tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ulpi.c - USB ULPI PHY bus
4 *
5 * Copyright (C) 2015 Intel Corporation
6 *
7 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
8 */
9
10#include <linux/ulpi/interface.h>
11#include <linux/ulpi/driver.h>
12#include <linux/ulpi/regs.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/acpi.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/clk/clk-conf.h>
19
20/* -------------------------------------------------------------------------- */
21
22int ulpi_read(struct ulpi *ulpi, u8 addr)
23{
24 return ulpi->ops->read(ulpi->dev.parent, addr);
25}
26EXPORT_SYMBOL_GPL(ulpi_read);
27
28int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
29{
30 return ulpi->ops->write(ulpi->dev.parent, addr, val);
31}
32EXPORT_SYMBOL_GPL(ulpi_write);
33
34/* -------------------------------------------------------------------------- */
35
36static int ulpi_match(struct device *dev, struct device_driver *driver)
37{
38 struct ulpi_driver *drv = to_ulpi_driver(driver);
39 struct ulpi *ulpi = to_ulpi_dev(dev);
40 const struct ulpi_device_id *id;
41
42 /* Some ULPI devices don't have a vendor id so rely on OF match */
43 if (ulpi->id.vendor == 0)
44 return of_driver_match_device(dev, driver);
45
46 for (id = drv->id_table; id->vendor; id++)
47 if (id->vendor == ulpi->id.vendor &&
48 id->product == ulpi->id.product)
49 return 1;
50
51 return 0;
52}
53
54static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
55{
56 struct ulpi *ulpi = to_ulpi_dev(dev);
57 int ret;
58
59 ret = of_device_uevent_modalias(dev, env);
60 if (ret != -ENODEV)
61 return ret;
62
63 if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
64 ulpi->id.vendor, ulpi->id.product))
65 return -ENOMEM;
66 return 0;
67}
68
69static int ulpi_probe(struct device *dev)
70{
71 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
72 int ret;
73
74 ret = of_clk_set_defaults(dev->of_node, false);
75 if (ret < 0)
76 return ret;
77
78 return drv->probe(to_ulpi_dev(dev));
79}
80
81static void ulpi_remove(struct device *dev)
82{
83 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
84
85 if (drv->remove)
86 drv->remove(to_ulpi_dev(dev));
87}
88
89static struct bus_type ulpi_bus = {
90 .name = "ulpi",
91 .match = ulpi_match,
92 .uevent = ulpi_uevent,
93 .probe = ulpi_probe,
94 .remove = ulpi_remove,
95};
96
97/* -------------------------------------------------------------------------- */
98
99static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
100 char *buf)
101{
102 int len;
103 struct ulpi *ulpi = to_ulpi_dev(dev);
104
105 len = of_device_modalias(dev, buf, PAGE_SIZE);
106 if (len != -ENODEV)
107 return len;
108
109 return sprintf(buf, "ulpi:v%04xp%04x\n",
110 ulpi->id.vendor, ulpi->id.product);
111}
112static DEVICE_ATTR_RO(modalias);
113
114static struct attribute *ulpi_dev_attrs[] = {
115 &dev_attr_modalias.attr,
116 NULL
117};
118
119static const struct attribute_group ulpi_dev_attr_group = {
120 .attrs = ulpi_dev_attrs,
121};
122
123static const struct attribute_group *ulpi_dev_attr_groups[] = {
124 &ulpi_dev_attr_group,
125 NULL
126};
127
128static void ulpi_dev_release(struct device *dev)
129{
130 kfree(to_ulpi_dev(dev));
131}
132
133static const struct device_type ulpi_dev_type = {
134 .name = "ulpi_device",
135 .groups = ulpi_dev_attr_groups,
136 .release = ulpi_dev_release,
137};
138
139/* -------------------------------------------------------------------------- */
140
141/**
142 * __ulpi_register_driver - register a driver with the ULPI bus
143 * @drv: driver being registered
144 * @module: ends up being THIS_MODULE
145 *
146 * Registers a driver with the ULPI bus.
147 */
148int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module)
149{
150 if (!drv->probe)
151 return -EINVAL;
152
153 drv->driver.owner = module;
154 drv->driver.bus = &ulpi_bus;
155
156 return driver_register(&drv->driver);
157}
158EXPORT_SYMBOL_GPL(__ulpi_register_driver);
159
160/**
161 * ulpi_unregister_driver - unregister a driver with the ULPI bus
162 * @drv: driver to unregister
163 *
164 * Unregisters a driver with the ULPI bus.
