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
12 struct udevice;
13
14 enum 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 */
40 enum 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 */
59 struct 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 */
86 struct 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) \
180 int 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 */
203 int 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 */
214 int 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 */
222 u32 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 */
232 int 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 */
256 int 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 */
265 int 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)
273 struct cmd_tbl *get_tpm1_commands(unsigned int *size);
274 #else
get_tpm1_commands(unsigned int * size)275 static inline struct cmd_tbl *get_tpm1_commands(unsigned int *size)
276 {
277 return NULL;
278 }
279 #endif
280 #if defined(CONFIG_TPM_V2)
281 struct cmd_tbl *get_tpm2_commands(unsigned int *size);
282 #else
get_tpm2_commands(unsigned int * size)283 static 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 */
298 enum 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