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
 20/* -------------------------------------------------------------------------- */
 21
 22int ulpi_read(struct ulpi *ulpi, u8 addr)
 23{
 24	return ulpi->ops->read(ulpi->ops, addr);
 25}
 26EXPORT_SYMBOL_GPL(ulpi_read);
 27
 28int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
 29{
 30	return ulpi->ops->write(ulpi->ops, addr, val);
 31}
 32EXPORT_SYMBOL_GPL(ulpi_write);
 33
 34/* -------------------------------------------------------------------------- */
 35
 36static 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	for (id = drv->id_table; id->vendor; id++)
 43		if (id->vendor == ulpi->id.vendor &&
 44		    id->product == ulpi->id.product)
 45			return 1;
 46
 47	return 0;
 48}
 49
 50static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
 51{
 52	struct ulpi *ulpi = to_ulpi_dev(dev);
 53
 54	if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
 55			   ulpi->id.vendor, ulpi->id.product))
 56		return -ENOMEM;
 57	return 0;
 58}
 59
 60static int ulpi_probe(struct device *dev)
 61{
 62	struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
 63
 64	return drv->probe(to_ulpi_dev(dev));
 65}
 66
 67static int ulpi_remove(struct device *dev)
 68{
 69	struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
 70
 71	if (drv->remove)
 72		drv->remove(to_ulpi_dev(dev));
 73
 74	return 0;
 75}
 76
 77static struct bus_type ulpi_bus = {
 78	.name = "ulpi",
 79	.match = ulpi_match,
 80	.uevent = ulpi_uevent,
 81	.probe = ulpi_probe,
 82	.remove = ulpi_remove,
 83};
 84
 85/* -------------------------------------------------------------------------- */
 86
 87static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 88			     char *buf)
 89{
 90	struct ulpi *ulpi = to_ulpi_dev(dev);
 91
 92	return sprintf(buf, "ulpi:v%04xp%04x\n",
 93		       ulpi->id.vendor, ulpi->id.product);
 94}
 95static DEVICE_ATTR_RO(modalias);
 96
 97static struct attribute *ulpi_dev_attrs[] = {
 98	&dev_attr_modalias.attr,
 99	NULL
100};
101
102static struct attribute_group ulpi_dev_attr_group = {
103	.attrs = ulpi_dev_attrs,
104};
105
106static const struct attribute_group *ulpi_dev_attr_groups[] = {
107	&ulpi_dev_attr_group,
108	NULL
109};
110
111static void ulpi_dev_release(struct device *dev)
112{
113	kfree(to_ulpi_dev(dev));
114}
115
116static struct device_type ulpi_dev_type = {
117	.name = "ulpi_device",
118	.groups = ulpi_dev_attr_groups,
119	.release = ulpi_dev_release,
120};
121
122/* -------------------------------------------------------------------------- */
123
124/**
125 * ulpi_register_driver - register a driver with the ULPI bus
126 * @drv: driver being registered
127 *
128 * Registers a driver with the ULPI bus.
129 */
130int ulpi_register_driver(struct ulpi_driver *drv)
131{
132	if (!drv->probe)
133		return -EINVAL;
134
135	drv->driver.bus = &ulpi_bus;
136
137	return driver_register(&drv->driver);
138}
139EXPORT_SYMBOL_GPL(ulpi_register_driver);
140
141/**
142 * ulpi_unregister_driver - unregister a driver with the ULPI bus
143 * @drv: driver to unregister
144 *
145 * Unregisters a driver with the ULPI bus.
146 */
147void ulpi_unregister_driver(struct ulpi_driver *drv)
148{
149	driver_unregister(&drv->driver);
150}
151EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
152
153/* -------------------------------------------------------------------------- */
154
155static int ulpi_register(struct device *dev, struct ulpi *ulpi)
156{
157	int ret;
158
159	/* Test the interface */
160	ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
161	if (ret < 0)
162		return ret;
163
164	ret = ulpi_read(ulpi, ULPI_SCRATCH);
165	if (ret < 0)
166		return ret;
167
168	if (ret != 0xaa)
169		return -ENODEV;
170
171	ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
172	ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
173
174	ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
175	ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
176
177	ulpi->dev.parent = dev;
178	ulpi->dev.bus = &ulpi_bus;
179	ulpi->dev.type = &ulpi_dev_type;
180	dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
181
182	ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
183
184	request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
185
186	ret = device_register(&ulpi->dev);
187	if (ret)
188		return ret;
189
190	dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
191		ulpi->id.vendor, ulpi->id.product);
192
193	return 0;
194}
195
196/**
197 * ulpi_register_interface - instantiate new ULPI device
198 * @dev: USB controller's device interface
199 * @ops: ULPI register access
200 *
201 * Allocates and registers a ULPI device and an interface for it. Called from
202 * the USB controller that provides the ULPI interface.
203 */
204struct ulpi *ulpi_register_interface(struct device *dev, struct ulpi_ops *ops)
205{
206	struct ulpi *ulpi;
207	int ret;
208
209	ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
210	if (!ulpi)
211		return ERR_PTR(-ENOMEM);
212
213	ulpi->ops = ops;
214	ops->dev = dev;
215
216	ret = ulpi_register(dev, ulpi);
217	if (ret) {
218		kfree(ulpi);
219		return ERR_PTR(ret);
220	}
221
222	return ulpi;
223}
224EXPORT_SYMBOL_GPL(ulpi_register_interface);
225
226/**
227 * ulpi_unregister_interface - unregister ULPI interface
228 * @intrf: struct ulpi_interface
229 *
230 * Unregisters a ULPI device and it's interface that was created with
231 * ulpi_create_interface().
232 */
233void ulpi_unregister_interface(struct ulpi *ulpi)
234{
235	device_unregister(&ulpi->dev);
236}
237EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
238
239/* -------------------------------------------------------------------------- */
240
241static int __init ulpi_init(void)
242{
243	return bus_register(&ulpi_bus);
244}
245subsys_initcall(ulpi_init);
246
247static void __exit ulpi_exit(void)
248{
249	bus_unregister(&ulpi_bus);
250}
251module_exit(ulpi_exit);
252
253MODULE_AUTHOR("Intel Corporation");
254MODULE_LICENSE("GPL v2");
255MODULE_DESCRIPTION("USB ULPI PHY bus");