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.h>
 24#include <linux/overflow.h>
 25#include <linux/regmap.h>
 26
 27#include "realtek.h"
 28#include "realtek-mdio.h"
 29#include "rtl83xx.h"
 30
 31/* Read/write via mdiobus */
 32#define REALTEK_MDIO_CTRL0_REG		31
 33#define REALTEK_MDIO_START_REG		29
 34#define REALTEK_MDIO_CTRL1_REG		21
 35#define REALTEK_MDIO_ADDRESS_REG	23
 36#define REALTEK_MDIO_DATA_WRITE_REG	24
 37#define REALTEK_MDIO_DATA_READ_REG	25
 38
 39#define REALTEK_MDIO_START_OP		0xFFFF
 40#define REALTEK_MDIO_ADDR_OP		0x000E
 41#define REALTEK_MDIO_READ_OP		0x0001
 42#define REALTEK_MDIO_WRITE_OP		0x0003
 43
 44static int realtek_mdio_write(void *ctx, u32 reg, u32 val)
 45{
 46	struct realtek_priv *priv = ctx;
 47	struct mii_bus *bus = priv->bus;
 48	int ret;
 49
 50	mutex_lock(&bus->mdio_lock);
 51
 52	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
 53	if (ret)
 54		goto out_unlock;
 55
 56	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
 57	if (ret)
 58		goto out_unlock;
 59
 60	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_DATA_WRITE_REG, val);
 61	if (ret)
 62		goto out_unlock;
 63
 64	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_WRITE_OP);
 65
 66out_unlock:
 67	mutex_unlock(&bus->mdio_lock);
 68
 69	return ret;
 70}
 71
 72static int realtek_mdio_read(void *ctx, u32 reg, u32 *val)
 73{
 74	struct realtek_priv *priv = ctx;
 75	struct mii_bus *bus = priv->bus;
 76	int ret;
 77
 78	mutex_lock(&bus->mdio_lock);
 79
 80	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL0_REG, REALTEK_MDIO_ADDR_OP);
 81	if (ret)
 82		goto out_unlock;
 83
 84	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_ADDRESS_REG, reg);
 85	if (ret)
 86		goto out_unlock;
 87
 88	ret = bus->write(bus, priv->mdio_addr, REALTEK_MDIO_CTRL1_REG, REALTEK_MDIO_READ_OP);
 89	if (ret)
 90		goto out_unlock;
 91
 92	ret = bus->read(bus, priv->mdio_addr, REALTEK_MDIO_DATA_READ_REG);
 93	if (ret >= 0) {
 94		*val = ret;
 95		ret = 0;
 96	}
 97
 98out_unlock:
 99	mutex_unlock(&bus->mdio_lock);
100
101	return ret;
102}
103
104static const struct realtek_interface_info realtek_mdio_info = {
105	.reg_read = realtek_mdio_read,
106	.reg_write = realtek_mdio_write,
107};
108
109/**
110 * realtek_mdio_probe() - Probe a platform device for an MDIO-connected switch
111 * @mdiodev: mdio_device to probe on.
112 *
113 * This function should be used as the .probe in an mdio_driver. After
114 * calling the common probe function for both interfaces, it initializes the
115 * values specific for MDIO-connected devices. Finally, it calls a common
116 * function to register the DSA switch.
117 *
118 * Context: Can sleep. Takes and releases priv->map_lock.
119 * Return: Returns 0 on success, a negative error on failure.
120 */
121int realtek_mdio_probe(struct mdio_device *mdiodev)
122{
123	struct device *dev = &mdiodev->dev;
124	struct realtek_priv *priv;
125	int ret;
126
127	priv = rtl83xx_probe(dev, &realtek_mdio_info);
128	if (IS_ERR(priv))
129		return PTR_ERR(priv);
130
131	priv->bus = mdiodev->bus;
132	priv->mdio_addr = mdiodev->addr;
133	priv->write_reg_noack = realtek_mdio_write;
134
135	ret = rtl83xx_register_switch(priv);
136	if (ret) {
137		rtl83xx_remove(priv);
138		return ret;
139	}
140
141	return 0;
142}
143EXPORT_SYMBOL_NS_GPL(realtek_mdio_probe, "REALTEK_DSA");
144
145/**
146 * realtek_mdio_remove() - Remove the driver of an MDIO-connected switch
147 * @mdiodev: mdio_device to be removed.
148 *
149 * This function should be used as the .remove in an mdio_driver. First
150 * it unregisters the DSA switch and then it calls the common remove function.
151 *
152 * Context: Can sleep.
153 * Return: Nothing.
154 */
155void realtek_mdio_remove(struct mdio_device *mdiodev)
156{
157	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
158
159	if (!priv)
160		return;
161
162	rtl83xx_unregister_switch(priv);
163
164	rtl83xx_remove(priv);
165}
166EXPORT_SYMBOL_NS_GPL(realtek_mdio_remove, "REALTEK_DSA");
167
168/**
169 * realtek_mdio_shutdown() - Shutdown the driver of a MDIO-connected switch
170 * @mdiodev: mdio_device shutting down.
171 *
172 * This function should be used as the .shutdown in a platform_driver. It calls
173 * the common shutdown function.
174 *
175 * Context: Can sleep.
176 * Return: Nothing.
177 */
178void realtek_mdio_shutdown(struct mdio_device *mdiodev)
179{
180	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
181
182	if (!priv)
183		return;
184
185	rtl83xx_shutdown(priv);
186}
187EXPORT_SYMBOL_NS_GPL(realtek_mdio_shutdown, "REALTEK_DSA");