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 #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
  29 enum 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  */
  47 struct 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  */
  77 struct 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  */
  93 static 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  */
 106 static 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  */
 118 struct 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  */
 135 struct 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
 144 void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
 145 int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
 146 int scmi_do_xfer_with_response(const struct scmi_handle *h,
 147                                struct scmi_xfer *xfer);
 148 int 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);
 150 void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
 151                             struct scmi_xfer *xfer);
 152 int scmi_handle_put(const struct scmi_handle *handle);
 153 struct scmi_handle *scmi_handle_get(struct device *dev);
 154 void scmi_set_handle(struct scmi_device *scmi_dev);
 155 int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
 156 void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
 157                                      u8 *prot_imp);
 158
 159 int scmi_base_protocol_init(struct scmi_handle *h);
 160
 161 int __init scmi_bus_init(void);
 162 void __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)
 167 DECLARE_SCMI_REGISTER_UNREGISTER(clock);
 168 DECLARE_SCMI_REGISTER_UNREGISTER(perf);
 169 DECLARE_SCMI_REGISTER_UNREGISTER(power);
 170 DECLARE_SCMI_REGISTER_UNREGISTER(reset);
 171 DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
 172 DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
 173 DECLARE_SCMI_REGISTER_UNREGISTER(system);
 174
 175 #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \
 176 int __init scmi_##name##_register(void) \
 177 { \
 178         return scmi_protocol_register((id), &scmi_##name##_protocol_init); \
 179 } \
 180 \
 181 void __exit scmi_##name##_unregister(void) \
 182 { \
 183         scmi_protocol_unregister((id)); \
 184 }
 185
 186 /* SCMI Transport */
 187 /**
 188  * struct scmi_chan_info - Structure representing a SCMI channel information
 189  *
 190  * @dev: Reference to device in the SCMI hierarchy corresponding to this
 191  *       channel
 192  * @handle: Pointer to SCMI entity handle
 193  * @transport_info: Transport layer related information
 194  */
 195 struct scmi_chan_info {
 196         struct device *dev;
 197         struct scmi_handle *handle;
 198         void *transport_info;
 199 };
 200
 201 /**
 202  * struct scmi_transport_ops - Structure representing a SCMI transport ops
 203  *
 204  * @chan_available: Callback to check if channel is available or not
 205  * @chan_setup: Callback to allocate and setup a channel
 206  * @chan_free: Callback to free a channel
 207  * @send_message: Callback to send a message
 208  * @mark_txdone: Callback to mark tx as done
 209  * @fetch_response: Callback to fetch response
 210  * @fetch_notification: Callback to fetch notification
 211  * @clear_channel: Callback to clear a channel
 212  * @poll_done: Callback to poll transfer status
 213  */
 214 struct scmi_transport_ops {
 215         bool (*chan_available)(struct device *dev, int idx);
 216         int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
 217                           bool tx);
 218         int (*chan_free)(int id, void *p, void *data);
 219         int (*send_message)(struct scmi_chan_info *cinfo,
 220                             struct scmi_xfer *xfer);
 221         void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
 222         void (*fetch_response)(struct scmi_chan_info *cinfo,
 223                                struct scmi_xfer *xfer);
 224         void (*fetch_notification)(struct scmi_chan_info *cinfo,
 225                                    size_t max_len, struct scmi_xfer *xfer);
 226         void (*clear_channel)(struct scmi_chan_info *cinfo);
 227         bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
 228 };
 229
 230 /**
 231  * struct scmi_desc - Description of SoC integration
 232  *
 233  * @ops: Pointer to the transport specific ops structure
 234  * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
 235  * @max_msg: Maximum number of messages that can be pending
 236  *      simultaneously in the system
 237  * @max_msg_size: Maximum size of data per message that can be handled.
 238  */
 239 struct scmi_desc {
 240         const struct scmi_transport_ops *ops;
 241         int max_rx_timeout_ms;
 242         int max_msg;
 243         int max_msg_size;
 244 };
 245
 246 extern const struct scmi_desc scmi_mailbox_desc;
 247 #ifdef CONFIG_HAVE_ARM_SMCCC
 248 extern const struct scmi_desc scmi_smc_desc;
 249 #endif
 250
 251 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
 252 void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
 253
 254 /* shmem related declarations */
 255 struct scmi_shared_mem;
 256
 257 void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
 258                       struct scmi_xfer *xfer);
 259 u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
 260 void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
 261                           struct scmi_xfer *xfer);
 262 void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
 263                               size_t max_len, struct scmi_xfer *xfer);
 264 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
 265 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
 266                      struct scmi_xfer *xfer);
 267
 268 #endif /* _SCMI_COMMON_H */