u-boot/board/gen860t/beeper.c

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2002-11-03 00:24:07 +00:00
/*
* (C) Copyright 2002
* Keith Outwater, keith_outwater@mvis.com
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <mpc8xx.h>
#include <asm/8xx_immap.h>
#include <linux/ctype.h>
/*
* Basic beeper support for the GEN860T board. The GEN860T includes
* an audio sounder driven by a Phillips TDA8551 amplifier. The
* TDA8551 features a digital volume control which uses a "trinary"
* input (high/high-Z/low) to set volume. The 860's SPKROUT pin
* drives the amplifier input.
*/
/*
* Initialize beeper-related hardware. Initialize timer 1 for use with
* the beeper. Use 66 Mhz internal clock with prescale of 33 to get
* 1 uS period per count.
* FIXME: we should really compute the prescale based on the reported
* core clock frequency.
*/
void
init_beeper(void)
{
volatile immap_t *immap = (immap_t *)CFG_IMMR;
immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_RST1 | TGCR_STP1;
immap->im_cpmtimer.cpmt_tmr1 = ((33 << TMR_PS_SHIFT) & TMR_PS_MSK)
| TMR_OM | TMR_FRR | TMR_ICLK_IN_GEN;
immap->im_cpmtimer.cpmt_tcn1 = 0;
immap->im_cpmtimer.cpmt_ter1 = 0xffff;
immap->im_cpmtimer.cpmt_tgcr |= TGCR_RST1;
}
/*
* Set beeper frequency. Max allowed frequency is 2.5 KHz. This limit
* is mostly arbitrary, but the beeper isn't really much good beyond this
* frequency.
*/
void
set_beeper_frequency(uint frequency)
{
#define FREQ_LIMIT 2500
volatile immap_t *immap = (immap_t *)CFG_IMMR;
/*
* Compute timer ticks given desired frequency. The timer is set up
* to count 0.5 uS per tick and it takes two ticks per cycle (Hz).
*/
if (frequency > FREQ_LIMIT) frequency = FREQ_LIMIT;
frequency = 1000000/frequency;
immap->im_cpmtimer.cpmt_trr1 = (ushort)frequency;
}
/*
* Turn the beeper on
*/
void
beeper_on(void)
{
volatile immap_t *immap = (immap_t *)CFG_IMMR;
immap->im_cpmtimer.cpmt_tgcr &= ~TGCR_STP1;
}
/*
* Turn the beeper off
*/
void
beeper_off(void)
{
volatile immap_t *immap = (immap_t *)CFG_IMMR;
immap->im_cpmtimer.cpmt_tgcr |= TGCR_STP1;
}
/*
* Increase or decrease the beeper volume. Volume can be set
* from off to full in 64 steps. To increase volume, the output
* pin is actively driven high, then returned to tristate.
* To decrease volume, output a low on the port pin (no need to
* change pin mode to tristate) then output a high to go back to
* tristate.
*/
void
set_beeper_volume(int steps)
{
volatile immap_t *immap = (immap_t *)CFG_IMMR;
int i;
if (steps >= 0) {
for (i = 0; i < (steps >= 64 ? 64 : steps); i++) {
immap->im_cpm.cp_pbodr &= ~(0x80000000 >> 19);
udelay(1);
immap->im_cpm.cp_pbodr |= (0x80000000 >> 19);
udelay(1);
}
}
else {
for (i = 0; i > (steps <= -64 ? -64 : steps); i--) {
immap->im_cpm.cp_pbdat &= ~(0x80000000 >> 19);
udelay(1);
immap->im_cpm.cp_pbdat |= (0x80000000 >> 19);
udelay(1);
}
}
}
/*
* Check the environment to see if the beeper needs beeping.
* Controlled by a sequence of the form:
* freq/delta volume/on time/off time;... where:
* freq = frequency in Hz (0 - 2500)
* delta volume = volume steps up or down (-64 <= vol <= 64)
* on time = time in mS
* off time = time in mS
*
* Return 1 on success, 0 on failure
*/
int
do_beeper(char *sequence)
{
#define DELIMITER ';'
int args[4];
int i;
int val;
char *p = sequence;
char *tp;
/*
* Parse the control sequence. This is a really simple parser
* without any real error checking. You can probably blow it
* up really easily.
*/
if (*p == '\0' || !isdigit(*p)) {
printf("%s:%d: null or invalid string (%s)\n",
__FILE__, __LINE__, p);
return 0;
}
i = 0;
while (*p != '\0') {
while (*p != DELIMITER) {
if (i > 3) i = 0;
val = (int) simple_strtol(p, &tp, 0);
if (tp == p) {
printf("%s:%d: no digits or bad format\n",
__FILE__,__LINE__);
return 0;
}
else {
args[i] = val;
}
i++;
if (*tp == DELIMITER)
p = tp;
else
p = ++tp;
}
p++;
/*
* Well, we got something that has a chance of being correct
*/
#if 0
for (i = 0; i < 4; i++) {
printf("%s:%d:arg %d = %d\n", __FILE__, __LINE__, i, args[i]);
}
printf("\n");
#endif
set_beeper_frequency(args[0]);
set_beeper_volume(args[1]);
beeper_on();
udelay(1000 * args[2]);
beeper_off();
udelay(1000 * args[3]);
}
return 1;
}
/* vim: set ts=4 sw=4 tw=78: */