swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: ce522ba9ef7e2d9fb22a39eb3371c0c64e2a433e authored by Linus Torvalds on 11 April 2022, 00:21:36 UTC
Linux 5.18-rc2
Linux 5.18-rc2
Tip revision: ce522ba
core.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
*
* Based on drivers/spmi/spmi.c:
* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
*/
#include <linux/acpi.h>
#include <linux/errno.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/serdev.h>
#include <linux/slab.h>
#include <linux/platform_data/x86/apple.h>
static bool is_registered;
static DEFINE_IDA(ctrl_ida);
static ssize_t modalias_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int len;
len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
if (len != -ENODEV)
return len;
return of_device_modalias(dev, buf, PAGE_SIZE);
}
static DEVICE_ATTR_RO(modalias);
static struct attribute *serdev_device_attrs[] = {
&dev_attr_modalias.attr,
NULL,
};
ATTRIBUTE_GROUPS(serdev_device);
static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
int rc;
/* TODO: platform modalias */
rc = acpi_device_uevent_modalias(dev, env);
if (rc != -ENODEV)
return rc;
return of_device_uevent_modalias(dev, env);
}
static void serdev_device_release(struct device *dev)
{
struct serdev_device *serdev = to_serdev_device(dev);
kfree(serdev);
}
static const struct device_type serdev_device_type = {
.groups = serdev_device_groups,
.uevent = serdev_device_uevent,
.release = serdev_device_release,
};
static bool is_serdev_device(const struct device *dev)
{
return dev->type == &serdev_device_type;
}
static void serdev_ctrl_release(struct device *dev)
{
struct serdev_controller *ctrl = to_serdev_controller(dev);
ida_simple_remove(&ctrl_ida, ctrl->nr);
kfree(ctrl);
}
static const struct device_type serdev_ctrl_type = {
.release = serdev_ctrl_release,
};
static int serdev_device_match(struct device *dev, struct device_driver *drv)
{
if (!is_serdev_device(dev))
return 0;
/* TODO: platform matching */
if (acpi_driver_match_device(dev, drv))
return 1;
return of_driver_match_device(dev, drv);
}
/**
* serdev_device_add() - add a device previously constructed via serdev_device_alloc()
* @serdev: serdev_device to be added
*/
int serdev_device_add(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
struct device *parent = serdev->dev.parent;
int err;
dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);
/* Only a single slave device is currently supported. */
if (ctrl->serdev) {
dev_err(&serdev->dev, "controller busy\n");
return -EBUSY;
}
ctrl->serdev = serdev;
err = device_add(&serdev->dev);
if (err < 0) {
dev_err(&serdev->dev, "Can't add %s, status %pe\n",
dev_name(&serdev->dev), ERR_PTR(err));
goto err_clear_serdev;
}
dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
return 0;
err_clear_serdev:
ctrl->serdev = NULL;
return err;
}
EXPORT_SYMBOL_GPL(serdev_device_add);
/**
* serdev_device_remove(): remove an serdev device
* @serdev: serdev_device to be removed
*/
void serdev_device_remove(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
device_unregister(&serdev->dev);
ctrl->serdev = NULL;
}
EXPORT_SYMBOL_GPL(serdev_device_remove);
int serdev_device_open(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
int ret;
if (!ctrl || !ctrl->ops->open)
return -EINVAL;
ret = ctrl->ops->open(ctrl);
if (ret)
return ret;
ret = pm_runtime_get_sync(&ctrl->dev);
if (ret < 0) {
pm_runtime_put_noidle(&ctrl->dev);
goto err_close;
}
return 0;
err_close:
if (ctrl->ops->close)
ctrl->ops->close(ctrl);
return ret;
}
EXPORT_SYMBOL_GPL(serdev_device_open);
void serdev_device_close(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->close)
return;
pm_runtime_put(&ctrl->dev);
ctrl->ops->close(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_close);
static void devm_serdev_device_release(struct device *dev, void *dr)
{
serdev_device_close(*(struct serdev_device **)dr);
}
int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
{
struct serdev_device **dr;
int ret;
dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
if (!dr)
return -ENOMEM;
ret = serdev_device_open(serdev);
if (ret) {
devres_free(dr);
return ret;
}
*dr = serdev;
devres_add(dev, dr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_serdev_device_open);
void serdev_device_write_wakeup(struct serdev_device *serdev)
{
complete(&serdev->write_comp);
}
EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
/**
* serdev_device_write_buf() - write data asynchronously
* @serdev: serdev device
* @buf: data to be written
* @count: number of bytes to write
*
* Write data to the device asynchronously.
