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/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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,
const struct i2c_device_id *id)
{
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);
}
#ifdef CONFIG_PM_SLEEP
static int 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 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;
}
#endif
static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend,
usb4604_i2c_resume);
static const struct i2c_device_id usb4604_id[] = {
{ "usb4604", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, usb4604_id);
#ifdef CONFIG_OF
static 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 = &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");
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