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 /*
10  */
11 
12 #include <asm/unaligned.h>
13 #include "iforce.h"
14 
15 static struct {
16 	__s32 x;
17 	__s32 y;
18 } iforce_hat_to_axis[16] = {{ 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};
19 
20 
21 void iforce_dump_packet(struct iforce *iforce, char *msg, u16 cmd, unsigned char *data)
22 {
23 	dev_dbg(iforce->dev->dev.parent, "%s %s cmd = %04x, data = %*ph\n",
24 		__func__, msg, cmd, LO(cmd), data);
25 }
26 
27 /*
28  * Send a packet of bytes to the device
29  */
30 int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data)
31 {
32 	/* Copy data to buffer */
33 	int n = LO(cmd);
34 	int c;
35 	int empty;
36 	int head, tail;
37 	unsigned long flags;
38 
39 /*
40  * Update head and tail of xmit buffer
41  */
42 	spin_lock_irqsave(&iforce->xmit_lock, flags);
43 
44 	head = iforce->xmit.head;
45 	tail = iforce->xmit.tail;
46 
47 
48 	if (CIRC_SPACE(head, tail, XMIT_SIZE) < n+2) {
49 		dev_warn(&iforce->dev->dev,
50 			 "not enough space in xmit buffer to send new packet\n");
51 		spin_unlock_irqrestore(&iforce->xmit_lock, flags);
52 		return -1;
53 	}
54 
55 	empty = head == tail;
56 	XMIT_INC(iforce->xmit.head, n+2);
57 
58 /*
59  * Store packet in xmit buffer
60  */
61 	iforce->xmit.buf[head] = HI(cmd);
62 	XMIT_INC(head, 1);
63 	iforce->xmit.buf[head] = LO(cmd);
64 	XMIT_INC(head, 1);
65 
66 	c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
67 	if (n < c) c=n;
68 
69 	memcpy(&iforce->xmit.buf[head],
70 	       data,
71 	       c);
72 	if (n != c) {
73 		memcpy(&iforce->xmit.buf[0],
74 		       data + c,
75 		       n - c);
76 	}
77 	XMIT_INC(head, n);
78 
79 	spin_unlock_irqrestore(&iforce->xmit_lock, flags);
80 /*
81  * If necessary, start the transmission
82  */
83 	if (empty)
84 		iforce->xport_ops->xmit(iforce);
85 
86 	return 0;
87 }
88 EXPORT_SYMBOL(iforce_send_packet);
89 
90 /* Start or stop an effect */
91 int iforce_control_playback(struct iforce* iforce, u16 id, unsigned int value)
92 {
93 	unsigned char data[3];
94 
95 	data[0] = LO(id);
96 	data[1] = (value > 0) ? ((value > 1) ? 0x41 : 0x01) : 0;
97 	data[2] = LO(value);
98 	return iforce_send_packet(iforce, FF_CMD_PLAY, data);
99 }
100 
101 /* Mark an effect that was being updated as ready. That means it can be updated
102  * again */
103 static int mark_core_as_ready(struct iforce *iforce, unsigned short addr)
104 {
105 	int i;
106 
107 	if (!iforce->dev->ff)
108 		return 0;
109 
110 	for (i = 0; i < iforce->dev->ff->max_effects; ++i) {
111 		if (test_bit(FF_CORE_IS_USED, iforce->core_effects[i].flags) &&
112 		    (iforce->core_effects[i].mod1_chunk.start == addr ||
113 		     iforce->core_effects[i].mod2_chunk.start == addr)) {
114 			clear_bit(FF_CORE_UPDATE, iforce->core_effects[i].flags);
115 			return 0;
116 		}
117 	}
118 	dev_warn(&iforce->dev->dev, "unused effect %04x updated !!!\n", addr);
119 	return -1;
120 }
121 
122 static void iforce_report_hats_buttons(struct iforce *iforce, u8 *data)
123 {
124 	struct input_dev *dev = iforce->dev;
125 	int i;
126 
127 	input_report_abs(dev, ABS_HAT0X, iforce_hat_to_axis[data[6] >> 4].x);
128 	input_report_abs(dev, ABS_HAT0Y, iforce_hat_to_axis[data[6] >> 4].y);
129 
130 	for (i = 0; iforce->type->btn[i] >= 0; i++)
131 		input_report_key(dev, iforce->type->btn[i],
132 				 data[(i >> 3) + 5] & (1 << (i & 7)));
133 
134 	/* If there are untouched bits left, interpret them as the second hat */
135 	if (i <= 8) {
136 		u8 btns = data[6];
137 
138 		if (test_bit(ABS_HAT1X, dev->absbit)) {
139 			if (btns & BIT(3))
140 				input_report_abs(dev, ABS_HAT1X, -1);
141 			else if (btns & BIT(1))
142 				input_report_abs(dev, ABS_HAT1X, 1);
143 			else
144 				input_report_abs(dev, ABS_HAT1X, 0);
145 		}
146 
147 		if (test_bit(ABS_HAT1Y, dev->absbit)) {
148 			if (btns & BIT(0))
149 				input_report_abs(dev, ABS_HAT1Y, -1);
150 			else if (btns & BIT(2))
151 				input_report_abs(dev, ABS_HAT1Y, 1);
152 			else
153 				input_report_abs(dev, ABS_HAT1Y, 0);
154 		}
155 	}
156 }
157 
158 void iforce_process_packet(struct iforce *iforce,
159 			   u8 packet_id, u8 *data, size_t len)
160 {
161 	struct input_dev *dev = iforce->dev;
162 	int i, j;
163 
164 	switch (packet_id) {
165 
166 	case 0x01:	/* joystick position data */
167 		input_report_abs(dev, ABS_X,
168 				 (__s16) get_unaligned_le16(data));
169 		input_report_abs(dev, ABS_Y,
170 				 (__s16) get_unaligned_le16(data + 2));
171 		input_report_abs(dev, ABS_THROTTLE, 255 - data[4]);
172 
173 		if (len >= 8 && test_bit(ABS_RUDDER ,dev->absbit))
174 			input_report_abs(dev, ABS_RUDDER, (__s8)data[7]);
175 
176 		iforce_report_hats_buttons(iforce, data);
177 
178 		input_sync(dev);
179 		break;
180 
181 	case 0x03:	/* wheel position data */
182 		input_report_abs(dev, ABS_WHEEL,
183 				 (__s16) get_unaligned_le16(data));
184 		input_report_abs(dev, ABS_GAS,   255 - data[2]);
185 		input_report_abs(dev, ABS_BRAKE, 255 - data[3]);
186 
187 		iforce_report_hats_buttons(iforce, data);
188 
189 		input_sync(dev);
190 		break;
191 
192 	case 0x02:	/* status report */
193 		input_report_key(dev, BTN_DEAD, data[0] & 0x02);
194 		input_sync(dev);
195 
196 		/* Check if an effect was just started or stopped */
197 		i = data[1] & 0x7f;
198 		if (data[1] & 0x80) {
199 			if (!test_and_set_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
200 				/* Report play event */
201 				input_report_ff_status(dev, i, FF_STATUS_PLAYING);
202 			}
203 		} else if (test_and_clear_bit(FF_CORE_IS_PLAYED, iforce->core_effects[i].flags)) {
204 			/* Report stop event */
205 			input_report_ff_status(dev, i, FF_STATUS_STOPPED);
206 		}
207 
208 		for (j = 3; j < len; j += 2)
209 			mark_core_as_ready(iforce, get_unaligned_le16(data + j));
210 
211 		break;
212 	}
213 }
214 EXPORT_SYMBOL(iforce_process_packet);
215