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47#include <linux/kernel.h>
48#include <linux/module.h>
49#include <linux/slab.h>
50#include <linux/bitrev.h>
51#include <linux/input.h>
52#include <linux/serio.h>
53
54#define DRIVER_DESC "RC transmitter with 5-byte Zhen Hua protocol joystick driver"
55
56MODULE_DESCRIPTION(DRIVER_DESC);
57MODULE_LICENSE("GPL");
58
59
60
61
62
63#define ZHENHUA_MAX_LENGTH 5
64
65
66
67
68
69struct zhenhua {
70 struct input_dev *dev;
71 int idx;
72 unsigned char data[ZHENHUA_MAX_LENGTH];
73 char phys[32];
74};
75
76
77
78
79
80
81static 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
96
97
98
99
100static irqreturn_t zhenhua_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
101{
102 struct zhenhua *zhenhua = serio_get_drvdata(serio);
103
104
105
106
107
108 if (data == 0xef)
109 zhenhua->idx = 0;
110 else if (zhenhua->idx == 0)
111 return IRQ_HANDLED;
112
113 if (zhenhua->idx < ZHENHUA_MAX_LENGTH)
114 zhenhua->data[zhenhua->idx++] = bitrev8(data);
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
126
127
128static 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
140
141
142
143
144static 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
193
194
195static 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
205MODULE_DEVICE_TABLE(serio, zhenhua_serio_ids);
206
207static 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
218module_serio_driver(zhenhua_drv);
219