tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/**
2 * ulpi.c - USB ULPI PHY bus
3 *
4 * Copyright (C) 2015 Intel Corporation
5 *
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/ulpi/interface.h>
14#include <linux/ulpi/driver.h>
15#include <linux/ulpi/regs.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/acpi.h>
19#include <linux/of.h>
20#include <linux/of_device.h>
21#include <linux/clk/clk-conf.h>
22
23/* -------------------------------------------------------------------------- */
24
25int ulpi_read(struct ulpi *ulpi, u8 addr)
26{
27 return ulpi->ops->read(ulpi->dev.parent, addr);
28}
29EXPORT_SYMBOL_GPL(ulpi_read);
30
31int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
32{
33 return ulpi->ops->write(ulpi->dev.parent, addr, val);
34}
35EXPORT_SYMBOL_GPL(ulpi_write);
36
37/* -------------------------------------------------------------------------- */
38
39static int ulpi_match(struct device *dev, struct device_driver *driver)
40{
41 struct ulpi_driver *drv = to_ulpi_driver(driver);
42 struct ulpi *ulpi = to_ulpi_dev(dev);
43 const struct ulpi_device_id *id;
44
45 /* Some ULPI devices don't have a vendor id so rely on OF match */
46 if (ulpi->id.vendor == 0)
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
57static 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
72static 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
84static 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
94static 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
104static 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_get_modalias(dev, buf, PAGE_SIZE - 1);
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}
117static DEVICE_ATTR_RO(modalias);
118
119static struct attribute *ulpi_dev_attrs[] = {
120 &dev_attr_modalias.attr,
121 NULL
122};
123
124static struct attribute_group ulpi_dev_attr_group = {
125 .attrs = ulpi_dev_attrs,
126};
127
128static const struct attribute_group *ulpi_dev_attr_groups[] = {
129 &ulpi_dev_attr_group,
130 NULL
131};
132
133static void ulpi_dev_release(struct device *dev)
134{
135 kfree(to_ulpi_dev(dev));
136}
137
138static 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 *
150 * Registers a driver with the ULPI bus.
151 */
152int __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}
162EXPORT_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 */
170void ulpi_unregister_driver(struct ulpi_driver *drv)
171{
172 driver_unregister(&drv->driver);
173}
174EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
175
176/* -------------------------------------------------------------------------- */
177
178static 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_find_node_by_name(parent->of_node, "ulpi");
187 else if (parent->parent && parent->parent->of_node)
188 np = of_find_node_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
202static 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;
230err:
231 of_device_request_module(&ulpi->dev);
232 return 0;
233}
234
235static 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 return ret;
253
254 ret = device_register(&ulpi->dev);
255 if (ret)
256 return ret;
257
258 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
259 ulpi->id.vendor, ulpi->id.product);
260
261 return 0;
262}
263
264/**
265 * ulpi_register_interface - instantiate new ULPI device
266 * @dev: USB controller's device interface
267 * @ops: ULPI register access
268 *
269 * Allocates and registers a ULPI device and an interface for it. Called from
270 * the USB controller that provides the ULPI interface.
271 */
272struct ulpi *ulpi_register_interface(struct device *dev,
273 const struct ulpi_ops *ops)
274{
275 struct ulpi *ulpi;
276 int ret;
277
278 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
279 if (!ulpi)
280 return ERR_PTR(-ENOMEM);
281
282 ulpi->ops = ops;
283
284 ret = ulpi_register(dev, ulpi);
285 if (ret) {
286 kfree(ulpi);
287 return ERR_PTR(ret);
288 }
289
290 return ulpi;
291}
292EXPORT_SYMBOL_GPL(ulpi_register_interface);
293
294/**
295 * ulpi_unregister_interface - unregister ULPI interface
296 * @intrf: struct ulpi_interface
297 *
298 * Unregisters a ULPI device and it's interface that was created with
299 * ulpi_create_interface().
300 */
301void ulpi_unregister_interface(struct ulpi *ulpi)
302{
303 of_node_put(ulpi->dev.of_node);
304 device_unregister(&ulpi->dev);
305}
306EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
307
308/* -------------------------------------------------------------------------- */
309
310static int __init ulpi_init(void)
311{
312 return bus_register(&ulpi_bus);
313}
314subsys_initcall(ulpi_init);
315
316static void __exit ulpi_exit(void)
317{
318 bus_unregister(&ulpi_bus);
319}
320module_exit(ulpi_exit);
321
322MODULE_AUTHOR("Intel Corporation");
323MODULE_LICENSE("GPL v2");
324MODULE_DESCRIPTION("USB ULPI PHY bus");