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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Surface System Aggregator Module (SSAM) bus and client-device subsystem.
*
* Main interface for the surface-aggregator bus, surface-aggregator client
* devices, and respective drivers building on top of the SSAM controller.
* Provides support for non-platform/non-ACPI SSAM clients via dedicated
* subsystem.
*
* Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
*/
#ifndef _LINUX_SURFACE_AGGREGATOR_DEVICE_H
#define _LINUX_SURFACE_AGGREGATOR_DEVICE_H
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
#include <linux/types.h>
#include <linux/surface_aggregator/controller.h>
/* -- Surface System Aggregator Module bus. --------------------------------- */
/**
* enum ssam_device_domain - SAM device domain.
* @SSAM_DOMAIN_VIRTUAL: Virtual device.
* @SSAM_DOMAIN_SERIALHUB: Physical device connected via Surface Serial Hub.
*/
enum ssam_device_domain {
SSAM_DOMAIN_VIRTUAL = 0x00,
SSAM_DOMAIN_SERIALHUB = 0x01,
};
/**
* enum ssam_virtual_tc - Target categories for the virtual SAM domain.
* @SSAM_VIRTUAL_TC_HUB: Device hub category.
*/
enum ssam_virtual_tc {
SSAM_VIRTUAL_TC_HUB = 0x00,
};
/**
* struct ssam_device_uid - Unique identifier for SSAM device.
* @domain: Domain of the device.
* @category: Target category of the device.
* @target: Target ID of the device.
* @instance: Instance ID of the device.
* @function: Sub-function of the device. This field can be used to split a
* single SAM device into multiple virtual subdevices to separate
* different functionality of that device and allow one driver per
* such functionality.
*/
struct ssam_device_uid {
u8 domain;
u8 category;
u8 target;
u8 instance;
u8 function;
};
/*
* Special values for device matching.
*
* These values are intended to be used with SSAM_DEVICE(), SSAM_VDEV(), and
* SSAM_SDEV() exclusively. Specifically, they are used to initialize the
* match_flags member of the device ID structure. Do not use them directly
* with struct ssam_device_id or struct ssam_device_uid.
*/
#define SSAM_SSH_TID_ANY 0xffff
#define SSAM_SSH_IID_ANY 0xffff
#define SSAM_SSH_FUN_ANY 0xffff
/**
* SSAM_DEVICE() - Initialize a &struct ssam_device_id with the given
* parameters.
* @d: Domain of the device.
* @cat: Target category of the device.
* @tid: Target ID of the device.
* @iid: Instance ID of the device.
* @fun: Sub-function of the device.
*
* Initializes a &struct ssam_device_id with the given parameters. See &struct
* ssam_device_uid for details regarding the parameters. The special values
* %SSAM_SSH_TID_ANY, %SSAM_SSH_IID_ANY, and %SSAM_SSH_FUN_ANY can be used to specify that
* matching should ignore target ID, instance ID, and/or sub-function,
* respectively. This macro initializes the ``match_flags`` field based on the
* given parameters.
*
* Note: The parameters @d and @cat must be valid &u8 values, the parameters
* @tid, @iid, and @fun must be either valid &u8 values or %SSAM_SSH_TID_ANY,
* %SSAM_SSH_IID_ANY, or %SSAM_SSH_FUN_ANY, respectively. Other non-&u8 values are not
* allowed.
*/
#define SSAM_DEVICE(d, cat, tid, iid, fun) \
.match_flags = (((tid) != SSAM_SSH_TID_ANY) ? SSAM_MATCH_TARGET : 0) \
| (((iid) != SSAM_SSH_IID_ANY) ? SSAM_MATCH_INSTANCE : 0) \
| (((fun) != SSAM_SSH_FUN_ANY) ? SSAM_MATCH_FUNCTION : 0), \
.domain = d, \
.category = cat, \
.target = __builtin_choose_expr((tid) != SSAM_SSH_TID_ANY, (tid), 0), \
.instance = __builtin_choose_expr((iid) != SSAM_SSH_IID_ANY, (iid), 0), \
.function = __builtin_choose_expr((fun) != SSAM_SSH_FUN_ANY, (fun), 0)
/**
* SSAM_VDEV() - Initialize a &struct ssam_device_id as virtual device with
* the given parameters.
* @cat: Target category of the device.
* @tid: Target ID of the device.
* @iid: Instance ID of the device.
* @fun: Sub-function of the device.
