FreeBSD/Linux Kernel Cross Reference
sys/dev/ic/tea5757.c

     /*      $OpenBSD: tea5757.c,v 1.4 2021/11/23 00:17:59 jsg Exp $ */
     
     /*
      * Copyright (c) 2001 Vladimir Popov <jumbo@narod.ru>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    /* Implementation of most common TEA5757 routines */
    
    /*
     * Philips TEA5757H Self Tuned Radio
     *         http://www.semiconductors.philips.com/pip/TEA5757H
     *
     * The TEA5757; TEA5759 is a 44-pin integrated AM/FM stereo radio circuit.
     * The radio part is based on the TEA5712.
     *
     * The TEA5757 is used in FM-standards in which the local oscillator
     * frequency is above the radio frequency (e.g. European and American
     * standards). The TEA5759 is the version in which the oscillator frequency
     * is below the radio frequency (e.g. Japanese standard).
     *
     * The TEA5757; TEA5759 radio has a bus which consists of three wires:
     * BUS-CLOCK: software driven clock input
     * DATA: data input/output
     * WRITE-ENABLE: write/read input
     *
     * The TEA5757; TEA5759 has a 25-bit shift register.
     *
     * The chips are used in Radiotrack II, Guillemot Maxi Radio FM 2000,
     * Gemtek PCI cards and most Mediaforte FM tuners and sound cards with
     * integrated FM tuners.
     */
    
    #include <sys/param.h>
    #include <sys/radioio.h>
    
    #include <dev/ic/tea5757.h>
    
    /*
     * Convert frequency to hardware representation
     */
    u_int32_t
    tea5757_encode_freq(u_int32_t freq, int tea5759)
    {
            if (tea5759)
                    freq -= IF_FREQ;
            else
                    freq += IF_FREQ;
    
            /*
             * NO FLOATING POINT!
             */
            freq *= 10;
            freq /= 125;
    
            return freq & TEA5757_FREQ;
    }
    
    /*
     * Convert frequency from hardware representation
     */
    u_int32_t
    tea5757_decode_freq(u_int32_t freq, int tea5759)
    {
            freq &= TEA5757_FREQ;
            freq *= 125; /* 12.5 kHz */
            freq /= 10;
    
            if (tea5759)
                    freq += IF_FREQ;
            else
                    freq -= IF_FREQ;
    
            return freq;
    }
    
    /*
     * Hardware search
     */
   void
   tea5757_search(struct tea5757_t *tea, u_int32_t stereo, u_int32_t lock, int dir)
   {
           u_int32_t reg;
           u_int co = 0;
   
           reg = stereo | lock | TEA5757_SEARCH_START;
           reg |= dir ? TEA5757_SEARCH_UP : TEA5757_SEARCH_DOWN;
           tea5757_hardware_write(tea, reg);
   
           DELAY(TEA5757_ACQUISITION_DELAY);
   
           do {
                   DELAY(TEA5757_WAIT_DELAY);
                   reg = tea->read(tea->iot, tea->ioh, tea->offset);
           } while ((reg & TEA5757_FREQ) == 0 && ++co < 200);
   }
   
   void
   tea5757_hardware_write(struct tea5757_t *tea, u_int32_t data)
   {
           int i = TEA5757_REGISTER_LENGTH;
   
           tea->init(tea->iot, tea->ioh, tea->offset, 0);
   
           while (i--)
                   if (data & (1 << i))
                           tea->write_bit(tea->iot, tea->ioh, tea->offset, 1);
                   else
                           tea->write_bit(tea->iot, tea->ioh, tea->offset, 0);
   
           tea->rset(tea->iot, tea->ioh, tea->offset, 0);
   }
   
   u_int32_t
   tea5757_set_freq(struct tea5757_t *tea, u_int32_t stereo, u_int32_t lock, u_int32_t freq)
   {
           u_int32_t data = 0ul;
   
           if (freq < MIN_FM_FREQ)
                   freq = MIN_FM_FREQ;
           if (freq > MAX_FM_FREQ)
                   freq = MAX_FM_FREQ;
   
           data |= tea5757_encode_freq(freq, tea->flags & TEA5757_TEA5759);
           data |= stereo | lock | TEA5757_SEARCH_END;
           tea5757_hardware_write(tea, data);
   
           return freq;
   }
   
   u_int32_t
   tea5757_encode_lock(u_int8_t lock)
   {
           u_int32_t ret;
   
           if (lock < 8)
                   ret = TEA5757_S005;
           else if (lock > 7 && lock < 15)
                   ret = TEA5757_S010;
           else if (lock > 14 && lock < 51)
                   ret = TEA5757_S030;
           else
                   ret = TEA5757_S150;
   
           return ret;
   }
   
   u_int8_t
   tea5757_decode_lock(u_int32_t lock)
   {
           u_int8_t ret = 150;
   
           switch (lock) {
           case TEA5757_S005:
                   ret = 5;
                   break;
           case TEA5757_S010:
                   ret = 10;
                   break;
           case TEA5757_S030:
                   ret = 30;
                   break;
           case TEA5757_S150:
                   ret = 150;
                   break;
           }
   
           return ret;
   }

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