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 <linux/mod_devicetable.h>
9 #include <linux/property.h>
10 
11 #include "ksz8.h"
12 #include "ksz_common.h"
13 
14 /* Serial Management Interface (SMI) uses the following frame format:
15  *
16  *       preamble|start|Read/Write|  PHY   |  REG  |TA|   Data bits      | Idle
17  *               |frame| OP code  |address |address|  |                  |
18  * read | 32x1´s | 01  |    00    | 1xRRR  | RRRRR |Z0| 00000000DDDDDDDD |  Z
19  * write| 32x1´s | 01  |    00    | 0xRRR  | RRRRR |10| xxxxxxxxDDDDDDDD |  Z
20  *
21  */
22 
23 #define SMI_KSZ88XX_READ_PHY	BIT(4)
24 
25 static int ksz8863_mdio_read(void *ctx, const void *reg_buf, size_t reg_len,
26 			     void *val_buf, size_t val_len)
27 {
28 	struct ksz_device *dev = ctx;
29 	struct mdio_device *mdev;
30 	u8 reg = *(u8 *)reg_buf;
31 	u8 *val = val_buf;
32 	int i, ret = 0;
33 
34 	mdev = dev->priv;
35 
36 	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
37 	for (i = 0; i < val_len; i++) {
38 		int tmp = reg + i;
39 
40 		ret = __mdiobus_read(mdev->bus, ((tmp & 0xE0) >> 5) |
41 				     SMI_KSZ88XX_READ_PHY, tmp);
42 		if (ret < 0)
43 			goto out;
44 
45 		val[i] = ret;
46 	}
47 	ret = 0;
48 
49  out:
50 	mutex_unlock(&mdev->bus->mdio_lock);
51 
52 	return ret;
53 }
54 
55 static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
56 {
57 	struct ksz_device *dev = ctx;
58 	struct mdio_device *mdev;
59 	int i, ret = 0;
60 	u32 reg;
61 	u8 *val;
62 
63 	mdev = dev->priv;
64 
65 	val = (u8 *)(data + 4);
66 	reg = *(u32 *)data;
67 
68 	mutex_lock_nested(&mdev->bus->mdio_lock, MDIO_MUTEX_NESTED);
69 	for (i = 0; i < (count - 4); i++) {
70 		int tmp = reg + i;
71 
72 		ret = __mdiobus_write(mdev->bus, ((tmp & 0xE0) >> 5),
73 				      tmp, val[i]);
74 		if (ret < 0)
75 			goto out;
76 	}
77 
78  out:
79 	mutex_unlock(&mdev->bus->mdio_lock);
80 
81 	return ret;
82 }
83 
84 static const struct regmap_bus regmap_smi[] = {
85 	{
86 		.read = ksz8863_mdio_read,
87 		.write = ksz8863_mdio_write,
88 	},
89 	{
90 		.read = ksz8863_mdio_read,
91 		.write = ksz8863_mdio_write,
92 		.val_format_endian_default = REGMAP_ENDIAN_BIG,
93 	},
94 	{
95 		.read = ksz8863_mdio_read,
96 		.write = ksz8863_mdio_write,
97 		.val_format_endian_default = REGMAP_ENDIAN_BIG,
98 	}
99 };
100 
101 static const struct regmap_config ksz8863_regmap_config[] = {
102 	{
103 		.name = "#8",
104 		.reg_bits = 8,
105 		.pad_bits = 24,
106 		.val_bits = 8,
107 		.cache_type = REGCACHE_NONE,
108 		.lock = ksz_regmap_lock,
109 		.unlock = ksz_regmap_unlock,
110 		.max_register = U8_MAX,
111 	},
112 	{
113 		.name = "#16",
114 		.reg_bits = 8,
115 		.pad_bits = 24,
116 		.val_bits = 16,
117 		.cache_type = REGCACHE_NONE,
118 		.lock = ksz_regmap_lock,