*
* Note that any accepted data has only been buffered by the controller; use
* serdev_device_wait_until_sent() to make sure the controller write buffer
* has actually been emptied.
*
* Return: The number of bytes written (less than count if not enough room in
* the write buffer), or a negative errno on errors.
*/
int serdev_device_write_buf(struct serdev_device *serdev,
const unsigned char *buf, size_t count)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->write_buf)
return -EINVAL;
return ctrl->ops->write_buf(ctrl, buf, count);
}
EXPORT_SYMBOL_GPL(serdev_device_write_buf);
/**
* serdev_device_write() - write data synchronously
* @serdev: serdev device
* @buf: data to be written
* @count: number of bytes to write
* @timeout: timeout in jiffies, or 0 to wait indefinitely
*
* Write data to the device synchronously by repeatedly calling
* serdev_device_write() until the controller has accepted all data (unless
* interrupted by a timeout or a signal).
*
* Note that any accepted data has only been buffered by the controller; use
* serdev_device_wait_until_sent() to make sure the controller write buffer
* has actually been emptied.
*
* Note that this function depends on serdev_device_write_wakeup() being
* called in the serdev driver write_wakeup() callback.
*
* Return: The number of bytes written (less than count if interrupted),
* -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
* a negative errno on errors.
*/
int serdev_device_write(struct serdev_device *serdev,
const unsigned char *buf, size_t count,
long timeout)
{
struct serdev_controller *ctrl = serdev->ctrl;
int written = 0;
int ret;
if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
return -EINVAL;
if (timeout == 0)
timeout = MAX_SCHEDULE_TIMEOUT;
mutex_lock(&serdev->write_lock);
do {
reinit_completion(&serdev->write_comp);
ret = ctrl->ops->write_buf(ctrl, buf, count);
if (ret < 0)
break;
written += ret;
buf += ret;
count -= ret;
if (count == 0)
break;
timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
timeout);
} while (timeout > 0);
mutex_unlock(&serdev->write_lock);
if (ret < 0)
return ret;
if (timeout <= 0 && written == 0) {
if (timeout == -ERESTARTSYS)
return -ERESTARTSYS;
else
return -ETIMEDOUT;
}
return written;
}
EXPORT_SYMBOL_GPL(serdev_device_write);
void serdev_device_write_flush(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->write_flush)
return;
ctrl->ops->write_flush(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_write_flush);
int serdev_device_write_room(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->write_room)
return 0;
return serdev->ctrl->ops->write_room(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_write_room);
unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->set_baudrate)
return 0;
return ctrl->ops->set_baudrate(ctrl, speed);
}
EXPORT_SYMBOL_GPL(serdev_device_set_baudrate);
void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->set_flow_control)
return;
ctrl->ops->set_flow_control(ctrl, enable);
}
EXPORT_SYMBOL_GPL(serdev_device_set_flow_control);
int serdev_device_set_parity(struct serdev_device *serdev,
enum serdev_parity parity)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->set_parity)
return -ENOTSUPP;
return ctrl->ops->set_parity(ctrl, parity);
}
EXPORT_SYMBOL_GPL(serdev_device_set_parity);
void serdev_device_wait_until_sent(struct serdev_device *serdev, long timeout)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->wait_until_sent)
return;
ctrl->ops->wait_until_sent(ctrl, timeout);
}
EXPORT_SYMBOL_GPL(serdev_device_wait_until_sent);
int serdev_device_get_tiocm(struct serdev_device *serdev)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->get_tiocm)
return -ENOTSUPP;
return ctrl->ops->get_tiocm(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_get_tiocm);
int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
