Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 810 insertions, 0 deletions

diff --git a/drivers/input/joystick/sidewinder.c b/drivers/input/joystick/sidewinder.c
new file mode 100644
index 000000000..7f37d18c8
--- /dev/null
+++ b/drivers/input/joystick/sidewinder.c
@@ -0,0 +1,810 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) 1998-2005 Vojtech Pavlik
+ */
+
+/*
+ * Microsoft SideWinder joystick family driver for Linux
+ */
+
+#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>
+#include <linux/string_choices.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;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * sw_init_digital() initializes a SideWinder 3D Pro joystick
+ * into digital mode.
+ */
+
+static void sw_init_digital(struct gameport *gameport)
+{
+	static const 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);
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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;
+}
+
+static void sw_poll(struct gameport *gameport)
+{
+	struct sw *sw = gameport_get_drvdata(gameport);
+
+	sw->reads++;
+	if (sw_read(sw))
+		sw->bads++;
+}
+
+static int sw_open(struct input_dev *dev)
+{
+	struct sw *sw = input_get_drvdata(dev);
+
+	gameport_start_polling(sw->gameport);
+	return 0;
+}
+
+static void sw_close(struct input_dev *dev)
+{
+	struct sw *sw = input_get_drvdata(dev);
+
+	gameport_stop_polling(sw->gameport);
+}
+
+/*
+ * 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");
+}
+
+/*
+ * 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,
+		 pnp, rev);
+}
+
+/*
+ * sw_guess_mode() checks the upper two button bits for toggling -
+ * indication of that the joystick is in 3-bit mode. This is documented
+ * behavior for 3DP ID packet, and for example the FSP does this in
+ * normal packets instead. Fun ...
+ */
+
+static int sw_guess_mode(unsigned char *buf, int len)
+{
+	int i;
+	unsigned char xor = 0;
+
+	for (i = 1; i < len; i++)
+		xor |= (buf[i - 1] ^ buf[i]) & 6;
+
+	return !!xor * 2 + 1;
+}
+
+/*
+ * sw_connect() probes for SideWinder type joysticks.
+ */
+
+static int sw_connect(struct gameport *gameport, struct gameport_driver *drv)
+{
+	struct sw *sw;
+	struct input_dev *input_dev;
+	int i, j, k, l;
+	int err = 0;
+	unsigned char *buf = NULL;	/* [SW_LENGTH] */
+	unsigned char *idbuf = NULL;	/* [SW_LENGTH] */
+	unsigned char m = 1;
+	char comment[40];
+
+	comment[0] = 0;
+
+	sw = kzalloc_obj(*sw);
+	buf = kmalloc(SW_LENGTH, GFP_KERNEL);
+	idbuf = kmalloc(SW_LENGTH, GFP_KERNEL);
+	if (!sw || !buf || !idbuf) {
+		err = -ENOMEM;
+		goto fail1;
+	}
+
+	sw->gameport = gameport;
+
+	gameport_set_drvdata(gameport, sw);
+
+	err = gameport_open(gameport, drv, GAMEPORT_MODE_RAW);
+	if (err)
+		goto fail1;
+
+	dbg("Init 0: Opened %s, io %#x, speed %d",
+		gameport->phys, gameport->io, gameport->speed);
+
+	i = sw_read_packet(gameport, buf, SW_LENGTH, 0);		/* Read normal packet */
+	msleep(SW_TIMEOUT);
+	dbg("Init 1: Mode %d. Length %d.", m , i);
+
+	if (!i) {							/* No data. 3d Pro analog mode? */
+		sw_init_digital(gameport);				/* Switch to digital */
+		msleep(SW_TIMEOUT);
+		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Retry reading packet */
+		msleep(SW_TIMEOUT);
+		dbg("Init 1b: Length %d.", i);
+		if (!i) {						/* No data -> FAIL */
+			err = -ENODEV;
+			goto fail2;
+		}
+	}
+
+	j = sw_read_packet(gameport, idbuf, SW_LENGTH, i);		/* Read ID. This initializes the stick */
+	m |= sw_guess_mode(idbuf, j);					/* ID packet should carry mode info [3DP] */
+	dbg("Init 2: Mode %d. ID Length %d.", m, j);
+
+	if (j <= 0) {							/* Read ID failed. Happens in 1-bit mode on PP */
+		msleep(SW_TIMEOUT);
+		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Retry reading packet */
+		m |= sw_guess_mode(buf, i);
+		dbg("Init 2b: Mode %d. Length %d.", m, i);
+		if (!i) {
+			err = -ENODEV;
+			goto fail2;
+		}
+		msleep(SW_TIMEOUT);
+		j = sw_read_packet(gameport, idbuf, SW_LENGTH, i);	/* Retry reading ID */
+		dbg("Init 2c: ID Length %d.", j);
+	}
+
+	sw->type = -1;
+	k = SW_FAIL;							/* Try SW_FAIL times */
+	l = 0;
+
+	do {
+		k--;
+		msleep(SW_TIMEOUT);
