cregit-Linux how code gets into the kernel

Release 4.11 drivers/input/joystick/sidewinder.c

/*
 *  Copyright (c) 1998-2005 Vojtech Pavlik
 */

/*
 * Microsoft SideWinder joystick family driver for Linux
 */

/*
 * 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
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/gameport.h>
#include <linux/jiffies.h>


#define DRIVER_DESC	"Microsoft SideWinder joystick family driver"

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * These are really magic values. Changing them can make a problem go away,
 * as well as break everything.
 */


#undef SW_DEBUG

#undef SW_DEBUG_DATA


#define SW_START	600	
/* The time we wait for the first bit [600 us] */

#define SW_STROBE	60	
/* Max time per bit [60 us] */

#define SW_TIMEOUT	6	
/* Wait for everything to settle [6 ms] */

#define SW_KICK		45	
/* Wait after A0 fall till kick [45 us] */

#define SW_END		8	
/* Number of bits before end of packet to kick */

#define SW_FAIL		16	
/* Number of packet read errors to fail and reinitialize */

#define SW_BAD		2	
/* Number of packet read errors to switch off 3d Pro optimization */

#define SW_OK		64	
/* Number of packet read successes to switch optimization back on */

#define SW_LENGTH	512	
/* Max number of bits in a packet */

#ifdef SW_DEBUG

#define dbg(format, arg...) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg)
#else

#define dbg(format, arg...) do {} while (0)
#endif

/*
 * SideWinder joystick types ...
 */


#define SW_ID_3DP	0

#define SW_ID_GP	1

#define SW_ID_PP	2

#define SW_ID_FFP	3

#define SW_ID_FSP	4

#define SW_ID_FFW	5

/*
 * Names, buttons, axes ...
 */


static char *sw_name[] = {	"3D Pro", "GamePad", "Precision Pro", "Force Feedback Pro", "FreeStyle Pro",
				"Force Feedback Wheel" };


static char sw_abs[][7] = {
	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
	{ ABS_X, ABS_Y },
	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
	{ ABS_X, ABS_Y, ABS_RZ, ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
	{ ABS_X, ABS_Y,         ABS_THROTTLE, ABS_HAT0X, ABS_HAT0Y },
	{ ABS_RX, ABS_RUDDER,   ABS_THROTTLE }};


static char sw_bit[][7] = {
	{ 10, 10,  9, 10,  1,  1 },
	{  1,  1                 },
	{ 10, 10,  6,  7,  1,  1 },
	{ 10, 10,  6,  7,  1,  1 },
	{ 10, 10,  6,  1,  1     },
	{ 10,  7,  7,  1,  1     }};


static short sw_btn[][12] = {
	{ BTN_TRIGGER, BTN_TOP, BTN_THUMB, BTN_THUMB2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_MODE },
	{ BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_START, BTN_MODE },
	{ BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_SELECT },
	{ BTN_TRIGGER, BTN_THUMB, BTN_TOP, BTN_TOP2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4, BTN_SELECT },
	{ BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_START, BTN_MODE, BTN_SELECT },
	{ BTN_TRIGGER, BTN_TOP, BTN_THUMB, BTN_THUMB2, BTN_BASE, BTN_BASE2, BTN_BASE3, BTN_BASE4 }};

static struct {
	
int x;
	
int y;
} 
sw_hat_to_axis[] = {{ 0, 0}, { 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};


struct sw {
	
struct gameport *gameport;
	
struct input_dev *dev[4];
	
char name[64];
	
char phys[4][32];
	
int length;
	
int type;
	
int bits;
	
int number;
	
int fail;
	
int ok;
	
int reads;
	
int bads;
};

/*
 * sw_read_packet() is a function which reads either a data packet, or an
 * identification packet from a SideWinder joystick. The protocol is very,
 * very, very braindamaged. Microsoft patented it in US patent #5628686.
 */


