~funderscore blog cgit wiki get in touch
aboutsummaryrefslogtreecommitdiff
blob: 84d3852723e2d228645a1e267cd1f95b25137551 (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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * LiteX Liteeth Ethernet
 *
 * Copyright 2021 Joel Stanley <joel@jms.id.au>, IBM Corp.
 */

#include <linux/litex.h>

#include <dm.h>
#include <dm/device_compat.h>
#include <net.h>

#define LITEETH_WRITER_SLOT       0x00
#define LITEETH_WRITER_LENGTH     0x04
#define LITEETH_WRITER_ERRORS     0x08
#define LITEETH_WRITER_EV_STATUS  0x0C
#define LITEETH_WRITER_EV_PENDING 0x10
#define LITEETH_WRITER_EV_ENABLE  0x14
#define LITEETH_READER_START      0x18
#define LITEETH_READER_READY      0x1C
#define LITEETH_READER_LEVEL      0x20
#define LITEETH_READER_SLOT       0x24
#define LITEETH_READER_LENGTH     0x28
#define LITEETH_READER_EV_STATUS  0x2C
#define LITEETH_READER_EV_PENDING 0x30
#define LITEETH_READER_EV_ENABLE  0x34
#define LITEETH_PREAMBLE_CRC      0x38
#define LITEETH_PREAMBLE_ERRORS   0x3C
#define LITEETH_CRC_ERRORS        0x40

struct liteeth {
	struct udevice *dev;

	void __iomem *base;
	u32 slot_size;

	/* Tx */
	u32 tx_slot;
	u32 num_tx_slots;
	void __iomem *tx_base;

	/* Rx */
	u32 rx_slot;
	u32 num_rx_slots;
	void __iomem *rx_base;
};

static int liteeth_recv(struct udevice *dev, int flags, uchar **packetp)
{
	struct liteeth *priv = dev_get_priv(dev);
	u8 rx_slot;
	int len;

	if (!litex_read8(priv->base + LITEETH_WRITER_EV_PENDING)) {
		debug("liteeth: No packet ready\n");
		return -EAGAIN;
	}

	rx_slot = litex_read8(priv->base + LITEETH_WRITER_SLOT);
	len = litex_read32(priv->base + LITEETH_WRITER_LENGTH);

	debug("%s: slot %d len 0x%x\n", __func__, rx_slot, len);

	*packetp = priv->rx_base + rx_slot * priv->slot_size;

	return len;
}

static int liteeth_free_pkt(struct udevice *dev, uchar *packet, int length)
{
	struct liteeth *priv = dev_get_priv(dev);

	litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1);

	return 0;
}

static int liteeth_start(struct udevice *dev)
{
	struct liteeth *priv = dev_get_priv(dev);

	/* Clear pending events */
	litex_write8(priv->base + LITEETH_WRITER_EV_PENDING, 1);
	litex_write8(priv->base + LITEETH_READER_EV_PENDING, 1);

	/* Enable events */
	litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 1);
	litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 1);

	return 0;
}

static void liteeth_stop(struct udevice *dev)
{
	struct liteeth *priv = dev_get_priv(dev);

	litex_write8(priv->base + LITEETH_WRITER_EV_ENABLE, 0);
	litex_write8(priv->base + LITEETH_READER_EV_ENABLE, 0);
}

static int liteeth_send(struct udevice *dev, void *packet, int len)
{
	struct liteeth *priv = dev_get_priv(dev);
	void __iomem *txbuffer;

	if (!litex_read8(priv->base + LITEETH_READER_READY)) {
		printf("liteeth: reader not ready\n");
		return -EAGAIN;
	}

	/* Reject oversize packets */
	if (unlikely(len > priv->slot_size))
		return -EMSGSIZE;

	txbuffer = priv->tx_base + priv->tx_slot * priv->slot_size;
	memcpy_toio(txbuffer, packet, len);
	litex_write8(priv->base + LITEETH_READER_SLOT, priv->tx_slot);
	litex_write16(priv->base + LITEETH_READER_LENGTH, len);
	litex_write8(priv->base + LITEETH_READER_START, 1);

	priv->tx_slot = (priv->tx_slot + 1) % priv->num_tx_slots;

	return 0;
}

static void liteeth_setup_slots(struct liteeth *priv)
{
	int err;

	err = ofnode_read_u32(dev_ofnode(priv->dev), "litex,rx-slots", &priv->num_rx_slots);
	if (err) {
		dev_dbg(priv->dev, "unable to get litex,rx-slots, using 2\n");
		priv->num_rx_slots = 2;
	}

	err = ofnode_read_u32(dev_ofnode(priv->dev), "litex,tx-slots", &priv->num_tx_slots);
	if (err) {
		dev_dbg(priv->dev, "unable to get litex,tx-slots, using 2\n");
		priv->num_tx_slots = 2;
	}

	err = ofnode_read_u32(dev_ofnode(priv->dev), "litex,slot-size", &priv->slot_size);
	if (err) {
		dev_dbg(priv->dev, "unable to get litex,slot-size, using 0x800\n");
		priv->slot_size = 0x800;
	}
}

static int liteeth_remove(struct udevice *dev)
{
	liteeth_stop(dev);

	return 0;
}

static const struct eth_ops liteeth_ops = {
	.start = liteeth_start,
	.stop = liteeth_stop,
	.send = liteeth_send,
	.recv = liteeth_recv,
	.free_pkt = liteeth_free_pkt,
};

static int liteeth_of_to_plat(struct udevice *dev)
{
	struct eth_pdata *pdata = dev_get_plat(dev);
	struct liteeth *priv = dev_get_priv(dev);
	void __iomem *buf_base;

	pdata->iobase = dev_read_addr(dev);

	priv->dev = dev;

	priv->base = dev_remap_addr_name(dev, "mac");
	if (!priv->base) {
		dev_err(dev, "failed to map registers\n");
		return -EINVAL;
	}

	buf_base = dev_remap_addr_name(dev, "buffer");
	if (!buf_base) {
		dev_err(dev, "failed to map buffer\n");
		return -EINVAL;
	}

	liteeth_setup_slots(priv);

	/* Rx slots */
	priv->rx_base = buf_base;
	priv->rx_slot = 0;

	/* Tx slots come after Rx slots */
	priv->tx_base = buf_base + priv->num_rx_slots * priv->slot_size;
	priv->tx_slot = 0;

	return 0;
}

static const struct udevice_id liteeth_ids[] = {
	{ .compatible = "litex,liteeth" },
	{}
};

U_BOOT_DRIVER(liteeth) = {
	.name = "liteeth",
	.id = UCLASS_ETH,
	.of_match = liteeth_ids,
	.of_to_plat = liteeth_of_to_plat,
	.plat_auto = sizeof(struct eth_pdata),
	.remove = liteeth_remove,
	.ops = &liteeth_ops,
	.priv_auto = sizeof(struct liteeth),
};