summaryrefslogtreecommitdiffstats
path: root/usb/endpt0.c
blob: 7791d38e54a08a42c6feacefcd45eb51f6597f89 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
#include <arrlen.h>
#include <le.h>
#include <reg/usbotg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#include <reg/gpio.h>

#include "bdt.h"
#include "endpt0.h"

#include "descriptors.h"

#define MAX_PACKET 64
static unsigned char buf[2][MAX_PACKET];
static bool odd;
static bool data01;

static volatile unsigned int nextaddr;

static const void *tx_data;
static size_t tx_size;

struct tok_setup {
	uint8_t reqtyp;
	uint8_t req;
	uint16_t value;
	uint16_t index;
	uint16_t length;
};

/* read_setup: parse a SETUP token's data */
static void read_setup(struct tok_setup *setup, const void *_data)
{
	const unsigned char *data = _data;

	setup->reqtyp = data[0];
	setup->req = data[1];
	setup->value = le16toh(&data[2]);
	setup->index = le16toh(&data[4]);
	setup->length = le16toh(&data[6]);
}

/* TODO: Make this a shared thing across all USB endpoints */

/* puttx: place data in the current buffer descriptor */
static bool puttx(const void *data, size_t size)
{
	if (GET_BIT(BDT_ENDPT(0, BDT_TX, odd).desc, BD_OWN))
		return false;

	BDT_ENDPT(0, BDT_TX, odd).addr = (void *)data;
	BDT_ENDPT(0, BDT_TX, odd).desc = USB0_BD_INIT(size, data01);
	odd = !odd;
	data01 = !data01;

	return true;
}

/* pushtx: attempt to push rest of the current transmission into a BD */
static bool pushtx(void)
{
	size_t size = tx_size;

	if (tx_data == NULL)
		return false;

	if (size > MAX_PACKET)
		size = MAX_PACKET;

	if (!puttx(tx_data, size))
		return false;

	tx_data = (const char *)tx_data + size;
	tx_size -= size;

	if (tx_size == 0 && size < MAX_PACKET)
		tx_data = NULL;

	return true;
}

/* quetx: enqueue a transmission */
static void quetx(const void *data, size_t size)
{
	tx_data = data;
	tx_size = size;

	while (pushtx())
		;
}

/* usb_endpt0_disable: Disable endpoint 0 (not valid) */
void usb_endpt0_disable(void)
{
}

/* usb_endpt0_enable: Enable and reset endpoint 0 */
void usb_endpt0_enable(void)
{
	BDT_ENDPT(0, BDT_RX, BDT_EVEN).addr = buf[0];
	BDT_ENDPT(0, BDT_RX, BDT_EVEN).desc = USB0_BD_INIT(sizeof buf[0], 0);

	BDT_ENDPT(0, BDT_RX, BDT_ODD).addr = buf[1];
	BDT_ENDPT(0, BDT_RX, BDT_ODD).desc = USB0_BD_INIT(sizeof buf[1], 0);

	BDT_ENDPT(0, BDT_TX, BDT_EVEN).addr = NULL;
	BDT_ENDPT(0, BDT_TX, BDT_EVEN).desc = 0;

	BDT_ENDPT(0, BDT_TX, BDT_ODD).addr = NULL;
	BDT_ENDPT(0, BDT_TX, BDT_ODD).desc = 0;

	USB0_ENDPT(0) = BV(ENDPT_EPRXEN) | BV(ENDPT_EPTXEN) | BV(ENDPT_EPHSHK);
	nextaddr = 0;
	tx_data = NULL;
	odd = 0;
	data01 = 0;
}

/* trunc: truncate size_t to a limit TODO: MOVE THIS */
static inline size_t trunc(size_t val, size_t max)
{
	if (val > max)
		return max;
	return val;
}

/* tok_setup: process a setup token */
static void tok_setup(struct tok_setup *setup)
{
	switch (setup->reqtyp << 8 | setup->req) {
	case 0x0005: /* SET ADDRESS */
		nextaddr = setup->value;
		puttx(NULL, 0);
		break;
	case 0x0009: /* SET CONFIGURATION */
		puttx(NULL, 0);
		break;
	case 0x8006: /* GET DESCRIPTOR */
		switch (setup->value) {
		case 0x0100: /* DEVICE */
			quetx(ds_dev, trunc(ARRLEN(ds_dev), setup->length));
			return;
		case 0x0200: /* CONFIGURATION */
			quetx(ds_conf, trunc(ARRLEN(ds_conf), setup->length));
			return;
		case 0x0300: /* STRING 0 */
			quetx(ds_lang, trunc(ARRLEN(ds_lang), setup->length));
			return;
		case 0x0301: /* STRING 1 */
			quetx(ds_str1, trunc(ARRLEN(ds_str1), setup->length));
			return;
		}
		/* fall through */
	default:
		SET_BIT(USB0_ENDPT(0), ENDPT_EPSTALL);
		break;
	}
}

void usb_endpt0_token(uint8_t state)
{
	struct usb0_bd *bd;
	struct tok_setup setup;

	bd = &BDT_ENDPT(0, GET_BIT(state, STAT_TX), GET_BIT(state, STAT_ODD));


	switch (GET_BITS(bd->desc, BD_TOK_PID)) {
	case BD_TOK_PID_OUT:
		bd->desc = USB0_BD_INIT(sizeof buf[0], 1);
		break;
	case BD_TOK_PID_IN:
		pushtx();
		if (nextaddr) {
			USB0_ADDR = nextaddr;
			nextaddr = 0;
		}
		break;
	case BD_TOK_PID_SETUP:
		read_setup(&setup, bd->addr);
		bd->desc = USB0_BD_INIT(sizeof buf[0], 1);

		BDT_ENDPT(0, BDT_TX, BDT_EVEN).desc = 0;
		BDT_ENDPT(0, BDT_TX, BDT_ODD).desc = 0;
		tx_data = NULL;

		data01 = 1;

		tok_setup(&setup);

		break;
	}

	USB0_CTL = BV(CTL_USBENSOFEN);
}