{
struct serdev_controller *ctrl = serdev->ctrl;
if (!ctrl || !ctrl->ops->set_tiocm)
return -ENOTSUPP;
return ctrl->ops->set_tiocm(ctrl, set, clear);
}
EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
static int serdev_drv_probe(struct device *dev)
{
const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
int ret;
ret = dev_pm_domain_attach(dev, true);
if (ret)
return ret;
ret = sdrv->probe(to_serdev_device(dev));
if (ret)
dev_pm_domain_detach(dev, true);
return ret;
}
static void serdev_drv_remove(struct device *dev)
{
const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
if (sdrv->remove)
sdrv->remove(to_serdev_device(dev));
dev_pm_domain_detach(dev, true);
}
static struct bus_type serdev_bus_type = {
.name = "serial",
.match = serdev_device_match,
.probe = serdev_drv_probe,
.remove = serdev_drv_remove,
};
/**
* serdev_device_alloc() - Allocate a new serdev device
* @ctrl: associated controller
*
* Caller is responsible for either calling serdev_device_add() to add the
* newly allocated controller, or calling serdev_device_put() to discard it.
*/
struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl)
{
struct serdev_device *serdev;
serdev = kzalloc(sizeof(*serdev), GFP_KERNEL);
if (!serdev)
return NULL;
serdev->ctrl = ctrl;
device_initialize(&serdev->dev);
serdev->dev.parent = &ctrl->dev;
serdev->dev.bus = &serdev_bus_type;
serdev->dev.type = &serdev_device_type;
init_completion(&serdev->write_comp);
mutex_init(&serdev->write_lock);
return serdev;
}
EXPORT_SYMBOL_GPL(serdev_device_alloc);
/**
* serdev_controller_alloc() - Allocate a new serdev controller
* @parent: parent device
* @size: size of private data
*
* Caller is responsible for either calling serdev_controller_add() to add the
* newly allocated controller, or calling serdev_controller_put() to discard it.
* The allocated private data region may be accessed via
* serdev_controller_get_drvdata()
*/
struct serdev_controller *serdev_controller_alloc(struct device *parent,
size_t size)
{
struct serdev_controller *ctrl;
int id;
if (WARN_ON(!parent))
return NULL;
ctrl = kzalloc(sizeof(*ctrl) + size, GFP_KERNEL);
if (!ctrl)
return NULL;
id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
if (id < 0) {
dev_err(parent,
"unable to allocate serdev controller identifier.\n");
goto err_free;
}
ctrl->nr = id;
device_initialize(&ctrl->dev);
ctrl->dev.type = &serdev_ctrl_type;
ctrl->dev.bus = &serdev_bus_type;
ctrl->dev.parent = parent;
ctrl->dev.of_node = parent->of_node;
serdev_controller_set_drvdata(ctrl, &ctrl[1]);
dev_set_name(&ctrl->dev, "serial%d", id);
pm_runtime_no_callbacks(&ctrl->dev);
pm_suspend_ignore_children(&ctrl->dev, true);
dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
return ctrl;
err_free:
kfree(ctrl);
return NULL;
}
EXPORT_SYMBOL_GPL(serdev_controller_alloc);
static int of_serdev_register_devices(struct serdev_controller *ctrl)
{
struct device_node *node;
struct serdev_device *serdev = NULL;
int err;
bool found = false;
for_each_available_child_of_node(ctrl->dev.of_node, node) {
if (!of_get_property(node, "compatible", NULL))
continue;
dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
serdev = serdev_device_alloc(ctrl);
if (!serdev)
continue;
serdev->dev.of_node = node;
err = serdev_device_add(serdev);
if (err) {
dev_err(&serdev->dev,
"failure adding device. status %pe\n",
ERR_PTR(err));
serdev_device_put(serdev);
} else
found = true;
}
if (!found)
return -ENODEV;
return 0;
}
#ifdef CONFIG_ACPI
#define SERDEV_ACPI_MAX_SCAN_DEPTH 32
struct acpi_serdev_lookup {
acpi_handle device_handle;
acpi_handle controller_handle;
int n;
int index;
};
/**
* serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
* @ares: ACPI resource
* @uart: Pointer to UARTSerialBus resource will be returned here
*
* Checks if the given ACPI resource is of type UARTSerialBus.
