mirror of
https://github.com/torvalds/linux.git
synced 2024-12-22 02:52:56 +00:00
7aea2a7ddc
Use the newly introduced pm_ptr() macro, and mark the suspend/resume functions __maybe_unused. These functions can then be moved outside the CONFIG_PM_SUSPEND block, and the compiler can then process them and detect build failures independently of the config. If unused, they will simply be discarded by the compiler. Signed-off-by: Paul Cercueil <paul@crapouillou.net> Link: https://lore.kernel.org/r/20200903112554.34263-9-paul@crapouillou.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
165 lines
3.4 KiB
C
165 lines
3.4 KiB
C
// 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,
|
|
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);
|
|
}
|
|
|
|
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[] = {
|
|
{ "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 = 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");
|