1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Microchip KSZ8863 series register access through SMI
4  *
5  * Copyright (C) 2019 Pengutronix, Michael Grzeschik <kernel@pengutronix.de>
6  */
7 
8 #include "ksz8.h"
9 #include "ksz_common.h"
10 
11 /* Serial Management Interface (SMI) uses the following frame format:
12  *
13  *       preamble|start|Read/Write|  PHY   |  REG  |TA|   Data bits      | Idle
14  *               |frame| OP code  |address |address|  |                  |
15  * read | 32x1´s | 01  |    00    | 1xRRR  | RRRRR |Z0| 00000000DDDDDDDD |  Z
16  * write| 32x1´s | 01  |    00    | 0xRRR  | RRRRR |10| xxxxxxxxDDDDDDDD |  Z
17  *
18  */
19 
20 #define SMI_KSZ88XX_READ_PHY	BIT(4)
21 
22 static int ksz8863_mdio_read(void *ctx, const void *reg_buf, size_t reg_len,
23 			     void *val_buf, size_t val_len)
24 {
25 	struct ksz_device *dev = ctx;
26 	struct mdio_device *mdev;
27 	u8 reg = *(u8 *)reg_buf;
28 	u8 *val = val_buf;
29 	int i, ret = 0;
30 
31 	mdev = dev->priv;
32 
33 	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
34 	for (i = 0; i < val_len; i++) {
35 		int tmp = reg + i;
36 
37 		ret = __mdiobus_read(mdev->bus, ((tmp & 0xE0) >> 5) |
38 				     SMI_KSZ88XX_READ_PHY, tmp);
39 		if (ret < 0)
40 			goto out;
41 
42 		val[i] = ret;
43 	}
44 	ret = 0;
45 
46  out:
47 	mutex_unlock(&mdev->bus->mdio_lock);
48 
49 	return ret;
50 }
51 
52 static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
53 {
54 	struct ksz_device *dev = ctx;
55 	struct mdio_device *mdev;
56 	int i, ret = 0;
57 	u32 reg;
58 	u8 *val;
59 
60 	mdev = dev->priv;
61 
62 	val = (u8 *)(data + 4);
63 	reg = *(u32 *)data;
64 
65 	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
66 	for (i = 0; i < (count - 4); i++) {
67 		int tmp = reg + i;
68 
69 		ret = __mdiobus_write(mdev->bus, ((tmp & 0xE0) >> 5),
70 				      tmp, val[i]);
71 		if (ret < 0)
72 			goto out;
73 	}
74 
75  out:
76 	mutex_unlock(&mdev->bus->mdio_lock);
77 
78 	return ret;
79 }
80 
81 static const struct regmap_bus regmap_smi[] = {
82 	{
83 		.read = ksz8863_mdio_read,
84 		.write = ksz8863_mdio_write,
85 	},
86 	{
87 		.read = ksz8863_mdio_read,
88 		.write = ksz8863_mdio_write,
89 		.val_format_endian_default = REGMAP_ENDIAN_BIG,
90 	},
91 	{
92 		.read = ksz8863_mdio_read,
93 		.write = ksz8863_mdio_write,
94 		.val_format_endian_default = REGMAP_ENDIAN_BIG,
95 	}
96 };
97 
98 static const struct regmap_config ksz8863_regmap_config[] = {
99 	{
100 		.name = "#8",
101 		.reg_bits = 8,
102 		.pad_bits = 24,
103 		.val_bits = 8,
104 		.cache_type = REGCACHE_NONE,
105 		.lock = ksz_regmap_lock,
106 		.unlock = ksz_regmap_unlock,
107 		.max_register = U8_MAX,
108 	},
109 	{
110 		.name = "#16",
111 		.reg_bits = 8,
112 		.pad_bits = 24,
113 		.val_bits = 16,
114 		.cache_type = REGCACHE_NONE,
115 		.lock = ksz_regmap_lock,
116 		.unlock = ksz_regmap_unlock,
117 		.max_register = U8_MAX,
118 	},
119 	{
120 		.name = "#32",
121 		.reg_bits = 8,
122 		.pad_bits = 24,
123 		.val_bits = 32,
124 		.cache_type = REGCACHE_NONE,
125 		.lock = ksz_regmap_lock,
126 		.unlock = ksz_regmap_unlock,
127 		.max_register = U8_MAX,
128 	}
129 };
130 
131 static int ksz8863_smi_probe(struct mdio_device *mdiodev)
132 {
133 	struct device *ddev = &mdiodev->dev;
134 	const struct ksz_chip_data *chip;
135 	struct regmap_config rc;
136 	struct ksz_device *dev;
137 	int ret;
138 	int i;
139 
140 	dev = ksz_switch_alloc(&mdiodev->dev, mdiodev);
141 	if (!dev)
142 		return -ENOMEM;
143 
144 	chip = device_get_match_data(ddev);
145 	if (!chip)
146 		return -EINVAL;
147 
148 	for (i = 0; i < __KSZ_NUM_REGMAPS; i++) {
149 		rc = ksz8863_regmap_config[i];
150 		rc.lock_arg = &dev->regmap_mutex;
151 		rc.wr_table = chip->wr_table;
152 		rc.rd_table = chip->rd_table;
153 		dev->regmap[i] = devm_regmap_init(&mdiodev->dev,
154 						  &regmap_smi[i], dev,
155 						  &rc);
156 		if (IS_ERR(dev->regmap[i])) {
157 			return dev_err_probe(&mdiodev->dev,
158 					     PTR_ERR(dev->regmap[i]),
159 					     "Failed to initialize regmap%i\n",
160 					     ksz8863_regmap_config[i].val_bits);
161 		}
162 	}
163 
164 	if (mdiodev->dev.platform_data)
165 		dev->pdata = mdiodev->dev.platform_data;
166 
167 	ret = ksz_switch_register(dev);
168 
169 	/* Main DSA driver may not be started yet. */
170 	if (ret)
171 		return ret;
172 
173 	dev_set_drvdata(&mdiodev->dev, dev);
174 
175 	return 0;
176 }
177 
178 static void ksz8863_smi_remove(struct mdio_device *mdiodev)
179 {
180 	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
181 
182 	if (dev)
183 		ksz_switch_remove(dev);
184 }
185 
186 static void ksz8863_smi_shutdown(struct mdio_device *mdiodev)
187 {
188 	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
189 
190 	if (dev)
191 		dsa_switch_shutdown(dev->ds);
192 
193 	dev_set_drvdata(&mdiodev->dev, NULL);
194 }
195 
196 static const struct of_device_id ksz8863_dt_ids[] = {
197 	{
198 		.compatible = "microchip,ksz8863",
199 		.data = &ksz_switch_chips[KSZ8830]
200 	},
201 	{
202 		.compatible = "microchip,ksz8873",
203 		.data = &ksz_switch_chips[KSZ8830]
204 	},
205 	{ },
206 };
207 MODULE_DEVICE_TABLE(of, ksz8863_dt_ids);
208 
209 static struct mdio_driver ksz8863_driver = {
210 	.probe	= ksz8863_smi_probe,
211 	.remove	= ksz8863_smi_remove,
212 	.shutdown = ksz8863_smi_shutdown,
213 	.mdiodrv.driver = {
214 		.name	= "ksz8863-switch",
215 		.of_match_table = ksz8863_dt_ids,
216 	},
217 };
218 
219 mdio_module_driver(ksz8863_driver);
220 
221 MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
222 MODULE_DESCRIPTION("Microchip KSZ8863 SMI Switch driver");
223 MODULE_LICENSE("GPL v2");
224