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