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 int 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 return 0;
92 }
93
94 static struct bus_type ulpi_bus = {
95 .name = "ulpi",
96 .match = ulpi_match,
97 .uevent = ulpi_uevent,
98 .probe = ulpi_probe,
99 .remove = ulpi_remove,
100 };
101
102 /* -------------------------------------------------------------------------- */
103
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)104 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
105 char *buf)
106 {
107 int len;
108 struct ulpi *ulpi = to_ulpi_dev(dev);
109
110 len = of_device_modalias(dev, buf, PAGE_SIZE);
111 if (len != -ENODEV)
112 return len;
113
114 return sprintf(buf, "ulpi:v%04xp%04x\n",
115 ulpi->id.vendor, ulpi->id.product);
116 }
117 static DEVICE_ATTR_RO(modalias);
118
119 static struct attribute *ulpi_dev_attrs[] = {
120 &dev_attr_modalias.attr,
121 NULL
122 };
123
124 static struct attribute_group ulpi_dev_attr_group = {
125 .attrs = ulpi_dev_attrs,
126 };
127
128 static const struct attribute_group *ulpi_dev_attr_groups[] = {
129 &ulpi_dev_attr_group,
130 NULL
131 };
132
ulpi_dev_release(struct device * dev)133 static void ulpi_dev_release(struct device *dev)
134 {
135 of_node_put(dev->of_node);
136 kfree(to_ulpi_dev(dev));
137 }
138
139 static const struct device_type ulpi_dev_type = {
140 .name = "ulpi_device",
141 .groups = ulpi_dev_attr_groups,
142 .release = ulpi_dev_release,
143 };
144
145 /* -------------------------------------------------------------------------- */
146
147 /**
148 * ulpi_register_driver - register a driver with the ULPI bus
149 * @drv: driver being registered
150 * @module: ends up being THIS_MODULE
151 *
152 * Registers a driver with the ULPI bus.
153 */
__ulpi_register_driver(struct ulpi_driver * drv,struct module * module)154 int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module)
155 {
156 if (!drv->probe)
157 return -EINVAL;
158
159 drv->driver.owner = module;
160 drv->driver.bus = &ulpi_bus;
161
162 return driver_register(&drv->driver);
163 }
164 EXPORT_SYMBOL_GPL(__ulpi_register_driver);
165
166 /**
167 * ulpi_unregister_driver - unregister a driver with the ULPI bus
168 * @drv: driver to unregister
169 *
170 * Unregisters a driver with the ULPI bus.
171 */
ulpi_unregister_driver(struct ulpi_driver * drv)172 void ulpi_unregister_driver(struct ulpi_driver *drv)
173 {
174 driver_unregister(&drv->driver);
175 }
176 EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
177
178 /* -------------------------------------------------------------------------- */
179
ulpi_of_register(struct ulpi * ulpi)180 static int ulpi_of_register(struct ulpi *ulpi)
181 {
182 struct device_node *np = NULL, *child;
183 struct device *parent;
184
185 /* Find a ulpi bus underneath the parent or the grandparent */
186 parent = ulpi->dev.parent;
187 if (parent->of_node)
188 np = of_get_child_by_name(parent->of_node, "ulpi");
189 else if (parent->parent && parent->parent->of_node)
190 np = of_get_child_by_name(parent->parent->of_node, "ulpi");
191 if (!np)
192 return 0;
193
194 child = of_get_next_available_child(np, NULL);
195 of_node_put(np);
196 if (!child)
197 return -EINVAL;
198
199 ulpi->dev.of_node = child;
200
201 return 0;
202 }
203
ulpi_read_id(struct ulpi * ulpi)204 static int ulpi_read_id(struct ulpi *ulpi)
205 {
206 int ret;
207
208 /* Test the interface */
209 ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
210 if (ret < 0)
211 goto err;
212
213 ret = ulpi_read(ulpi, ULPI_SCRATCH);
214 if (ret < 0)
215 return ret;
216
217 if (ret != 0xaa)
218 goto err;
219
220 ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
221 ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
222
223 ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
224 ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
225
226 /* Some ULPI devices don't have a vendor id so rely on OF match */
227 if (ulpi->id.vendor == 0)
228 goto err;
229
230 request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
231 return 0;
232 err:
233 of_device_request_module(&ulpi->dev);
234 return 0;
235 }
236
ulpi_register(struct device * dev,struct ulpi * ulpi)237 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
238 {
239 int ret;
240
241 ulpi->dev.parent = dev; /* needed early for ops */
242 ulpi->dev.bus = &ulpi_bus;
243 ulpi->dev.type = &ulpi_dev_type;
244 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
245
246 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
247
248 ret = ulpi_of_register(ulpi);
249 if (ret)
250 return ret;
251
252 ret = ulpi_read_id(ulpi);
253 if (ret) {
254 of_node_put(ulpi->dev.of_node);
255 return ret;
256 }
257
258 ret = device_register(&ulpi->dev);
259 if (ret) {
260 put_device(&ulpi->dev);
261 return ret;
262 }
263
264 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
265 ulpi->id.vendor, ulpi->id.product);
266
267 return 0;
268 }
269
270 /**
271 * ulpi_register_interface - instantiate new ULPI device
272 * @dev: USB controller's device interface
273 * @ops: ULPI register access
274 *
275 * Allocates and registers a ULPI device and an interface for it. Called from
276 * the USB controller that provides the ULPI interface.
277 */
ulpi_register_interface(struct device * dev,const struct ulpi_ops * ops)278 struct ulpi *ulpi_register_interface(struct device *dev,
279 const struct ulpi_ops *ops)
280 {
281 struct ulpi *ulpi;
282 int ret;
283
284 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
285 if (!ulpi)
286 return ERR_PTR(-ENOMEM);
287
288 ulpi->ops = ops;
289
290 ret = ulpi_register(dev, ulpi);
291 if (ret) {
292 kfree(ulpi);
293 return ERR_PTR(ret);
294 }
295
296 return ulpi;
297 }
298 EXPORT_SYMBOL_GPL(ulpi_register_interface);
299
300 /**
301 * ulpi_unregister_interface - unregister ULPI interface
302 * @ulpi: struct ulpi_interface
303 *
304 * Unregisters a ULPI device and it's interface that was created with
305 * ulpi_create_interface().
306 */
ulpi_unregister_interface(struct ulpi * ulpi)307 void ulpi_unregister_interface(struct ulpi *ulpi)
308 {
309 device_unregister(&ulpi->dev);
310 }
311 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
312
313 /* -------------------------------------------------------------------------- */
314
ulpi_init(void)315 static int __init ulpi_init(void)
316 {
317 return bus_register(&ulpi_bus);
318 }
319 subsys_initcall(ulpi_init);
320
ulpi_exit(void)321 static void __exit ulpi_exit(void)
322 {
323 bus_unregister(&ulpi_bus);
324 }
325 module_exit(ulpi_exit);
326
327 MODULE_AUTHOR("Intel Corporation");
328 MODULE_LICENSE("GPL v2");
329 MODULE_DESCRIPTION("USB ULPI PHY bus");
330