xref: /linux/drivers/input/joystick/iforce/iforce-packets.c (revision 8a7c601e14576a22c2bbf7f67455ccf3f3d2737f)
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 
13 static 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 
19 void 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  */
28 int 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 }
79 EXPORT_SYMBOL(iforce_send_packet);
80 
81 /* Start or stop an effect */
82 int 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 */
94 static 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 
113 static 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 
149 void 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 }
205 EXPORT_SYMBOL(iforce_process_packet);
206