1 // SPDX-License-Identifier: GPL-2.0+
2 /* Realtek MDIO interface driver
3 *
4 * ASICs we intend to support with this driver:
5 *
6 * RTL8366 - The original version, apparently
7 * RTL8369 - Similar enough to have the same datsheet as RTL8366
8 * RTL8366RB - Probably reads out "RTL8366 revision B", has a quite
9 * different register layout from the other two
10 * RTL8366S - Is this "RTL8366 super"?
11 * RTL8367 - Has an OpenWRT driver as well
12 * RTL8368S - Seems to be an alternative name for RTL8366RB
13 * RTL8370 - Also uses SMI
14 *
15 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
16 * Copyright (C) 2010 Antti Seppälä <a.seppala@gmail.com>
17 * Copyright (C) 2010 Roman Yeryomin <roman@advem.lv>
18 * Copyright (C) 2011 Colin Leitner <colin.leitner@googlemail.com>
19 * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
20 */
21
22 #include <linux/module.h>
23 #include <linux/of_device.h>
24 #include <linux/regmap.h>
25
26 #include "realtek.h"
27
28 /* Read/write via mdiobus */
29 #define REALTEK_MDIO_CTRL0_REG 31
30 #define REALTEK_MDIO_START_REG 29
31 #define REALTEK_MDIO_CTRL1_REG 21
32 #define REALTEK_MDIO_ADDRESS_REG 23
33 #define REALTEK_MDIO_DATA_WRITE_REG 24
34 #define REALTEK_MDIO_DATA_READ_REG 25
35
36 #define REALTEK_MDIO_START_OP 0xFFFF
37 #define REALTEK_MDIO_ADDR_OP 0x000E
38 #define REALTEK_MDIO_READ_OP 0x0001
39 #define REALTEK_MDIO_WRITE_OP 0x0003
40
realtek_mdio_write(void * ctx,u32 reg,u32 val)41 static int realtek_mdio_write(void *ctx, u32 reg, u32 val)
42 {
43 struct realtek_priv *priv = ctx;
44 struct mii_bus *bus = priv->bus;
45 int ret;
46
47 mutex_lock(&bus->mdio_lock);
48
49 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
50 if (ret)
51 goto out_unlock;
52
53 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
54 if (ret)
55 goto out_unlock;
56
57 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_DATA_WRITE_REG, val);
58 if (ret)
59 goto out_unlock;
60
61 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_WRITE_OP);
62
63 out_unlock:
64 mutex_unlock(&bus->mdio_lock);
65
66 return ret;
67 }
68
realtek_mdio_read(void * ctx,u32 reg,u32 * val)69 static int realtek_mdio_read(void *ctx, u32 reg, u32 *val)
70 {
71 struct realtek_priv *priv = ctx;
72 struct mii_bus *bus = priv->bus;
73 int ret;
74
75 mutex_lock(&bus->mdio_lock);
76
77 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
78 if (ret)
79 goto out_unlock;
80
81 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
82 if (ret)
83 goto out_unlock;
84
85 ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_READ_OP);
86 if (ret)
87 goto out_unlock;
88
89 ret = bus->read(bus, priv->mdio_addr, REALTEK_MDIO_DATA_READ_REG);
90 if (ret >= 0) {
91 *val = ret;
92 ret = 0;
93 }
94
95 out_unlock:
96 mutex_unlock(&bus->mdio_lock);
97
98 return ret;
99 }
100
realtek_mdio_lock(void * ctx)101 static void realtek_mdio_lock(void *ctx)
102 {
103 struct realtek_priv *priv = ctx;
104
105 mutex_lock(&priv->map_lock);
106 }
107
realtek_mdio_unlock(void * ctx)108 static void realtek_mdio_unlock(void *ctx)
109 {
110 struct realtek_priv *priv = ctx;
111
112 mutex_unlock(&priv->map_lock);
113 }
114
115 static const struct regmap_config realtek_mdio_regmap_config = {
116 .reg_bits = 10, /* A4..A0 R4..R0 */
117 .val_bits = 16,
118 .reg_stride = 1,
119 /* PHY regs are at 0x8000 */
120 .max_register = 0xffff,
121 .reg_format_endian = REGMAP_ENDIAN_BIG,
122 .reg_read = realtek_mdio_read,
123 .reg_write = realtek_mdio_write,
124 .cache_type = REGCACHE_NONE,
125 .lock = realtek_mdio_lock,
126 .unlock = realtek_mdio_unlock,
127 };
128
129 static const struct regmap_config realtek_mdio_nolock_regmap_config = {
130 .reg_bits = 10, /* A4..A0 R4..R0 */
131 .val_bits = 16,
132 .reg_stride = 1,
133 /* PHY regs are at 0x8000 */
134 .max_register = 0xffff,
135 .reg_format_endian = REGMAP_ENDIAN_BIG,
136 .reg_read = realtek_mdio_read,
137 .reg_write = realtek_mdio_write,
138 .cache_type = REGCACHE_NONE,
139 .disable_locking = true,
140 };
141
realtek_mdio_probe(struct mdio_device * mdiodev)142 static int realtek_mdio_probe(struct mdio_device *mdiodev)
143 {
