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/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <arch/io.h>
#include <console/spkmodem.h>
#include <cpu/x86/tsc.h>
#define SPEAKER_PIT_FREQUENCY 0x1234dd
enum {
PIT_COUNTER_0 = 0x40,
PIT_COUNTER_1 = 0x41,
PIT_COUNTER_2 = 0x42,
PIT_CTRL = 0x43,
PIT_SPEAKER_PORT = 0x61,
};
enum {
PIT_SPK_TMR2 = 0x01,
PIT_SPK_DATA = 0x02,
PIT_SPK_TMR2_LATCH = 0x20
};
enum {
PIT_CTRL_SELECT_MASK = 0xc0,
PIT_CTRL_SELECT_0 = 0x00,
PIT_CTRL_SELECT_1 = 0x40,
PIT_CTRL_SELECT_2 = 0x80,
PIT_CTRL_READLOAD_MASK = 0x30,
PIT_CTRL_COUNTER_LATCH = 0x00,
PIT_CTRL_READLOAD_LSB = 0x10,
PIT_CTRL_READLOAD_MSB = 0x20,
PIT_CTRL_READLOAD_WORD = 0x30,
PIT_CTRL_MODE_MASK = 0x0e,
PIT_CTRL_INTR_ON_TERM = 0x00,
PIT_CTRL_PROGR_ONE_SHOT = 0x02,
PIT_CTRL_RATE_GEN = 0x04,
PIT_CTRL_SQUAREWAVE_GEN = 0x06,
PIT_CTRL_SOFTSTROBE = 0x08,
PIT_CTRL_HARDSTROBE = 0x0a,
PIT_CTRL_COUNT_MASK = 0x01,
PIT_CTRL_COUNT_BINARY = 0x00,
PIT_CTRL_COUNT_BCD = 0x01
};
static void
make_tone(uint16_t freq_count, unsigned int duration)
{
outb(PIT_CTRL_SELECT_2
| PIT_CTRL_READLOAD_WORD
| PIT_CTRL_SQUAREWAVE_GEN
| PIT_CTRL_COUNT_BINARY, PIT_CTRL);
outb(freq_count & 0xff, PIT_COUNTER_2);
outb((freq_count >> 8) & 0xff, PIT_COUNTER_2);
outb(inb(PIT_SPEAKER_PORT)
| PIT_SPK_TMR2 | PIT_SPK_DATA,
PIT_SPEAKER_PORT);
for (; duration; duration--) {
unsigned short counter, previous_counter = 0xffff;
while (1) {
counter = inb(PIT_COUNTER_2);
counter |= ((uint16_t)inb(PIT_COUNTER_2)) << 8;
if (counter > previous_counter) {
previous_counter = counter;
break;
}
previous_counter = counter;
}
}
}
void spkmodem_tx_byte(unsigned char c)
{
int i;
make_tone(SPEAKER_PIT_FREQUENCY / 200, 4);
for (i = 7; i >= 0; i--) {
if ((c >> i) & 1)
make_tone(SPEAKER_PIT_FREQUENCY / 2000, 20);
else
make_tone(SPEAKER_PIT_FREQUENCY / 4000, 40);
make_tone(SPEAKER_PIT_FREQUENCY / 1000, 10);
}
make_tone(SPEAKER_PIT_FREQUENCY / 200, 0);
}
void spkmodem_init(void)
{
/* Some cards need time to come online.
* Output some message to get it started.
*/
spkmodem_tx_byte('S');
spkmodem_tx_byte('P');
spkmodem_tx_byte('K');
spkmodem_tx_byte('\r');
spkmodem_tx_byte('\n');
}
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