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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 <[email protected]>
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/debugfs.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19#include <linux/clk/clk-conf.h>
20
21/* -------------------------------------------------------------------------- */
22
23int ulpi_read(struct ulpi *ulpi, u8 addr)
24{
25 return ulpi->ops->read(ulpi->dev.parent, addr);
26}
27EXPORT_SYMBOL_GPL(ulpi_read);
28
29int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
30{
31 return ulpi->ops->write(ulpi->dev.parent, addr, val);
32}
33EXPORT_SYMBOL_GPL(ulpi_write);
34
35/* -------------------------------------------------------------------------- */
36
37static int ulpi_match(struct device *dev, const struct device_driver *driver)
38{
39 struct ulpi_driver *drv = to_ulpi_driver(driver);
40 struct ulpi *ulpi = to_ulpi_dev(dev);
41 const struct ulpi_device_id *id;
42
43 /*
44 * Some ULPI devices don't have a vendor id
45 * or provide an id_table so rely on OF match.
46 */
47 if (ulpi->id.vendor == 0 || !drv->id_table)
48 return of_driver_match_device(dev, driver);
49
50 for (id = drv->id_table; id->vendor; id++)
51 if (id->vendor == ulpi->id.vendor &&
52 id->product == ulpi->id.product)
53 return 1;
54
55 return 0;
56}
57
58static int ulpi_uevent(const struct device *dev, struct kobj_uevent_env *env)
59{
60 const struct ulpi *ulpi = to_ulpi_dev(dev);
61 int ret;
62
63 ret = of_device_uevent_modalias(dev, env);
64 if (ret != -ENODEV)
65 return ret;
66
67 if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
68 ulpi->id.vendor, ulpi->id.product))
69 return -ENOMEM;
70 return 0;
71}
72
73static int ulpi_probe(struct device *dev)
74{
75 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
76 int ret;
77
78 ret = of_clk_set_defaults(dev->of_node, false);
79 if (ret < 0)
80 return ret;
81
82 return drv->probe(to_ulpi_dev(dev));
83}
84
85static void ulpi_remove(struct device *dev)
86{
87 struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
88
89 if (drv->remove)
90 drv->remove(to_ulpi_dev(dev));
91}
92
93static const struct bus_type ulpi_bus = {
94 .name = "ulpi",
95 .match = ulpi_match,
96 .uevent = ulpi_uevent,
97 .probe = ulpi_probe,
98 .remove = ulpi_remove,
99};
100
101/* -------------------------------------------------------------------------- */
102
103static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
104 char *buf)
105{
106 int len;
107 struct ulpi *ulpi = to_ulpi_dev(dev);
108
109 len = of_device_modalias(dev, buf, PAGE_SIZE);
110 if (len != -ENODEV)
111 return len;
112
113 return sprintf(buf, "ulpi:v%04xp%04x\n",
114 ulpi->id.vendor, ulpi->id.product);
115}
116static DEVICE_ATTR_RO(modalias);
117
118static struct attribute *ulpi_dev_attrs[] = {
119 &dev_attr_modalias.attr,
120 NULL
121};
122
123static const struct attribute_group ulpi_dev_attr_group = {
124 .attrs = ulpi_dev_attrs,
125};
126
127static const struct attribute_group *ulpi_dev_attr_groups[] = {
128 &ulpi_dev_attr_group,
129 NULL
130};
131
132static void ulpi_dev_release(struct device *dev)
133{
134 of_node_put(dev->of_node);
135 kfree(to_ulpi_dev(dev));
136}
137
138static 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 */
153int __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}
163EXPORT_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 */
171void ulpi_unregister_driver(struct ulpi_driver *drv)
172{
173 driver_unregister(&drv->driver);
174}
175EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
176
177/* -------------------------------------------------------------------------- */
178
179static 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
203static 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;
231err:
232 of_request_module(ulpi->dev.of_node);
233 return 0;
234}
235
236static int ulpi_regs_show(struct seq_file *seq, void *data)
237{
238 struct ulpi *ulpi = seq->private;
239
240#define ulpi_print(name, reg) do { \
241 int ret = ulpi_read(ulpi, reg); \
242 if (ret < 0) \
243 return ret; \
