Files
86Box/src/joystick_sw_pad.c

251 lines
7.3 KiB
C

/*Sidewinder game pad notes :
- Write to 0x201 starts packet transfer (5*N or 15*N bits)
- Currently alternates between Mode A and Mode B (is there any way of
actually controlling which is used?)
- Windows 9x drivers require Mode B when more than 1 pad connected
- Packet preceeded by high data (currently 50us), and followed by low
data (currently 160us) - timings are probably wrong, but good enough
for everything I've tried
- Analogue inputs are only used to time ID packet request. If A0 timing
out is followed after ~64us by another 0x201 write then an ID packet
is triggered
- Sidewinder game pad ID is 'H0003'
- ID is sent in Mode A (1 bit per clock), but data bit 2 must change
during ID packet transfer, or Windows 9x drivers won't use Mode B. I
don't know if it oscillates, mirrors the data transfer, or something
else - the drivers only check that it changes at least 10 times during
the transfer
- Some DOS stuff will write to 0x201 while a packet is being transferred.
This seems to be ignored.
*/
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "timer.h"
#include "gameport.h"
#include "joystick_sw_pad.h"
#include "plat_joystick.h"
typedef struct
{
int poll_time;
int poll_left;
int poll_clock;
uint64_t poll_data;
int poll_mode;
int trigger_time;
int data_mode;
} sw_data;
static void sw_timer_over(void *p)
{
sw_data *sw = (sw_data *)p;
while (sw->poll_time <= 0 && sw->poll_left)
{
sw->poll_clock = !sw->poll_clock;
if (sw->poll_clock)
{
sw->poll_data >>= (sw->poll_mode ? 3 : 1);
sw->poll_left--;
}
if (sw->poll_left == 1 && !sw->poll_clock)
sw->poll_time += TIMER_USEC * 160;
else if (sw->poll_left)
sw->poll_time += TIMER_USEC * 5;
else
sw->poll_time = 0;
}
if (!sw->poll_left)
sw->poll_time = 0;
}
static void sw_trigger_timer_over(void *p)
{
sw_data *sw = (sw_data *)p;
sw->trigger_time = 0;
}
static int sw_parity(uint16_t data)
{
int bits_set = 0;
while (data)
{
bits_set++;
data &= (data - 1);
}
return bits_set & 1;
}
static void *sw_init()
{
sw_data *sw = (sw_data *)malloc(sizeof(sw_data));
memset(sw, 0, sizeof(sw_data));
timer_add(sw_timer_over, &sw->poll_time, &sw->poll_time, sw);
timer_add(sw_trigger_timer_over, &sw->trigger_time, &sw->trigger_time, sw);
return sw;
}
static void sw_close(void *p)
{
sw_data *sw = (sw_data *)p;
free(sw);
}
static uint8_t sw_read(void *p)
{
sw_data *sw = (sw_data *)p;
uint8_t temp = 0;
if (!JOYSTICK_PRESENT(0))
return 0xff;
if (sw->poll_time)
{
if (sw->poll_clock)
temp |= 0x10;
if (sw->poll_mode)
temp |= (sw->poll_data & 7) << 5;
else
{
temp |= ((sw->poll_data & 1) << 5) | 0xc0;
if (sw->poll_left > 31 && !(sw->poll_left & 1))
temp &= ~0x80;
}
}
else
temp |= 0xf0;
return temp;
}
static void sw_write(void *p)
{
sw_data *sw = (sw_data *)p;
int time_since_last = sw->trigger_time / TIMER_USEC;
if (!JOYSTICK_PRESENT(0))
return;
timer_process();
if (!sw->poll_left)
{
sw->poll_clock = 1;
sw->poll_time = TIMER_USEC * 50;
if (time_since_last > 9900 && time_since_last < 9940)
{
sw->poll_mode = 0;
sw->poll_left = 49;
sw->poll_data = 0x2400ull | (0x1830ull << 15) | (0x19b0ull << 30);
}
else
{
int c;
sw->poll_mode = sw->data_mode;
sw->data_mode = !sw->data_mode;
if (sw->poll_mode)
{
sw->poll_left = 1;
sw->poll_data = 7;
}
else
{
sw->poll_left = 1;
sw->poll_data = 1;
}
for (c = 0; c < 4; c++)
{
uint64_t data = 0x3fff;
int b;
if (!JOYSTICK_PRESENT(c))
break;
if (joystick_state[c].axis[1] < -16383)
data &= ~1;
if (joystick_state[c].axis[1] > 16383)
data &= ~2;
if (joystick_state[c].axis[0] > 16383)
data &= ~4;
if (joystick_state[c].axis[0] < -16383)
data &= ~8;
for (b = 0; b < 10; b++)
{
if (joystick_state[c].button[b])
data &= ~(1 << (b + 4));
}
if (sw_parity(data))
data |= 0x4000;
if (sw->poll_mode)
{
sw->poll_left += 5;
sw->poll_data |= (data << (c*15 + 3));
}
else
{
sw->poll_left += 15;
sw->poll_data |= (data << (c*15 + 1));
}
}
}
}
sw->trigger_time = 0;
timer_update_outstanding();
}
static int sw_read_axis(void *p, int axis)
{
if (!JOYSTICK_PRESENT(0))
return AXIS_NOT_PRESENT;
return 0; /*No analogue support on Sidewinder game pad*/
}
static void sw_a0_over(void *p)
{
sw_data *sw = (sw_data *)p;
sw->trigger_time = TIMER_USEC * 10000;
}
joystick_if_t joystick_sw_pad =
{
"Microsoft SideWinder Pad",
sw_init,
sw_close,
sw_read,
sw_write,
sw_read_axis,
sw_a0_over,
4,
2,
10,
0,
{"X axis", "Y axis"},
{"A", "B", "C", "X", "Y", "Z", "L", "R", "Start", "M"}
};