1/* SPDX-License-Identifier: GPL-2.0+ */ 2/* 3 * Copyright (c) 2013 The Chromium OS Authors. 4 * Coypright (c) 2013 Guntermann & Drunck GmbH 5 */ 6 7#ifndef __TPM_COMMON_H 8#define __TPM_COMMON_H 9 10#include <command.h> 11 12struct udevice; 13 14enum tpm_duration { 15 TPM_SHORT = 0, 16 TPM_MEDIUM = 1, 17 TPM_LONG = 2, 18 TPM_UNDEFINED, 19 20 TPM_DURATION_COUNT, 21}; 22 23/* 24 * Here is a partial implementation of TPM commands. Please consult TCG Main 25 * Specification for definitions of TPM commands. 26 */ 27 28#define TPM_HEADER_SIZE 10 29 30/* Max buffer size supported by our tpm */ 31#define TPM_DEV_BUFSIZE 1260 32 33#define TPM_PCR_MINIMUM_DIGEST_SIZE 20 34 35/** 36 * enum tpm_version - The version of the TPM stack to be used 37 * @TPM_V1: Use TPM v1.x stack 38 * @TPM_V2: Use TPM v2.x stack 39 */ 40enum tpm_version { 41 TPM_V1 = 0, 42 TPM_V2, 43}; 44 45/** 46 * struct tpm_chip_priv - Information about a TPM, stored by the uclass 47 * 48 * These values must be set up by the device's probe() method before 49 * communcation is attempted. If the device has an xfer() method, this is 50 * not needed. There is no need to set up @buf. 51 * 52 * @version: TPM stack to be used 53 * @duration_ms: Length of each duration type in milliseconds 54 * @retry_time_ms: Time to wait before retrying receive 55 * @buf: Buffer used during the exchanges with the chip 56 * @pcr_count: Number of PCR per bank 57 * @pcr_select_min: Minimum size in bytes of the pcrSelect array 58 */ 59struct tpm_chip_priv { 60 enum tpm_version version; 61 62 uint duration_ms[TPM_DURATION_COUNT]; 63 uint retry_time_ms; 64 u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */ 65 66 /* TPM v2 specific data */ 67 uint pcr_count; 68 uint pcr_select_min; 69}; 70 71/** 72 * struct tpm_ops - low-level TPM operations 73 * 74 * These are designed to avoid loops and delays in the driver itself. These 75 * should be handled in the uclass. 76 * 77 * In gneral you should implement everything except xfer(). Where you need 78 * complete control of the transfer, then xfer() can be provided and will 79 * override the other methods. 80 * 81 * This interface is for low-level TPM access. It does not understand the 82 * concept of localities or the various TPM messages. That interface is 83 * defined in the functions later on in this file, but they all translate 84 * to bytes which are sent and received. 85 */ 86struct tpm_ops { 87 /** 88 * open() - Request access to locality 0 for the caller 89 * 90 * After all commands have been completed the caller should call 91 * close(). 92 * 93 * @dev: Device to open 94 * @return 0 ok OK, -ve on error 95 */ 96 int (*open)(struct udevice *dev); 97 98 /** 99 * close() - Close the current session 100 * 101 * Releasing the locked locality. Returns 0 on success, -ve 1 on 102 * failure (in case lock removal did not succeed). 103 * 104 * @dev: Device to close 105 * @return 0 ok OK, -ve on error 106 */ 107 int (*close)(struct udevice *dev); 108 109 /** 110 * get_desc() - Get a text description of the TPM 111 * 112 * @dev: Device to check 113 * @buf: Buffer to put the string 114 * @size: Maximum size of buffer 115 * @return length of string, or -ENOSPC it no space 116 */ 117 int (*get_desc)(struct udevice *dev, char *buf, int size); 118 119 /** 120 * send() - send data to the TPM 121 * 122 * @dev: Device to talk to 123 * @sendbuf: Buffer of the data to send 124 * @send_size: Size of the data to send 125 * 126 * Returns 0 on success or -ve on failure. 127 */ 128 int (*send)(struct udevice *dev, const u8 *sendbuf, size_t send_size); 129 130 /** 131 * recv() - receive a response from the TPM 132 * 133 * @dev: Device to talk to 134 * @recvbuf: Buffer to save the response to 135 * @max_size: Maximum number of bytes to receive 136 * 137 * Returns number of bytes received on success, -EAGAIN if the TPM 138 * response is not ready, -EINTR if cancelled, or other -ve value on 139 * failure. 140 */ 141 int (*recv)(struct udevice *dev, u8 *recvbuf, size_t max_size); 142 143 /** 144 * cleanup() - clean up after an operation in progress 145 * 146 * This is called if receiving times out. The TPM may need to abort 147 * the current transaction if it did not complete, and make itself 148 * ready for another. 149 * 150 * @dev: Device to talk to 151 */ 152 int (*cleanup)(struct udevice *dev); 153 154 /** 155 * xfer() - send data to the TPM and get response 156 * 157 * This method is optional. If it exists it is used in preference 158 * to send(), recv() and cleanup(). It should handle all aspects of 159 * TPM communication for a single transfer. 