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3e24e2b5 MK |
1 | /* |
2 | * derived from "twidjoy.c" | |
3 | * | |
4 | * Copyright (c) 2008 Martin Kebert | |
5 | * Copyright (c) 2001 Arndt Schoenewald | |
6 | * Copyright (c) 2000-2001 Vojtech Pavlik | |
7 | * Copyright (c) 2000 Mark Fletcher | |
8 | * | |
9 | */ | |
10 | ||
11 | /* | |
12 | * Driver to use 4CH RC transmitter using Zhen Hua 5-byte protocol (Walkera Lama, | |
13 | * EasyCopter etc.) as a joystick under Linux. | |
14 | * | |
15 | * RC transmitters using Zhen Hua 5-byte protocol are cheap four channels | |
16 | * transmitters for control a RC planes or RC helicopters with possibility to | |
17 | * connect on a serial port. | |
18 | * Data coming from transmitter is in this order: | |
19 | * 1. byte = synchronisation byte | |
20 | * 2. byte = X axis | |
21 | * 3. byte = Y axis | |
22 | * 4. byte = RZ axis | |
23 | * 5. byte = Z axis | |
24 | * (and this is repeated) | |
25 | * | |
26 | * For questions or feedback regarding this driver module please contact: | |
27 | * Martin Kebert <gkmarty@gmail.com> - but I am not a C-programmer nor kernel | |
28 | * coder :-( | |
29 | */ | |
30 | ||
31 | /* | |
32 | * This program is free software; you can redistribute it and/or modify | |
33 | * it under the terms of the GNU General Public License as published by | |
34 | * the Free Software Foundation; either version 2 of the License, or | |
35 | * (at your option) any later version. | |
36 | * | |
37 | * This program is distributed in the hope that it will be useful, | |
38 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
39 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
40 | * GNU General Public License for more details. | |
41 | * | |
42 | * You should have received a copy of the GNU General Public License | |
43 | * along with this program; if not, write to the Free Software | |
44 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
45 | */ | |
46 | ||
47 | #include <linux/kernel.h> | |
48 | #include <linux/module.h> | |
49 | #include <linux/slab.h> | |
012bd2a5 | 50 | #include <linux/bitrev.h> |
3e24e2b5 MK |
51 | #include <linux/input.h> |
52 | #include <linux/serio.h> | |
3e24e2b5 MK |
53 | |
54 | #define DRIVER_DESC "RC transmitter with 5-byte Zhen Hua protocol joystick driver" | |
55 | ||
56 | MODULE_DESCRIPTION(DRIVER_DESC); | |
57 | MODULE_LICENSE("GPL"); | |
58 | ||
59 | /* | |
60 | * Constants. | |
61 | */ | |
62 | ||
63 | #define ZHENHUA_MAX_LENGTH 5 | |
64 | ||
65 | /* | |
66 | * Zhen Hua data. | |
67 | */ | |
68 | ||
69 | struct zhenhua { | |
70 | struct input_dev *dev; | |
71 | int idx; | |
72 | unsigned char data[ZHENHUA_MAX_LENGTH]; | |
73 | char phys[32]; | |
74 | }; | |
75 | ||
3e24e2b5 MK |
76 | /* |
77 | * zhenhua_process_packet() decodes packets the driver receives from the | |
78 | * RC transmitter. It updates the data accordingly. | |
79 | */ | |
80 | ||
81 | static void zhenhua_process_packet(struct zhenhua *zhenhua) | |
82 | { | |
83 | struct input_dev *dev = zhenhua->dev; | |
84 | unsigned char *data = zhenhua->data; | |
85 | ||
86 | input_report_abs(dev, ABS_Y, data[1]); | |
87 | input_report_abs(dev, ABS_X, data[2]); | |
88 | input_report_abs(dev, ABS_RZ, data[3]); | |
89 | input_report_abs(dev, ABS_Z, data[4]); | |
90 | ||
91 | input_sync(dev); | |
92 | } | |
93 | ||
94 | /* | |
95 | * zhenhua_interrupt() is called by the low level driver when characters | |
96 | * are ready for us. We then buffer them for further processing, or call the | |
97 | * packet processing routine. | |
98 | */ | |
99 | ||
100 | static irqreturn_t zhenhua_interrupt(struct serio *serio, unsigned char data, unsigned int flags) | |
101 | { | |
102 | struct zhenhua *zhenhua = serio_get_drvdata(serio); | |
103 | ||
