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