text: /*****************************************************************************/
  
  /*
   *	smdma.h  --  soundcard radio modem driver dma buffer routines.
   *
   *	Copyright (C) 1996  Thomas Sailer (sailer@ife.ee.ethz.ch)
   *
   *	This program is free software; you can redistribute it and/or modify
   *	it under the terms of the GNU General Public License as published by
   *	the Free Software Foundation; either version 2 of the License, or
   *	(at your option) any later version.
   *
   *	This program is distributed in the hope that it will be useful,
   *	but WITHOUT ANY WARRANTY; without even the implied warranty of
   *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *	GNU General Public License for more details.
   *
   *	You should have received a copy of the GNU General Public License
   *	along with this program; if not, write to the Free Software
   *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   *  Please note that the GPL allows you to use the driver, NOT the radio.
   *  In order to use the radio, you need a license from the communications
   *  authority of your country.
   *
   */
  
  #ifndef _SMDMA_H
  #define _SMDMA_H
  
  /* ---------------------------------------------------------------------- */
  
  #include "sm.h"
  
  /* ---------------------------------------------------------------------- */
  
  #define DMA_MODE_AUTOINIT      0x10
  #define NUM_FRAGMENTS          4
  
  /*
   * NOTE: make sure that hdlcdrv_hdlcbuffer contains enough space
   * for the modulator to fill the whole DMA buffer without underrun
   * at the highest possible baud rate, otherwise the TX state machine will
   * not work correctly. That is (9k6 FSK): HDLCDRV_HDLCBUFFER > 6*NUM_FRAGMENTS
   */ 
  
  /* --------------------------------------------------------------------- */
  /*
   * ===================== DMA buffer management ===========================
   */
  
  /*
   * returns the number of samples per fragment
   */
  extern __inline__ unsigned int dma_setup(struct sm_state *sm, int send, unsigned int dmanr)
  {
  	if (send) {
  		disable_dma(dmanr);
  		clear_dma_ff(dmanr);
  		set_dma_mode(dmanr, DMA_MODE_WRITE | DMA_MODE_AUTOINIT);
  		set_dma_addr(dmanr, virt_to_bus(sm->dma.obuf));
  		set_dma_count(dmanr, sm->dma.ofragsz * NUM_FRAGMENTS);
  		enable_dma(dmanr);
  		if (sm->dma.o16bit)
  			return sm->dma.ofragsz/2;
  		return sm->dma.ofragsz;
  	} else {
  		disable_dma(dmanr);
  		clear_dma_ff(dmanr);
  		set_dma_mode(dmanr, DMA_MODE_READ | DMA_MODE_AUTOINIT);
  		set_dma_addr(dmanr, virt_to_bus(sm->dma.ibuf));
  		set_dma_count(dmanr, sm->dma.ifragsz * NUM_FRAGMENTS);
  		enable_dma(dmanr);
  		if (sm->dma.i16bit)
  			return sm->dma.ifragsz/2;
  		return sm->dma.ifragsz;
  	}
  }
  
  /* --------------------------------------------------------------------- */
  
  extern __inline__ unsigned int dma_ptr(struct sm_state *sm, int send, unsigned int dmanr,
  				       unsigned int *curfrag)
  {
  	unsigned int dmaptr, sz, frg, offs;
  	
  	dmaptr = get_dma_residue(dmanr);
  	if (send) {
  		sz = sm->dma.ofragsz * NUM_FRAGMENTS;
  		if (dmaptr == 0 || dmaptr > sz)
  			dmaptr = sz;
  		dmaptr--;
  		frg = dmaptr / sm->dma.ofragsz;
  		offs = (dmaptr % sm->dma.ofragsz) + 1;
  		*curfrag = NUM_FRAGMENTS - 1 - frg;
  #ifdef SM_DEBUG
  		if (!sm->debug_vals.dma_residue || offs < sm->debug_vals.dma_residue)
  			sm->debug_vals.dma_residue = offs;
  #endif /* SM_DEBUG */
  		if (sm->dma.o16bit)
  			return offs/2;
  		return offs;
  	} else {
  		sz = sm->dma.ifragsz * NUM_FRAGMENTS;
  		if (dmaptr == 0 || dmaptr > sz)
  			dmaptr = sz;
  		dmaptr--;
  		frg = dmaptr / sm->dma.ifragsz;
  		offs = (dmaptr % sm->dma.ifragsz) + 1;
  		*curfrag = NUM_FRAGMENTS - 1 - frg;
  #ifdef SM_DEBUG
  		if (!sm->debug_vals.dma_residue || offs < sm->debug_vals.dma_residue)
  			sm->debug_vals.dma_residue = offs;
  #endif /* SM_DEBUG */
  		if (sm->dma.i16bit)
  			return offs/2;
  		return offs;
  	}
  }
  
