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![Johan Hovold](/assets/img/avatar_default.png)
Fix bus-node lookup during registration, which ended up searching the whole
device tree depth-first starting at the parent (or grand parent) rather
than just matching on its children.
To make things worse, the parent (or grand-parent) node could end being
prematurely freed as well.
Fixes: ef6a7bcfb0
("usb: ulpi: Support device discovery via DT")
Reported-by: Peter Robinson <pbrobinson@gmail.com>
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable <stable@vger.kernel.org> # 4.10
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
321 lines
7.1 KiB
C
321 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/**
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* ulpi.c - USB ULPI PHY bus
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*
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* Copyright (C) 2015 Intel Corporation
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*
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* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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*/
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#include <linux/ulpi/interface.h>
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#include <linux/ulpi/driver.h>
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#include <linux/ulpi/regs.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/clk/clk-conf.h>
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/* -------------------------------------------------------------------------- */
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int ulpi_read(struct ulpi *ulpi, u8 addr)
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{
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return ulpi->ops->read(ulpi->dev.parent, addr);
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}
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EXPORT_SYMBOL_GPL(ulpi_read);
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int ulpi_write(struct ulpi *ulpi, u8 addr, u8 val)
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{
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return ulpi->ops->write(ulpi->dev.parent, addr, val);
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}
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EXPORT_SYMBOL_GPL(ulpi_write);
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/* -------------------------------------------------------------------------- */
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static int ulpi_match(struct device *dev, struct device_driver *driver)
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{
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struct ulpi_driver *drv = to_ulpi_driver(driver);
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struct ulpi *ulpi = to_ulpi_dev(dev);
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const struct ulpi_device_id *id;
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/* Some ULPI devices don't have a vendor id so rely on OF match */
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if (ulpi->id.vendor == 0)
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return of_driver_match_device(dev, driver);
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for (id = drv->id_table; id->vendor; id++)
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if (id->vendor == ulpi->id.vendor &&
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id->product == ulpi->id.product)
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return 1;
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return 0;
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}
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static int ulpi_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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struct ulpi *ulpi = to_ulpi_dev(dev);
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int ret;
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ret = of_device_uevent_modalias(dev, env);
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if (ret != -ENODEV)
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return ret;
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if (add_uevent_var(env, "MODALIAS=ulpi:v%04xp%04x",
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ulpi->id.vendor, ulpi->id.product))
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return -ENOMEM;
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return 0;
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}
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static int ulpi_probe(struct device *dev)
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{
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struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
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int ret;
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ret = of_clk_set_defaults(dev->of_node, false);
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if (ret < 0)
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return ret;
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return drv->probe(to_ulpi_dev(dev));
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}
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static int ulpi_remove(struct device *dev)
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{
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struct ulpi_driver *drv = to_ulpi_driver(dev->driver);
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if (drv->remove)
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drv->remove(to_ulpi_dev(dev));
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return 0;
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}
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static struct bus_type ulpi_bus = {
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.name = "ulpi",
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.match = ulpi_match,
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.uevent = ulpi_uevent,
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.probe = ulpi_probe,
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.remove = ulpi_remove,
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};
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/* -------------------------------------------------------------------------- */
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static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int len;
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struct ulpi *ulpi = to_ulpi_dev(dev);
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len = of_device_modalias(dev, buf, PAGE_SIZE);
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if (len != -ENODEV)
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return len;
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return sprintf(buf, "ulpi:v%04xp%04x\n",
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ulpi->id.vendor, ulpi->id.product);
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}
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static DEVICE_ATTR_RO(modalias);
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static struct attribute *ulpi_dev_attrs[] = {
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&dev_attr_modalias.attr,
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NULL
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};
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static struct attribute_group ulpi_dev_attr_group = {
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.attrs = ulpi_dev_attrs,
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};
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static const struct attribute_group *ulpi_dev_attr_groups[] = {
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&ulpi_dev_attr_group,
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NULL
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};
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static void ulpi_dev_release(struct device *dev)
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{
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kfree(to_ulpi_dev(dev));
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}
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static const struct device_type ulpi_dev_type = {
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.name = "ulpi_device",
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.groups = ulpi_dev_attr_groups,
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.release = ulpi_dev_release,
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};
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/* -------------------------------------------------------------------------- */
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/**
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* ulpi_register_driver - register a driver with the ULPI bus
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* @drv: driver being registered
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*
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* Registers a driver with the ULPI bus.
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*/
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int __ulpi_register_driver(struct ulpi_driver *drv, struct module *module)
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{
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if (!drv->probe)
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return -EINVAL;
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drv->driver.owner = module;
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drv->driver.bus = &ulpi_bus;
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return driver_register(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(__ulpi_register_driver);
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/**
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* ulpi_unregister_driver - unregister a driver with the ULPI bus
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* @drv: driver to unregister
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*
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* Unregisters a driver with the ULPI bus.
