1/*
2 * NXP ISP1301 USB transceiver driver
3 *
4 * Copyright (C) 2012 Roland Stigge
5 *
6 * Author: Roland Stigge <stigge@antcom.de>
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/module.h>
14#include <linux/mutex.h>
15#include <linux/i2c.h>
16#include <linux/usb/phy.h>
17#include <linux/usb/isp1301.h>
18
19#define DRV_NAME		"isp1301"
20
21struct isp1301 {
22	struct usb_phy		phy;
23	struct mutex		mutex;
24
25	struct i2c_client	*client;
26};
27
28#define phy_to_isp(p)		(container_of((p), struct isp1301, phy))
29
30static const struct i2c_device_id isp1301_id[] = {
31	{ "isp1301", 0 },
32	{ }
33};
34
35static struct i2c_client *isp1301_i2c_client;
36
37static int __isp1301_write(struct isp1301 *isp, u8 reg, u8 value, u8 clear)
38{
39	return i2c_smbus_write_byte_data(isp->client, reg | clear, value);
40}
41
42static int isp1301_write(struct isp1301 *isp, u8 reg, u8 value)
43{
44	return __isp1301_write(isp, reg, value, 0);
45}
46
47static int isp1301_clear(struct isp1301 *isp, u8 reg, u8 value)
48{
49	return __isp1301_write(isp, reg, value, ISP1301_I2C_REG_CLEAR_ADDR);
50}
51
52static int isp1301_phy_init(struct usb_phy *phy)
53{
54	struct isp1301 *isp = phy_to_isp(phy);
55
56	/* Disable transparent UART mode first */
57	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_UART_EN);
58	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_1, ~MC1_SPEED_REG);
59	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_SPEED_REG);
60	isp1301_clear(isp, ISP1301_I2C_MODE_CONTROL_2, ~0);
61	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_2, (MC2_BI_DI | MC2_PSW_EN
62				| MC2_SPD_SUSP_CTRL));
63
64	isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, ~0);
65	isp1301_write(isp, ISP1301_I2C_MODE_CONTROL_1, MC1_DAT_SE0);
66	isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLDOWN
67				| OTG1_DP_PULLDOWN));
68	isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, (OTG1_DM_PULLUP
69				| OTG1_DP_PULLUP));
70
71	/* mask all interrupts */
72	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_LATCH, ~0);
73	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_FALLING, ~0);
74	isp1301_clear(isp, ISP1301_I2C_INTERRUPT_RISING, ~0);
75
76	return 0;
77}
78
79static int isp1301_phy_set_vbus(struct usb_phy *phy, int on)
80{
81	struct isp1301 *isp = phy_to_isp(phy);
82
83	if (on)
84		isp1301_write(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);
85	else
86		isp1301_clear(isp, ISP1301_I2C_OTG_CONTROL_1, OTG1_VBUS_DRV);
87
88	return 0;
89}
90
91static int isp1301_probe(struct i2c_client *client,
92			 const struct i2c_device_id *i2c_id)
93{
94	struct isp1301 *isp;
95	struct usb_phy *phy;
96
97	isp = devm_kzalloc(&client->dev, sizeof(*isp), GFP_KERNEL);
98	if (!isp)
99		return -ENOMEM;
100
101	isp->client = client;
102	mutex_init(&isp->mutex);
103
104	phy = &isp->phy;
105	phy->dev = &client->dev;
106	phy->label = DRV_NAME;
107	phy->init = isp1301_phy_init;
108	phy->set_vbus = isp1301_phy_set_vbus;
109	phy->type = USB_PHY_TYPE_USB2;
110
111	i2c_set_clientdata(client, isp);
112	usb_add_phy_dev(phy);
113
114	isp1301_i2c_client = client;
115
116	return 0;
117}
118
119static int isp1301_remove(struct i2c_client *client)
120{
121	struct isp1301 *isp = i2c_get_clientdata(client);
122
123	usb_remove_phy(&isp->phy);
124	isp1301_i2c_client = NULL;
125
126	return 0;
127}
128
129static struct i2c_driver isp1301_driver = {
130	.driver = {
131		.name = DRV_NAME,
132	},
133	.probe = isp1301_probe,
134	.remove = isp1301_remove,
135	.id_table = isp1301_id,
136};
137
138module_i2c_driver(isp1301_driver);
139
140static int match(struct device *dev, void *data)
141{
142	struct device_node *node = (struct device_node *)data;
143	return (dev->of_node == node) &&
144		(dev->driver == &isp1301_driver.driver);
145}
146
147struct i2c_client *isp1301_get_client(struct device_node *node)
148{
149	if (node) { /* reference of ISP1301 I2C node via DT */
150		struct device *dev = bus_find_device(&i2c_bus_type, NULL,
151						     node, match);
152		if (!dev)
153			return NULL;
154		return to_i2c_client(dev);
155	} else { /* non-DT: only one ISP1301 chip supported */
156		return isp1301_i2c_client;
157	}
158}
159EXPORT_SYMBOL_GPL(isp1301_get_client);
160
161MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
162MODULE_DESCRIPTION("NXP ISP1301 USB transceiver driver");
163MODULE_LICENSE("GPL");
164