static int sw_read_packet(struct gameport *gameport, unsigned char *buf, int length, int id) { unsigned long flags; int timeout, bitout, sched, i, kick, start, strobe; unsigned char pending, u, v; i = -id; /* Don't care about data, only want ID */ timeout = id ? gameport_time(gameport, SW_TIMEOUT * 1000) : 0; /* Set up global timeout for ID packet */ kick = id ? gameport_time(gameport, SW_KICK) : 0; /* Set up kick timeout for ID packet */ start = gameport_time(gameport, SW_START); strobe = gameport_time(gameport, SW_STROBE); bitout = start; pending = 0; sched = 0; local_irq_save(flags); /* Quiet, please */ gameport_trigger(gameport); /* Trigger */ v = gameport_read(gameport); do { bitout--; u = v; v = gameport_read(gameport); } while (!(~v & u & 0x10) && (bitout > 0)); /* Wait for first falling edge on clock */ if (bitout > 0) bitout = strobe; /* Extend time if not timed out */ while ((timeout > 0 || bitout > 0) && (i < length)) { timeout--; bitout--; /* Decrement timers */ sched--; u = v; v = gameport_read(gameport); if ((~u & v & 0x10) && (bitout > 0)) { /* Rising edge on clock - data bit */ if (i >= 0) /* Want this data */ buf[i] = v >> 5; /* Store it */ i++; /* Advance index */ bitout = strobe; /* Extend timeout for next bit */ } if (kick && (~v & u & 0x01)) { /* Falling edge on axis 0 */ sched = kick; /* Schedule second trigger */ kick = 0; /* Don't schedule next time on falling edge */ pending = 1; /* Mark schedule */ } if (pending && sched < 0 && (i > -SW_END)) { /* Second trigger time */ gameport_trigger(gameport); /* Trigger */ bitout = start; /* Long bit timeout */ pending = 0; /* Unmark schedule */ timeout = 0; /* Switch from global to bit timeouts */ } } local_irq_restore(flags); /* Done - relax */ #ifdef SW_DEBUG_DATA { int j; printk(KERN_DEBUG "sidewinder.c: Read %d triplets. [", i); for (j = 0; j < i; j++) printk("%d", buf[j]); printk("]\n"); } #endif return i; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)38998.73%350.00%
Vojtech Pavlik30.76%116.67%
Ingo Molnar20.51%233.33%
Total394100.00%6100.00%

/* * sw_get_bits() and GB() compose bits from the triplet buffer into a __u64. * Parameter 'pos' is bit number inside packet where to start at, 'num' is number * of bits to be read, 'shift' is offset in the resulting __u64 to start at, bits * is number of bits per triplet. */ #define GB(pos,num) sw_get_bits(buf, pos, num, sw->bits)
static __u64 sw_get_bits(unsigned char *buf, int pos, int num, char bits) { __u64 data = 0; int tri = pos % bits; /* Start position */ int i = pos / bits; int bit = 0; while (num--) { data |= (__u64)((buf[i] >> tri++) & 1) << bit++; /* Transfer bit */ if (tri == bits) { i++; /* Next triplet */ tri = 0; } } return data; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)94100.00%3100.00%
Total94100.00%3100.00%

/* * sw_init_digital() initializes a SideWinder 3D Pro joystick * into digital mode. */
static void sw_init_digital(struct gameport *gameport) { int seq[] = { 140, 140+725, 140+300, 0 }; unsigned long flags; int i, t; local_irq_save(flags); i = 0; do { gameport_trigger(gameport); /* Trigger */ t = gameport_time(gameport, SW_TIMEOUT * 1000); while ((gameport_read(gameport) & 1) && t) t--; /* Wait for axis to fall back to 0 */ udelay(seq[i]); /* Delay magic time */ } while (seq[++i]); gameport_trigger(gameport); /* Last trigger */ local_irq_restore(flags); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10996.46%240.00%
Ingo Molnar21.77%240.00%
Vojtech Pavlik21.77%120.00%
Total113100.00%5100.00%

/* * sw_parity() computes parity of __u64 */
static int sw_parity(__u64 t) { int x = t ^ (t >> 32); x ^= x >> 16; x ^= x >> 8; x ^= x >> 4; x ^= x >> 2; x ^= x >> 1; return x & 1; }

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Linus Torvalds (pre-git)55100.00%2100.00%
Total55100.00%2100.00%

/* * sw_ccheck() checks synchronization bits and computes checksum of nibbles. */
static int sw_check(__u64 t) { unsigned char sum = 0; if ((t & 0x8080808080808080ULL) ^ 0x80) /* Sync */ return -1; while (t) { /* Sum */ sum += t & 0xf; t >>= 4; } return sum & 0xf; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)52100.00%3100.00%
Total52100.00%3100.00%

