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
ulpi_read(struct ulpi * ulpi,u8 addr)22 int ulpi_read(struct ulpi *ulpi, u8 addr)
23 {
24 return ulpi->ops->read(ulpi->dev.parent, addr);
25 }
26 EXPORT_SYMBOL_GPL(ulpi_read);
27
ulpi_write(struct ulpi * ulpi,u8 addr,u8 val)28 int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
29 {
30 return ulpi->ops->write(ulpi->dev.parent, addr, val);
31 }
32 EXPORT_SYMBOL_GPL(ulpi_write);
33
34 /* -------------------------------------------------------------------------- */
35
ulpi_match(struct device * dev,struct device_driver * driver)36 static 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 /*
43 * Some ULPI devices don't have a vendor id
44 * or provide an id_table so rely on OF match.
45 */
46 if (ulpi->id.vendor == 0 || !drv->id_table)
47 return of_driver_match_device(dev, driver);
48
49 for (id = drv->id_table; id->vendor; id++)
50 if (id->vendor == ulpi->id.vendor &&
51 id->product == ulpi->id.product)
52 return 1;
53
54 return 0;
55 }
56
ulpi_uevent(struct device * dev,struct kobj_uevent_env * env)57 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
58 {
59 struct ulpi *ulpi = to_ulpi_dev(dev);
60 int ret;
61
62 ret = of_device_uevent_modalias(dev, env);
63 if (ret != -ENODEV)
64 return ret;
65
66 if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
67 ulpi->id.vendor, ulpi->id.product))
68 return -ENOMEM;
69 return 0;
70 }
71
ulpi_probe(struct device * dev)72 static int ulpi_probe(struct device *dev)
73 {
74 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
75 int ret;
76
77 ret = of_clk_set_defaults(dev->of_node, false);
78 if (ret < 0)
79 return ret;
80
81 return drv->probe(to_ulpi_dev(dev));
82 }
83
ulpi_remove(struct device * dev)84 static void ulpi_remove(struct device *dev)
85 {
86 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
87
88 if (drv->remove)
89 drv->remove(to_ulpi_dev(dev));
90 }
91
92 static struct bus_type ulpi_bus = {
93 .name = "ulpi",
94 .match = ulpi_match,
95 .uevent = ulpi_uevent,
96 .probe = ulpi_probe,
97 .remove = ulpi_remove,
98 };
99
100 /* -------------------------------------------------------------------------- */
101
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)102 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
103 char *buf)
104 {
105 int len;
106 struct ulpi *ulpi = to_ulpi_dev(dev);
107
108 len = of_device_modalias(dev, buf, PAGE_SIZE);
109 if (len != -ENODEV)
110 return len;
111
112 return sprintf(buf, "ulpi:v%04xp%04x\n",
113 ulpi->id.vendor, ulpi->id.product);
114 }
115 static DEVICE_ATTR_RO(modalias);
116
117 static struct attribute *ulpi_dev_attrs[] = {
118 &dev_attr_modalias.attr,
119 NULL
120 };
121
122 static const struct attribute_group ulpi_dev_attr_group = {
123 .attrs = ulpi_dev_attrs,
124 };
125
126 static const struct attribute_group *ulpi_dev_attr_groups[] = {
127 &ulpi_dev_attr_group,
128 NULL
129 };
130
ulpi_dev_release(struct device * dev)131 static void ulpi_dev_release(struct device *dev)
132 {
133 of_node_put(dev->of_node);
134 kfree(to_ulpi_dev(dev));
135 }
136
137 static const struct device_type ulpi_dev_type = {
138 .name = "ulpi_device",
139 .groups = ulpi_dev_attr_groups,
140 .release = ulpi_dev_release,
141 };
142
143 /* -------------------------------------------------------------------------- */
144
145 /**
146 * __ulpi_register_driver - register a driver with the ULPI bus
147 * @drv: driver being registered
148 * @module: ends up being THIS_MODULE
149 *
150 * Registers a driver with the ULPI bus.
151 */
__ulpi_register_driver(struct ulpi_driver * drv,struct module * module)152 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module)
153 {
154 if (!drv->probe)
155 return -EINVAL;
156
157 drv->driver.owner = module;
158 drv->driver.bus = &ulpi_bus;
159
160 return driver_register(&drv->driver);
161 }
162 EXPORT_SYMBOL_GPL(__ulpi_register_driver);
163
164 /**
165 * ulpi_unregister_driver - unregister a driver with the ULPI bus
166 * @drv: driver to unregister
167 *
168 * Unregisters a driver with the ULPI bus.
