1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * System Control and Management Interface (SCMI) Message Protocol
4 * driver common header file containing some definitions, structures
5 * and function prototypes used in all the different SCMI protocols.
6 *
7 * Copyright (C) 2018 ARM Ltd.
8 */
9#ifndef _SCMI_COMMON_H
10#define _SCMI_COMMON_H
11
12#include <linux/bitfield.h>
13#include <linux/completion.h>
14#include <linux/device.h>
15#include <linux/errno.h>
16#include <linux/kernel.h>
17#include <linux/scmi_protocol.h>
18#include <linux/types.h>
19
20#include <asm/unaligned.h>
21
22#define PROTOCOL_REV_MINOR_MASK	GENMASK(15, 0)
23#define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
24#define PROTOCOL_REV_MAJOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
25#define PROTOCOL_REV_MINOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
26#define MAX_PROTOCOLS_IMP	16
27#define MAX_OPPS		16
28
29enum scmi_common_cmd {
30	PROTOCOL_VERSION = 0x0,
31	PROTOCOL_ATTRIBUTES = 0x1,
32	PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
33};
34
35/**
36 * struct scmi_msg_resp_prot_version - Response for a message
37 *
38 * @minor_version: Minor version of the ABI that firmware supports
39 * @major_version: Major version of the ABI that firmware supports
40 *
41 * In general, ABI version changes follow the rule that minor version increments
42 * are backward compatible. Major revision changes in ABI may not be
43 * backward compatible.
44 *
45 * Response to a generic message with message type SCMI_MSG_VERSION
46 */
47struct scmi_msg_resp_prot_version {
48	__le16 minor_version;
49	__le16 major_version;
50};
51
52#define MSG_ID_MASK		GENMASK(7, 0)
53#define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
54#define MSG_TYPE_MASK		GENMASK(9, 8)
55#define MSG_XTRACT_TYPE(hdr)	FIELD_GET(MSG_TYPE_MASK, (hdr))
56#define MSG_TYPE_COMMAND	0
57#define MSG_TYPE_DELAYED_RESP	2
58#define MSG_TYPE_NOTIFICATION	3
59#define MSG_PROTOCOL_ID_MASK	GENMASK(17, 10)
60#define MSG_XTRACT_PROT_ID(hdr)	FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
61#define MSG_TOKEN_ID_MASK	GENMASK(27, 18)
62#define MSG_XTRACT_TOKEN(hdr)	FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
63#define MSG_TOKEN_MAX		(MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
64
65/**
66 * struct scmi_msg_hdr - Message(Tx/Rx) header
67 *
68 * @id: The identifier of the message being sent
69 * @protocol_id: The identifier of the protocol used to send @id message
70 * @seq: The token to identify the message. When a message returns, the
71 *	platform returns the whole message header unmodified including the
72 *	token
73 * @status: Status of the transfer once it's complete
74 * @poll_completion: Indicate if the transfer needs to be polled for
75 *	completion or interrupt mode is used
76 */
77struct scmi_msg_hdr {
78	u8 id;
79	u8 protocol_id;
80	u16 seq;
81	u32 status;
82	bool poll_completion;
83};
84
85/**
86 * pack_scmi_header() - packs and returns 32-bit header
87 *
88 * @hdr: pointer to header containing all the information on message id,
89 *	protocol id and sequence id.
90 *
91 * Return: 32-bit packed message header to be sent to the platform.
92 */
93static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
94{
95	return FIELD_PREP(MSG_ID_MASK, hdr->id) |
96		FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
97		FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
98}
99
100/**
101 * unpack_scmi_header() - unpacks and records message and protocol id
102 *
103 * @msg_hdr: 32-bit packed message header sent from the platform
104 * @hdr: pointer to header to fetch message and protocol id.
105 */
106static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
107{
108	hdr->id = MSG_XTRACT_ID(msg_hdr);
109	hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
110}
111
112/**
113 * struct scmi_msg - Message(Tx/Rx) structure
114 *
115 * @buf: Buffer pointer
116 * @len: Length of data in the Buffer
117 */
118struct scmi_msg {
119	void *buf;
120	size_t len;
121};
122
123/**
124 * struct scmi_xfer - Structure representing a message flow
125 *
126 * @transfer_id: Unique ID for debug & profiling purpose
127 * @hdr: Transmit message header
128 * @tx: Transmit message
129 * @rx: Receive message, the buffer should be pre-allocated to store
130 *	message. If request-ACK protocol is used, we can reuse the same
131 *	buffer for the rx path as we use for the tx path.
