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1/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
2/*
3 * Apple RTKit IPC Library
4 * Copyright (C) The Asahi Linux Contributors
5 *
6 * Apple's SoCs come with various co-processors running their RTKit operating
7 * system. This protocol library is used by client drivers to use the
8 * features provided by them.
9 */
10#ifndef _LINUX_APPLE_RTKIT_H_
11#define _LINUX_APPLE_RTKIT_H_
12
13#include <linux/device.h>
14#include <linux/types.h>
15#include <linux/mailbox_client.h>
16
17/*
18 * Struct to represent implementation-specific RTKit operations.
19 *
20 * @buffer: Shared memory buffer allocated inside normal RAM.
21 * @iomem: Shared memory buffer controlled by the co-processors.
22 * @size: Size of the shared memory buffer.
23 * @iova: Device VA of shared memory buffer.
24 * @is_mapped: Shared memory buffer is managed by the co-processor.
25 * @private: Private data pointer for the parent driver.
26 */
27
28struct apple_rtkit_shmem {
29 void *buffer;
30 void __iomem *iomem;
31 size_t size;
32 dma_addr_t iova;
33 bool is_mapped;
34 void *private;
35};
36
37/*
38 * Struct to represent implementation-specific RTKit operations.
39 *
40 * @crashed: Called when the co-processor has crashed. Runs in process
41 * context.
42 * @recv_message: Function called when a message from RTKit is received
43 * on a non-system endpoint. Called from a worker thread.
44 * @recv_message_early:
45 * Like recv_message, but called from atomic context. It
46 * should return true if it handled the message. If it
47 * returns false, the message will be passed on to the
48 * worker thread.
49 * @shmem_setup: Setup shared memory buffer. If bfr.is_iomem is true the
50 * buffer is managed by the co-processor and needs to be mapped.
51 * Otherwise the buffer is managed by Linux and needs to be
52 * allocated. If not specified dma_alloc_coherent is used.
53 * Called in process context.
54 * @shmem_destroy: Undo the shared memory buffer setup in shmem_setup. If not
55 * specified dma_free_coherent is used. Called in process
56 * context.
57 */
58struct apple_rtkit_ops {
59 void (*crashed)(void *cookie);
60 void (*recv_message)(void *cookie, u8 endpoint, u64 message);
61 bool (*recv_message_early)(void *cookie, u8 endpoint, u64 message);
62 int (*shmem_setup)(void *cookie, struct apple_rtkit_shmem *bfr);
63 void (*shmem_destroy)(void *cookie, struct apple_rtkit_shmem *bfr);
64};
65
66struct apple_rtkit;
67
68/*
69 * Initializes the internal state required to handle RTKit. This
70 * should usually be called within _probe.
71 *
72 * @dev: Pointer to the device node this coprocessor is assocated with
73 * @cookie: opaque cookie passed to all functions defined in rtkit_ops
74 * @mbox_name: mailbox name used to communicate with the co-processor
75 * @mbox_idx: mailbox index to be used if mbox_name is NULL
76 * @ops: pointer to rtkit_ops to be used for this co-processor
77 */
78struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
79 const char *mbox_name, int mbox_idx,
80 const struct apple_rtkit_ops *ops);
81
82/*
83 * Non-devm version of devm_apple_rtkit_init. Must be freed with
84 * apple_rtkit_free.
85 *
86 * @dev: Pointer to the device node this coprocessor is assocated with
87 * @cookie: opaque cookie passed to all functions defined in rtkit_ops
88 * @mbox_name: mailbox name used to communicate with the co-processor
89 * @mbox_idx: mailbox index to be used if mbox_name is NULL
90 * @ops: pointer to rtkit_ops to be used for this co-processor
91 */
92struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
93 const char *mbox_name, int mbox_idx,
94 const struct apple_rtkit_ops *ops);
95
96/*
97 * Free an instance of apple_rtkit.
98 */
99void apple_rtkit_free(struct apple_rtkit *rtk);
100
101/*
102 * Reinitialize internal structures. Must only be called with the co-processor
103 * is held in reset.
104 */
105int apple_rtkit_reinit(struct apple_rtkit *rtk);
106
107/*
108 * Handle RTKit's boot process. Should be called after the CPU of the
109 * co-processor has been started.
110 */
111int apple_rtkit_boot(struct apple_rtkit *rtk);
112
113/*
114 * Quiesce the co-processor.
115 */
116int apple_rtkit_quiesce(struct apple_rtkit *rtk);
117
118/*
119 * Wake the co-processor up from hibernation mode.
120 */
121int apple_rtkit_wake(struct apple_rtkit *rtk);
122
123/*
124 * Shutdown the co-processor
125 */
126int apple_rtkit_shutdown(struct apple_rtkit *rtk);
127
128/*
129 * Put the co-processor into idle mode
130 */
131int apple_rtkit_idle(struct apple_rtkit *rtk);
132
133/*
134 * Checks if RTKit is running and ready to handle messages.
135 */
136bool apple_rtkit_is_running(struct apple_rtkit *rtk);
137
138/*
139 * Checks if RTKit has crashed.
140 */
141bool apple_rtkit_is_crashed(struct apple_rtkit *rtk);
142
143/*
144 * Starts an endpoint. Must be called after boot but before any messages can be
145 * sent or received from that endpoint.
146 */
147int apple_rtkit_start_ep(struct apple_rtkit *rtk, u8 endpoint);
148
149/*
150 * Send a message to the given endpoint.
151 *
152 * @rtk: RTKit reference
153 * @ep: target endpoint
154 * @message: message to be sent
155 * @completeion: will be completed once the message has been submitted
156 * to the hardware FIFO. Can be NULL.
157 * @atomic: if set to true this function can be called from atomic
158 * context.
159 */
160int apple_rtkit_send_message(struct apple_rtkit *rtk, u8 ep, u64 message,
161 struct completion *completion, bool atomic);
162
163/*
164 * Process incoming messages in atomic context.
165 * This only guarantees that messages arrive as far as the recv_message_early
166 * callback; drivers expecting to handle incoming messages synchronously
167 * by calling this function must do it that way.
168 * Will return 1 if some data was processed, 0 if none was, or a
169 * negative error code on failure.
170 *
171 * @rtk: RTKit reference
172 */
173int apple_rtkit_poll(struct apple_rtkit *rtk);
174
175#endif /* _LINUX_APPLE_RTKIT_H_ */