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*/
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void ulpi_unregister_driver(struct ulpi_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(ulpi_unregister_driver);
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/* -------------------------------------------------------------------------- */
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static int ulpi_of_register(struct ulpi *ulpi)
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{
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struct device_node *np = NULL, *child;
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struct device *parent;
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/* Find a ulpi bus underneath the parent or the grandparent */
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parent = ulpi->dev.parent;
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if (parent->of_node)
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np = of_get_child_by_name(parent->of_node, "ulpi");
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else if (parent->parent && parent->parent->of_node)
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np = of_get_child_by_name(parent->parent->of_node, "ulpi");
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if (!np)
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return 0;
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child = of_get_next_available_child(np, NULL);
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of_node_put(np);
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if (!child)
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return -EINVAL;
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ulpi->dev.of_node = child;
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return 0;
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}
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static int ulpi_read_id(struct ulpi *ulpi)
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{
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int ret;
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/* Test the interface */
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ret = ulpi_write(ulpi, ULPI_SCRATCH, 0xaa);
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if (ret < 0)
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goto err;
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ret = ulpi_read(ulpi, ULPI_SCRATCH);
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if (ret < 0)
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return ret;
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if (ret != 0xaa)
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goto err;
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ulpi->id.vendor = ulpi_read(ulpi, ULPI_VENDOR_ID_LOW);
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ulpi->id.vendor |= ulpi_read(ulpi, ULPI_VENDOR_ID_HIGH) << 8;
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ulpi->id.product = ulpi_read(ulpi, ULPI_PRODUCT_ID_LOW);
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ulpi->id.product |= ulpi_read(ulpi, ULPI_PRODUCT_ID_HIGH) << 8;
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/* Some ULPI devices don't have a vendor id so rely on OF match */
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if (ulpi->id.vendor == 0)
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goto err;
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request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
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return 0;
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err:
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of_device_request_module(&ulpi->dev);
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return 0;
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}
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static int ulpi_register(struct device *dev, struct ulpi *ulpi)
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{
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int ret;
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ulpi->dev.parent = dev; /* needed early for ops */
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ulpi->dev.bus = &ulpi_bus;
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ulpi->dev.type = &ulpi_dev_type;
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dev_set_name(&ulpi->dev, "%s.ulpi", dev_name(dev));
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ACPI_COMPANION_SET(&ulpi->dev, ACPI_COMPANION(dev));
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ret = ulpi_of_register(ulpi);
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if (ret)
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return ret;
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ret = ulpi_read_id(ulpi);
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if (ret)
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return ret;
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ret = device_register(&ulpi->dev);
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if (ret)
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return ret;
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dev_dbg(&ulpi->dev, "registered ULPI PHY: vendor %04x, product %04x\n",
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ulpi->id.vendor, ulpi->id.product);
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return 0;
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}
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/**
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* ulpi_register_interface - instantiate new ULPI device
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* @dev: USB controller's device interface
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* @ops: ULPI register access
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*
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* Allocates and registers a ULPI device and an interface for it. Called from
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* the USB controller that provides the ULPI interface.
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*/
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struct ulpi *ulpi_register_interface(struct device *dev,
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const struct ulpi_ops *ops)
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{
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struct ulpi *ulpi;
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int ret;
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ulpi = kzalloc(sizeof(*ulpi), GFP_KERNEL);
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if (!ulpi)
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return ERR_PTR(-ENOMEM);
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ulpi->ops = ops;
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ret = ulpi_register(dev, ulpi);
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if (ret) {
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kfree(ulpi);
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return ERR_PTR(ret);
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}
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return ulpi;
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}
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EXPORT_SYMBOL_GPL(ulpi_register_interface);
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/**
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* ulpi_unregister_interface - unregister ULPI interface
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* @intrf: struct ulpi_interface
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*
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* Unregisters a ULPI device and it's interface that was created with
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* ulpi_create_interface().
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*/
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void ulpi_unregister_interface(struct ulpi *ulpi)
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{
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of_node_put(ulpi->dev.of_node);
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device_unregister(&ulpi->dev);
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}
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EXPORT_SYMBOL_GPL(ulpi_unregister_interface);
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/* -------------------------------------------------------------------------- */
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static int __init ulpi_init(void)
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{
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return bus_register(&ulpi_bus);
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}
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subsys_initcall(ulpi_init);
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static void __exit ulpi_exit(void)
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{
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bus_unregister(&ulpi_bus);
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}
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module_exit(ulpi_exit);
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MODULE_AUTHOR("Intel Corporation");
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("USB ULPI PHY bus");
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