board/gen860t/beeper.c

   1 /*
   2  * (C) Copyright 2002
   3  * Keith Outwater, keith_outwater@mvis.com
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <common.h>
  25 #include <mpc8xx.h>
  26 #include <asm/8xx_immap.h>
  27 #include <linux/ctype.h>
  28
  29 /*
  30  * Basic beeper support for the GEN860T board.  The GEN860T includes
  31  * an audio sounder driven by a Phillips TDA8551 amplifier.  The
  32  * TDA8551 features a digital volume control which uses a "trinary"
  33  * input (high/high-Z/low) to set volume.  The 860's SPKROUT pin
  34  * drives the amplifier input.
  35  */
  36
  37 /*
  38  * Initialize beeper-related hardware. Initialize timer 1 for use with
  39  * the beeper. Use 66 Mhz internal clock with prescale of 33 to get
  40  * 1 uS period per count.
  41  * FIXME: we should really compute the prescale based on the reported
  42  * core clock frequency.
  43  */
  44 void init_beeper (void)
  45 {
  46         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  47
  48         immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_RST1 | TGCR_STP1;
  49         immap->im_cpmtimer.cpmt_tmr1 = ((33 << TMR_PS_SHIFT) & TMR_PS_MSK)
  50                 | TMR_OM | TMR_FRR | TMR_ICLK_IN_GEN;
  51         immap->im_cpmtimer.cpmt_tcn1 = 0;
  52         immap->im_cpmtimer.cpmt_ter1 = 0xffff;
  53         immap->im_cpmtimer.cpmt_tgcr |= TGCR_RST1;
  54 }
  55
  56 /*
  57  * Set beeper frequency.  Max allowed frequency is 2.5 KHz.  This limit
  58  * is mostly arbitrary, but the beeper isn't really much good beyond this
  59  * frequency.
  60  */
  61 void set_beeper_frequency (uint frequency)
  62 {
  63 #define FREQ_LIMIT      2500
  64
  65         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  66
  67         /*
  68          * Compute timer ticks given desired frequency.  The timer is set up
  69          * to count 0.5 uS per tick and it takes two ticks per cycle (Hz).
  70          */
  71         if (frequency > FREQ_LIMIT)
  72                 frequency = FREQ_LIMIT;
  73         frequency = 1000000 / frequency;
  74         immap->im_cpmtimer.cpmt_trr1 = (ushort) frequency;
  75 }
  76
  77 /*
  78  * Turn the beeper on
  79  */
  80 void beeper_on (void)
  81 {
  82         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  83
  84         immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_STP1;
  85 }
  86
  87 /*
  88  * Turn the beeper off
  89  */
  90 void beeper_off (void)
  91 {
  92         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  93
  94         immap->im_cpmtimer.cpmt_tgcr |= TGCR_STP1;
  95 }
  96
  97 /*
  98  * Increase or decrease the beeper volume.  Volume can be set
  99  * from off to full in 64 steps.  To increase volume, the output
 100  * pin is actively driven high, then returned to tristate.
 101  * To decrease volume, output a low on the port pin (no need to
 102  * change pin mode to tristate) then output a high to go back to
 103  * tristate.
 104  */
 105 void set_beeper_volume (int steps)
 106 {
 107         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 108         int i;
 109
 110         if (steps >= 0) {
 111                 for (i = 0; i < (steps >= 64 ? 64 : steps); i++) {
 112                         immap->im_cpm.cp_pbodr &= ~(0x80000000 >> 19);
 113                         udelay (1);
 114                         immap->im_cpm.cp_pbodr |= (0x80000000 >> 19);
 115                         udelay (1);
 116                 }
 117         } else {
 118                 for (i = 0; i > (steps <= -64 ? -64 : steps); i--) {
 119                         immap->im_cpm.cp_pbdat &= ~(0x80000000 >> 19);
 120                         udelay (1);
 121                         immap->im_cpm.cp_pbdat |= (0x80000000 >> 19);
 122                         udelay (1);
 123                 }
 124         }
 125 }
 126
 127 /*
 128  * Check the environment to see if the beeper needs beeping.
 129  * Controlled by a sequence of the form:
 130  * freq/delta volume/on time/off time;... where:
 131  * freq                 = frequency in Hz (0 - 2500)
 132  * delta volume = volume steps up or down (-64 <= vol <= 64)
 133  * on time              = time in mS
 134  * off time             = time in mS
 135  *
 136  * Return 1 on success, 0 on failure
 137  */
 138 int do_beeper (char *sequence)
 139 {
 140 #define DELIMITER       ';'
 141
 142         int args[4];
 143         int i;
 144         int val;
 145         char *p = sequence;
 146         char *tp;
 147
 148         /*
 149          * Parse the control sequence.  This is a really simple parser
 150          * without any real error checking.  You can probably blow it
 151          * up really easily.
 152          */
 153         if (*p == '\0' || !isdigit (*p)) {
 154                 printf ("%s:%d: null or invalid string (%s)\n",
 155                         __FILE__, __LINE__, p);
 156                 return 0;
 157         }
 158
 159         i = 0;
 160         while (*p != '\0') {
 161                 while (*p != DELIMITER) {
 162                         if (i > 3)
 163                                 i = 0;
 164                         val = (int) simple_strtol (p, &tp, 0);
 165                         if (tp == p) {
 166                                 printf ("%s:%d: no digits or bad format\n",
 167                                         __FILE__, __LINE__);
 168                                 return 0;
 169                         } else {
 170                                 args[i] = val;
 171                         }
 172
 173                         i++;
 174                         if (*tp == DELIMITER)
 175                                 p = tp;
 176                         else
 177                                 p = ++tp;
 178                 }
 179                 p++;
 180
 181                 /*
 182                  * Well, we got something that has a chance of being correct
 183                  */
 184 #if 0
 185                 for (i = 0; i < 4; i++) {
 186                         printf ("%s:%d:arg %d = %d\n", __FILE__, __LINE__, i,
 187                                 args[i]);
 188                 }
 189                 printf ("\n");
 190 #endif
 191                 set_beeper_frequency (args[0]);
 192                 set_beeper_volume (args[1]);
 193                 beeper_on ();
 194                 udelay (1000 * args[2]);
 195                 beeper_off ();
 196                 udelay (1000 * args[3]);
 197         }
 198         return 1;
 199 }