132 * @done: command message transmit completion event
133 * @async_done: pointer to delayed response message received event completion
134 */
135struct scmi_xfer {
136	int transfer_id;
137	struct scmi_msg_hdr hdr;
138	struct scmi_msg tx;
139	struct scmi_msg rx;
140	struct completion done;
141	struct completion *async_done;
142};
143
144void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
145int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
146int scmi_do_xfer_with_response(const struct scmi_handle *h,
147			       struct scmi_xfer *xfer);
148int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
149		       size_t tx_size, size_t rx_size, struct scmi_xfer **p);
150void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
151			    struct scmi_xfer *xfer);
152int scmi_handle_put(const struct scmi_handle *handle);
153struct scmi_handle *scmi_handle_get(struct device *dev);
154void scmi_set_handle(struct scmi_device *scmi_dev);
155int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
156void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
157				     u8 *prot_imp);
158
159int scmi_base_protocol_init(struct scmi_handle *h);
160
161int __init scmi_bus_init(void);
162void __exit scmi_bus_exit(void);
163
164#define DECLARE_SCMI_REGISTER_UNREGISTER(func)		\
165	int __init scmi_##func##_register(void);	\
166	void __exit scmi_##func##_unregister(void)
167DECLARE_SCMI_REGISTER_UNREGISTER(clock);
168DECLARE_SCMI_REGISTER_UNREGISTER(perf);
169DECLARE_SCMI_REGISTER_UNREGISTER(power);
170DECLARE_SCMI_REGISTER_UNREGISTER(reset);
171DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
172DECLARE_SCMI_REGISTER_UNREGISTER(system);
173
174#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \
175int __init scmi_##name##_register(void) \
176{ \
177	return scmi_protocol_register((id), &scmi_##name##_protocol_init); \
178} \
179\
180void __exit scmi_##name##_unregister(void) \
181{ \
182	scmi_protocol_unregister((id)); \
183}
184
185/* SCMI Transport */
186/**
187 * struct scmi_chan_info - Structure representing a SCMI channel information
188 *
189 * @dev: Reference to device in the SCMI hierarchy corresponding to this
190 *	 channel
191 * @handle: Pointer to SCMI entity handle
192 * @transport_info: Transport layer related information
193 */
194struct scmi_chan_info {
195	struct device *dev;
196	struct scmi_handle *handle;
197	void *transport_info;
198};
199
200/**
201 * struct scmi_transport_ops - Structure representing a SCMI transport ops
202 *
203 * @chan_available: Callback to check if channel is available or not
204 * @chan_setup: Callback to allocate and setup a channel
205 * @chan_free: Callback to free a channel
206 * @send_message: Callback to send a message
207 * @mark_txdone: Callback to mark tx as done
208 * @fetch_response: Callback to fetch response
209 * @fetch_notification: Callback to fetch notification
210 * @clear_channel: Callback to clear a channel
211 * @poll_done: Callback to poll transfer status
212 */
213struct scmi_transport_ops {
214	bool (*chan_available)(struct device *dev, int idx);
215	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
216			  bool tx);
217	int (*chan_free)(int id, void *p, void *data);
218	int (*send_message)(struct scmi_chan_info *cinfo,
219			    struct scmi_xfer *xfer);
220	void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
221	void (*fetch_response)(struct scmi_chan_info *cinfo,
222			       struct scmi_xfer *xfer);
223	void (*fetch_notification)(struct scmi_chan_info *cinfo,
224				   size_t max_len, struct scmi_xfer *xfer);
225	void (*clear_channel)(struct scmi_chan_info *cinfo);
226	bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
227};
228
229/**
230 * struct scmi_desc - Description of SoC integration
231 *
232 * @ops: Pointer to the transport specific ops structure
233 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
234 * @max_msg: Maximum number of messages that can be pending
235 *	simultaneously in the system
236 * @max_msg_size: Maximum size of data per message that can be handled.
237 */
238struct scmi_desc {
239	const struct scmi_transport_ops *ops;
240	int max_rx_timeout_ms;
241	int max_msg;
242	int max_msg_size;
243};
244
245extern const struct scmi_desc scmi_mailbox_desc;
246#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
247extern const struct scmi_desc scmi_smc_desc;
248#endif
249
250void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
251void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
252
253/* shmem related declarations */
254struct scmi_shared_mem;
255
256void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
257		      struct scmi_xfer *xfer);
258u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
259void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
260			  struct scmi_xfer *xfer);
261void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
262			      size_t max_len, struct scmi_xfer *xfer);
263void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
264bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
265		     struct scmi_xfer *xfer);
266
267#endif /* _SCMI_COMMON_H */
268