* In this case, returns a pointer to it to the caller.
*
* Return: True if resource type is of UARTSerialBus, otherwise false.
*/
bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
struct acpi_resource_uart_serialbus **uart)
{
struct acpi_resource_uart_serialbus *sb;
if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
return false;
sb = &ares->data.uart_serial_bus;
if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
return false;
*uart = sb;
return true;
}
EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
{
struct acpi_serdev_lookup *lookup = data;
struct acpi_resource_uart_serialbus *sb;
acpi_status status;
if (!serdev_acpi_get_uart_resource(ares, &sb))
return 1;
if (lookup->index != -1 && lookup->n++ != lookup->index)
return 1;
status = acpi_get_handle(lookup->device_handle,
sb->resource_source.string_ptr,
&lookup->controller_handle);
if (ACPI_FAILURE(status))
return 1;
/*
* NOTE: Ideally, we would also want to retrieve other properties here,
* once setting them before opening the device is supported by serdev.
*/
return 1;
}
static int acpi_serdev_do_lookup(struct acpi_device *adev,
struct acpi_serdev_lookup *lookup)
{
struct list_head resource_list;
int ret;
lookup->device_handle = acpi_device_handle(adev);
lookup->controller_handle = NULL;
lookup->n = 0;
INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list,
acpi_serdev_parse_resource, lookup);
acpi_dev_free_resource_list(&resource_list);
if (ret < 0)
return -EINVAL;
return 0;
}
static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
struct acpi_device *adev)
{
struct acpi_serdev_lookup lookup;
int ret;
if (acpi_bus_get_status(adev) || !adev->status.present)
return -EINVAL;
/* Look for UARTSerialBusV2 resource */
lookup.index = -1; // we only care for the last device
ret = acpi_serdev_do_lookup(adev, &lookup);
if (ret)
return ret;
/*
* Apple machines provide an empty resource template, so on those
* machines just look for immediate children with a "baud" property
* (from the _DSM method) instead.
*/
if (!lookup.controller_handle && x86_apple_machine &&
!acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
acpi_get_parent(adev->handle, &lookup.controller_handle);
/* Make sure controller and ResourceSource handle match */
if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle)
return -ENODEV;
return 0;
}
static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
struct acpi_device *adev)
{
struct serdev_device *serdev;
int err;
serdev = serdev_device_alloc(ctrl);
if (!serdev) {
dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
dev_name(&adev->dev));
return AE_NO_MEMORY;
}
ACPI_COMPANION_SET(&serdev->dev, adev);
acpi_device_set_enumerated(adev);
err = serdev_device_add(serdev);
if (err) {
dev_err(&serdev->dev,
"failure adding ACPI serdev device. status %pe\n",
ERR_PTR(err));
serdev_device_put(serdev);
}
return AE_OK;
}
static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
{ "INT3511", 0 },
{ "INT3512", 0 },
{ },
};
static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
void *data, void **return_value)
{
struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
struct serdev_controller *ctrl = data;
if (!adev || acpi_device_enumerated(adev))
return AE_OK;
/* Skip if black listed */
if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
return AE_OK;
if (acpi_serdev_check_resources(ctrl, adev))
return AE_OK;
return acpi_serdev_register_device(ctrl, adev);
}
static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
{
acpi_status status;
bool skip;
int ret;
if (!has_acpi_companion(ctrl->dev.parent))
return -ENODEV;
/*
* Skip registration on boards where the ACPI tables are known to
* contain buggy devices. Note serdev_controller_add() must still
* succeed in this case, so that the proper serdev devices can be
* added "manually" later.
