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 <asm/unaligned.h>
10 #include "iforce.h"
11 
12 static struct {
13 	__s32 x;
14 	__s32 y;
15 } iforce_hat_to_axis[16] = {{ 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};
16 
17 
iforce_dump_packet(struct iforce * iforce,char * msg,u16 cmd,unsigned char * data)18 void iforce_dump_packet(struct iforce *iforce, char *msg, u16 cmd, unsigned char *data)
19 {
20 	dev_dbg(iforce->dev->dev.parent, "%s %s cmd = %04x, data = %*ph\n",
21 		__func__, msg, cmd, LO(cmd), data);
22 }
23 
24 /*
25  * Send a packet of bytes to the device
26  */
iforce_send_packet(struct iforce * iforce,u16 cmd,unsigned char * data)27 int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data)
28 {
29 	/* Copy data to buffer */
30 	int n = LO(cmd);
31 	int c;
32 	int empty;
33 	int head, tail;
34 	unsigned long flags;
35 
36 /*
37  * Update head and tail of xmit buffer
38  */
39 	spin_lock_irqsave(&iforce->xmit_lock, flags);
40 
41 	head = iforce->xmit.head;
42 	tail = iforce->xmit.tail;
43 
44 
45 	if (CIRC_SPACE(head, tail, XMIT_SIZE) < n+2) {
46 		dev_warn(&iforce->dev->dev,
47 			 "not enough space in xmit buffer to send new packet\n");
48 		spin_unlock_irqrestore(&iforce->xmit_lock, flags);
49 		return -1;
50 	}
51 
52 	empty = head == tail;
53 	XMIT_INC(iforce->xmit.head, n+2);
54 
55 /*
56  * Store packet in xmit buffer
57  */
58 	iforce->xmit.buf[head] = HI(cmd);
59 	XMIT_INC(head, 1);
60 	iforce->xmit.buf[head] = LO(cmd);
61 	XMIT_INC(head, 1);
62 
63 	c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
64 	if (n < c) c=n;
65 
66 	memcpy(&iforce->xmit.buf[head],
67 	       data,
68 	       c);
69 	if (n != c) {
70 		memcpy(&iforce->xmit.buf[0],
71 		       data + c,
72 		       n - c);
73 	}
74 	XMIT_INC(head, n);
75 
76 	spin_unlock_irqrestore(&iforce->xmit_lock, flags);
77 /*
78  * If necessary, start the transmission
79  */
80 	if (empty)
81 		iforce->xport_ops->xmit(iforce);
82 
83 	return 0;
84 }
85 EXPORT_SYMBOL(iforce_send_packet);
86 
87 /* Start or stop an effect */
iforce_control_playback(struct iforce * iforce,u16 id,unsigned int value)88 int iforce_control_playback(struct iforce* iforce, u16 id, unsigned int value)
89 {
90 	unsigned char data[3];
91 
92 	data[0] = LO(id);
93 	data[1] = (value > 0) ? ((value > 1) ? 0x41 : 0x01) : 0;
94 	data[2] = LO(value);
95 	return iforce_send_packet(iforce, FF_CMD_PLAY, data);
96 }
97 
98 /* Mark an effect that was being updated as ready. That means it can be updated
99  * again */
mark_core_as_ready(struct iforce * iforce,unsigned short addr)100 static int mark_core_as_ready(struct iforce *iforce, unsigned short addr)
101 {
102 	int i;
103 
104 	if (!iforce->dev->ff)
105 		return 0;
106 
107 	for (i = 0; i < iforce->dev->ff->max_effects; ++i) {
108 		if (test_bit(FF_CORE_IS_USED, iforce->core_effects[i].flags) &&
109 		    (iforce->core_effects[i].mod1_chunk.start == addr ||
110 		     iforce->core_effects[i].mod2_chunk.start == addr)) {
111 			clear_bit(FF_CORE_UPDATE, iforce->core_effects[i].flags);
112 			return 0;
113 		}
114 	}