+		i = sw_read_packet(gameport, buf, SW_LENGTH, 0);	/* Read data packet */
+		dbg("Init 3: Mode %d. Length %d. Last %d. Tries %d.", m, i, l, k);
+
+		if (i > l) {						/* Longer? As we can only lose bits, it makes */
+									/* no sense to try detection for a packet shorter */
+			l = i;						/* than the previous one */
+
+			sw->number = 1;
+			sw->gameport = gameport;
+			sw->length = i;
+			sw->bits = m;
+
+			dbg("Init 3a: Case %d.\n", i * m);
+
+			switch (i * m) {
+				case 60:
+					sw->number++;
+					fallthrough;
+				case 45:				/* Ambiguous packet length */
+					if (j <= 40) {			/* ID length less or eq 40 -> FSP */
+					fallthrough;
+				case 43:
+						sw->type = SW_ID_FSP;
+						break;
+					}
+					sw->number++;
+					fallthrough;
+				case 30:
+					sw->number++;
+					fallthrough;
+				case 15:
+					sw->type = SW_ID_GP;
+					break;
+				case 33:
+				case 31:
+					sw->type = SW_ID_FFW;
+					break;
+				case 48:				/* Ambiguous */
+					if (j == 14) {			/* ID length 14*3 -> FFP */
+						sw->type = SW_ID_FFP;
+						sprintf(comment, " [AC %s]", str_off_on(sw_get_bits(idbuf,38,1,3)));
+					} else
+						sw->type = SW_ID_PP;
+					break;
+				case 66:
+					sw->bits = 3;
+					fallthrough;
+				case 198:
+					sw->length = 22;
+					fallthrough;
+				case 64:
+					sw->type = SW_ID_3DP;
+					if (j == 160)
+						sw_3dp_id(idbuf, comment, sizeof(comment));
+					break;
+			}
+		}
+
+	} while (k && sw->type == -1);
+
+	if (sw->type == -1) {
+		printk(KERN_WARNING "sidewinder.c: unknown joystick device detected "
+			"on %s, contact <vojtech@ucw.cz>\n", gameport->phys);
+		sw_print_packet("ID", j * 3, idbuf, 3);
+		sw_print_packet("Data", i * m, buf, m);
+		err = -ENODEV;
+		goto fail2;
+	}
+
+#ifdef SW_DEBUG
+	sw_print_packet("ID", j * 3, idbuf, 3);
+	sw_print_packet("Data", i * m, buf, m);
+#endif
+
+	gameport_set_poll_handler(gameport, sw_poll);
+	gameport_set_poll_interval(gameport, 20);
+
+	k = i;
+	l = j;
+
+	for (i = 0; i < sw->number; i++) {
+		int bits, code;
+
+		snprintf(sw->name, sizeof(sw->name),
+			 "Microsoft SideWinder %s", sw_name[sw->type]);
+		snprintf(sw->phys[i], sizeof(sw->phys[i]),
+			 "%s/input%d", gameport->phys, i);
+
+		sw->dev[i] = input_dev = input_allocate_device();
+		if (!input_dev) {
+			err = -ENOMEM;
+			goto fail3;
+		}
+
+		input_dev->name = sw->name;
+		input_dev->phys = sw->phys[i];
+		input_dev->id.bustype = BUS_GAMEPORT;
+		input_dev->id.vendor = GAMEPORT_ID_VENDOR_MICROSOFT;
+		input_dev->id.product = sw->type;
+		input_dev->id.version = 0x0100;
+		input_dev->dev.parent = &gameport->dev;
+
+		input_set_drvdata(input_dev, sw);
+
+		input_dev->open = sw_open;
+		input_dev->close = sw_close;
+
+		input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+
+		for (j = 0; (bits = sw_bit[sw->type][j]); j++) {
+			int min, max, fuzz, flat;
+
+			code = sw_abs[sw->type][j];
+			min = bits == 1 ? -1 : 0;
+			max = (1 << bits) - 1;
+			fuzz = (bits >> 1) >= 2 ? 1 << ((bits >> 1) - 2) : 0;
+			flat = code == ABS_THROTTLE || bits < 5 ?
+				0 : 1 << (bits - 5);
+
+			input_set_abs_params(input_dev, code,
+					     min, max, fuzz, flat);
+		}
+
+		for (j = 0; (code = sw_btn[sw->type][j]); j++)
+			__set_bit(code, input_dev->keybit);
+
+		dbg("%s%s [%d-bit id %d data %d]\n", sw->name, comment, m, l, k);
+
+		err = input_register_device(sw->dev[i]);
+		if (err)
+			goto fail4;
+	}
+
+ out:	kfree(buf);
+	kfree(idbuf);
+
+	return err;
+
+ fail4:	input_free_device(sw->dev[i]);
+ fail3:	while (--i >= 0)
+		input_unregister_device(sw->dev[i]);
+ fail2:	gameport_close(gameport);
+ fail1:	gameport_set_drvdata(gameport, NULL);
+	kfree(sw);
+	goto out;
+}
+
+static void sw_disconnect(struct gameport *gameport)
+{
+	struct sw *sw = gameport_get_drvdata(gameport);
+	int i;
+
+	for (i = 0; i < sw->number; i++)
+		input_unregister_device(sw->dev[i]);
+	gameport_close(gameport);
+	gameport_set_drvdata(gameport, NULL);
+	kfree(sw);
+}
+
+static struct gameport_driver sw_drv = {
+	.driver		= {
+		.name	= "sidewinder",
+		.owner	= THIS_MODULE,
+	},
+	.description	= DRIVER_DESC,
+	.connect	= sw_connect,
+	.disconnect	= sw_disconnect,
+};
+
+module_gameport_driver(sw_drv);