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/debugfs.h>
17 #include <linux/of.h>
18 #include <linux/of_device.h>
19 #include <linux/clk/clk-conf.h>
20
21 /* -------------------------------------------------------------------------- */
22
ulpi_read(struct ulpi * ulpi,u8 addr)23 int ulpi_read(struct ulpi *ulpi, u8 addr)
24 {
25 return ulpi->ops->read(ulpi->dev.parent, addr);
26 }
27 EXPORT_SYMBOL_GPL(ulpi_read);
28
ulpi_write(struct ulpi * ulpi,u8 addr,u8 val)29 int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
30 {
31 return ulpi->ops->write(ulpi->dev.parent, addr, val);
32 }
33 EXPORT_SYMBOL_GPL(ulpi_write);
34
35 /* -------------------------------------------------------------------------- */
36
ulpi_match(struct device * dev,struct device_driver * driver)37 static int ulpi_match(struct device *dev, 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
ulpi_uevent(struct device * dev,struct kobj_uevent_env * env)58 static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
59 {
60 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
ulpi_probe(struct device * dev)73 static 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
ulpi_remove(struct device * dev)85 static 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
93 static 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
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)103 static 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 }
116 static DEVICE_ATTR_RO(modalias);
117
118 static struct attribute *ulpi_dev_attrs[] = {
119 &dev_attr_modalias.attr,
120 NULL
121 };
122
123 static const struct attribute_group ulpi_dev_attr_group = {
124 .attrs = ulpi_dev_attrs,
125 };
126
127 static const struct attribute_group *ulpi_dev_attr_groups[] = {
128 &ulpi_dev_attr_group,
129 NULL
130 };
131
ulpi_dev_release(struct device * dev)132 static void ulpi_dev_release(struct device *dev)
133 {
134 of_node_put(dev->of_node);
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_regs_read(struct seq_file * seq,void * data)236 static int ulpi_regs_read(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 }
272
ulpi_regs_open(struct inode * inode,struct file * f)273 static int ulpi_regs_open(struct inode *inode, struct file *f)
274 {
275 struct ulpi *ulpi = inode->i_private;
276
277 return single_open(f, ulpi_regs_read, ulpi);
278 }
279
280 static const struct file_operations ulpi_regs_ops = {
281 .owner = THIS_MODULE,
282 .open = ulpi_regs_open,
283 .release = single_release,
284 .read = seq_read,
285 .llseek = seq_lseek
286 };
287
288 #define ULPI_ROOT debugfs_lookup(KBUILD_MODNAME, NULL)
289
ulpi_register(struct device * dev,struct ulpi * ulpi)290 static int ulpi_register(struct device *dev, struct ulpi *ulpi)
291 {
292 int ret;
293 struct dentry *root;
294
295 ulpi->dev.parent = dev; /* needed early for ops */
296 ulpi->dev.bus = &ulpi_bus;
297 ulpi->dev.type = &ulpi_dev_type;
298 dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
299
300 ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
301
302 ret = ulpi_of_register(ulpi);
303 if (ret)
304 return ret;
305
306 ret = ulpi_read_id(ulpi);
307 if (ret) {
308 of_node_put(ulpi->dev.of_node);
309 return ret;
310 }
311
312 ret = device_register(&ulpi->dev);
313 if (ret) {
314 put_device(&ulpi->dev);
315 return ret;
316 }
317
318 root = debugfs_create_dir(dev_name(dev), ULPI_ROOT);
319 debugfs_create_file("regs", 0444, root, ulpi, &ulpi_regs_ops);
320
321 dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
322 ulpi->id.vendor, ulpi->id.product);
323
324 return 0;
325 }
326
327 /**
328 * ulpi_register_interface - instantiate new ULPI device
329 * @dev: USB controller's device interface
330 * @ops: ULPI register access
331 *
332 * Allocates and registers a ULPI device and an interface for it. Called from
333 * the USB controller that provides the ULPI interface.
334 */
ulpi_register_interface(struct device * dev,const struct ulpi_ops * ops)335 struct ulpi *ulpi_register_interface(struct device *dev,
336 const struct ulpi_ops *ops)
337 {
338 struct ulpi *ulpi;
339 int ret;
340
341 ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
342 if (!ulpi)
343 return ERR_PTR(-ENOMEM);
344
345 ulpi->ops = ops;
346
347 ret = ulpi_register(dev, ulpi);
348 if (ret) {
349 kfree(ulpi);
350 return ERR_PTR(ret);
351 }
352
353 return ulpi;
354 }
355 EXPORT_SYMBOL_GPL(ulpi_register_interface);
356
357 /**
358 * ulpi_unregister_interface - unregister ULPI interface
359 * @ulpi: struct ulpi_interface
360 *
361 * Unregisters a ULPI device and it's interface that was created with
362 * ulpi_create_interface().
363 */
ulpi_unregister_interface(struct ulpi * ulpi)364 void ulpi_unregister_interface(struct ulpi *ulpi)
365 {
366 debugfs_remove_recursive(debugfs_lookup(dev_name(&ulpi->dev),
367 ULPI_ROOT));
368 device_unregister(&ulpi->dev);
369 }
370 EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
371
372 /* -------------------------------------------------------------------------- */
373
ulpi_init(void)374 static int __init ulpi_init(void)
375 {
376 int ret;
377 struct dentry *root;
378
379 root = debugfs_create_dir(KBUILD_MODNAME, NULL);
380 ret = bus_register(&ulpi_bus);
381 if (ret)
382 debugfs_remove(root);
383 return ret;
384 }
385 subsys_initcall(ulpi_init);
386
ulpi_exit(void)387 static void __exit ulpi_exit(void)
388 {
389 bus_unregister(&ulpi_bus);
390 debugfs_remove_recursive(ULPI_ROOT);
391 }
392 module_exit(ulpi_exit);
393
394 MODULE_AUTHOR("Intel Corporation");
395 MODULE_LICENSE("GPL v2");
396 MODULE_DESCRIPTION("USB ULPI PHY bus");
397