1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux driver for TerraTec DMX 6Fire USB
4  *
5  * Device communications
6  *
7  * Author:	Torsten Schenk <torsten.schenk@zoho.com>
8  * Created:	Jan 01, 2011
9  * Copyright:	(C) Torsten Schenk
10  */
11 
12 #include "comm.h"
13 #include "chip.h"
14 #include "midi.h"
15 
16 enum {
17 	COMM_EP = 1,
18 	COMM_FPGA_EP = 2
19 };
20 
usb6fire_comm_init_urb(struct comm_runtime * rt,struct urb * urb,u8 * buffer,void * context,void (* handler)(struct urb * urb))21 static void usb6fire_comm_init_urb(struct comm_runtime *rt, struct urb *urb,
22 		u8 *buffer, void *context, void(*handler)(struct urb *urb))
23 {
24 	usb_init_urb(urb);
25 	urb->transfer_buffer = buffer;
26 	urb->pipe = usb_sndintpipe(rt->chip->dev, COMM_EP);
27 	urb->complete = handler;
28 	urb->context = context;
29 	urb->interval = 1;
30 	urb->dev = rt->chip->dev;
31 }
32 
usb6fire_comm_receiver_handler(struct urb * urb)33 static void usb6fire_comm_receiver_handler(struct urb *urb)
34 {
35 	struct comm_runtime *rt = urb->context;
36 	struct midi_runtime *midi_rt = rt->chip->midi;
37 
38 	if (!urb->status) {
39 		if (rt->receiver_buffer[0] == 0x10) /* midi in event */
40 			if (midi_rt)
41 				midi_rt->in_received(midi_rt,
42 						rt->receiver_buffer + 2,
43 						rt->receiver_buffer[1]);
44 	}
45 
46 	if (!rt->chip->shutdown) {
47 		urb->status = 0;
48 		urb->actual_length = 0;
49 		if (usb_submit_urb(urb, GFP_ATOMIC) < 0)
50 			dev_warn(&urb->dev->dev,
51 					"comm data receiver aborted.\n");
52 	}
53 }
54 
usb6fire_comm_init_buffer(u8 * buffer,u8 id,u8 request,u8 reg,u8 vl,u8 vh)55 static void usb6fire_comm_init_buffer(u8 *buffer, u8 id, u8 request,
56 		u8 reg, u8 vl, u8 vh)
57 {
58 	buffer[0] = 0x01;
59 	buffer[2] = request;
60 	buffer[3] = id;
61 	switch (request) {
62 	case 0x02:
63 		buffer[1] = 0x05; /* length (starting at buffer[2]) */
64 		buffer[4] = reg;
65 		buffer[5] = vl;
66 		buffer[6] = vh;
67 		break;
68 
69 	case 0x12:
70 		buffer[1] = 0x0b; /* length (starting at buffer[2]) */
71 		buffer[4] = 0x00;
72 		buffer[5] = 0x18;
73 		buffer[6] = 0x05;
74 		buffer[7] = 0x00;
75 		buffer[8] = 0x01;
76 		buffer[9] = 0x00;
77 		buffer[10] = 0x9e;
78 		buffer[11] = reg;
79 		buffer[12] = vl;
80 		break;
81 
82 	case 0x20:
83 	case 0x21:
84 	case 0x22:
85 		buffer[1] = 0x04;
86 		buffer[4] = reg;
87 		buffer[5] = vl;
88 		break;
89 	}
90 }
91 
usb6fire_comm_send_buffer(u8 * buffer,struct usb_device * dev)92 static int usb6fire_comm_send_buffer(u8 *buffer, struct usb_device *dev)
93 {
94 	int ret;
95 	int actual_len;
96 
97 	ret = usb_interrupt_msg(dev, usb_sndintpipe(dev, COMM_EP),
98 			buffer, buffer[1] + 2, &actual_len, 1000);
99 	if (ret < 0)
100 		return ret;
101 	else if (actual_len != buffer[1] + 2)
102 		return -EIO;