160 * 161 * @dev: Device to talk to 162 * @sendbuf: Buffer of the data to send 163 * @send_size: Size of the data to send 164 * @recvbuf: Buffer to save the response to 165 * @recv_size: Pointer to the size of the response buffer 166 * 167 * Returns 0 on success (and places the number of response bytes at 168 * recv_size) or -ve on failure. 169 */ 170 int (*xfer)(struct udevice *dev, const u8 *sendbuf, size_t send_size, 171 u8 *recvbuf, size_t *recv_size); 172}; 173 174#define tpm_get_ops(dev) ((struct tpm_ops *)device_get_ops(dev)) 175 176#define MAKE_TPM_CMD_ENTRY(cmd) \ 177 U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "") 178 179#define TPM_COMMAND_NO_ARG(cmd) \ 180int do_##cmd(struct cmd_tbl *cmdtp, int flag, \ 181 int argc, char *const argv[]) \ 182{ \ 183 struct udevice *dev; \ 184 int rc; \ 185 \ 186 rc = get_tpm(&dev); \ 187 if (rc) \ 188 return rc; \ 189 if (argc != 1) \ 190 return CMD_RET_USAGE; \ 191 return report_return_code(cmd(dev)); \ 192} 193 194/** 195 * tpm_open() - Request access to locality 0 for the caller 196 * 197 * After all commands have been completed the caller is supposed to 198 * call tpm_close(). 199 * 200 * @dev - TPM device 201 * Returns 0 on success, -ve on failure. 202 */ 203int tpm_open(struct udevice *dev); 204 205/** 206 * tpm_close() - Close the current session 207 * 208 * Releasing the locked locality. Returns 0 on success, -ve 1 on 209 * failure (in case lock removal did not succeed). 210 * 211 * @dev - TPM device 212 * Returns 0 on success, -ve on failure. 213 */ 214int tpm_close(struct udevice *dev); 215 216/** 217 * tpm_clear_and_reenable() - Force clear the TPM and reenable it 218 * 219 * @dev: TPM device 220 * @return 0 on success, -ve on failure 221 */ 222u32 tpm_clear_and_reenable(struct udevice *dev); 223 224/** 225 * tpm_get_desc() - Get a text description of the TPM 226 * 227 * @dev: Device to check 228 * @buf: Buffer to put the string 229 * @size: Maximum size of buffer 230 * @return length of string, or -ENOSPC it no space 231 */ 232int tpm_get_desc(struct udevice *dev, char *buf, int size); 233 234/** 235 * tpm_xfer() - send data to the TPM and get response 236 * 237 * This first uses the device's send() method to send the bytes. Then it calls 238 * recv() to get the reply. If recv() returns -EAGAIN then it will delay a 239 * short time and then call recv() again. 240 * 241 * Regardless of whether recv() completes successfully, it will then call 242 * cleanup() to finish the transaction. 243 * 244 * Note that the outgoing data is inspected to determine command type 245 * (ordinal) and a timeout is used for that command type. 246 * 247 * @dev - TPM device 248 * @sendbuf - buffer of the data to send 249 * @send_size size of the data to send 250 * @recvbuf - memory to save the response to 251 * @recv_len - pointer to the size of the response buffer 252 * 253 * Returns 0 on success (and places the number of response bytes at 254 * recv_len) or -ve on failure. 255 */ 256int tpm_xfer(struct udevice *dev, const u8 *sendbuf, size_t send_size, 257 u8 *recvbuf, size_t *recv_size); 258 259/** 260 * Initialize TPM device. It must be called before any TPM commands. 261 * 262 * @dev - TPM device 263 * @return 0 on success, non-0 on error. 264 */ 265int tpm_init(struct udevice *dev); 266 267/** 268 * Retrieve the array containing all the v1 (resp. v2) commands. 269 * 270 * @return a struct cmd_tbl array. 271 */ 272#if defined(CONFIG_TPM_V1) 273struct cmd_tbl *get_tpm1_commands(unsigned int *size); 274#else 275static inline struct cmd_tbl *get_tpm1_commands(unsigned int *size) 276{ 277 return NULL; 278} 279#endif 280#if defined(CONFIG_TPM_V2) 281struct cmd_tbl *get_tpm2_commands(unsigned int *size); 282#else 283static inline struct cmd_tbl *get_tpm2_commands(unsigned int *size) 284{ 285 return NULL; 286} 287#endif 288 289/** 290 * tpm_get_version() - Find the version of a TPM 291 * 292 * This checks the uclass data for a TPM device and returns the version number 293 * it supports. 294 * 295 * @dev: TPM device 296 * @return version number (TPM_V1 or TPMV2) 297 */ 298enum tpm_version tpm_get_version(struct udevice *dev); 299 300/* Iterate on all TPM devices */ 301#define for_each_tpm_device(dev) uclass_foreach_dev_probe(UCLASS_TPM, (dev)) 302 303#endif /* __TPM_COMMON_H */ 304