176 lines
3.8 KiB
C
176 lines
3.8 KiB
C
/*
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* Driver for SMSC USB4604 USB HSIC 4-port 2.0 hub controller driver
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* Based on usb3503 driver
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*
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* Copyright (c) 2012-2013 Dongjin Kim (tobetter@gmail.com)
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* Copyright (c) 2016 Linaro Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/i2c.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/gpio/consumer.h>
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enum usb4604_mode {
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USB4604_MODE_UNKNOWN,
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USB4604_MODE_HUB,
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USB4604_MODE_STANDBY,
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};
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struct usb4604 {
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enum usb4604_mode mode;
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struct device *dev;
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struct gpio_desc *gpio_reset;
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};
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static void usb4604_reset(struct usb4604 *hub, int state)
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{
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gpiod_set_value_cansleep(hub->gpio_reset, state);
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/* Wait for i2c logic to come up */
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if (state)
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msleep(250);
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}
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static int usb4604_connect(struct usb4604 *hub)
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{
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struct device *dev = hub->dev;
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struct i2c_client *client = to_i2c_client(dev);
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int err;
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u8 connect_cmd[] = { 0xaa, 0x55, 0x00 };
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usb4604_reset(hub, 1);
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err = i2c_master_send(client, connect_cmd, ARRAY_SIZE(connect_cmd));
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if (err < 0) {
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usb4604_reset(hub, 0);
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return err;
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}
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hub->mode = USB4604_MODE_HUB;
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dev_dbg(dev, "switched to HUB mode\n");
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return 0;
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}
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static int usb4604_switch_mode(struct usb4604 *hub, enum usb4604_mode mode)
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{
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struct device *dev = hub->dev;
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int err = 0;
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switch (mode) {
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case USB4604_MODE_HUB:
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err = usb4604_connect(hub);
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break;
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case USB4604_MODE_STANDBY:
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usb4604_reset(hub, 0);
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dev_dbg(dev, "switched to STANDBY mode\n");
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break;
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default:
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dev_err(dev, "unknown mode is requested\n");
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err = -EINVAL;
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break;
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}
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return err;
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}
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static int usb4604_probe(struct usb4604 *hub)
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{
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struct device *dev = hub->dev;
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struct device_node *np = dev->of_node;
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struct gpio_desc *gpio;
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u32 mode = USB4604_MODE_HUB;
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gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
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if (IS_ERR(gpio))
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return PTR_ERR(gpio);
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hub->gpio_reset = gpio;
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if (of_property_read_u32(np, "initial-mode", &hub->mode))
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hub->mode = mode;
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return usb4604_switch_mode(hub, hub->mode);
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}
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static int usb4604_i2c_probe(struct i2c_client *i2c,
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const struct i2c_device_id *id)
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{
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struct usb4604 *hub;
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hub = devm_kzalloc(&i2c->dev, sizeof(*hub), GFP_KERNEL);
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if (!hub)
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return -ENOMEM;
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i2c_set_clientdata(i2c, hub);
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hub->dev = &i2c->dev;
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return usb4604_probe(hub);
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}
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#ifdef CONFIG_PM_SLEEP
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static int usb4604_i2c_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct usb4604 *hub = i2c_get_clientdata(client);
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usb4604_switch_mode(hub, USB4604_MODE_STANDBY);
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return 0;
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}
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static int usb4604_i2c_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct usb4604 *hub = i2c_get_clientdata(client);
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usb4604_switch_mode(hub, hub->mode);
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(usb4604_i2c_pm_ops, usb4604_i2c_suspend,
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usb4604_i2c_resume);
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static const struct i2c_device_id usb4604_id[] = {
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{ "usb4604", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, usb4604_id);
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#ifdef CONFIG_OF
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static const struct of_device_id usb4604_of_match[] = {
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{ .compatible = "smsc,usb4604" },
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{}
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};
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MODULE_DEVICE_TABLE(of, usb4604_of_match);
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#endif
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static struct i2c_driver usb4604_i2c_driver = {
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.driver = {
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.name = "usb4604",
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.pm = &usb4604_i2c_pm_ops,
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.of_match_table = of_match_ptr(usb4604_of_match),
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},
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.probe = usb4604_i2c_probe,
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.id_table = usb4604_id,
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};
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module_i2c_driver(usb4604_i2c_driver);
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MODULE_DESCRIPTION("USB4604 USB HUB driver");
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MODULE_LICENSE("GPL v2");
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