// SPDX-License-Identifier: GPL-2.0+/* * Driver for SMSC USB4604 USB HSIC 4-port 2.0 hub controller driver * Based on usb3503 driver * * Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com) * Copyright (c) 2016 Linaro Ltd. */ #include <linux/i2c.h>#include <linux/delay.h>#include <linux/slab.h>#include <linux/module.h>#include <linux/gpio/consumer.h> enum usb4604_mode {	USB4604_MODE_UNKNOWN,	USB4604_MODE_HUB,	USB4604_MODE_STANDBY,}; struct usb4604 {	enum usb4604_mode	mode;	struct device		*dev;	struct gpio_desc	*gpio_reset;}; static void usb4604_reset(struct usb4604 *hub, int state){	gpiod_set_value_cansleep(hub->gpio_reset, state); 	/* Wait for i2c logic to come up */	if (state)		msleep(250);} static int usb4604_connect(struct usb4604 *hub){	struct device *dev = hub->dev;	struct i2c_client *client = to_i2c_client(dev);	int err;	u8 connect_cmd[] = { 0xaa, 0x55, 0x00 }; 	usb4604_reset(hub, 1); 	err = i2c_master_send(client, connect_cmd, ARRAY_SIZE(connect_cmd));	if (err < 0) {		usb4604_reset(hub, 0);		return err;	} 	hub->mode = USB4604_MODE_HUB;	dev_dbg(dev, "switched to HUB mode\n"); 	return 0;} static int usb4604_switch_mode(struct usb4604 *hub, enum usb4604_mode mode){	struct device *dev = hub->dev;	int err = 0; 	switch (mode) {	case USB4604_MODE_HUB:		err = usb4604_connect(hub);		break; 	case USB4604_MODE_STANDBY:		usb4604_reset(hub, 0);		dev_dbg(dev, "switched to STANDBY mode\n");		break; 	default:		dev_err(dev, "unknown mode is requested\n");		err = -EINVAL;		break;	} 	return err;} static int usb4604_probe(struct usb4604 *hub){	struct device *dev = hub->dev;	struct device_node *np = dev->of_node;	struct gpio_desc *gpio;	u32 mode = USB4604_MODE_HUB; 	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);	if (IS_ERR(gpio))		return PTR_ERR(gpio);	hub->gpio_reset = gpio; 	if (of_property_read_u32(np, "initial-mode", &hub->mode))		hub->mode = mode; 	return usb4604_switch_mode(hub, hub->mode);} static int usb4604_i2c_probe(struct i2c_client *i2c){	struct usb4604 *hub; 	hub = devm_kzalloc(&i2c->dev, sizeof(*hub), GFP_KERNEL);	if (!hub)		return -ENOMEM; 	i2c_set_clientdata(i2c, hub);	hub->dev = &i2c->dev; 	return usb4604_probe(hub);} static int __maybe_unused usb4604_i2c_suspend(struct device *dev){	struct i2c_client *client = to_i2c_client(dev);	struct usb4604 *hub = i2c_get_clientdata(client); 	usb4604_switch_mode(hub, USB4604_MODE_STANDBY); 	return 0;} static int __maybe_unused usb4604_i2c_resume(struct device *dev){	struct i2c_client *client = to_i2c_client(dev);	struct usb4604 *hub = i2c_get_clientdata(client); 	usb4604_switch_mode(hub, hub->mode); 	return 0;} static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend,		usb4604_i2c_resume); static const struct i2c_device_id usb4604_id[] = {	{ .name = "usb4604" },	{ }};MODULE_DEVICE_TABLE(i2c, usb4604_id); #ifdef CONFIG_OFstatic const struct of_device_id usb4604_of_match[] = {	{ .compatible = "smsc,usb4604" },	{}};MODULE_DEVICE_TABLE(of, usb4604_of_match);#endif static struct i2c_driver usb4604_i2c_driver = {	.driver = {		.name = "usb4604",		.pm = pm_ptr(&usb4604_i2c_pm_ops),		.of_match_table = of_match_ptr(usb4604_of_match),	},	.probe		= usb4604_i2c_probe,	.id_table	= usb4604_id,};module_i2c_driver(usb4604_i2c_driver); MODULE_DESCRIPTION("USB4604 USB HUB driver");MODULE_LICENSE("GPL v2");