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");