/* * sw_parse() analyzes SideWinder joystick data, and writes the results into * the axes and buttons arrays. */
static int sw_parse(unsigned char *buf, struct sw *sw) { int hat, i, j; struct input_dev *dev; switch (sw->type) { case SW_ID_3DP: if (sw_check(GB(0,64)) || (hat = (GB(6,1) << 3) | GB(60,3)) > 8) return -1; dev = sw->dev[0]; input_report_abs(dev, ABS_X, (GB( 3,3) << 7) | GB(16,7)); input_report_abs(dev, ABS_Y, (GB( 0,3) << 7) | GB(24,7)); input_report_abs(dev, ABS_RZ, (GB(35,2) << 7) | GB(40,7)); input_report_abs(dev, ABS_THROTTLE, (GB(32,3) << 7) | GB(48,7)); input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x); input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y); for (j = 0; j < 7; j++) input_report_key(dev, sw_btn[SW_ID_3DP][j], !GB(j+8,1)); input_report_key(dev, BTN_BASE4, !GB(38,1)); input_report_key(dev, BTN_BASE5, !GB(37,1)); input_sync(dev); return 0; case SW_ID_GP: for (i = 0; i < sw->number; i ++) { if (sw_parity(GB(i*15,15))) return -1; input_report_abs(sw->dev[i], ABS_X, GB(i*15+3,1) - GB(i*15+2,1)); input_report_abs(sw->dev[i], ABS_Y, GB(i*15+0,1) - GB(i*15+1,1)); for (j = 0; j < 10; j++) input_report_key(sw->dev[i], sw_btn[SW_ID_GP][j], !GB(i*15+j+4,1)); input_sync(sw->dev[i]); } return 0; case SW_ID_PP: case SW_ID_FFP: if (!sw_parity(GB(0,48)) || (hat = GB(42,4)) > 8) return -1; dev = sw->dev[0]; input_report_abs(dev, ABS_X, GB( 9,10)); input_report_abs(dev, ABS_Y, GB(19,10)); input_report_abs(dev, ABS_RZ, GB(36, 6)); input_report_abs(dev, ABS_THROTTLE, GB(29, 7)); input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x); input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y); for (j = 0; j < 9; j++) input_report_key(dev, sw_btn[SW_ID_PP][j], !GB(j,1)); input_sync(dev); return 0; case SW_ID_FSP: if (!sw_parity(GB(0,43)) || (hat = GB(28,4)) > 8) return -1; dev = sw->dev[0]; input_report_abs(dev, ABS_X, GB( 0,10)); input_report_abs(dev, ABS_Y, GB(16,10)); input_report_abs(dev, ABS_THROTTLE, GB(32, 6)); input_report_abs(dev, ABS_HAT0X, sw_hat_to_axis[hat].x); input_report_abs(dev, ABS_HAT0Y, sw_hat_to_axis[hat].y); for (j = 0; j < 6; j++) input_report_key(dev, sw_btn[SW_ID_FSP][j], !GB(j+10,1)); input_report_key(dev, BTN_TR, !GB(26,1)); input_report_key(dev, BTN_START, !GB(27,1)); input_report_key(dev, BTN_MODE, !GB(38,1)); input_report_key(dev, BTN_SELECT, !GB(39,1)); input_sync(dev); return 0; case SW_ID_FFW: if (!sw_parity(GB(0,33))) return -1; dev = sw->dev[0]; input_report_abs(dev, ABS_RX, GB( 0,10)); input_report_abs(dev, ABS_RUDDER, GB(10, 6)); input_report_abs(dev, ABS_THROTTLE, GB(16, 6)); for (j = 0; j < 8; j++) input_report_key(dev, sw_btn[SW_ID_FFW][j], !GB(j+22,1)); input_sync(dev); return 0; } return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)87791.35%450.00%
Dmitry Torokhov525.42%112.50%
Vojtech Pavlik303.12%225.00%
Linus Torvalds10.10%112.50%
Total960100.00%8100.00%

