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 
mdio_device_free(struct mdio_device * mdiodev)26 void mdio_device_free(struct mdio_device *mdiodev)
27 {
28 	put_device(&mdiodev->dev);
29 }
30 EXPORT_SYMBOL(mdio_device_free);
31 
mdio_device_release(struct device * dev)32 static void mdio_device_release(struct device *dev)
33 {
34 	fwnode_handle_put(dev->fwnode);
35 	kfree(to_mdio_device(dev));
36 }
37 
mdio_device_bus_match(struct device * dev,struct device_driver * drv)38 int 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 
mdio_device_create(struct mii_bus * bus,int addr)49 struct 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 }
72 EXPORT_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  */
mdio_device_register(struct mdio_device * mdiodev)78 int 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 }
100 EXPORT_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  */
mdio_device_remove(struct mdio_device * mdiodev)111 void mdio_device_remove(struct mdio_device *mdiodev)
112 {
113 	device_del(&mdiodev->dev);
114 	mdiobus_unregister_device(mdiodev);
115 }
116 EXPORT_SYMBOL(mdio_device_remove);
117 
mdio_device_reset(struct mdio_device * mdiodev,int value)118 void 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 }
139 EXPORT_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  */
mdio_probe(struct device * dev)148 static 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 
mdio_remove(struct device * dev)169 static 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 
mdio_shutdown(struct device * dev)184 static 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  */
mdio_driver_register(struct mdio_driver * drv)198 int 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 }
220 EXPORT_SYMBOL(mdio_driver_register);
221 
mdio_driver_unregister(struct mdio_driver * drv)222 void mdio_driver_unregister(struct mdio_driver *drv)
223 {
224 	struct mdio_driver_common *mdiodrv = &drv->mdiodrv;
225 
226 	driver_unregister(&mdiodrv->driver);
227 }
228 EXPORT_SYMBOL(mdio_driver_unregister);
229