linux/drivers/input/joystick/grip_mp.c
Erick Archer 4654c4cc79 Input: joystick - use sizeof(*pointer) instead of sizeof(type)
It is preferred to use sizeof(*pointer) instead of sizeof(type)
due to the type of the variable can change and one needs not
change the former (unlike the latter).

At the same time refactor the code to not use assignment in "if"
conditions.

This patch has no effect on runtime behavior.

Signed-off-by: Erick Archer <erick.archer@outlook.com>
Link: https://lore.kernel.org/r/AS8PR02MB7237FEA55FAC8A9453F2DA6F8BC42@AS8PR02MB7237.eurprd02.prod.outlook.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2024-06-09 14:38:43 -07:00

692 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for the Gravis Grip Multiport, a gamepad "hub" that
* connects up to four 9-pin digital gamepads/joysticks.
* Driver tested on SMP and UP kernel versions 2.4.18-4 and 2.4.18-5.
*
* Thanks to Chris Gassib for helpful advice.
*
* Copyright (c) 2002 Brian Bonnlander, Bill Soudan
* Copyright (c) 1998-2000 Vojtech Pavlik
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/gameport.h>
#include <linux/input.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/jiffies.h>
#define DRIVER_DESC "Gravis Grip Multiport driver"
MODULE_AUTHOR("Brian Bonnlander");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
#ifdef GRIP_DEBUG
#define dbg(format, arg...) printk(KERN_ERR __FILE__ ": " format "\n" , ## arg)
#else
#define dbg(format, arg...) do {} while (0)
#endif
#define GRIP_MAX_PORTS 4
/*
* Grip multiport state
*/
struct grip_port {
struct input_dev *dev;
int mode;
int registered;
/* individual gamepad states */
int buttons;
int xaxes;
int yaxes;
int dirty; /* has the state been updated? */
};
struct grip_mp {
struct gameport *gameport;
struct grip_port *port[GRIP_MAX_PORTS];
int reads;
int bads;
};
/*
* Multiport packet interpretation
*/
#define PACKET_FULL 0x80000000 /* packet is full */
#define PACKET_IO_FAST 0x40000000 /* 3 bits per gameport read */
#define PACKET_IO_SLOW 0x20000000 /* 1 bit per gameport read */
#define PACKET_MP_MORE 0x04000000 /* multiport wants to send more */
#define PACKET_MP_DONE 0x02000000 /* multiport done sending */
/*
* Packet status code interpretation
*/
#define IO_GOT_PACKET 0x0100 /* Got a packet */
#define IO_MODE_FAST 0x0200 /* Used 3 data bits per gameport read */
#define IO_SLOT_CHANGE 0x0800 /* Multiport physical slot status changed */
#define IO_DONE 0x1000 /* Multiport is done sending packets */
#define IO_RETRY 0x4000 /* Try again later to get packet */
#define IO_RESET 0x8000 /* Force multiport to resend all packets */
/*
* Gamepad configuration data. Other 9-pin digital joystick devices
* may work with the multiport, so this may not be an exhaustive list!
* Commodore 64 joystick remains untested.
*/
#define GRIP_INIT_DELAY 2000 /* 2 ms */
#define GRIP_MODE_NONE 0
#define GRIP_MODE_RESET 1
#define GRIP_MODE_GP 2
#define GRIP_MODE_C64 3
static const int grip_btn_gp[] = { BTN_TR, BTN_TL, BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, -1 };
static const int grip_btn_c64[] = { BTN_JOYSTICK, -1 };
static const int grip_abs_gp[] = { ABS_X, ABS_Y, -1 };
static const int grip_abs_c64[] = { ABS_X, ABS_Y, -1 };
static const int *grip_abs[] = { NULL, NULL, grip_abs_gp, grip_abs_c64 };
static const int *grip_btn[] = { NULL, NULL, grip_btn_gp, grip_btn_c64 };
static const char *grip_name[] = { NULL, NULL, "Gravis Grip Pad", "Commodore 64 Joystick" };
static const int init_seq[] = {
1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1,
1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1,
1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1,
0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1 };
/* Maps multiport directional values to X,Y axis values (each axis encoded in 3 bits) */
static const int axis_map[] = { 5, 9, 1, 5, 6, 10, 2, 6, 4, 8, 0, 4, 5, 9, 1, 5 };
static int register_slot(int i, struct grip_mp *grip);
/*
* Returns whether an odd or even number of bits are on in pkt.
