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1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * Main SSAM/SSH controller structure and functionality.
4 *
5 * Copyright (C) 2019-2022 Maximilian Luz <[email protected]>
6 */
7
8#ifndef _SURFACE_AGGREGATOR_CONTROLLER_H
9#define _SURFACE_AGGREGATOR_CONTROLLER_H
10
11#include <linux/kref.h>
12#include <linux/list.h>
13#include <linux/mutex.h>
14#include <linux/rbtree.h>
15#include <linux/rwsem.h>
16#include <linux/serdev.h>
17#include <linux/spinlock.h>
18#include <linux/srcu.h>
19#include <linux/types.h>
20#include <linux/workqueue.h>
21
22#include <linux/surface_aggregator/controller.h>
23#include <linux/surface_aggregator/serial_hub.h>
24
25#include "ssh_request_layer.h"
26
27
28/* -- Safe counters. -------------------------------------------------------- */
29
30/**
31 * struct ssh_seq_counter - Safe counter for SSH sequence IDs.
32 * @value: The current counter value.
33 */
34struct ssh_seq_counter {
35 u8 value;
36};
37
38/**
39 * struct ssh_rqid_counter - Safe counter for SSH request IDs.
40 * @value: The current counter value.
41 */
42struct ssh_rqid_counter {
43 u16 value;
44};
45
46
47/* -- Event/notification system. -------------------------------------------- */
48
49/**
50 * struct ssam_nf_head - Notifier head for SSAM events.
51 * @srcu: The SRCU struct for synchronization.
52 * @head: List-head for notifier blocks registered under this head.
53 */
54struct ssam_nf_head {
55 struct srcu_struct srcu;
56 struct list_head head;
57};
58
59/**
60 * struct ssam_nf - Notifier callback- and activation-registry for SSAM events.
61 * @lock: Lock guarding (de-)registration of notifier blocks. Note: This
62 * lock does not need to be held for notifier calls, only
63 * registration and deregistration.
64 * @refcount: The root of the RB-tree used for reference-counting enabled
65 * events/notifications.
66 * @head: The list of notifier heads for event/notification callbacks.
67 */
68struct ssam_nf {
69 struct mutex lock;
70 struct rb_root refcount;
71 struct ssam_nf_head head[SSH_NUM_EVENTS];
72};
73
74
75/* -- Event/async request completion system. -------------------------------- */
76
77struct ssam_cplt;
78
79/**
80 * struct ssam_event_item - Struct for event queuing and completion.
81 * @node: The node in the queue.
82 * @rqid: The request ID of the event.
83 * @ops: Instance specific functions.
84 * @ops.free: Callback for freeing this event item.
85 * @event: Actual event data.
86 */
87struct ssam_event_item {
88 struct list_head node;
89 u16 rqid;
90
91 struct {
92 void (*free)(struct ssam_event_item *event);
93 } ops;
94
95 struct ssam_event event; /* must be last */
96};
97
98/**
99 * struct ssam_event_queue - Queue for completing received events.
100 * @cplt: Reference to the completion system on which this queue is active.
101 * @lock: The lock for any operation on the queue.
102 * @head: The list-head of the queue.
103 * @work: The &struct work_struct performing completion work for this queue.
104 */
105struct ssam_event_queue {
106 struct ssam_cplt *cplt;
107
108 spinlock_t lock;
109 struct list_head head;
110 struct work_struct work;
111};
112
113/**
114 * struct ssam_event_target - Set of queues for a single SSH target ID.
115 * @queue: The array of queues, one queue per event ID.
116 */
117struct ssam_event_target {
118 struct ssam_event_queue queue[SSH_NUM_EVENTS];
119};
120
121/**
122 * struct ssam_cplt - SSAM event/async request completion system.
123 * @dev: The device with which this system is associated. Only used
124 * for logging.
125 * @wq: The &struct workqueue_struct on which all completion work
126 * items are queued.
127 * @event: Event completion management.
128 * @event.target: Array of &struct ssam_event_target, one for each target.
129 * @event.notif: Notifier callbacks and event activation reference counting.
130 */
131struct ssam_cplt {
132 struct device *dev;
133 struct workqueue_struct *wq;
134
135 struct {
136 struct ssam_event_target target[SSH_NUM_TARGETS];
137 struct ssam_nf notif;
138 } event;
139};
140
141
142/* -- Main SSAM device structures. ------------------------------------------ */
143
144/**
145 * enum ssam_controller_state - State values for &struct ssam_controller.
146 * @SSAM_CONTROLLER_UNINITIALIZED:
147 * The controller has not been initialized yet or has been deinitialized.
148 * @SSAM_CONTROLLER_INITIALIZED:
149 * The controller is initialized, but has not been started yet.
150 * @SSAM_CONTROLLER_STARTED:
151 * The controller has been started and is ready to use.
152 * @SSAM_CONTROLLER_STOPPED:
153 * The controller has been stopped.
154 * @SSAM_CONTROLLER_SUSPENDED:
155 * The controller has been suspended.
156 */
157enum ssam_controller_state {
158 SSAM_CONTROLLER_UNINITIALIZED,
159 SSAM_CONTROLLER_INITIALIZED,
160 SSAM_CONTROLLER_STARTED,
161 SSAM_CONTROLLER_STOPPED,
162 SSAM_CONTROLLER_SUSPENDED,
163};
164
165/**
166 * struct ssam_controller_caps - Controller device capabilities.