169 */
ulpi_unregister_driver(struct ulpi_driver * drv)170 void ulpi_unregister_driver(struct ulpi_driver *drv)
171 {
172 driver_unregister(&drv->driver);
173 }
174 EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
175
176 /* -------------------------------------------------------------------------- */
177
ulpi_of_register(struct ulpi * ulpi)178 static int ulpi_of_register(struct ulpi *ulpi)
179 {
180 struct device_node *np = NULL, *child;
181 struct device *parent;
182
183 /* Find a ulpi bus underneath the parent or the grandparent */
184 parent = ulpi->dev.parent;
185 if (parent->of_node)
186 np = of_get_child_by_name(parent->of_node, "ulpi");
187 else if (parent->parent && parent->parent->of_node)
188 np = of_get_child_by_name(parent->parent->of_node, "ulpi");
189 if (!np)
190 return 0;
191
192 child = of_get_next_available_child(np, NULL);
193 of_node_put(np);
194 if (!child)
195 return -EINVAL;
196
197 ulpi->dev.of_node = child;
198
199 return 0;
200 }
201
ulpi_read_id(struct ulpi * ulpi)202 static int ulpi_read_id(struct ulpi *ulpi)
203 {
204 int ret;
205
206 /* Test the interface */
207 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
208 if (ret < 0)
209 goto err;
210
211 ret = ulpi_read(ulpi, ULPI_SCRATCH);
212 if (ret < 0)
213 return ret;
214
215 if (ret != 0xaa)
216 goto err;
217
218 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
219 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
220
221 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
222 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
223
224 /* Some ULPI devices don't have a vendor id so rely on OF match */
225 if (ulpi->id.vendor == 0)
226 goto err;
227
228 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
229 return 0;
230 err:
231 of_device_request_module(&ulpi->dev);
232 return 0;
233 }
234
ulpi_register(struct device * dev,struct ulpi * ulpi)235 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
236 {
237 int ret;
238
239 ulpi->dev.parent = dev; /* needed early for ops */
240 ulpi->dev.bus = &ulpi_bus;
241 ulpi->dev.type = &ulpi_dev_type;
242 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
243
244 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
245
246 ret = ulpi_of_register(ulpi);
247 if (ret)
248 return ret;
249
250 ret = ulpi_read_id(ulpi);
251 if (ret) {
252 of_node_put(ulpi->dev.of_node);
253 return ret;
254 }
255
256 ret = device_register(&ulpi->dev);
257 if (ret) {
258 put_device(&ulpi->dev);
259 return ret;
260 }
261
262 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
263 ulpi->id.vendor, ulpi->id.product);
264
265 return 0;
266 }
267
268 /**
269 * ulpi_register_interface - instantiate new ULPI device
270 * @dev: USB controller's device interface
271 * @ops: ULPI register access
272 *
273 * Allocates and registers a ULPI device and an interface for it. Called from
274 * the USB controller that provides the ULPI interface.
275 */
ulpi_register_interface(struct device * dev,const struct ulpi_ops * ops)276 struct ulpi *ulpi_register_interface(struct device *dev,
277 const struct ulpi_ops *ops)
278 {
279 struct ulpi *ulpi;
280 int ret;
281
282 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
283 if (!ulpi)
284 return ERR_PTR(-ENOMEM);
285
286 ulpi->ops = ops;
287
288 ret = ulpi_register(dev, ulpi);
289 if (ret) {
290 kfree(ulpi);
291 return ERR_PTR(ret);
292 }
293
294 return ulpi;
295 }
296 EXPORT_SYMBOL_GPL(ulpi_register_interface);
297
298 /**
299 * ulpi_unregister_interface - unregister ULPI interface
300 * @ulpi: struct ulpi_interface
301 *
302 * Unregisters a ULPI device and it's interface that was created with
303 * ulpi_create_interface().
304 */
ulpi_unregister_interface(struct ulpi * ulpi)305 void ulpi_unregister_interface(struct ulpi *ulpi)
306 {
307 device_unregister(&ulpi->dev);
308 }
309 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
310
311 /* -------------------------------------------------------------------------- */
312
ulpi_init(void)313 static int __init ulpi_init(void)
314 {
315 return bus_register(&ulpi_bus);
316 }
317 subsys_initcall(ulpi_init);
318
ulpi_exit(void)319 static void __exit ulpi_exit(void)
320 {
321 bus_unregister(&ulpi_bus);
322 }
323 module_exit(ulpi_exit);
324
325 MODULE_AUTHOR("Intel Corporation");
326 MODULE_LICENSE("GPL v2");
327 MODULE_DESCRIPTION("USB ULPI PHY bus");
328