*/
static int bit_parity(u32 pkt)
{
int x = pkt ^ (pkt >> 16);
x ^= x >> 8;
x ^= x >> 4;
x ^= x >> 2;
x ^= x >> 1;
return x & 1;
}
/*
* Poll gameport; return true if all bits set in 'onbits' are on and
* all bits set in 'offbits' are off.
*/
static inline int poll_until(u8 onbits, u8 offbits, int u_sec, struct gameport* gp, u8 *data)
{
int i, nloops;
nloops = gameport_time(gp, u_sec);
for (i = 0; i < nloops; i++) {
*data = gameport_read(gp);
if ((*data & onbits) == onbits &&
(~(*data) & offbits) == offbits)
return 1;
}
dbg("gameport timed out after %d microseconds.\n", u_sec);
return 0;
}
/*
* Gets a 28-bit packet from the multiport.
*
* After getting a packet successfully, commands encoded by sendcode may
* be sent to the multiport.
*
* The multiport clock value is reflected in gameport bit B4.
*
* Returns a packet status code indicating whether packet is valid, the transfer
* mode, and any error conditions.
*
* sendflags: current I/O status
* sendcode: data to send to the multiport if sendflags is nonzero
*/
static int mp_io(struct gameport* gameport, int sendflags, int sendcode, u32 *packet)
{
u8 raw_data; /* raw data from gameport */
u8 data_mask; /* packet data bits from raw_data */
u32 pkt; /* packet temporary storage */
int bits_per_read; /* num packet bits per gameport read */
int portvals = 0; /* used for port value sanity check */
int i;
/* Gameport bits B0, B4, B5 should first be off, then B4 should come on. */
*packet = 0;
raw_data = gameport_read(gameport);
if (raw_data & 1)
return IO_RETRY;
for (i = 0; i < 64; i++) {
raw_data = gameport_read(gameport);
portvals |= 1 << ((raw_data >> 4) & 3); /* Demux B4, B5 */
}
if (portvals == 1) { /* B4, B5 off */
raw_data = gameport_read(gameport);
portvals = raw_data & 0xf0;
if (raw_data & 0x31)
return IO_RESET;
gameport_trigger(gameport);
if (!poll_until(0x10, 0, 308, gameport, &raw_data))
return IO_RESET;
} else
return IO_RETRY;
/* Determine packet transfer mode and prepare for packet construction. */
if (raw_data & 0x20) { /* 3 data bits/read */
portvals |= raw_data >> 4; /* Compare B4-B7 before & after trigger */
if (portvals != 0xb)
return 0;
data_mask = 7;
bits_per_read = 3;
pkt = (PACKET_FULL | PACKET_IO_FAST) >> 28;
} else { /* 1 data bit/read */
data_mask = 1;
bits_per_read = 1;
pkt = (PACKET_FULL | PACKET_IO_SLOW) >> 28;
}
/* Construct a packet. Final data bits must be zero. */
while (1) {
if (!poll_until(0, 0x10, 77, gameport, &raw_data))
return IO_RESET;
raw_data = (raw_data >> 5) & data_mask;
if (pkt & PACKET_FULL)
break;
pkt = (pkt << bits_per_read) | raw_data;
if (!poll_until(0x10, 0, 77, gameport, &raw_data))
return IO_RESET;
}
if (raw_data)
return IO_RESET;
/* If 3 bits/read used, drop from 30 bits to 28. */
if (bits_per_read == 3) {
pkt = (pkt & 0xffff0000) | ((pkt << 1) & 0xffff);
pkt = (pkt >> 2) | 0xf0000000;
}
if (bit_parity(pkt) == 1)
return IO_RESET;
/* Acknowledge packet receipt */
if (!poll_until(0x30, 0, 77, gameport, &raw_data))
return IO_RESET;
raw_data = gameport_read(gameport);
