1// SPDX-License-Identifier: GPL-2.0+
2/* Framework for MDIO devices, other than PHYs.
3 *
4 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
5 */
6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/delay.h>
10#include <linux/errno.h>
11#include <linux/gpio.h>
12#include <linux/gpio/consumer.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/kernel.h>
16#include <linux/mdio.h>
17#include <linux/mii.h>
18#include <linux/module.h>
19#include <linux/phy.h>
20#include <linux/reset.h>
21#include <linux/slab.h>
22#include <linux/string.h>
23#include <linux/unistd.h>
24#include <linux/property.h>
25
26void mdio_device_free(struct mdio_device *mdiodev)
27{
28	put_device(&mdiodev->dev);
29}
30EXPORT_SYMBOL(mdio_device_free);
31
32static void mdio_device_release(struct device *dev)
33{
34	fwnode_handle_put(dev->fwnode);
35	kfree(to_mdio_device(dev));
36}
37
38int mdio_device_bus_match(struct device *dev, struct device_driver *drv)
39{
40	struct mdio_device *mdiodev = to_mdio_device(dev);
41	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
42
43	if (mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY)
44		return 0;
45
46	return strcmp(mdiodev->modalias, drv->name) == 0;
47}
48
49struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr)
50{
51	struct mdio_device *mdiodev;
52
53	/* We allocate the device, and initialize the default values */
54	mdiodev = kzalloc(sizeof(*mdiodev), GFP_KERNEL);
55	if (!mdiodev)
56		return ERR_PTR(-ENOMEM);
57
58	mdiodev->dev.release = mdio_device_release;
59	mdiodev->dev.parent = &bus->dev;
60	mdiodev->dev.bus = &mdio_bus_type;
61	mdiodev->device_free = mdio_device_free;
62	mdiodev->device_remove = mdio_device_remove;
63	mdiodev->bus = bus;
64	mdiodev->addr = addr;
65
66	dev_set_name(&mdiodev->dev, PHY_ID_FMT, bus->id, addr);
67
68	device_initialize(&mdiodev->dev);
69
70	return mdiodev;
71}
72EXPORT_SYMBOL(mdio_device_create);
73
74/**
75 * mdio_device_register - Register the mdio device on the MDIO bus
76 * @mdiodev: mdio_device structure to be added to the MDIO bus
77 */
78int mdio_device_register(struct mdio_device *mdiodev)
79{
80	int err;
81
82	dev_dbg(&mdiodev->dev, "%s\n", __func__);
83
84	err = mdiobus_register_device(mdiodev);
85	if (err)
86		return err;
87
88	err = device_add(&mdiodev->dev);
89	if (err) {
90		pr_err("MDIO %d failed to add\n", mdiodev->addr);
91		goto out;
92	}
93
94	return 0;
95
96 out:
97	mdiobus_unregister_device(mdiodev);
98	return err;
99}
100EXPORT_SYMBOL(mdio_device_register);
101
102/**
103 * mdio_device_remove - Remove a previously registered mdio device from the
104 *			MDIO bus
105 * @mdiodev: mdio_device structure to remove
106 *
107 * This doesn't free the mdio_device itself, it merely reverses the effects
108 * of mdio_device_register(). Use mdio_device_free() to free the device
109 * after calling this function.
110 */
111void mdio_device_remove(struct mdio_device *mdiodev)
112{
113	device_del(&mdiodev->dev);
114	mdiobus_unregister_device(mdiodev);
115}
116EXPORT_SYMBOL(mdio_device_remove);
117
118void mdio_device_reset(struct mdio_device *mdiodev, int value)
119{
120	unsigned int d;
121
122	if (!mdiodev->reset_gpio && !mdiodev->reset_ctrl)
123		return;
124
125	if (mdiodev->reset_gpio)
126		gpiod_set_value_cansleep(mdiodev->reset_gpio, value);
127
128	if (mdiodev->reset_ctrl) {
129		if (value)
130			reset_control_assert(mdiodev->reset_ctrl);
131		else
132			reset_control_deassert(mdiodev->reset_ctrl);
133	}
134
135	d = value ? mdiodev->reset_assert_delay : mdiodev->reset_deassert_delay;
136	if (d)
137		fsleep(d);
138}
139EXPORT_SYMBOL(mdio_device_reset);
140
141/**
142 * mdio_probe - probe an MDIO device
143 * @dev: device to probe
144 *
145 * Description: Take care of setting up the mdio_device structure
146 * and calling the driver to probe the device.
147 */
148static int mdio_probe(struct device *dev)
149{
150	struct mdio_device *mdiodev = to_mdio_device(dev);
151	struct device_driver *drv = mdiodev->dev.driver;
152	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
153	int err = 0;
154
155	/* Deassert the reset signal */
156	mdio_device_reset(mdiodev, 0);
157
158	if (mdiodrv->probe) {
159		err = mdiodrv->probe(mdiodev);
160		if (err) {
161			/* Assert the reset signal */
162			mdio_device_reset(mdiodev, 1);
163		}
164	}
165
166	return err;
167}
168
169static int mdio_remove(struct device *dev)
170{
171	struct mdio_device *mdiodev = to_mdio_device(dev);
172	struct device_driver *drv = mdiodev->dev.driver;
173	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
174
175	if (mdiodrv->remove)
176		mdiodrv->remove(mdiodev);
177
178	/* Assert the reset signal */
179	mdio_device_reset(mdiodev, 1);
180
181	return 0;
182}
183
184static void mdio_shutdown(struct device *dev)
185{
186	struct mdio_device *mdiodev = to_mdio_device(dev);
187	struct device_driver *drv = mdiodev->dev.driver;
188	struct mdio_driver *mdiodrv = to_mdio_driver(drv);
189
190	if (mdiodrv->shutdown)
191		mdiodrv->shutdown(mdiodev);
192}
193
194/**
195 * mdio_driver_register - register an mdio_driver with the MDIO layer
196 * @drv: new mdio_driver to register
197 */
198int mdio_driver_register(struct mdio_driver *drv)
199{
200	struct mdio_driver_common *mdiodrv = &drv->mdiodrv;
201	int retval;
202
203	pr_debug("%s: %s\n", __func__, mdiodrv->driver.name);
204
205	mdiodrv->driver.bus = &mdio_bus_type;
206	mdiodrv->driver.probe = mdio_probe;
207	mdiodrv->driver.remove = mdio_remove;
208	mdiodrv->driver.shutdown = mdio_shutdown;
209
210	retval = driver_register(&mdiodrv->driver);
211	if (retval) {
212		pr_err("%s: Error %d in registering driver\n",
213		       mdiodrv->driver.name, retval);
214
215		return retval;
216	}
217
218	return 0;
219}
220EXPORT_SYMBOL(mdio_driver_register);
221
222void mdio_driver_unregister(struct mdio_driver *drv)
223{
224	struct mdio_driver_common *mdiodrv = &drv->mdiodrv;
225
226	driver_unregister(&mdiodrv->driver);
227}
228EXPORT_SYMBOL(mdio_driver_unregister);
229