167 * @ssh_power_profile: SSH power profile.
168 * @ssh_buffer_size: SSH driver UART buffer size.
169 * @screen_on_sleep_idle_timeout: SAM UART screen-on sleep idle timeout.
170 * @screen_off_sleep_idle_timeout: SAM UART screen-off sleep idle timeout.
171 * @d3_closes_handle: SAM closes UART handle in D3.
172 *
173 * Controller and SSH device capabilities found in ACPI.
174 */
175struct ssam_controller_caps {
176 u32 ssh_power_profile;
177 u32 ssh_buffer_size;
178 u32 screen_on_sleep_idle_timeout;
179 u32 screen_off_sleep_idle_timeout;
180 u32 d3_closes_handle:1;
181};
182
183/**
184 * struct ssam_controller - SSAM controller device.
185 * @kref: Reference count of the controller.
186 * @lock: Main lock for the controller, used to guard state changes.
187 * @state: Controller state.
188 * @rtl: Request transport layer for SSH I/O.
189 * @cplt: Completion system for SSH/SSAM events and asynchronous requests.
190 * @counter: Safe SSH message ID counters.
191 * @counter.seq: Sequence ID counter.
192 * @counter.rqid: Request ID counter.
193 * @irq: Wakeup IRQ resources.
194 * @irq.num: The wakeup IRQ number.
195 * @irq.wakeup_enabled: Whether wakeup by IRQ is enabled during suspend.
196 * @caps: The controller device capabilities.
197 */
198struct ssam_controller {
199 struct kref kref;
200
201 struct rw_semaphore lock;
202 enum ssam_controller_state state;
203
204 struct ssh_rtl rtl;
205 struct ssam_cplt cplt;
206
207 struct {
208 struct ssh_seq_counter seq;
209 struct ssh_rqid_counter rqid;
210 } counter;
211
212 struct {
213 int num;
214 bool wakeup_enabled;
215 } irq;
216
217 struct ssam_controller_caps caps;
218};
219
220#define to_ssam_controller(ptr, member) \
221 container_of(ptr, struct ssam_controller, member)
222
223#define ssam_dbg(ctrl, fmt, ...) rtl_dbg(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
224#define ssam_info(ctrl, fmt, ...) rtl_info(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
225#define ssam_warn(ctrl, fmt, ...) rtl_warn(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
226#define ssam_err(ctrl, fmt, ...) rtl_err(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
227
228/**
229 * ssam_controller_receive_buf() - Provide input-data to the controller.
230 * @ctrl: The controller.
231 * @buf: The input buffer.
232 * @n: The number of bytes in the input buffer.
233 *
234 * Provide input data to be evaluated by the controller, which has been
235 * received via the lower-level transport.
236 *
237 * Return: Returns the number of bytes consumed, or, if the packet transport
238 * layer of the controller has been shut down, %-ESHUTDOWN.
239 */
240static inline
241ssize_t ssam_controller_receive_buf(struct ssam_controller *ctrl, const u8 *buf,
242 size_t n)
243{
244 return ssh_ptl_rx_rcvbuf(&ctrl->rtl.ptl, buf, n);
245}
246
247/**
248 * ssam_controller_write_wakeup() - Notify the controller that the underlying
249 * device has space available for data to be written.
250 * @ctrl: The controller.
251 */
252static inline void ssam_controller_write_wakeup(struct ssam_controller *ctrl)
253{
254 ssh_ptl_tx_wakeup_transfer(&ctrl->rtl.ptl);
255}
256
257int ssam_controller_init(struct ssam_controller *ctrl, struct serdev_device *s);
258int ssam_controller_start(struct ssam_controller *ctrl);
259void ssam_controller_shutdown(struct ssam_controller *ctrl);
260void ssam_controller_destroy(struct ssam_controller *ctrl);
261
262int ssam_notifier_disable_registered(struct ssam_controller *ctrl);
263void ssam_notifier_restore_registered(struct ssam_controller *ctrl);
264
265int ssam_irq_setup(struct ssam_controller *ctrl);
266void ssam_irq_free(struct ssam_controller *ctrl);
267int ssam_irq_arm_for_wakeup(struct ssam_controller *ctrl);
268void ssam_irq_disarm_wakeup(struct ssam_controller *ctrl);
269
270void ssam_controller_lock(struct ssam_controller *c);
271void ssam_controller_unlock(struct ssam_controller *c);
272
273int ssam_get_firmware_version(struct ssam_controller *ctrl, u32 *version);
274int ssam_ctrl_notif_display_off(struct ssam_controller *ctrl);
275int ssam_ctrl_notif_display_on(struct ssam_controller *ctrl);
276int ssam_ctrl_notif_d0_exit(struct ssam_controller *ctrl);
277int ssam_ctrl_notif_d0_entry(struct ssam_controller *ctrl);
278
279int ssam_controller_suspend(struct ssam_controller *ctrl);
280int ssam_controller_resume(struct ssam_controller *ctrl);
281
282int ssam_event_item_cache_init(void);
283void ssam_event_item_cache_destroy(void);
284
285#endif /* _SURFACE_AGGREGATOR_CONTROLLER_H */