if (raw_data & 1)
return IO_RESET;
gameport_trigger(gameport);
if (!poll_until(0, 0x20, 77, gameport, &raw_data))
return IO_RESET;
/* Return if we just wanted the packet or multiport wants to send more */
*packet = pkt;
if ((sendflags == 0) || ((sendflags & IO_RETRY) && !(pkt & PACKET_MP_DONE)))
return IO_GOT_PACKET;
if (pkt & PACKET_MP_MORE)
return IO_GOT_PACKET | IO_RETRY;
/* Multiport is done sending packets and is ready to receive data */
if (!poll_until(0x20, 0, 77, gameport, &raw_data))
return IO_GOT_PACKET | IO_RESET;
raw_data = gameport_read(gameport);
if (raw_data & 1)
return IO_GOT_PACKET | IO_RESET;
/* Trigger gameport based on bits in sendcode */
gameport_trigger(gameport);
do {
if (!poll_until(0x20, 0x10, 116, gameport, &raw_data))
return IO_GOT_PACKET | IO_RESET;
if (!poll_until(0x30, 0, 193, gameport, &raw_data))
return IO_GOT_PACKET | IO_RESET;
if (raw_data & 1)
return IO_GOT_PACKET | IO_RESET;
if (sendcode & 1)
gameport_trigger(gameport);
sendcode >>= 1;
} while (sendcode);
return IO_GOT_PACKET | IO_MODE_FAST;
}
/*
* Disables and restores interrupts for mp_io(), which does the actual I/O.
*/
static int multiport_io(struct gameport* gameport, int sendflags, int sendcode, u32 *packet)
{
int status;
unsigned long flags;
local_irq_save(flags);
status = mp_io(gameport, sendflags, sendcode, packet);
local_irq_restore(flags);
return status;
}
/*
* Puts multiport into digital mode. Multiport LED turns green.
*
* Returns true if a valid digital packet was received, false otherwise.
*/
static int dig_mode_start(struct gameport *gameport, u32 *packet)
{
int i;
int flags, tries = 0, bads = 0;
for (i = 0; i < ARRAY_SIZE(init_seq); i++) { /* Send magic sequence */
if (init_seq[i])
gameport_trigger(gameport);
udelay(GRIP_INIT_DELAY);
}
for (i = 0; i < 16; i++) /* Wait for multiport to settle */
udelay(GRIP_INIT_DELAY);
while (tries < 64 && bads < 8) { /* Reset multiport and try getting a packet */
flags = multiport_io(gameport, IO_RESET, 0x27, packet);
if (flags & IO_MODE_FAST)
return 1;
if (flags & IO_RETRY)
tries++;
else
bads++;
}
return 0;
}
/*
* Packet structure: B0-B15 => gamepad state
* B16-B20 => gamepad device type
* B21-B24 => multiport slot index (1-4)
*
* Known device types: 0x1f (grip pad), 0x0 (no device). Others may exist.
*
* Returns the packet status.
*/
static int get_and_decode_packet(struct grip_mp *grip, int flags)
{
struct grip_port *port;
u32 packet;
int joytype = 0;
int slot;
/* Get a packet and check for validity */
flags &= IO_RESET | IO_RETRY;
flags = multiport_io(grip->gameport, flags, 0, &packet);
grip->reads++;
if (packet & PACKET_MP_DONE)
flags |= IO_DONE;
if (flags && !(flags & IO_GOT_PACKET)) {
grip->bads++;
return flags;
}
/* Ignore non-gamepad packets, e.g. multiport hardware version */
slot = ((packet >> 21) & 0xf) - 1;
if ((slot < 0) || (slot > 3))
return flags;
port = grip->port[slot];
/*
* Handle "reset" packets, which occur at startup, and when gamepads
* are removed or plugged in. May contain configuration of a new gamepad.