*
* Initializes a &struct ssam_device_id with the given parameters in the
* virtual domain. See &struct ssam_device_uid for details regarding the
* parameters. The special values %SSAM_SSH_TID_ANY, %SSAM_SSH_IID_ANY, and
* %SSAM_SSH_FUN_ANY can be used to specify that matching should ignore target ID,
* instance ID, and/or sub-function, respectively. This macro initializes the
* ``match_flags`` field based on the given parameters.
*
* Note: The parameter @cat must be a valid &u8 value, the parameters @tid,
* @iid, and @fun must be either valid &u8 values or %SSAM_SSH_TID_ANY,
* %SSAM_SSH_IID_ANY, or %SSAM_SSH_FUN_ANY, respectively. Other non-&u8 values are not
* allowed.
*/
#define SSAM_VDEV(cat, tid, iid, fun) \
SSAM_DEVICE(SSAM_DOMAIN_VIRTUAL, SSAM_VIRTUAL_TC_##cat, SSAM_SSH_TID_##tid, iid, fun)
/**
* SSAM_SDEV() - Initialize a &struct ssam_device_id as physical SSH device
* with the given parameters.
* @cat: Target category of the device.
* @tid: Target ID of the device.
* @iid: Instance ID of the device.
* @fun: Sub-function of the device.
*
* Initializes a &struct ssam_device_id with the given parameters in the SSH
* domain. See &struct ssam_device_uid for details regarding the parameters.
* The special values %SSAM_SSH_TID_ANY, %SSAM_SSH_IID_ANY, and
* %SSAM_SSH_FUN_ANY can be used to specify that matching should ignore target
* ID, instance ID, and/or sub-function, respectively. This macro initializes
* the ``match_flags`` field based on the given parameters.
*
* Note: The parameter @cat must be a valid &u8 value, the parameters @tid,
* @iid, and @fun must be either valid &u8 values or %SSAM_SSH_TID_ANY,
* %SSAM_SSH_IID_ANY, or %SSAM_SSH_FUN_ANY, respectively. Other non-&u8 values
* are not allowed.
*/
#define SSAM_SDEV(cat, tid, iid, fun) \
SSAM_DEVICE(SSAM_DOMAIN_SERIALHUB, SSAM_SSH_TC_##cat, SSAM_SSH_TID_##tid, iid, fun)
/*
* enum ssam_device_flags - Flags for SSAM client devices.
* @SSAM_DEVICE_HOT_REMOVED_BIT:
* The device has been hot-removed. Further communication with it may time
* out and should be avoided.
*/
enum ssam_device_flags {
SSAM_DEVICE_HOT_REMOVED_BIT = 0,
};
/**
* struct ssam_device - SSAM client device.
* @dev: Driver model representation of the device.
* @ctrl: SSAM controller managing this device.
* @uid: UID identifying the device.
* @flags: Device state flags, see &enum ssam_device_flags.
*/
struct ssam_device {
struct device dev;
struct ssam_controller *ctrl;
struct ssam_device_uid uid;
unsigned long flags;
};
/**
* struct ssam_device_driver - SSAM client device driver.
* @driver: Base driver model structure.
* @match_table: Match table specifying which devices the driver should bind to.
* @probe: Called when the driver is being bound to a device.
* @remove: Called when the driver is being unbound from the device.
*/
struct ssam_device_driver {
struct device_driver driver;
const struct ssam_device_id *match_table;
int (*probe)(struct ssam_device *sdev);
void (*remove)(struct ssam_device *sdev);
};
#ifdef CONFIG_SURFACE_AGGREGATOR_BUS
extern const struct device_type ssam_device_type;
/**
* is_ssam_device() - Check if the given device is a SSAM client device.
* @d: The device to test the type of.
*
* Return: Returns %true if the specified device is of type &struct
* ssam_device, i.e. the device type points to %ssam_device_type, and %false
* otherwise.
*/
static inline bool is_ssam_device(struct device *d)
{
return d->type == &ssam_device_type;
}
#else /* CONFIG_SURFACE_AGGREGATOR_BUS */
static inline bool is_ssam_device(struct device *d)
{
return false;
}
#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */
/**
* to_ssam_device() - Casts the given device to a SSAM client device.
* @d: The device to cast.
*
* Casts the given &struct device to a &struct ssam_device. The caller has to
* ensure that the given device is actually enclosed in a &struct ssam_device,
* e.g. by calling is_ssam_device().
*
* Return: Returns a pointer to the &struct ssam_device wrapping the given
* device @d.
*/
#define to_ssam_device(d) container_of_const(d, struct ssam_device, dev)
/**
* to_ssam_device_driver() - Casts the given device driver to a SSAM client
* device driver.
* @d: The driver to cast.