165 */
166void ulpi_unregister_driver(struct ulpi_driver *drv)
167{
168 driver_unregister(&drv->driver);
169}
170EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
171
172/* -------------------------------------------------------------------------- */
173
174static int ulpi_of_register(struct ulpi *ulpi)
175{
176 struct device_node *np = NULL, *child;
177 struct device *parent;
178
179 /* Find a ulpi bus underneath the parent or the grandparent */
180 parent = ulpi->dev.parent;
181 if (parent->of_node)
182 np = of_get_child_by_name(parent->of_node, "ulpi");
183 else if (parent->parent && parent->parent->of_node)
184 np = of_get_child_by_name(parent->parent->of_node, "ulpi");
185 if (!np)
186 return 0;
187
188 child = of_get_next_available_child(np, NULL);
189 of_node_put(np);
190 if (!child)
191 return -EINVAL;
192
193 ulpi->dev.of_node = child;
194
195 return 0;
196}
197
198static int ulpi_read_id(struct ulpi *ulpi)
199{
200 int ret;
201
202 /* Test the interface */
203 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
204 if (ret < 0)
205 goto err;
206
207 ret = ulpi_read(ulpi, ULPI_SCRATCH);
208 if (ret < 0)
209 return ret;
210
211 if (ret != 0xaa)
212 goto err;
213
214 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
215 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
216
217 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
218 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
219
220 /* Some ULPI devices don't have a vendor id so rely on OF match */
221 if (ulpi->id.vendor == 0)
222 goto err;
223
224 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
225 return 0;
226err:
227 of_device_request_module(&ulpi->dev);
228 return 0;
229}
230
231static int ulpi_register(struct device *dev, struct ulpi *ulpi)
232{
233 int ret;
234
235 ulpi->dev.parent = dev; /* needed early for ops */
236 ulpi->dev.bus = &ulpi_bus;
237 ulpi->dev.type = &ulpi_dev_type;
238 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
239
240 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
241
242 ret = ulpi_of_register(ulpi);
243 if (ret)
244 return ret;
245
246 ret = ulpi_read_id(ulpi);
247 if (ret)
248 return ret;
249
250 ret = device_register(&ulpi->dev);
251 if (ret)
252 return ret;
253
254 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
255 ulpi->id.vendor, ulpi->id.product);
256
257 return 0;
258}
259
260/**
261 * ulpi_register_interface - instantiate new ULPI device
262 * @dev: USB controller's device interface
263 * @ops: ULPI register access
264 *
265 * Allocates and registers a ULPI device and an interface for it. Called from
266 * the USB controller that provides the ULPI interface.
267 */
268struct ulpi *ulpi_register_interface(struct device *dev,
269 const struct ulpi_ops *ops)
270{
271 struct ulpi *ulpi;
272 int ret;
273
274 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
275 if (!ulpi)
276 return ERR_PTR(-ENOMEM);
277
278 ulpi->ops = ops;
279
280 ret = ulpi_register(dev, ulpi);
281 if (ret) {
282 kfree(ulpi);
283 return ERR_PTR(ret);
284 }
285
286 return ulpi;
287}
288EXPORT_SYMBOL_GPL(ulpi_register_interface);
289
290/**
291 * ulpi_unregister_interface - unregister ULPI interface
292 * @ulpi: struct ulpi_interface
293 *
294 * Unregisters a ULPI device and it's interface that was created with
295 * ulpi_create_interface().
296 */
297void ulpi_unregister_interface(struct ulpi *ulpi)
298{
299 of_node_put(ulpi->dev.of_node);
300 device_unregister(&ulpi->dev);
301}
302EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
303
304/* -------------------------------------------------------------------------- */
305
306static int __init ulpi_init(void)
307{
308 return bus_register(&ulpi_bus);
309}
310subsys_initcall(ulpi_init);
311
312static void __exit ulpi_exit(void)
313{
314 bus_unregister(&ulpi_bus);
315}
316module_exit(ulpi_exit);
317
318MODULE_AUTHOR("Intel Corporation");
319MODULE_LICENSE("GPL v2");
320MODULE_DESCRIPTION("USB ULPI PHY bus");