pin_bit_newf(HAL_IN, &(str->enable), comp_id,
	"streamer.%d.enable", num);
    if (retval != 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: 'enable' pin export failed\n");
	return -EIO;
    }
    retval = hal_pin_s32_newf(HAL_OUT, &(str->curr_depth), comp_id,
	"streamer.%d.curr-depth", num);
    if (retval != 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: 'curr_depth' pin export failed\n");
	return -EIO;
    }
    retval = hal_pin_s32_newf(HAL_IO, &(str->underruns), comp_id,
	"streamer.%d.underruns", num);
    if (retval != 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: 'underruns' pin export failed\n");
	return -EIO;
    }
    /* init the standard pins and params */
    *(str->empty) = 1;
    *(str->enable) = 1;
    *(str->curr_depth) = 0;
    *(str->underruns) = 0;
    /* HAL pins are right after the streamer_t struct in HAL shmem */
    pptr = (pin_data_t *)(str+1);
    usefp = 0;
    /* export user specified pins (the ones that stream data) */
    for ( n = 0 ; n < tmp_fifo->num_pins ; n++ ) {
	rtapi_snprintf(buf, sizeof(buf), "streamer.%d.pin.%d", num, n);
	retval = hal_pin_new(buf, tmp_fifo->type[n], HAL_OUT, (void **)pptr, comp_id );
	if (retval != 0 ) {
	    rtapi_print_msg(RTAPI_MSG_ERR,
		"STREAMER: ERROR: pin '%s' export failed\n", buf);
	    return -EIO;
	}
	/* init the pin value */
	switch ( tmp_fifo->type[n] ) {
	case HAL_FLOAT:
	    *(pptr->hfloat) = 0.0;
	    usefp = 1;
	    break;
	case HAL_BIT:
	    *(pptr->hbit) = 0;
	    break;
	case HAL_U32:
	    *(pptr->hu32) = 0;
	    break;
	case HAL_S32:
	    *(pptr->hs32) = 0;
	    break;
	default:
	    break;
	}
	pptr++;
    }
    /* export update function */
    rtapi_snprintf(buf, sizeof(buf), "streamer.%d", num);
    retval = hal_export_funct(buf, update, str, usefp, 0, comp_id);
    if (retval != 0) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: function export failed\n");
	return retval;
    }

    /* alloc shmem for user/RT comms (fifo) */
    size = sizeof(fifo_t) + tmp_fifo->num_pins * tmp_fifo->depth * sizeof(shmem_data_t);
    shmem_id[num] = rtapi_shmem_new(STREAMER_SHMEM_KEY+num, comp_id, size);
    if ( shmem_id[num] < 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: couldn't allocate user/RT shared memory\n");
	return -ENOMEM;
    }
    retval = rtapi_shmem_getptr(shmem_id[num], &shmem_ptr);
    if ( retval < 0 ) {
	rtapi_print_msg(RTAPI_MSG_ERR,
	    "STREAMER: ERROR: couldn't map user/RT shared memory\n");
	return -ENOMEM;
    }
    fifo = shmem_ptr;
    str->fifo = fifo;
    /* copy data from temp_fifo */
    *fifo = *tmp_fifo;
    /* init fields */
    fifo->in = 0;
    fifo->out = 0;
    fifo->last_sample = 0;

    /* mark it inited for user program */
    fifo->magic = FIFO_MAGIC_NUM;
    return 0;
}