1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Main SSAM/SSH controller structure and functionality. 4 * 5 * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com> 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 */ 34 struct 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 */ 42 struct 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 */ 54 struct 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 */ 68 struct 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 77 struct 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 */ 87 struct 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 */ 105 struct 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 */ 117 struct 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 */ 131 struct 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 */ 157 enum 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 */ 175 struct 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 */ 198 struct 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 */ 240 static inline 241 int ssam_controller_receive_buf(struct ssam_controller *ctrl, 242 const unsigned char *buf, 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 */ 252 static inline void ssam_controller_write_wakeup(struct ssam_controller *ctrl) 253 { 254 ssh_ptl_tx_wakeup_transfer(&ctrl->rtl.ptl); 255 } 256 257 int ssam_controller_init(struct ssam_controller *ctrl, struct serdev_device *s); 258 int ssam_controller_start(struct ssam_controller *ctrl); 259 void ssam_controller_shutdown(struct ssam_controller *ctrl); 260 void ssam_controller_destroy(struct ssam_controller *ctrl); 261 262 int ssam_notifier_disable_registered(struct ssam_controller *ctrl); 263 void ssam_notifier_restore_registered(struct ssam_controller *ctrl); 264 265 int ssam_irq_setup(struct ssam_controller *ctrl); 266 void ssam_irq_free(struct ssam_controller *ctrl); 267 int ssam_irq_arm_for_wakeup(struct ssam_controller *ctrl); 268 void ssam_irq_disarm_wakeup(struct ssam_controller *ctrl); 269 270 void ssam_controller_lock(struct ssam_controller *c); 271 void ssam_controller_unlock(struct ssam_controller *c); 272 273 int ssam_get_firmware_version(struct ssam_controller *ctrl, u32 *version); 274 int ssam_ctrl_notif_display_off(struct ssam_controller *ctrl); 275 int ssam_ctrl_notif_display_on(struct ssam_controller *ctrl); 276 int ssam_ctrl_notif_d0_exit(struct ssam_controller *ctrl); 277 int ssam_ctrl_notif_d0_entry(struct ssam_controller *ctrl); 278 279 int ssam_controller_suspend(struct ssam_controller *ctrl); 280 int ssam_controller_resume(struct ssam_controller *ctrl); 281 282 int ssam_event_item_cache_init(void); 283 void ssam_event_item_cache_destroy(void); 284 285 #endif /* _SURFACE_AGGREGATOR_CONTROLLER_H */ 286