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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for onboard USB hubs
*
* Copyright (c) 2022, Google LLC
*/
#include <driver.h>
#include <linux/gpio/consumer.h>
#include <init.h>
#include <of.h>
#include <linux/printk.h>
#include <of_device.h>
#include <regulator.h>
#include <linux/usb/usb.h>
#include "onboard_usb_hub.h"
void of_usb_host_probe_hubs(struct usb_host *host)
{
struct device_node *np;
np = dev_of_node(host->hw_dev);
if (!np)
return;
of_platform_populate(np, onboard_hub_match, host->hw_dev);
}
struct onboard_hub {
struct regulator *vdd;
struct device *dev;
const struct onboard_hub_pdata *pdata;
struct gpio_desc *reset_gpio;
};
static int onboard_hub_power_on(struct onboard_hub *hub)
{
int err;
err = regulator_enable(hub->vdd);
if (err) {
dev_err(hub->dev, "failed to enable regulator: %pe\n",
ERR_PTR(err));
return err;
}
udelay(hub->pdata->reset_us);
gpiod_set_value(hub->reset_gpio, 0);
return 0;
}
static int onboard_hub_probe(struct device *dev)
{
struct device_node *peer_node;
struct device *peer_dev;
struct onboard_hub *hub;
peer_node = of_parse_phandle(dev->of_node, "peer-hub", 0);
if (peer_node) {
peer_dev = of_find_device_by_node(peer_node);
if (peer_dev && peer_dev->priv)
return 0;
}
hub = xzalloc(sizeof(*hub));
hub->pdata = device_get_match_data(dev);
if (!hub->pdata)
return -EINVAL;
hub->vdd = regulator_get(dev, "vdd");
if (IS_ERR(hub->vdd))
return PTR_ERR(hub->vdd);
hub->reset_gpio = gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(hub->reset_gpio))
return dev_errp_probe(dev, hub->reset_gpio,
"failed to get reset GPIO\n");
hub->dev = dev;
dev->priv = hub;
return onboard_hub_power_on(hub);
}
static struct driver onboard_hub_driver = {
.name = "onboard-usb-hub",
.probe = onboard_hub_probe,
.of_compatible = onboard_hub_match,
};
device_platform_driver(onboard_hub_driver);
MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
MODULE_LICENSE("GPL v2");
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