144 struct realtek_priv *priv;
145 struct device *dev = &mdiodev->dev;
146 const struct realtek_variant *var;
147 struct regmap_config rc;
148 struct device_node *np;
149 int ret;
150
151 var = of_device_get_match_data(dev);
152 if (!var)
153 return -EINVAL;
154
155 priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
156 if (!priv)
157 return -ENOMEM;
158
159 mutex_init(&priv->map_lock);
160
161 rc = realtek_mdio_regmap_config;
162 rc.lock_arg = priv;
163 priv->map = devm_regmap_init(dev, NULL, priv, &rc);
164 if (IS_ERR(priv->map)) {
165 ret = PTR_ERR(priv->map);
166 dev_err(dev, "regmap init failed: %d\n", ret);
167 return ret;
168 }
169
170 rc = realtek_mdio_nolock_regmap_config;
171 priv->map_nolock = devm_regmap_init(dev, NULL, priv, &rc);
172 if (IS_ERR(priv->map_nolock)) {
173 ret = PTR_ERR(priv->map_nolock);
174 dev_err(dev, "regmap init failed: %d\n", ret);
175 return ret;
176 }
177
178 priv->mdio_addr = mdiodev->addr;
179 priv->bus = mdiodev->bus;
180 priv->dev = &mdiodev->dev;
181 priv->chip_data = (void *)priv + sizeof(*priv);
182
183 priv->clk_delay = var->clk_delay;
184 priv->cmd_read = var->cmd_read;
185 priv->cmd_write = var->cmd_write;
186 priv->ops = var->ops;
187
188 priv->write_reg_noack = realtek_mdio_write;
189
190 np = dev->of_node;
191
192 dev_set_drvdata(dev, priv);
193
194 /* TODO: if power is software controlled, set up any regulators here */
195 priv->leds_disabled = of_property_read_bool(np, "realtek,disable-leds");
196
197 priv->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
198 if (IS_ERR(priv->reset)) {
199 dev_err(dev, "failed to get RESET GPIO\n");
200 return PTR_ERR(priv->reset);
201 }
202
203 if (priv->reset) {
204 gpiod_set_value(priv->reset, 1);
205 dev_dbg(dev, "asserted RESET\n");
206 msleep(REALTEK_HW_STOP_DELAY);
207 gpiod_set_value(priv->reset, 0);
208 msleep(REALTEK_HW_START_DELAY);
209 dev_dbg(dev, "deasserted RESET\n");
210 }
211
212 ret = priv->ops->detect(priv);
213 if (ret) {
214 dev_err(dev, "unable to detect switch\n");
215 return ret;
216 }
217
218 priv->ds = devm_kzalloc(dev, sizeof(*priv->ds), GFP_KERNEL);
219 if (!priv->ds)
220 return -ENOMEM;
221
222 priv->ds->dev = dev;
223 priv->ds->num_ports = priv->num_ports;
224 priv->ds->priv = priv;
225 priv->ds->ops = var->ds_ops_mdio;
226
227 ret = dsa_register_switch(priv->ds);
228 if (ret) {
229 dev_err(priv->dev, "unable to register switch ret = %d\n", ret);
230 return ret;
231 }
232
233 return 0;
234 }
235
realtek_mdio_remove(struct mdio_device * mdiodev)236 static void realtek_mdio_remove(struct mdio_device *mdiodev)
237 {
238 struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
239
240 if (!priv)
241 return;
242
243 dsa_unregister_switch(priv->ds);
244
245 /* leave the device reset asserted */
246 if (priv->reset)
247 gpiod_set_value(priv->reset, 1);
248 }
249
realtek_mdio_shutdown(struct mdio_device * mdiodev)250 static void realtek_mdio_shutdown(struct mdio_device *mdiodev)
251 {
252 struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
253
254 if (!priv)
255 return;
256
257 dsa_switch_shutdown(priv->ds);
258
259 dev_set_drvdata(&mdiodev->dev, NULL);
260 }
261
262 static const struct of_device_id realtek_mdio_of_match[] = {
263 #if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8366RB)
264 { .compatible = "realtek,rtl8366rb", .data = &rtl8366rb_variant, },
265 #endif
266 #if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8365MB)
267 { .compatible = "realtek,rtl8365mb", .data = &rtl8365mb_variant, },
268 #endif
269 { /* sentinel */ },
270 };
271 MODULE_DEVICE_TABLE(of, realtek_mdio_of_match);
272
273 static struct mdio_driver realtek_mdio_driver = {
274 .mdiodrv.driver = {
275 .name = "realtek-mdio",
276 .of_match_table = of_match_ptr(realtek_mdio_of_match),
277 },
278 .probe = realtek_mdio_probe,
279 .remove = realtek_mdio_remove,
280 .shutdown = realtek_mdio_shutdown,
281 };
282
283 mdio_module_driver(realtek_mdio_driver);
284
285 MODULE_AUTHOR("Luiz Angelo Daros de Luca <luizluca@gmail.com>");
286 MODULE_DESCRIPTION("Driver for Realtek ethernet switch connected via MDIO interface");
287 MODULE_LICENSE("GPL");
288