104 | /* All Zhen Hua packets are 5 bytes. The fact that the first byte | |
105 | * is allways 0xf7 and all others are in range 0x32 - 0xc8 (50-200) | |
106 | * can be used to check and regain sync. */ | |
107 | ||
108 | if (data == 0xef) | |
109 | zhenhua->idx = 0; /* this byte starts a new packet */ | |
110 | else if (zhenhua->idx == 0) | |
111 | return IRQ_HANDLED; /* wrong MSB -- ignore this byte */ | |
112 | ||
113 | if (zhenhua->idx < ZHENHUA_MAX_LENGTH) | |
012bd2a5 | 114 | zhenhua->data[zhenhua->idx++] = bitrev8(data); |
3e24e2b5 MK |
115 | |
116 | if (zhenhua->idx == ZHENHUA_MAX_LENGTH) { | |
117 | zhenhua_process_packet(zhenhua); | |
118 | zhenhua->idx = 0; | |
119 | } | |
120 | ||
121 | return IRQ_HANDLED; | |
122 | } | |
123 | ||
124 | /* | |
125 | * zhenhua_disconnect() is the opposite of zhenhua_connect() | |
126 | */ | |
127 | ||
128 | static void zhenhua_disconnect(struct serio *serio) | |
129 | { | |
130 | struct zhenhua *zhenhua = serio_get_drvdata(serio); | |
131 | ||
132 | serio_close(serio); | |
133 | serio_set_drvdata(serio, NULL); | |
134 | input_unregister_device(zhenhua->dev); | |
135 | kfree(zhenhua); | |
136 | } | |
137 | ||
138 | /* | |
139 | * zhenhua_connect() is the routine that is called when someone adds a | |
140 | * new serio device. It looks for the Twiddler, and if found, registers | |
141 | * it as an input device. | |
142 | */ | |
143 | ||
144 | static int zhenhua_connect(struct serio *serio, struct serio_driver *drv) | |
145 | { | |
146 | struct zhenhua *zhenhua; | |
147 | struct input_dev *input_dev; | |
148 | int err = -ENOMEM; | |
149 | ||
150 | zhenhua = kzalloc(sizeof(struct zhenhua), GFP_KERNEL); | |
151 | input_dev = input_allocate_device(); | |
152 | if (!zhenhua || !input_dev) | |
153 | goto fail1; | |
154 | ||
155 | zhenhua->dev = input_dev; | |
156 | snprintf(zhenhua->phys, sizeof(zhenhua->phys), "%s/input0", serio->phys); | |
157 | ||
158 | input_dev->name = "Zhen Hua 5-byte device"; | |
159 | input_dev->phys = zhenhua->phys; | |
160 | input_dev->id.bustype = BUS_RS232; | |
161 | input_dev->id.vendor = SERIO_ZHENHUA; | |
162 | input_dev->id.product = 0x0001; | |
163 | input_dev->id.version = 0x0100; | |
164 | input_dev->dev.parent = &serio->dev; | |
165 | ||
166 | input_dev->evbit[0] = BIT(EV_ABS); | |
167 | input_set_abs_params(input_dev, ABS_X, 50, 200, 0, 0); | |
168 | input_set_abs_params(input_dev, ABS_Y, 50, 200, 0, 0); | |
169 | input_set_abs_params(input_dev, ABS_Z, 50, 200, 0, 0); | |
170 | input_set_abs_params(input_dev, ABS_RZ, 50, 200, 0, 0); | |
171 | ||
172 | serio_set_drvdata(serio, zhenhua); | |
173 | ||
174 | err = serio_open(serio, drv); | |
175 | if (err) | |
176 | goto fail2; | |
177 | ||
178 | err = input_register_device(zhenhua->dev); | |
179 | if (err) | |
180 | goto fail3; | |
181 | ||
182 | return 0; | |
183 | ||
184 | fail3: serio_close(serio); | |
185 | fail2: serio_set_drvdata(serio, NULL); | |
186 | fail1: input_free_device(input_dev); | |
187 | kfree(zhenhua); | |
188 | return err; | |
189 | } | |
190 | ||
191 | /* | |
192 | * The serio driver structure. | |
193 | */ | |
194 | ||
195 | static struct serio_device_id zhenhua_serio_ids[] = { | |
196 | { | |
197 | .type = SERIO_RS232, | |
198 | .proto = SERIO_ZHENHUA, | |
199 | .id = SERIO_ANY, | |
200 | .extra = SERIO_ANY, | |
201 | }, | |
202 | { 0 } | |
203 | }; | |
204 | ||
205 | MODULE_DEVICE_TABLE(serio, zhenhua_serio_ids); | |
206 | ||
207 | static struct serio_driver zhenhua_drv = { | |
208 | .driver = { | |
209 | .name = "zhenhua", | |
210 | }, | |
211 | .description = DRIVER_DESC, | |
212 | .id_table = zhenhua_serio_ids, | |
213 | .interrupt = zhenhua_interrupt, | |
214 | .connect = zhenhua_connect, | |
215 | .disconnect = zhenhua_disconnect, | |
216 | }; | |
217 | ||
65ac9f7a | 218 | module_serio_driver(zhenhua_drv); |