iforce-packets.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  Copyright (c) 2000-2002 Vojtech Pavlik <vojtech@ucw.cz>
  4 *  Copyright (c) 2001-2002, 2007 Johann Deneux <johann.deneux@gmail.com>
  5 *
  6 *  USB/RS232 I-Force joysticks and wheels.
  7 */
  8
  9#include <linux/export.h>
 10#include <linux/unaligned.h>
 11#include "iforce.h"
 12
 13static struct {
 14	__s32 x;
 15	__s32 y;
 16} iforce_hat_to_axis[16] = {{ 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};
 17
 18
 19void iforce_dump_packet(struct iforce *iforce, char *msg, u16 cmd, unsigned char *data)
 20{
 21	dev_dbg(iforce->dev->dev.parent, "%s %s cmd = %04x, data = %*ph\n",
 22		__func__, msg, cmd, LO(cmd), data);
 23}
 24
 25/*
 26 * Send a packet of bytes to the device
 27 */
 28int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data)
 29{
 30	/* Copy data to buffer */
 31	int n = LO(cmd);
 32	int c;
 33	int empty;
 34	int head, tail;
 35
 36/*
 37 * Update head and tail of xmit buffer
 38 */
 39	scoped_guard(spinlock_irqsave, &iforce->xmit_lock) {
 40		head = iforce->xmit.head;
 41		tail = iforce->xmit.tail;
 42
 43		if (CIRC_SPACE(head, tail, XMIT_SIZE) < n + 2) {
 44			dev_warn(&iforce->dev->dev,
 45				 "not enough space in xmit buffer to send new packet\n");
 46			return -1;
 47		}
 48
 49		empty = head == tail;
 50		XMIT_INC(iforce->xmit.head, n + 2);
 51
 52/*
 53 * Store packet in xmit buffer
 54 */
 55		iforce->xmit.buf[head] = HI(cmd);
 56		XMIT_INC(head, 1);
 57		iforce->xmit.buf[head] = LO(cmd);
 58		XMIT_INC(head, 1);
 59
 60		c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
 61		if (n < c)
 62			c = n;
 63
 64		memcpy(&iforce->xmit.buf[head], data, c);
 65		if (n != c)
 66			memcpy(&iforce->xmit.buf[0], data + c, n - c);
 67
 68		XMIT_INC(head, n);
 69	}
 70
 71/*
 72 * If necessary, start the transmission
 73 */
 74	if (empty)
 75		iforce->xport_ops->xmit(iforce);
 76
 77	return 0;
 78}
 79EXPORT_SYMBOL(iforce_send_packet);
 80
 81/* Start or stop an effect */
 82int iforce_control_playback(struct iforce* iforce, u16 id, unsigned int value)
 83{
 84	unsigned char data[3];
 85
 86	data[0] = LO(id);
 87	data[1] = (value > 0) ? ((value > 1) ? 0x41 : 0x01) : 0;
 88	data[2] = LO(value);
 89	return iforce_send_packet(iforce, FF_CMD_PLAY, data);
 90}
 91
 92/* Mark an effect that was being updated as ready. That means it can be updated
 93 * again */
 94static int mark_core_as_ready(struct iforce *iforce, unsigned short addr)
 95{
 96	int i;
 97
 98	if (!iforce->dev->ff)
 99		return 0;
100
101	for (i = 0; i < iforce->dev->ff->max_effects; ++i) {
102		if (test_bit(FF_CORE_IS_USED, iforce->core_effects[i].flags) &&
103		    (iforce->core_effects[i].mod1_chunk.start == addr ||
104		     iforce->core_effects[i].mod2_chunk.start == addr)) {
105			clear_bit(FF_CORE_UPDATE, iforce->core_effects[i].flags);
106			return 0;
107		}
108	}
109	dev_warn(&iforce->dev->dev, "unused effect %04x updated !!!\n", addr);
110	return -1;
111}
112
113static void iforce_report_hats_buttons(struct iforce *iforce, u8 *data)
114{
115	struct input_dev *dev = iforce->dev;
116	int i;
117
118	input_report_abs(dev, ABS_HAT0X, iforce_hat_to_axis[data[6] >> 4].x);
119	input_report_abs(dev, ABS_HAT0Y, iforce_hat_to_axis[data[6] >> 4].y);
120
121	for (i = 0; iforce->type->btn[i] >= 0; i++)
122		input_report_key(dev, iforce->type->btn[i],
123				 data[(i >> 3) + 5] & (1 << (i & 7)));
124
125	/* If there are untouched bits left, interpret them as the second hat */
126	if (i <= 8) {
127		u8 btns = data[6];
128
129		if (test_bit(ABS_HAT1X, dev->absbit)) {
130			if (btns & BIT(3))
131				input_report_abs(dev, ABS_HAT1X, -1);
132			else if (btns & BIT(1))
133				input_report_abs(dev, ABS_HAT1X, 1);
134			else
135				input_report_abs(dev, ABS_HAT1X, 0);
136		}
137
138		if (test_bit(ABS_HAT1Y, dev->absbit)) {
139			if (btns & BIT(0))
140				input_report_abs(dev, ABS_HAT1Y, -1);
141			else if (btns & BIT(2))
142				input_report_abs(dev, ABS_HAT1Y, 1);
143			else
144				input_report_abs(dev, ABS_HAT1Y, 0);
145		}
146	}
147}
148
149void iforce_process_packet(struct iforce *iforce,
150			   u8 packet_id, u8 *data, size_t len)
151{
152	struct input_dev *dev = iforce->dev;
153	int i, j;
154
155	switch (packet_id) {
156
157	case 0x01:	/* joystick position data */
158		input_report_abs(dev, ABS_X,
159				 (__s16) get_unaligned_le16(data));
160		input_report_abs(dev, ABS_Y,
161				 (__s16) get_unaligned_le16(data + 2));
162		input_report_abs(dev, ABS_THROTTLE, 255 - data[4]);
163
164		if (len >= 8 && test_bit(ABS_RUDDER ,dev->absbit))
165			input_report_abs(dev, ABS_RUDDER, (__s8)data[7]);
166
167		iforce_report_hats_buttons(iforce, data);
168
169		input_sync(dev);
170		break;
171
172	case 0x03:	/* wheel position data */
173		input_report_abs(dev, ABS_WHEEL,
174				 (__s16) get_unaligned_le16(data));
175		input_report_abs(dev, ABS_GAS,   255 - data[2]);
176		input_report_abs(dev, ABS_BRAKE, 255 - data[3]);
177
178		iforce_report_hats_buttons(iforce, data);
179
180		input_sync(dev);
181		break;
182
183	case 0x02:	/* status report */
184		input_report_key(dev, BTN_DEAD, data[0] & 0x02);
185		input_sync(dev);
186
187		/* Check if an effect was just started or stopped */
188		i = data[1] & 0x7f;
189		if (data[1] & 0x80) {
190			if (!test_and_set_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
191				/* Report play event */
192				input_report_ff_status(dev, i, FF_STATUS_PLAYING);
193			}
194		} else if (test_and_clear_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
195			/* Report stop event */
196			input_report_ff_status(dev, i, FF_STATUS_STOPPED);
197		}
198
199		for (j = 3; j < len; j += 2)
200			mark_core_as_ready(iforce, get_unaligned_le16(data + j));
201
202		break;
203	}
204}
205EXPORT_SYMBOL(iforce_process_packet);