*
* Casts the given &struct device_driver to a &struct ssam_device_driver. The
* caller has to ensure that the given driver is actually enclosed in a
* &struct ssam_device_driver.
*
* Return: Returns the pointer to the &struct ssam_device_driver wrapping the
* given device driver @d.
*/
#define to_ssam_device_driver(d) container_of_const(d, struct ssam_device_driver, driver)
const struct ssam_device_id *ssam_device_id_match(const struct ssam_device_id *table,
const struct ssam_device_uid uid);
const struct ssam_device_id *ssam_device_get_match(const struct ssam_device *dev);
const void *ssam_device_get_match_data(const struct ssam_device *dev);
struct ssam_device *ssam_device_alloc(struct ssam_controller *ctrl,
struct ssam_device_uid uid);
int ssam_device_add(struct ssam_device *sdev);
void ssam_device_remove(struct ssam_device *sdev);
/**
* ssam_device_mark_hot_removed() - Mark the given device as hot-removed.
* @sdev: The device to mark as hot-removed.
*
* Mark the device as having been hot-removed. This signals drivers using the
* device that communication with the device should be avoided and may lead to
* timeouts.
*/
static inline void ssam_device_mark_hot_removed(struct ssam_device *sdev)
{
dev_dbg(&sdev->dev, "marking device as hot-removed\n");
set_bit(SSAM_DEVICE_HOT_REMOVED_BIT, &sdev->flags);
}
/**
* ssam_device_is_hot_removed() - Check if the given device has been
* hot-removed.
* @sdev: The device to check.
*
* Checks if the given device has been marked as hot-removed. See
* ssam_device_mark_hot_removed() for more details.
*
* Return: Returns ``true`` if the device has been marked as hot-removed.
*/
static inline bool ssam_device_is_hot_removed(struct ssam_device *sdev)
{
return test_bit(SSAM_DEVICE_HOT_REMOVED_BIT, &sdev->flags);
}
/**
* ssam_device_get() - Increment reference count of SSAM client device.
* @sdev: The device to increment the reference count of.
*
* Increments the reference count of the given SSAM client device by
* incrementing the reference count of the enclosed &struct device via
* get_device().
*
* See ssam_device_put() for the counter-part of this function.
*
* Return: Returns the device provided as input.
*/
static inline struct ssam_device *ssam_device_get(struct ssam_device *sdev)
{
return sdev ? to_ssam_device(get_device(&sdev->dev)) : NULL;
}
/**
* ssam_device_put() - Decrement reference count of SSAM client device.
* @sdev: The device to decrement the reference count of.
*
* Decrements the reference count of the given SSAM client device by
* decrementing the reference count of the enclosed &struct device via
* put_device().
*
* See ssam_device_get() for the counter-part of this function.
*/
static inline void ssam_device_put(struct ssam_device *sdev)
{
if (sdev)
put_device(&sdev->dev);
}
/**
* ssam_device_get_drvdata() - Get driver-data of SSAM client device.
* @sdev: The device to get the driver-data from.
*
* Return: Returns the driver-data of the given device, previously set via
* ssam_device_set_drvdata().
*/
static inline void *ssam_device_get_drvdata(struct ssam_device *sdev)
{
return dev_get_drvdata(&sdev->dev);
}
/**
* ssam_device_set_drvdata() - Set driver-data of SSAM client device.
* @sdev: The device to set the driver-data of.
* @data: The data to set the device's driver-data pointer to.
*/
static inline void ssam_device_set_drvdata(struct ssam_device *sdev, void *data)
{
dev_set_drvdata(&sdev->dev, data);
}
int __ssam_device_driver_register(struct ssam_device_driver *d, struct module *o);
void ssam_device_driver_unregister(struct ssam_device_driver *d);
/**
* ssam_device_driver_register() - Register a SSAM client device driver.
* @drv: The driver to register.
*/
#define ssam_device_driver_register(drv) \
__ssam_device_driver_register(drv, THIS_MODULE)
/**
* module_ssam_device_driver() - Helper macro for SSAM device driver
* registration.
* @drv: The driver managed by this module.
*
* Helper macro to register a SSAM device driver via module_init() and
* module_exit(). This macro may only be used once per module and replaces the
* aforementioned definitions.
*/
#define module_ssam_device_driver(drv) \
module_driver(drv, ssam_device_driver_register, \
ssam_device_driver_unregister)
/* -- Helpers for controller and hub devices. ------------------------------- */
#ifdef CONFIG_SURFACE_AGGREGATOR_BUS
int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl,
struct fwnode_handle *node);
void ssam_remove_clients(struct device *dev);
#else /* CONFIG_SURFACE_AGGREGATOR_BUS */
static inline int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl,
struct fwnode_handle *node)
{
return 0;
}
static inline void ssam_remove_clients(struct device *dev) {}
#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */
/**
* ssam_register_clients() - Register all client devices defined under the
* given parent device.