244 seq_printf(seq, name " %.02x\n", ret); \
245} while (0)
246
247 ulpi_print("Vendor ID Low ", ULPI_VENDOR_ID_LOW);
248 ulpi_print("Vendor ID High ", ULPI_VENDOR_ID_HIGH);
249 ulpi_print("Product ID Low ", ULPI_PRODUCT_ID_LOW);
250 ulpi_print("Product ID High ", ULPI_PRODUCT_ID_HIGH);
251 ulpi_print("Function Control ", ULPI_FUNC_CTRL);
252 ulpi_print("Interface Control ", ULPI_IFC_CTRL);
253 ulpi_print("OTG Control ", ULPI_OTG_CTRL);
254 ulpi_print("USB Interrupt Enable Rising ", ULPI_USB_INT_EN_RISE);
255 ulpi_print("USB Interrupt Enable Falling", ULPI_USB_INT_EN_FALL);
256 ulpi_print("USB Interrupt Status ", ULPI_USB_INT_STS);
257 ulpi_print("USB Interrupt Latch ", ULPI_USB_INT_LATCH);
258 ulpi_print("Debug ", ULPI_DEBUG);
259 ulpi_print("Scratch Register ", ULPI_SCRATCH);
260 ulpi_print("Carkit Control ", ULPI_CARKIT_CTRL);
261 ulpi_print("Carkit Interrupt Delay ", ULPI_CARKIT_INT_DELAY);
262 ulpi_print("Carkit Interrupt Enable ", ULPI_CARKIT_INT_EN);
263 ulpi_print("Carkit Interrupt Status ", ULPI_CARKIT_INT_STS);
264 ulpi_print("Carkit Interrupt Latch ", ULPI_CARKIT_INT_LATCH);
265 ulpi_print("Carkit Pulse Control ", ULPI_CARKIT_PLS_CTRL);
266 ulpi_print("Transmit Positive Width ", ULPI_TX_POS_WIDTH);
267 ulpi_print("Transmit Negative Width ", ULPI_TX_NEG_WIDTH);
268 ulpi_print("Receive Polarity Recovery ", ULPI_POLARITY_RECOVERY);
269
270 return 0;
271}
272DEFINE_SHOW_ATTRIBUTE(ulpi_regs);
273
274static struct dentry *ulpi_root;
275
276static int ulpi_register(struct device *dev, struct ulpi *ulpi)
277{
278 int ret;
279 struct dentry *root;
280
281 ulpi->dev.parent = dev; /* needed early for ops */
282 ulpi->dev.bus = &ulpi_bus;
283 ulpi->dev.type = &ulpi_dev_type;
284
285 device_initialize(&ulpi->dev);
286
287 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
288
289 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
290
291 ret = ulpi_of_register(ulpi);
292 if (ret)
293 return ret;
294
295 ret = ulpi_read_id(ulpi);
296 if (ret)
297 return ret;
298
299 ret = device_add(&ulpi->dev);
300 if (ret)
301 return ret;
302
303 root = debugfs_create_dir(dev_name(&ulpi->dev), ulpi_root);
304 debugfs_create_file("regs", 0444, root, ulpi, &ulpi_regs_fops);
305
306 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
307 ulpi->id.vendor, ulpi->id.product);
308
309 return 0;
310}
311
312/**
313 * ulpi_register_interface - instantiate new ULPI device
314 * @dev: USB controller's device interface
315 * @ops: ULPI register access
316 *
317 * Allocates and registers a ULPI device and an interface for it. Called from
318 * the USB controller that provides the ULPI interface.
319 */
320struct ulpi *ulpi_register_interface(struct device *dev,
321 const struct ulpi_ops *ops)
322{
323 struct ulpi *ulpi;
324 int ret;
325
326 ulpi = kzalloc_obj(*ulpi);
327 if (!ulpi)
328 return ERR_PTR(-ENOMEM);
329
330 ulpi->ops = ops;
331
332 ret = ulpi_register(dev, ulpi);
333 if (ret) {
334 put_device(&ulpi->dev);
335 return ERR_PTR(ret);
336 }
337
338 return ulpi;
339}
340EXPORT_SYMBOL_GPL(ulpi_register_interface);
341
342/**
343 * ulpi_unregister_interface - unregister ULPI interface
344 * @ulpi: struct ulpi_interface
345 *
346 * Unregisters a ULPI device and it's interface that was created with
347 * ulpi_create_interface().
348 */
349void ulpi_unregister_interface(struct ulpi *ulpi)
350{
351 debugfs_lookup_and_remove(dev_name(&ulpi->dev), ulpi_root);
352 device_unregister(&ulpi->dev);
353}
354EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
355
356/* -------------------------------------------------------------------------- */
357
358static int __init ulpi_init(void)
359{
360 int ret;
361
362 ulpi_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
363 ret = bus_register(&ulpi_bus);
364 if (ret)
365 debugfs_remove(ulpi_root);
366 return ret;
367}
368subsys_initcall(ulpi_init);
369
370static void __exit ulpi_exit(void)
371{
372 bus_unregister(&ulpi_bus);
373 debugfs_remove(ulpi_root);
374}
375module_exit(ulpi_exit);
376
377MODULE_AUTHOR("Intel Corporation");
378MODULE_LICENSE("GPL v2");
379MODULE_DESCRIPTION("USB ULPI PHY bus");