1// SPDX-License-Identifier: GPL-2.0
  2/* DSA driver for:
  3 * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch
  4 * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch
  5 * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch
  6 * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch
  7 *
  8 * This driver takes control of the switch chip over SPI and
  9 * configures it to route packages around when connected to a CPU port.
 10 *
 11 * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org>
 12 * Includes portions of code from the firmware uploader by:
 13 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
 14 */
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/of.h>
 18#include <linux/spi/spi.h>
 19
 20#include "vitesse-vsc73xx.h"
 21
 22#define VSC73XX_CMD_SPI_MODE_READ		0
 23#define VSC73XX_CMD_SPI_MODE_WRITE		1
 24#define VSC73XX_CMD_SPI_MODE_SHIFT		4
 25#define VSC73XX_CMD_SPI_BLOCK_SHIFT		5
 26#define VSC73XX_CMD_SPI_BLOCK_MASK		0x7
 27#define VSC73XX_CMD_SPI_SUBBLOCK_MASK		0xf
 28
 29/*
 30 * struct vsc73xx_spi - VSC73xx SPI state container
 31 */
 32struct vsc73xx_spi {
 33	struct spi_device	*spi;
 34	struct mutex		lock; /* Protects SPI traffic */
 35	struct vsc73xx		vsc;
 36};
 37
 38static const struct vsc73xx_ops vsc73xx_spi_ops;
 39
 40static u8 vsc73xx_make_addr(u8 mode, u8 block, u8 subblock)
 41{
 42	u8 ret;
 43
 44	ret =
 45	    (block & VSC73XX_CMD_SPI_BLOCK_MASK) << VSC73XX_CMD_SPI_BLOCK_SHIFT;
 46	ret |= (mode & 1) << VSC73XX_CMD_SPI_MODE_SHIFT;
 47	ret |= subblock & VSC73XX_CMD_SPI_SUBBLOCK_MASK;
 48
 49	return ret;
 50}
 51
 52static int vsc73xx_spi_read(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
 53			    u32 *val)
 54{
 55	struct vsc73xx_spi *vsc_spi = vsc->priv;
 56	struct spi_transfer t[2];
 57	struct spi_message m;
 58	u8 cmd[4];
 59	u8 buf[4];
 60	int ret;
 61
 62	if (!vsc73xx_is_addr_valid(block, subblock))
 63		return -EINVAL;
 64
 65	spi_message_init(&m);
 66
 67	memset(&t, 0, sizeof(t));
 68
 69	t[0].tx_buf = cmd;
 70	t[0].len = sizeof(cmd);
 71	spi_message_add_tail(&t[0], &m);
 72
 73	t[1].rx_buf = buf;
 74	t[1].len = sizeof(buf);
 75	spi_message_add_tail(&t[1], &m);
 76
 77	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_READ, block, subblock);
 78	cmd[1] = reg;
 79	cmd[2] = 0;
 80	cmd[3] = 0;
 81
 82	mutex_lock(&vsc_spi->lock);
 83	ret = spi_sync(vsc_spi->spi, &m);
 84	mutex_unlock(&vsc_spi->lock);
 85
 86	if (ret)
 87		return ret;
 88
 89	*val = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
 90
 91	return 0;
 92}
 93
 94static int vsc73xx_spi_write(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg,
 95			     u32 val)
 96{
 97	struct vsc73xx_spi *vsc_spi = vsc->priv;
 98	struct spi_transfer t[2];
 99	struct spi_message m;
100	u8 cmd[2];
101	u8 buf[4];
102	int ret;
103
104	if (!vsc73xx_is_addr_valid(block, subblock))
105		return -EINVAL;
106
107	spi_message_init(&m);
108
109	memset(&t, 0, sizeof(t));
110
111	t[0].tx_buf = cmd;
112	t[0].len = sizeof(cmd);
113	spi_message_add_tail(&t[0], &m);
114
115	t[1].tx_buf = buf;
116	t[1].len = sizeof(buf);
117	spi_message_add_tail(&t[1], &m);
118
119	cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_WRITE, block, subblock);
120	cmd[1] = reg;
121
122	buf[0] = (val >> 24) & 0xff;
123	buf[1] = (val >> 16) & 0xff;
124	buf[2] = (val >> 8) & 0xff;
125	buf[3] = val & 0xff;
126
127	mutex_lock(&vsc_spi->lock);
128	ret = spi_sync(vsc_spi->spi, &m);
129	mutex_unlock(&vsc_spi->lock);
130
131	return ret;
132}
133
134static int vsc73xx_spi_probe(struct spi_device *spi)
135{
136	struct device *dev = &spi->dev;
137	struct vsc73xx_spi *vsc_spi;
138	int ret;
139
140	vsc_spi = devm_kzalloc(dev, sizeof(*vsc_spi), GFP_KERNEL);
141	if (!vsc_spi)
142		return -ENOMEM;
143
144	spi_set_drvdata(spi, vsc_spi);
145	vsc_spi->spi = spi_dev_get(spi);
146	vsc_spi->vsc.dev = dev;
147	vsc_spi->vsc.priv = vsc_spi;
148	vsc_spi->vsc.ops = &vsc73xx_spi_ops;
149	mutex_init(&vsc_spi->lock);
150
151	spi->mode = SPI_MODE_0;
152	spi->bits_per_word = 8;
153	ret = spi_setup(spi);
154	if (ret < 0) {
155		dev_err(dev, "spi setup failed.\n");
156		return ret;
157	}
158
159	return vsc73xx_probe(&vsc_spi->vsc);
160}
161
162static void vsc73xx_spi_remove(struct spi_device *spi)
163{
164	struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi);
165
166	if (!vsc_spi)
167		return;
168
169	vsc73xx_remove(&vsc_spi->vsc);
170}
171
172static void vsc73xx_spi_shutdown(struct spi_device *spi)
173{
174	struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi);
175
176	if (!vsc_spi)
177		return;
178
179	vsc73xx_shutdown(&vsc_spi->vsc);
180
181	spi_set_drvdata(spi, NULL);
182}
183
184static const struct vsc73xx_ops vsc73xx_spi_ops = {
185	.read = vsc73xx_spi_read,
186	.write = vsc73xx_spi_write,
187};
188
189static const struct of_device_id vsc73xx_of_match[] = {
190	{
191		.compatible = "vitesse,vsc7385",
192	},
193	{
194		.compatible = "vitesse,vsc7388",
195	},
196	{
197		.compatible = "vitesse,vsc7395",
198	},
199	{
200		.compatible = "vitesse,vsc7398",
201	},
202	{ },
203};
204MODULE_DEVICE_TABLE(of, vsc73xx_of_match);
205
206static const struct spi_device_id vsc73xx_spi_ids[] = {
207	{ "vsc7385" },
208	{ "vsc7388" },
209	{ "vsc7395" },
210	{ "vsc7398" },
211	{ },
212};
213MODULE_DEVICE_TABLE(spi, vsc73xx_spi_ids);
214
215static struct spi_driver vsc73xx_spi_driver = {
216	.probe = vsc73xx_spi_probe,
217	.remove = vsc73xx_spi_remove,
218	.shutdown = vsc73xx_spi_shutdown,
219	.id_table = vsc73xx_spi_ids,
220	.driver = {
221		.name = "vsc73xx-spi",
222		.of_match_table = vsc73xx_of_match,
223	},
224};
225module_spi_driver(vsc73xx_spi_driver);
226
227MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
228MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 SPI driver");
229MODULE_LICENSE("GPL v2");