*/
joytype = (packet >> 16) & 0x1f;
if (!joytype) {
if (port->registered) {
printk(KERN_INFO "grip_mp: removing %s, slot %d\n",
grip_name[port->mode], slot);
input_unregister_device(port->dev);
port->registered = 0;
}
dbg("Reset: grip multiport slot %d\n", slot);
port->mode = GRIP_MODE_RESET;
flags |= IO_SLOT_CHANGE;
return flags;
}
/* Interpret a grip pad packet */
if (joytype == 0x1f) {
int dir = (packet >> 8) & 0xf; /* eight way directional value */
port->buttons = (~packet) & 0xff;
port->yaxes = ((axis_map[dir] >> 2) & 3) - 1;
port->xaxes = (axis_map[dir] & 3) - 1;
port->dirty = 1;
if (port->mode == GRIP_MODE_RESET)
flags |= IO_SLOT_CHANGE;
port->mode = GRIP_MODE_GP;
if (!port->registered) {
dbg("New Grip pad in multiport slot %d.\n", slot);
if (register_slot(slot, grip)) {
port->mode = GRIP_MODE_RESET;
port->dirty = 0;
}
}
return flags;
}
/* Handle non-grip device codes. For now, just print diagnostics. */
{
static int strange_code = 0;
if (strange_code != joytype) {
printk(KERN_INFO "Possible non-grip pad/joystick detected.\n");
printk(KERN_INFO "Got joy type 0x%x and packet 0x%x.\n", joytype, packet);
strange_code = joytype;
}
}
return flags;
}
/*
* Returns true if all multiport slot states appear valid.
*/
static int slots_valid(struct grip_mp *grip)
{
int flags, slot, invalid = 0, active = 0;
flags = get_and_decode_packet(grip, 0);
if (!(flags & IO_GOT_PACKET))
return 0;
for (slot = 0; slot < 4; slot++) {
if (grip->port[slot]->mode == GRIP_MODE_RESET)
invalid = 1;
if (grip->port[slot]->mode != GRIP_MODE_NONE)
active = 1;
}
/* Return true if no active slot but multiport sent all its data */
if (!active)
return (flags & IO_DONE) ? 1 : 0;
/* Return false if invalid device code received */
return invalid ? 0 : 1;
}
/*
* Returns whether the multiport was placed into digital mode and
* able to communicate its state successfully.
*/
static int multiport_init(struct grip_mp *grip)
{
int dig_mode, initialized = 0, tries = 0;
u32 packet;
dig_mode = dig_mode_start(grip->gameport, &packet);
while (!dig_mode && tries < 4) {
dig_mode = dig_mode_start(grip->gameport, &packet);
tries++;
}
if (dig_mode)
dbg("multiport_init(): digital mode activated.\n");
else {
dbg("multiport_init(): unable to activate digital mode.\n");
return 0;
}
/* Get packets, store multiport state, and check state's validity */
for (tries = 0; tries < 4096; tries++) {
if (slots_valid(grip)) {
initialized = 1;
break;
}
}
dbg("multiport_init(): initialized == %d\n", initialized);
return initialized;
}
/*
* Reports joystick state to the linux input layer.
*/
static void report_slot(struct grip_mp *grip, int slot)
{
struct grip_port *port = grip->port[slot];
int i;
/* Store button states with linux input driver */
for (i = 0; i < 8; i++)
input_report_key(port->dev, grip_btn_gp[i], (port->buttons >> i) & 1);
/* Store axis states with linux driver */
input_report_abs(port->dev, ABS_X, port->xaxes);
input_report_abs(port->dev, ABS_Y, port->yaxes);
/* Tell the receiver of the events to process them */
input_sync(port->dev);
port->dirty = 0;
}
/*
* Get the multiport state.