* @dev: The parent device under which clients should be registered.
* @ctrl: The controller with which client should be registered.
*
* Register all clients that have via firmware nodes been defined as children
* of the given (parent) device. The respective child firmware nodes will be
* associated with the correspondingly created child devices.
*
* The given controller will be used to instantiate the new devices. See
* ssam_device_add() for details.
*
* Return: Returns zero on success, nonzero on failure.
*/
static inline int ssam_register_clients(struct device *dev, struct ssam_controller *ctrl)
{
return __ssam_register_clients(dev, ctrl, dev_fwnode(dev));
}
/**
* ssam_device_register_clients() - Register all client devices defined under
* the given SSAM parent device.
* @sdev: The parent device under which clients should be registered.
*
* Register all clients that have via firmware nodes been defined as children
* of the given (parent) device. The respective child firmware nodes will be
* associated with the correspondingly created child devices.
*
* The controller used by the parent device will be used to instantiate the new
* devices. See ssam_device_add() for details.
*
* Return: Returns zero on success, nonzero on failure.
*/
static inline int ssam_device_register_clients(struct ssam_device *sdev)
{
return ssam_register_clients(&sdev->dev, sdev->ctrl);
}
/* -- Helpers for client-device requests. ----------------------------------- */
/**
* SSAM_DEFINE_SYNC_REQUEST_CL_N() - Define synchronous client-device SAM
* request function with neither argument nor return value.
* @name: Name of the generated function.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request having neither argument nor return value. Device
* specifying parameters are not hard-coded, but instead are provided via the
* client device, specifically its UID, supplied when calling this function.
* The generated function takes care of setting up the request struct, buffer
* allocation, as well as execution of the request itself, returning once the
* request has been fully completed. The required transport buffer will be
* allocated on the stack.
*
* The generated function is defined as ``static int name(struct ssam_device
* *sdev)``, returning the status of the request, which is zero on success and
* negative on failure. The ``sdev`` parameter specifies both the target
* device of the request and by association the controller via which the
* request is sent.
*
* Refer to ssam_request_do_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_CL_N(name, spec...) \
SSAM_DEFINE_SYNC_REQUEST_MD_N(__raw_##name, spec) \
static int name(struct ssam_device *sdev) \
{ \
return __raw_##name(sdev->ctrl, sdev->uid.target, \
sdev->uid.instance); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_CL_W() - Define synchronous client-device SAM
* request function with argument.
* @name: Name of the generated function.
* @atype: Type of the request's argument.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking an argument of type @atype and having no
* return value. Device specifying parameters are not hard-coded, but instead
* are provided via the client device, specifically its UID, supplied when
* calling this function. The generated function takes care of setting up the
* request struct, buffer allocation, as well as execution of the request
* itself, returning once the request has been fully completed. The required
* transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct ssam_device
* *sdev, const atype *arg)``, returning the status of the request, which is
* zero on success and negative on failure. The ``sdev`` parameter specifies
* both the target device of the request and by association the controller via
* which the request is sent. The request's argument is specified via the
* ``arg`` pointer.
*
* Refer to ssam_request_do_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_CL_W(name, atype, spec...) \
SSAM_DEFINE_SYNC_REQUEST_MD_W(__raw_##name, atype, spec) \
static int name(struct ssam_device *sdev, const atype *arg) \
{ \
return __raw_##name(sdev->ctrl, sdev->uid.target, \
sdev->uid.instance, arg); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_CL_R() - Define synchronous client-device SAM
* request function with return value.
* @name: Name of the generated function.
* @rtype: Type of the request's return value.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by
* @spec, with the request taking no argument but having a return value of
* type @rtype. Device specifying parameters are not hard-coded, but instead
* are provided via the client device, specifically its UID, supplied when
* calling this function. The generated function takes care of setting up the
* request struct, buffer allocation, as well as execution of the request
* itself, returning once the request has been fully completed. The required
* transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct ssam_device
* *sdev, rtype *ret)``, returning the status of the request, which is zero on
* success and negative on failure. The ``sdev`` parameter specifies both the
* target device of the request and by association the controller via which
* the request is sent. The request's return value is written to the memory
* pointed to by the ``ret`` parameter.
