1 // SPDX-License-Identifier: GPL-2.0-or-later
7  *  Copyright (c) 2000-2001 Vojtech Pavlik
12  * Driver to use 4CH RC transmitter using Zhen Hua 5-byte protocol (Walkera Lama,
15  * RC transmitters using Zhen Hua 5-byte protocol are cheap four channels
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
27  * Martin Kebert <gkmarty@gmail.com> - but I am not a C-programmer nor kernel
28  * coder :-(
38 #define DRIVER_DESC	"RC transmitter with 5-byte Zhen Hua protocol joystick driver"
47 #define ZHENHUA_MAX_LENGTH 5
67 	struct input_dev *dev = zhenhua->dev;  in zhenhua_process_packet()
68 	unsigned char *data = zhenhua->data;  in zhenhua_process_packet()
88 	/* All Zhen Hua packets are 5 bytes. The fact that the first byte  in zhenhua_interrupt()
89 	 * is allways 0xf7 and all others are in range 0x32 - 0xc8 (50-200)  in zhenhua_interrupt()
93 		zhenhua->idx = 0;	/* this byte starts a new packet */  in zhenhua_interrupt()
94 	else if (zhenhua->idx == 0)  in zhenhua_interrupt()
95 		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */  in zhenhua_interrupt()
97 	if (zhenhua->idx < ZHENHUA_MAX_LENGTH)  in zhenhua_interrupt()
98 		zhenhua->data[zhenhua->idx++] = bitrev8(data);  in zhenhua_interrupt()
100 	if (zhenhua->idx == ZHENHUA_MAX_LENGTH) {  in zhenhua_interrupt()
102 		zhenhua->idx = 0;  in zhenhua_interrupt()
118 	input_unregister_device(zhenhua->dev);  in zhenhua_disconnect()
132 	int err = -ENOMEM;  in zhenhua_connect()
139 	zhenhua->dev = input_dev;  in zhenhua_connect()
140 	snprintf(zhenhua->phys, sizeof(zhenhua->phys), "%s/input0", serio->phys);  in zhenhua_connect()
142 	input_dev->name = "Zhen Hua 5-byte device";  in zhenhua_connect()
143 	input_dev->phys = zhenhua->phys;  in zhenhua_connect()
144 	input_dev->id.bustype = BUS_RS232;  in zhenhua_connect()
145 	input_dev->id.vendor = SERIO_ZHENHUA;  in zhenhua_connect()
146 	input_dev->id.product = 0x0001;  in zhenhua_connect()
147 	input_dev->id.version = 0x0100;  in zhenhua_connect()
148 	input_dev->dev.parent = &serio->dev;  in zhenhua_connect()
150 	input_dev->evbit[0] = BIT(EV_ABS);  in zhenhua_connect()
162 	err = input_register_device(zhenhua->dev);  in zhenhua_connect()