*/
static void grip_poll(struct gameport *gameport)
{
struct grip_mp *grip = gameport_get_drvdata(gameport);
int i, npkts, flags;
for (npkts = 0; npkts < 4; npkts++) {
flags = IO_RETRY;
for (i = 0; i < 32; i++) {
flags = get_and_decode_packet(grip, flags);
if ((flags & IO_GOT_PACKET) || !(flags & IO_RETRY))
break;
}
if (flags & IO_DONE)
break;
}
for (i = 0; i < 4; i++)
if (grip->port[i]->dirty)
report_slot(grip, i);
}
/*
* Called when a joystick device file is opened
*/
static int grip_open(struct input_dev *dev)
{
struct grip_mp *grip = input_get_drvdata(dev);
gameport_start_polling(grip->gameport);
return 0;
}
/*
* Called when a joystick device file is closed
*/
static void grip_close(struct input_dev *dev)
{
struct grip_mp *grip = input_get_drvdata(dev);
gameport_stop_polling(grip->gameport);
}
/*
* Tell the linux input layer about a newly plugged-in gamepad.
*/
static int register_slot(int slot, struct grip_mp *grip)
{
struct grip_port *port = grip->port[slot];
struct input_dev *input_dev;
int j, t;
int err;
port->dev = input_dev = input_allocate_device();
if (!input_dev)
return -ENOMEM;
input_dev->name = grip_name[port->mode];
input_dev->id.bustype = BUS_GAMEPORT;
input_dev->id.vendor = GAMEPORT_ID_VENDOR_GRAVIS;
input_dev->id.product = 0x0100 + port->mode;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &grip->gameport->dev;
input_set_drvdata(input_dev, grip);
input_dev->open = grip_open;
input_dev->close = grip_close;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
for (j = 0; (t = grip_abs[port->mode][j]) >= 0; j++)
input_set_abs_params(input_dev, t, -1, 1, 0, 0);
for (j = 0; (t = grip_btn[port->mode][j]) >= 0; j++)
if (t > 0)
set_bit(t, input_dev->keybit);
err = input_register_device(port->dev);
if (err) {
input_free_device(port->dev);
return err;
}
port->registered = 1;
if (port->dirty) /* report initial state, if any */
report_slot(grip, slot);
return 0;
}
static int grip_connect(struct gameport *gameport, struct gameport_driver *drv)
{
struct grip_mp *grip;
int err;
grip = kzalloc(sizeof(*grip), GFP_KERNEL);
if (!grip)
return -ENOMEM;
grip->gameport = gameport;
gameport_set_drvdata(gameport, grip);
err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
if (err)
goto fail1;
gameport_set_poll_handler(gameport, grip_poll);
gameport_set_poll_interval(gameport, 20);
if (!multiport_init(grip)) {
err = -ENODEV;
goto fail2;
}
if (!grip->port[0]->mode && !grip->port[1]->mode && !grip->port[2]->mode && !grip->port[3]->mode) {
/* nothing plugged in */
err = -ENODEV;
goto fail2;
}
return 0;
fail2: gameport_close(gameport);
fail1: gameport_set_drvdata(gameport, NULL);
kfree(grip);
return err;
}
static void grip_disconnect(struct gameport *gameport)
{
struct grip_mp *grip = gameport_get_drvdata(gameport);
int i;
for (i = 0; i < 4; i++)
if (grip->port[i]->registered)
input_unregister_device(grip->port[i]->dev);
gameport_close(gameport);
gameport_set_drvdata(gameport, NULL);
kfree(grip);
}
static struct gameport_driver grip_drv = {
.driver = {
.name = "grip_mp",
},
.description = DRIVER_DESC,
.connect = grip_connect,
.disconnect = grip_disconnect,
};
module_gameport_driver(grip_drv);