drivers/firmware/arm_scmi/common.h

   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
  10 #include <linux/bitfield.h>
  11 #include <linux/completion.h>
  12 #include <linux/device.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/scmi_protocol.h>
  16 #include <linux/types.h>
  17
  18 #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0)
  19 #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16)
  20 #define PROTOCOL_REV_MAJOR(x)   (u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
  21 #define PROTOCOL_REV_MINOR(x)   (u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
  22 #define MAX_PROTOCOLS_IMP       16
  23 #define MAX_OPPS                16
  24
  25 enum scmi_common_cmd {
  26         PROTOCOL_VERSION = 0x0,
  27         PROTOCOL_ATTRIBUTES = 0x1,
  28         PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
  29 };
  30
  31 /**
  32  * struct scmi_msg_resp_prot_version - Response for a message
  33  *
  34  * @major_version: Major version of the ABI that firmware supports
  35  * @minor_version: Minor version of the ABI that firmware supports
  36  *
  37  * In general, ABI version changes follow the rule that minor version increments
  38  * are backward compatible. Major revision changes in ABI may not be
  39  * backward compatible.
  40  *
  41  * Response to a generic message with message type SCMI_MSG_VERSION
  42  */
  43 struct scmi_msg_resp_prot_version {
  44         __le16 minor_version;
  45         __le16 major_version;
  46 };
  47
  48 /**
  49  * struct scmi_msg_hdr - Message(Tx/Rx) header
  50  *
  51  * @id: The identifier of the command being sent
  52  * @protocol_id: The identifier of the protocol used to send @id command
  53  * @seq: The token to identify the message. when a message/command returns,
  54  *      the platform returns the whole message header unmodified including
  55  *      the token
  56  * @status: Status of the transfer once it's complete
  57  * @poll_completion: Indicate if the transfer needs to be polled for
  58  *      completion or interrupt mode is used
  59  */
  60 struct scmi_msg_hdr {
  61         u8 id;
  62         u8 protocol_id;
  63         u16 seq;
  64         u32 status;
  65         bool poll_completion;
  66 };
  67
  68 /**
  69  * struct scmi_msg - Message(Tx/Rx) structure
  70  *
  71  * @buf: Buffer pointer
  72  * @len: Length of data in the Buffer
  73  */
  74 struct scmi_msg {
  75         void *buf;
  76         size_t len;
  77 };
  78
  79 /**
  80  * struct scmi_xfer - Structure representing a message flow
  81  *
  82  * @hdr: Transmit message header
  83  * @tx: Transmit message
  84  * @rx: Receive message, the buffer should be pre-allocated to store
  85  *      message. If request-ACK protocol is used, we can reuse the same
  86  *      buffer for the rx path as we use for the tx path.
  87  * @done: completion event
  88  */
  89 struct scmi_xfer {
  90         struct scmi_msg_hdr hdr;
  91         struct scmi_msg tx;
  92         struct scmi_msg rx;
  93         struct completion done;
  94 };
  95
  96 void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
  97 int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
  98 int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
  99                        size_t tx_size, size_t rx_size, struct scmi_xfer **p);
 100 int scmi_handle_put(const struct scmi_handle *handle);
 101 struct scmi_handle *scmi_handle_get(struct device *dev);
 102 void scmi_set_handle(struct scmi_device *scmi_dev);
 103 int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
 104 void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
 105                                      u8 *prot_imp);
 106
 107 int scmi_base_protocol_init(struct scmi_handle *h);