  /* --------------------------------------------------------------------- */
  
  extern __inline__ int dma_end_transmit(struct sm_state *sm, unsigned int curfrag)
  {
  	unsigned int diff = (NUM_FRAGMENTS + curfrag - sm->dma.ofragptr) % NUM_FRAGMENTS;
  
  	sm->dma.ofragptr = curfrag;
  	if (sm->dma.ptt_cnt <= 0) {
  		sm->dma.ptt_cnt = 0;
  		return 0;
  	}
  	sm->dma.ptt_cnt -= diff;
  	if (sm->dma.ptt_cnt <= 0) {
  		sm->dma.ptt_cnt = 0;
  		return -1;
  	}
  	return 0;
  }
  
  extern __inline__ void dma_transmit(struct sm_state *sm)
  {
  	void *p;
  
  	while (sm->dma.ptt_cnt < NUM_FRAGMENTS && hdlcdrv_ptt(&sm->hdrv)) {
  		p = (unsigned char *)sm->dma.obuf + sm->dma.ofragsz *
  			((sm->dma.ofragptr + sm->dma.ptt_cnt) % NUM_FRAGMENTS);
  		if (sm->dma.o16bit) {
  			time_exec(sm->debug_vals.mod_cyc, 
  				  sm->mode_tx->modulator_s16(sm, p, sm->dma.ofragsz/2));
  		} else {
  			time_exec(sm->debug_vals.mod_cyc, 
  				  sm->mode_tx->modulator_u8(sm, p, sm->dma.ofragsz));
  		}
  		sm->dma.ptt_cnt++;
  	}
  }
  
  extern __inline__ void dma_init_transmit(struct sm_state *sm)
  {
  	sm->dma.ofragptr = 0;
  	sm->dma.ptt_cnt = 0;
  }
  
  extern __inline__ void dma_start_transmit(struct sm_state *sm)
  {
  	sm->dma.ofragptr = 0;
  	if (sm->dma.o16bit) {
  		time_exec(sm->debug_vals.mod_cyc, 
  			  sm->mode_tx->modulator_s16(sm, sm->dma.obuf, sm->dma.ofragsz/2));
  	} else {
  		time_exec(sm->debug_vals.mod_cyc, 
  			  sm->mode_tx->modulator_u8(sm, sm->dma.obuf, sm->dma.ofragsz));
  	}
  	sm->dma.ptt_cnt = 1;
  }
  
  extern __inline__ void dma_clear_transmit(struct sm_state *sm)
  {
  	sm->dma.ptt_cnt = 0;
  	memset(sm->dma.obuf, (sm->dma.o16bit) ? 0 : 0x80, sm->dma.ofragsz * NUM_FRAGMENTS);
  }
  
  /* --------------------------------------------------------------------- */
  
  extern __inline__ void dma_receive(struct sm_state *sm, unsigned int curfrag)
  {
  	void *p;
  
  	while (sm->dma.ifragptr != curfrag) {
  		if (sm->dma.ifragptr)
  			p = (unsigned char *)sm->dma.ibuf + 
  				sm->dma.ifragsz * sm->dma.ifragptr;
  		else {
  			p = (unsigned char *)sm->dma.ibuf + NUM_FRAGMENTS * sm->dma.ifragsz;
  			memcpy(p, sm->dma.ibuf, sm->dma.ifragsz);
  		}
  		if (sm->dma.o16bit) {
  			time_exec(sm->debug_vals.demod_cyc, 
  				  sm->mode_rx->demodulator_s16(sm, p, sm->dma.ifragsz/2));
  		} else {
  			time_exec(sm->debug_vals.demod_cyc, 
  				  sm->mode_rx->demodulator_u8(sm, p, sm->dma.ifragsz));
  		}
  		sm->dma.ifragptr = (sm->dma.ifragptr + 1) % NUM_FRAGMENTS;
  	}
  }
  
  extern __inline__ void dma_init_receive(struct sm_state *sm)
  {
  	sm->dma.ifragptr = 0;
  }
  
  /* --------------------------------------------------------------------- */
  #endif /* _SMDMA_H */
  
  
  
  