119 		.unlock = ksz_regmap_unlock,
120 		.max_register = U8_MAX,
121 	},
122 	{
123 		.name = "#32",
124 		.reg_bits = 8,
125 		.pad_bits = 24,
126 		.val_bits = 32,
127 		.cache_type = REGCACHE_NONE,
128 		.lock = ksz_regmap_lock,
129 		.unlock = ksz_regmap_unlock,
130 		.max_register = U8_MAX,
131 	}
132 };
133 
134 static int ksz8863_smi_probe(struct mdio_device *mdiodev)
135 {
136 	struct device *ddev = &mdiodev->dev;
137 	const struct ksz_chip_data *chip;
138 	struct regmap_config rc;
139 	struct ksz_device *dev;
140 	int ret;
141 	int i;
142 
143 	dev = ksz_switch_alloc(&mdiodev->dev, mdiodev);
144 	if (!dev)
145 		return -ENOMEM;
146 
147 	chip = device_get_match_data(ddev);
148 	if (!chip)
149 		return -EINVAL;
150 
151 	for (i = 0; i < __KSZ_NUM_REGMAPS; i++) {
152 		rc = ksz8863_regmap_config[i];
153 		rc.lock_arg = &dev->regmap_mutex;
154 		rc.wr_table = chip->wr_table;
155 		rc.rd_table = chip->rd_table;
156 		dev->regmap[i] = devm_regmap_init(&mdiodev->dev,
157 						  &regmap_smi[i], dev,
158 						  &rc);
159 		if (IS_ERR(dev->regmap[i])) {
160 			return dev_err_probe(&mdiodev->dev,
161 					     PTR_ERR(dev->regmap[i]),
162 					     "Failed to initialize regmap%i\n",
163 					     ksz8863_regmap_config[i].val_bits);
164 		}
165 	}
166 
167 	if (mdiodev->dev.platform_data)
168 		dev->pdata = mdiodev->dev.platform_data;
169 
170 	ret = ksz_switch_register(dev);
171 
172 	/* Main DSA driver may not be started yet. */
173 	if (ret)
174 		return ret;
175 
176 	dev_set_drvdata(&mdiodev->dev, dev);
177 
178 	return 0;
179 }
180 
181 static void ksz8863_smi_remove(struct mdio_device *mdiodev)
182 {
183 	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
184 
185 	if (dev)
186 		ksz_switch_remove(dev);
187 }
188 
189 static void ksz8863_smi_shutdown(struct mdio_device *mdiodev)
190 {
191 	struct ksz_device *dev = dev_get_drvdata(&mdiodev->dev);
192 
193 	if (dev)
194 		dsa_switch_shutdown(dev->ds);
195 
196 	dev_set_drvdata(&mdiodev->dev, NULL);
197 }
198 
199 static const struct of_device_id ksz8863_dt_ids[] = {
200 	{
201 		.compatible = "microchip,ksz8863",
202 		.data = &ksz_switch_chips[KSZ8830]
203 	},
204 	{
205 		.compatible = "microchip,ksz8873",
206 		.data = &ksz_switch_chips[KSZ8830]
207 	},
208 	{ },
209 };
210 MODULE_DEVICE_TABLE(of, ksz8863_dt_ids);
211 
212 static struct mdio_driver ksz8863_driver = {
213 	.probe	= ksz8863_smi_probe,
214 	.remove	= ksz8863_smi_remove,
215 	.shutdown = ksz8863_smi_shutdown,
216 	.mdiodrv.driver = {
217 		.name	= "ksz8863-switch",
218 		.of_match_table = ksz8863_dt_ids,
219 	},
220 };
221 
222 mdio_module_driver(ksz8863_driver);
223 
224 MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
225 MODULE_DESCRIPTION("Microchip KSZ8863 SMI Switch driver");
226 MODULE_LICENSE("GPL v2");
227