115 	dev_warn(&iforce->dev->dev, "unused effect %04x updated !!!\n", addr);
116 	return -1;
117 }
118 
iforce_report_hats_buttons(struct iforce * iforce,u8 * data)119 static void iforce_report_hats_buttons(struct iforce *iforce, u8 *data)
120 {
121 	struct input_dev *dev = iforce->dev;
122 	int i;
123 
124 	input_report_abs(dev, ABS_HAT0X, iforce_hat_to_axis[data[6] >> 4].x);
125 	input_report_abs(dev, ABS_HAT0Y, iforce_hat_to_axis[data[6] >> 4].y);
126 
127 	for (i = 0; iforce->type->btn[i] >= 0; i++)
128 		input_report_key(dev, iforce->type->btn[i],
129 				 data[(i >> 3) + 5] & (1 << (i & 7)));
130 
131 	/* If there are untouched bits left, interpret them as the second hat */
132 	if (i <= 8) {
133 		u8 btns = data[6];
134 
135 		if (test_bit(ABS_HAT1X, dev->absbit)) {
136 			if (btns & BIT(3))
137 				input_report_abs(dev, ABS_HAT1X, -1);
138 			else if (btns & BIT(1))
139 				input_report_abs(dev, ABS_HAT1X, 1);
140 			else
141 				input_report_abs(dev, ABS_HAT1X, 0);
142 		}
143 
144 		if (test_bit(ABS_HAT1Y, dev->absbit)) {
145 			if (btns & BIT(0))
146 				input_report_abs(dev, ABS_HAT1Y, -1);
147 			else if (btns & BIT(2))
148 				input_report_abs(dev, ABS_HAT1Y, 1);
149 			else
150 				input_report_abs(dev, ABS_HAT1Y, 0);
151 		}
152 	}
153 }
154 
iforce_process_packet(struct iforce * iforce,u8 packet_id,u8 * data,size_t len)155 void iforce_process_packet(struct iforce *iforce,
156 			   u8 packet_id, u8 *data, size_t len)
157 {
158 	struct input_dev *dev = iforce->dev;
159 	int i, j;
160 
161 	switch (packet_id) {
162 
163 	case 0x01:	/* joystick position data */
164 		input_report_abs(dev, ABS_X,
165 				 (__s16) get_unaligned_le16(data));
166 		input_report_abs(dev, ABS_Y,
167 				 (__s16) get_unaligned_le16(data + 2));
168 		input_report_abs(dev, ABS_THROTTLE, 255 - data[4]);
169 
170 		if (len >= 8 && test_bit(ABS_RUDDER ,dev->absbit))
171 			input_report_abs(dev, ABS_RUDDER, (__s8)data[7]);
172 
173 		iforce_report_hats_buttons(iforce, data);
174 
175 		input_sync(dev);
176 		break;
177 
178 	case 0x03:	/* wheel position data */
179 		input_report_abs(dev, ABS_WHEEL,
180 				 (__s16) get_unaligned_le16(data));
181 		input_report_abs(dev, ABS_GAS,   255 - data[2]);
182 		input_report_abs(dev, ABS_BRAKE, 255 - data[3]);
183 
184 		iforce_report_hats_buttons(iforce, data);
185 
186 		input_sync(dev);
187 		break;
188 
189 	case 0x02:	/* status report */
190 		input_report_key(dev, BTN_DEAD, data[0] & 0x02);
191 		input_sync(dev);
192 
193 		/* Check if an effect was just started or stopped */
194 		i = data[1] & 0x7f;
195 		if (data[1] & 0x80) {
196 			if (!test_and_set_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
197 				/* Report play event */
198 				input_report_ff_status(dev, i, FF_STATUS_PLAYING);
199 			}
200 		} else if (test_and_clear_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
201 			/* Report stop event */
202 			input_report_ff_status(dev, i, FF_STATUS_STOPPED);
203 		}
204 
205 		for (j = 3; j < len; j += 2)
206 			mark_core_as_ready(iforce, get_unaligned_le16(data + j));
207 
208 		break;
209 	}
210 }
211 EXPORT_SYMBOL(iforce_process_packet);
212