Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * PCC (Platform Communications Channel) methods
4 */
5
6#ifndef _PCC_H
7#define _PCC_H
8
9#include <linux/mailbox_controller.h>
10#include <linux/mailbox_client.h>
11
12struct pcc_mbox_chan {
13 struct mbox_chan *mchan;
14 u64 shmem_base_addr;
15 void __iomem *shmem;
16 u64 shmem_size;
17 u32 latency;
18 u32 max_access_rate;
19 u16 min_turnaround_time;
20
21 /* Set to true to indicate that the mailbox should manage
22 * writing the dat to the shared buffer. This differs from
23 * the case where the drivesr are writing to the buffer and
24 * using send_data only to ring the doorbell. If this flag
25 * is set, then the void * data parameter of send_data must
26 * point to a kernel-memory buffer formatted in accordance with
27 * the PCC specification.
28 *
29 * The active buffer management will include reading the
30 * notify_on_completion flag, and will then
31 * call mbox_chan_txdone when the acknowledgment interrupt is
32 * received.
33 */
34 bool manage_writes;
35
36 /* Optional callback that allows the driver
37 * to allocate the memory used for receiving
38 * messages. The return value is the location
39 * inside the buffer where the mailbox should write the data.
40 */
41 void *(*rx_alloc)(struct mbox_client *cl, int size);
42};
43
44struct pcc_header {
45 u32 signature;
46 u32 flags;
47 u32 length;
48 u32 command;
49};
50
51/* Generic Communications Channel Shared Memory Region */
52#define PCC_SIGNATURE 0x50434300
53/* Generic Communications Channel Command Field */
54#define PCC_CMD_GENERATE_DB_INTR BIT(15)
55/* Generic Communications Channel Status Field */
56#define PCC_STATUS_CMD_COMPLETE BIT(0)
57#define PCC_STATUS_SCI_DOORBELL BIT(1)
58#define PCC_STATUS_ERROR BIT(2)
59#define PCC_STATUS_PLATFORM_NOTIFY BIT(3)
60/* Initiator Responder Communications Channel Flags */
61#define PCC_CMD_COMPLETION_NOTIFY BIT(0)
62
63#define MAX_PCC_SUBSPACES 256
64
65#ifdef CONFIG_PCC
66extern struct pcc_mbox_chan *
67pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);
68extern void pcc_mbox_free_channel(struct pcc_mbox_chan *chan);
69#else
70static inline struct pcc_mbox_chan *
71pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
72{
73 return ERR_PTR(-ENODEV);
74}
75static inline void pcc_mbox_free_channel(struct pcc_mbox_chan *chan) { }
76#endif
77
78#endif /* _PCC_H */