/* * sw_read() reads SideWinder joystick data, and reinitializes * the joystick in case of persistent problems. This is the function that is * called from the generic code to poll the joystick. */
static int sw_read(struct sw *sw) { unsigned char buf[SW_LENGTH]; int i; i = sw_read_packet(sw->gameport, buf, sw->length, 0); if (sw->type == SW_ID_3DP && sw->length == 66 && i != 66) { /* Broken packet, try to fix */ if (i == 64 && !sw_check(sw_get_bits(buf,0,64,1))) { /* Last init failed, 1 bit mode */ printk(KERN_WARNING "sidewinder.c: Joystick in wrong mode on %s" " - going to reinitialize.\n", sw->gameport->phys); sw->fail = SW_FAIL; /* Reinitialize */ i = 128; /* Bogus value */ } if (i < 66 && GB(0,64) == GB(i*3-66,64)) /* 1 == 3 */ i = 66; /* Everything is fine */ if (i < 66 && GB(0,64) == GB(66,64)) /* 1 == 2 */ i = 66; /* Everything is fine */ if (i < 66 && GB(i*3-132,64) == GB(i*3-66,64)) { /* 2 == 3 */ memmove(buf, buf + i - 22, 22); /* Move data */ i = 66; /* Carry on */ } } if (i == sw->length && !sw_parse(buf, sw)) { /* Parse data */ sw->fail = 0; sw->ok++; if (sw->type == SW_ID_3DP && sw->length == 66 /* Many packets OK */ && sw->ok > SW_OK) { printk(KERN_INFO "sidewinder.c: No more trouble on %s" " - enabling optimization again.\n", sw->gameport->phys); sw->length = 22; } return 0; } sw->ok = 0; sw->fail++; if (sw->type == SW_ID_3DP && sw->length == 22 && sw->fail > SW_BAD) { /* Consecutive bad packets */ printk(KERN_INFO "sidewinder.c: Many bit errors on %s" " - disabling optimization.\n", sw->gameport->phys); sw->length = 66; } if (sw->fail < SW_FAIL) return -1; /* Not enough, don't reinitialize yet */ printk(KERN_WARNING "sidewinder.c: Too many bit errors on %s" " - reinitializing joystick.\n", sw->gameport->phys); if (!i && sw->type == SW_ID_3DP) { /* 3D Pro can be in analog mode */ mdelay(3 * SW_TIMEOUT); sw_init_digital(sw->gameport); } mdelay(SW_TIMEOUT); i = sw_read_packet(sw->gameport, buf, SW_LENGTH, 0); /* Read normal data packet */ mdelay(SW_TIMEOUT); sw_read_packet(sw->gameport, buf, SW_LENGTH, i); /* Read ID packet, this initializes the stick */ sw->fail = SW_FAIL; return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)43597.53%360.00%
Vojtech Pavlik112.47%240.00%
Total446100.00%5100.00%


static void sw_poll(struct gameport *gameport) { struct sw *sw = gameport_get_drvdata(gameport); sw->reads++; if (sw_read(sw)) sw->bads++; }

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Linus Torvalds (pre-git)2976.32%150.00%
Dmitry Torokhov923.68%150.00%
Total38100.00%2100.00%


static int sw_open(struct input_dev *dev) { struct sw *sw = input_get_drvdata(dev); gameport_start_polling(sw->gameport); return 0; }

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Linus Torvalds (pre-git)2683.87%250.00%
Dmitry Torokhov516.13%250.00%
Total31100.00%4100.00%


static void sw_close(struct input_dev *dev) { struct sw *sw = input_get_drvdata(dev); gameport_stop_polling(sw->gameport); }

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Linus Torvalds (pre-git)2382.14%250.00%
Dmitry Torokhov517.86%250.00%
Total28100.00%4100.00%

/* * sw_print_packet() prints the contents of a SideWinder packet. */
static void sw_print_packet(char *name, int length, unsigned char *buf, char bits) { int i; printk(KERN_INFO "sidewinder.c: %s packet, %d bits. [", name, length); for (i = (((length + 3) >> 2) - 1); i >= 0; i--) printk("%x", (int)sw_get_bits(buf, i << 2, 4, bits)); printk("]\n"); }

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Linus Torvalds (pre-git)85100.00%3100.00%
Total85100.00%3100.00%

/* * sw_3dp_id() translates the 3DP id into a human legible string. * Unfortunately I don't know how to do this for the other SW types. */
static void sw_3dp_id(unsigned char *buf, char *comment, size_t size) { int i; char pnp[8], rev[9]; for (i = 0; i < 7; i++) /* ASCII PnP ID */ pnp[i] = sw_get_bits(buf, 24+8*i, 8, 1); for (i = 0; i < 8; i++) /* ASCII firmware revision */ rev[i] = sw_get_bits(buf, 88+8*i, 8, 1); pnp[7] = rev[8] = 0; snprintf(comment, size, " [PnP %d.%02d id %s rev %s]", (int) ((sw_get_bits(buf, 8, 6, 1) << 6) | /* Two 6-bit values */ sw_get_bits(buf, 16, 6, 1)) / 100, (int) ((sw_get_bits(buf, 8, 6, 1) << 6) | sw_get_bits(buf, 16, 6, 1)) % 100,