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