board/gen860t/beeper.c

   1 /*
   2  * (C) Copyright 2002
   3  * Keith Outwater, keith_outwater@mvis.com
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <mpc8xx.h>
  10 #include <asm/8xx_immap.h>
  11 #include <linux/ctype.h>
  12
  13 /*
  14  * Basic beeper support for the GEN860T board.  The GEN860T includes
  15  * an audio sounder driven by a Phillips TDA8551 amplifier.  The
  16  * TDA8551 features a digital volume control which uses a "trinary"
  17  * input (high/high-Z/low) to set volume.  The 860's SPKROUT pin
  18  * drives the amplifier input.
  19  */
  20
  21 /*
  22  * Initialize beeper-related hardware. Initialize timer 1 for use with
  23  * the beeper. Use 66 MHz internal clock with prescale of 33 to get
  24  * 1 uS period per count.
  25  * FIXME: we should really compute the prescale based on the reported
  26  * core clock frequency.
  27  */
  28 void init_beeper (void)
  29 {
  30         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  31
  32         immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_RST1 | TGCR_STP1;
  33         immap->im_cpmtimer.cpmt_tmr1 = ((33 << TMR_PS_SHIFT) & TMR_PS_MSK)
  34                 | TMR_OM | TMR_FRR | TMR_ICLK_IN_GEN;
  35         immap->im_cpmtimer.cpmt_tcn1 = 0;
  36         immap->im_cpmtimer.cpmt_ter1 = 0xffff;
  37         immap->im_cpmtimer.cpmt_tgcr |= TGCR_RST1;
  38 }
  39
  40 /*
  41  * Set beeper frequency.  Max allowed frequency is 2.5 KHz.  This limit
  42  * is mostly arbitrary, but the beeper isn't really much good beyond this
  43  * frequency.
  44  */
  45 void set_beeper_frequency (uint frequency)
  46 {
  47 #define FREQ_LIMIT      2500
  48
  49         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  50
  51         /*
  52          * Compute timer ticks given desired frequency.  The timer is set up
  53          * to count 0.5 uS per tick and it takes two ticks per cycle (Hz).
  54          */
  55         if (frequency > FREQ_LIMIT)
  56                 frequency = FREQ_LIMIT;
  57         frequency = 1000000 / frequency;
  58         immap->im_cpmtimer.cpmt_trr1 = (ushort) frequency;
  59 }
  60
  61 /*
  62  * Turn the beeper on
  63  */
  64 void beeper_on (void)
  65 {
  66         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  67
  68         immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_STP1;
  69 }
  70
  71 /*
  72  * Turn the beeper off
  73  */
  74 void beeper_off (void)
  75 {
  76         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  77
  78         immap->im_cpmtimer.cpmt_tgcr |= TGCR_STP1;
  79 }
  80
  81 /*
  82  * Increase or decrease the beeper volume.  Volume can be set
  83  * from off to full in 64 steps.  To increase volume, the output
  84  * pin is actively driven high, then returned to tristate.
  85  * To decrease volume, output a low on the port pin (no need to
  86  * change pin mode to tristate) then output a high to go back to
  87  * tristate.
  88  */
  89 void set_beeper_volume (int steps)
  90 {
  91         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  92         int i;
  93
  94         if (steps >= 0) {
  95                 for (i = 0; i < (steps >= 64 ? 64 : steps); i++) {
  96                         immap->im_cpm.cp_pbodr &= ~(0x80000000 >> 19);
  97                         udelay (1);
  98                         immap->im_cpm.cp_pbodr |= (0x80000000 >> 19);
  99                         udelay (1);
 100                 }
 101         } else {
 102                 for (i = 0; i > (steps <= -64 ? -64 : steps); i--) {
 103                         immap->im_cpm.cp_pbdat &= ~(0x80000000 >> 19);
 104                         udelay (1);
 105                         immap->im_cpm.cp_pbdat |= (0x80000000 >> 19);
 106                         udelay (1);
 107                 }
 108         }
 109 }
 110
 111 /*
 112  * Check the environment to see if the beeper needs beeping.
 113  * Controlled by a sequence of the form:
 114  * freq/delta volume/on time/off time;... where:
 115  * freq                 = frequency in Hz (0 - 2500)
 116  * delta volume = volume steps up or down (-64 <= vol <= 64)
 117  * on time              = time in mS
 118  * off time             = time in mS
 119  *
 120  * Return 1 on success, 0 on failure
 121  */
 122 int do_beeper (char *sequence)
 123 {
 124 #define DELIMITER       ';'
 125
 126         int args[4];
 127         int i;
 128         int val;
 129         char *p = sequence;
 130         char *tp;
 131
 132         /*
 133          * Parse the control sequence.  This is a really simple parser
 134          * without any real error checking.  You can probably blow it
 135          * up really easily.
 136          */
 137         if (*p == '\0' || !isdigit (*p)) {
 138                 printf ("%s:%d: null or invalid string (%s)\n",
 139                         __FILE__, __LINE__, p);
 140                 return 0;
 141         }
 142
 143         i = 0;
 144         while (*p != '\0') {
 145                 while (*p != DELIMITER) {
 146                         if (i > 3)
 147                                 i = 0;
 148                         val = (int) simple_strtol (p, &tp, 0);
 149                         if (tp == p) {
 150                                 printf ("%s:%d: no digits or bad format\n",
 151                                         __FILE__, __LINE__);
 152                                 return 0;
 153                         } else {
 154                                 args[i] = val;
 155                         }
 156
 157                         i++;
 158                         if (*tp == DELIMITER)
 159                                 p = tp;
 160                         else
 161                                 p = ++tp;
 162                 }
 163                 p++;
 164
 165                 /*
 166                  * Well, we got something that has a chance of being correct
 167                  */
 168 #if 0
 169                 for (i = 0; i < 4; i++) {
 170                         printf ("%s:%d:arg %d = %d\n", __FILE__, __LINE__, i,
 171                                 args[i]);
 172                 }
 173                 printf ("\n");
 174 #endif
 175                 set_beeper_frequency (args[0]);
 176                 set_beeper_volume (args[1]);
 177                 beeper_on ();
 178                 udelay (1000 * args[2]);
 179                 beeper_off ();
 180                 udelay (1000 * args[3]);
 181         }
 182         return 1;
 183 }