103 	return 0;
104 }
105 
usb6fire_comm_write8(struct comm_runtime * rt,u8 request,u8 reg,u8 value)106 static int usb6fire_comm_write8(struct comm_runtime *rt, u8 request,
107 		u8 reg, u8 value)
108 {
109 	u8 *buffer;
110 	int ret;
111 
112 	/* 13: maximum length of message */
113 	buffer = kmalloc(13, GFP_KERNEL);
114 	if (!buffer)
115 		return -ENOMEM;
116 
117 	usb6fire_comm_init_buffer(buffer, 0x00, request, reg, value, 0x00);
118 	ret = usb6fire_comm_send_buffer(buffer, rt->chip->dev);
119 
120 	kfree(buffer);
121 	return ret;
122 }
123 
usb6fire_comm_write16(struct comm_runtime * rt,u8 request,u8 reg,u8 vl,u8 vh)124 static int usb6fire_comm_write16(struct comm_runtime *rt, u8 request,
125 		u8 reg, u8 vl, u8 vh)
126 {
127 	u8 *buffer;
128 	int ret;
129 
130 	/* 13: maximum length of message */
131 	buffer = kmalloc(13, GFP_KERNEL);
132 	if (!buffer)
133 		return -ENOMEM;
134 
135 	usb6fire_comm_init_buffer(buffer, 0x00, request, reg, vl, vh);
136 	ret = usb6fire_comm_send_buffer(buffer, rt->chip->dev);
137 
138 	kfree(buffer);
139 	return ret;
140 }
141 
usb6fire_comm_init(struct sfire_chip * chip)142 int usb6fire_comm_init(struct sfire_chip *chip)
143 {
144 	struct comm_runtime *rt = kzalloc(sizeof(struct comm_runtime),
145 			GFP_KERNEL);
146 	struct urb *urb;
147 	int ret;
148 
149 	if (!rt)
150 		return -ENOMEM;
151 
152 	rt->receiver_buffer = kzalloc(COMM_RECEIVER_BUFSIZE, GFP_KERNEL);
153 	if (!rt->receiver_buffer) {
154 		kfree(rt);
155 		return -ENOMEM;
156 	}
157 
158 	urb = &rt->receiver;
159 	rt->serial = 1;
160 	rt->chip = chip;
161 	usb_init_urb(urb);
162 	rt->init_urb = usb6fire_comm_init_urb;
163 	rt->write8 = usb6fire_comm_write8;
164 	rt->write16 = usb6fire_comm_write16;
165 
166 	/* submit an urb that receives communication data from device */
167 	urb->transfer_buffer = rt->receiver_buffer;
168 	urb->transfer_buffer_length = COMM_RECEIVER_BUFSIZE;
169 	urb->pipe = usb_rcvintpipe(chip->dev, COMM_EP);
170 	urb->dev = chip->dev;
171 	urb->complete = usb6fire_comm_receiver_handler;
172 	urb->context = rt;
173 	urb->interval = 1;
174 	ret = usb_submit_urb(urb, GFP_KERNEL);
175 	if (ret < 0) {
176 		kfree(rt->receiver_buffer);
177 		kfree(rt);
178 		dev_err(&chip->dev->dev, "cannot create comm data receiver.");
179 		return ret;
180 	}
181 	chip->comm = rt;
182 	return 0;
183 }
184 
usb6fire_comm_abort(struct sfire_chip * chip)185 void usb6fire_comm_abort(struct sfire_chip *chip)
186 {
187 	struct comm_runtime *rt = chip->comm;
188 
189 	if (rt)
190 		usb_poison_urb(&rt->receiver);
191 }
192 
usb6fire_comm_destroy(struct sfire_chip * chip)193 void usb6fire_comm_destroy(struct sfire_chip *chip)
194 {
195 	struct comm_runtime *rt = chip->comm;
196 
197 	kfree(rt->receiver_buffer);
198 	kfree(rt);
199 	chip->comm = NULL;
200 }
201