*
* Refer to ssam_request_do_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_CL_R(name, rtype, spec...) \
SSAM_DEFINE_SYNC_REQUEST_MD_R(__raw_##name, rtype, spec) \
static int name(struct ssam_device *sdev, rtype *ret) \
{ \
return __raw_##name(sdev->ctrl, sdev->uid.target, \
sdev->uid.instance, ret); \
}
/**
* SSAM_DEFINE_SYNC_REQUEST_CL_WR() - Define synchronous client-device SAM
* request function with argument and return value.
* @name: Name of the generated function.
* @atype: Type of the request's argument.
* @rtype: Type of the request's return value.
* @spec: Specification (&struct ssam_request_spec_md) defining the request.
*
* Defines a function executing the synchronous SAM request specified by @spec,
* with the request taking an argument of type @atype and having a return value
* of type @rtype. Device specifying parameters are not hard-coded, but instead
* are provided via the client device, specifically its UID, supplied when
* calling this function. The generated function takes care of setting up the
* request struct, buffer allocation, as well as execution of the request
* itself, returning once the request has been fully completed. The required
* transport buffer will be allocated on the stack.
*
* The generated function is defined as ``static int name(struct ssam_device
* *sdev, const atype *arg, rtype *ret)``, returning the status of the request,
* which is zero on success and negative on failure. The ``sdev`` parameter
* specifies both the target device of the request and by association the
* controller via which the request is sent. The request's argument is
* specified via the ``arg`` pointer. The request's return value is written to
* the memory pointed to by the ``ret`` parameter.
*
* Refer to ssam_request_do_sync_onstack() for more details on the behavior of
* the generated function.
*/
#define SSAM_DEFINE_SYNC_REQUEST_CL_WR(name, atype, rtype, spec...) \
SSAM_DEFINE_SYNC_REQUEST_MD_WR(__raw_##name, atype, rtype, spec) \
static int name(struct ssam_device *sdev, const atype *arg, rtype *ret) \
{ \
return __raw_##name(sdev->ctrl, sdev->uid.target, \
sdev->uid.instance, arg, ret); \
}
/* -- Helpers for client-device notifiers. ---------------------------------- */
/**
* ssam_device_notifier_register() - Register an event notifier for the
* specified client device.
* @sdev: The device the notifier should be registered on.
* @n: The event notifier to register.
*
* Register an event notifier. Increment the usage counter of the associated
* SAM event if the notifier is not marked as an observer. If the event is not
* marked as an observer and is currently not enabled, it will be enabled
* during this call. If the notifier is marked as an observer, no attempt will
* be made at enabling any event and no reference count will be modified.
*
* Notifiers marked as observers do not need to be associated with one specific
* event, i.e. as long as no event matching is performed, only the event target
* category needs to be set.
*
* Return: Returns zero on success, %-ENOSPC if there have already been
* %INT_MAX notifiers for the event ID/type associated with the notifier block
* registered, %-ENOMEM if the corresponding event entry could not be
* allocated, %-ENODEV if the device is marked as hot-removed. If this is the
* first time that a notifier block is registered for the specific associated
* event, returns the status of the event-enable EC-command.
*/
static inline int ssam_device_notifier_register(struct ssam_device *sdev,
struct ssam_event_notifier *n)
{
/*
* Note that this check does not provide any guarantees whatsoever as
* hot-removal could happen at any point and we can't protect against
* it. Nevertheless, if we can detect hot-removal, bail early to avoid
* communication timeouts.
*/
if (ssam_device_is_hot_removed(sdev))
return -ENODEV;
return ssam_notifier_register(sdev->ctrl, n);
}
/**
* ssam_device_notifier_unregister() - Unregister an event notifier for the
* specified client device.
* @sdev: The device the notifier has been registered on.
* @n: The event notifier to unregister.
*
* Unregister an event notifier. Decrement the usage counter of the associated
* SAM event if the notifier is not marked as an observer. If the usage counter
* reaches zero, the event will be disabled.
*
* In case the device has been marked as hot-removed, the event will not be
* disabled on the EC, as in those cases any attempt at doing so may time out.
*
* Return: Returns zero on success, %-ENOENT if the given notifier block has
* not been registered on the controller. If the given notifier block was the
* last one associated with its specific event, returns the status of the
* event-disable EC-command.
*/
static inline int ssam_device_notifier_unregister(struct ssam_device *sdev,
struct ssam_event_notifier *n)
{
return __ssam_notifier_unregister(sdev->ctrl, n,
!ssam_device_is_hot_removed(sdev));
}
#endif /* _LINUX_SURFACE_AGGREGATOR_DEVICE_H */