summaryrefslogtreecommitdiffstats
path: root/drivers/net/dsa/vitesse-vsc73xx-spi.c
blob: e73c8fcddc9fcbd80630fd4b74b15dba15dafc54 (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
// SPDX-License-Identifier: GPL-2.0
/* DSA driver for:
 * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch
 * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch
 *
 * This driver takes control of the switch chip over SPI and
 * configures it to route packages around when connected to a CPU port.
 *
 * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org>
 * Includes portions of code from the firmware uploader by:
 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/spi/spi.h>

#include "vitesse-vsc73xx.h"

#define VSC73XX_CMD_SPI_MODE_READ		0
#define VSC73XX_CMD_SPI_MODE_WRITE		1
#define VSC73XX_CMD_SPI_MODE_SHIFT		4
#define VSC73XX_CMD_SPI_BLOCK_SHIFT		5
#define VSC73XX_CMD_SPI_BLOCK_MASK		0x7
#define VSC73XX_CMD_SPI_SUBBLOCK_MASK		0xf

/**
 * struct vsc73xx_spi - VSC73xx SPI state container
 */
struct vsc73xx_spi {
	struct spi_device	*spi;
	struct mutex		lock; /* Protects SPI traffic */
	struct vsc73xx		vsc;
};

static const struct vsc73xx_ops vsc73xx_spi_ops;

static u8 vsc73xx_make_addr(u8 mode, u8 block, u8 subblock)
{
	u8 ret;

	ret =
	    (block & VSC73XX_CMD_SPI_BLOCK_MASK) << VSC73XX_CMD_SPI_BLOCK_SHIFT;
	ret |= (mode & 1) << VSC73XX_CMD_SPI_MODE_SHIFT;
	ret |= subblock & VSC73XX_CMD_SPI_SUBBLOCK_MASK;

	return ret;
}

static int vsc73xx_spi_read(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
			    u32 *val)
{
	struct vsc73xx_spi *vsc_spi = vsc->priv;
	struct spi_transfer t[2];
	struct spi_message m;
	u8 cmd[4];
	u8 buf[4];
	int ret;

	if (!vsc73xx_is_addr_valid(block, subblock))
		return -EINVAL;

	spi_message_init(&m);

	memset(&t, 0, sizeof(t));

	t[0].tx_buf = cmd;
	t[0].len = sizeof(cmd);
	spi_message_add_tail(&t[0], &m);

	t[1].rx_buf = buf;
	t[1].len = sizeof(buf);
	spi_message_add_tail(&t[1], &m);

	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_READ, block, subblock);
	cmd[1] = reg;
	cmd[2] = 0;
	cmd[3] = 0;

	mutex_lock(&vsc_spi->lock);
	ret = spi_sync(vsc_spi->spi, &m);
	mutex_unlock(&vsc_spi->lock);

	if (ret)
		return ret;

	*val = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

	return 0;
}

static int vsc73xx_spi_write(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
			     u32 val)
{
	struct vsc73xx_spi *vsc_spi = vsc->priv;
	struct spi_transfer t[2];
	struct spi_message m;
	u8 cmd[2];
	u8 buf[4];
	int ret;

	if (!vsc73xx_is_addr_valid(block, subblock))
		return -EINVAL;

	spi_message_init(&m);

	memset(&t, 0, sizeof(t));

	t[0].tx_buf = cmd;
	t[0].len = sizeof(cmd);
	spi_message_add_tail(&t[0], &m);

	t[1].tx_buf = buf;
	t[1].len = sizeof(buf);
	spi_message_add_tail(&t[1], &m);

	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_WRITE, block, subblock);
	cmd[1] = reg;

	buf[0] = (val >> 24) & 0xff;
	buf[1] = (val >> 16) & 0xff;
	buf[2] = (val >> 8) & 0xff;
	buf[3] = val & 0xff;

	mutex_lock(&vsc_spi->lock);
	ret = spi_sync(vsc_spi->spi, &m);
	mutex_unlock(&vsc_spi->lock);

	return ret;
}

static int vsc73xx_spi_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	struct vsc73xx_spi *vsc_spi;
	int ret;

	vsc_spi = devm_kzalloc(dev, sizeof(*vsc_spi), GFP_KERNEL);
	if (!vsc_spi)
		return -ENOMEM;

	spi_set_drvdata(spi, vsc_spi);
	vsc_spi->spi = spi_dev_get(spi);
	vsc_spi->vsc.dev = dev;
	vsc_spi->vsc.priv = vsc_spi;
	vsc_spi->vsc.ops = &vsc73xx_spi_ops;
	mutex_init(&vsc_spi->lock);

	spi->mode = SPI_MODE_0;
	spi->bits_per_word = 8;
	ret = spi_setup(spi);
	if (ret < 0) {
		dev_err(dev, "spi setup failed.\n");
		return ret;
	}

	return vsc73xx_probe(&vsc_spi->vsc);
}

static int vsc73xx_spi_remove(struct spi_device *spi)
{
	struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi);

	return vsc73xx_remove(&vsc_spi->vsc);
}

static const struct vsc73xx_ops vsc73xx_spi_ops = {
	.read = vsc73xx_spi_read,
	.write = vsc73xx_spi_write,
};

static const struct of_device_id vsc73xx_of_match[] = {
	{
		.compatible = "vitesse,vsc7385",
	},
	{
		.compatible = "vitesse,vsc7388",
	},
	{
		.compatible = "vitesse,vsc7395",
	},
	{
		.compatible = "vitesse,vsc7398",
	},
	{ },
};
MODULE_DEVICE_TABLE(of, vsc73xx_of_match);

static struct spi_driver vsc73xx_spi_driver = {
	.probe = vsc73xx_spi_probe,
	.remove = vsc73xx_spi_remove,
	.driver = {
		.name = "vsc73xx-spi",
		.of_match_table = vsc73xx_of_match,
	},
};
module_spi_driver(vsc73xx_spi_driver);

MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 SPI driver");
MODULE_LICENSE("GPL v2");