*/
ret = acpi_quirk_skip_serdev_enumeration(ctrl->dev.parent, &skip);
if (ret)
return ret;
if (skip)
return 0;
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
SERDEV_ACPI_MAX_SCAN_DEPTH,
acpi_serdev_add_device, NULL, ctrl, NULL);
if (ACPI_FAILURE(status))
dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
if (!ctrl->serdev)
return -ENODEV;
return 0;
}
#else
static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
{
return -ENODEV;
}
#endif /* CONFIG_ACPI */
/**
* serdev_controller_add() - Add an serdev controller
* @ctrl: controller to be registered.
*
* Register a controller previously allocated via serdev_controller_alloc() with
* the serdev core.
*/
int serdev_controller_add(struct serdev_controller *ctrl)
{
int ret_of, ret_acpi, ret;
/* Can't register until after driver model init */
if (WARN_ON(!is_registered))
return -EAGAIN;
ret = device_add(&ctrl->dev);
if (ret)
return ret;
pm_runtime_enable(&ctrl->dev);
ret_of = of_serdev_register_devices(ctrl);
ret_acpi = acpi_serdev_register_devices(ctrl);
if (ret_of && ret_acpi) {
dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
ERR_PTR(ret_of), ERR_PTR(ret_acpi));
ret = -ENODEV;
goto err_rpm_disable;
}
dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
ctrl->nr, &ctrl->dev);
return 0;
err_rpm_disable:
pm_runtime_disable(&ctrl->dev);
device_del(&ctrl->dev);
return ret;
};
EXPORT_SYMBOL_GPL(serdev_controller_add);
/* Remove a device associated with a controller */
static int serdev_remove_device(struct device *dev, void *data)
{
struct serdev_device *serdev = to_serdev_device(dev);
if (dev->type == &serdev_device_type)
serdev_device_remove(serdev);
return 0;
}
/**
* serdev_controller_remove(): remove an serdev controller
* @ctrl: controller to remove
*
* Remove a serdev controller. Caller is responsible for calling
* serdev_controller_put() to discard the allocated controller.
*/
void serdev_controller_remove(struct serdev_controller *ctrl)
{
if (!ctrl)
return;
device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
pm_runtime_disable(&ctrl->dev);
device_del(&ctrl->dev);
}
EXPORT_SYMBOL_GPL(serdev_controller_remove);
/**
* __serdev_device_driver_register() - Register client driver with serdev core
* @sdrv: client driver to be associated with client-device.
* @owner: client driver owner to set.
*
* This API will register the client driver with the serdev framework.
* It is typically called from the driver's module-init function.
*/
int __serdev_device_driver_register(struct serdev_device_driver *sdrv, struct module *owner)
{
sdrv->driver.bus = &serdev_bus_type;
sdrv->driver.owner = owner;
/* force drivers to async probe so I/O is possible in probe */
sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
return driver_register(&sdrv->driver);
}
EXPORT_SYMBOL_GPL(__serdev_device_driver_register);
static void __exit serdev_exit(void)
{
bus_unregister(&serdev_bus_type);
ida_destroy(&ctrl_ida);
}
module_exit(serdev_exit);
static int __init serdev_init(void)
{
int ret;
ret = bus_register(&serdev_bus_type);
if (ret)
return ret;
is_registered = true;
return 0;
}
/* Must be before serial drivers register */
postcore_initcall(serdev_init);
MODULE_AUTHOR("Rob Herring <robh@kernel.org>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Serial attached device bus");