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164 lines
3.4 KiB
164 lines
3.4 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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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 ([email protected]) |
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* Copyright (c) 2016 Linaro Ltd. |
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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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static int __maybe_unused 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 __maybe_unused 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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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 = pm_ptr(&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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