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 * @plat_hier_disabled:	Platform hierarchy has been disabled (TPM is locked
59 *			down until next reboot)
60 */
61struct tpm_chip_priv {
62	enum tpm_version version;
63
64	uint duration_ms[TPM_DURATION_COUNT];
65	uint retry_time_ms;
66	u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)];  /* Max buffer size + addr */
67
68	/* TPM v2 specific data */
69	uint pcr_count;
70	uint pcr_select_min;
71	bool plat_hier_disabled;
72};
73
74/**
75 * struct tpm_ops - low-level TPM operations
76 *
77 * These are designed to avoid loops and delays in the driver itself. These
78 * should be handled in the uclass.
79 *
80 * In gneral you should implement everything except xfer(). Where you need
81 * complete control of the transfer, then xfer() can be provided and will
82 * override the other methods.
83 *
84 * This interface is for low-level TPM access. It does not understand the
85 * concept of localities or the various TPM messages. That interface is
86 * defined in the functions later on in this file, but they all translate
87 * to bytes which are sent and received.
88 */
89struct tpm_ops {
90	/**
91	 * open() - Request access to locality 0 for the caller
92	 *
93	 * After all commands have been completed the caller should call
94	 * close().
95	 *
96	 * @dev:	Device to open
97	 * @return 0 ok OK, -EBUSY if already opened, other -ve on other error
98	 */
99	int (*open)(struct udevice *dev);
100
101	/**
102	 * close() - Close the current session
103	 *
104	 * Releasing the locked locality. Returns 0 on success, -ve 1 on
105	 * failure (in case lock removal did not succeed).
106	 *
107	 * @dev:	Device to close
108	 * @return 0 ok OK, -ve on error
109	 */
110	int (*close)(struct udevice *dev);
111
112	/**
113	 * get_desc() - Get a text description of the TPM
114	 *
115	 * @dev:	Device to check
116	 * @buf:	Buffer to put the string
117	 * @size:	Maximum size of buffer
118	 * @return length of string, or -ENOSPC it no space
119	 */
120	int (*get_desc)(struct udevice *dev, char *buf, int size);
121
122	/**
123	 * report_state() - Collect information about the current TPM state
124	 *
125	 * @dev:	Device to check
126	 * @buf:	Buffer to put the string
127	 * @size:	Maximum size of buffer
128	 * Return: return code of the operation (0 = success)
129	 */
130	int (*report_state)(struct udevice *dev, char *buf, int size);
131
132	/**
133	 * send() - send data to the TPM
134	 *
135	 * @dev:	Device to talk to
136	 * @sendbuf:	Buffer of the data to send
137	 * @send_size:	Size of the data to send
138	 *
139	 * Returns 0 on success or -ve on failure.
140	 */
141	int (*send)(struct udevice *dev, const u8 *sendbuf, size_t send_size);
142
143	/**
144	 * recv() - receive a response from the TPM
145	 *
146	 * @dev:	Device to talk to
147	 * @recvbuf:	Buffer to save the response to
148	 * @max_size:	Maximum number of bytes to receive
149	 *
150	 * Returns number of bytes received on success, -EAGAIN if the TPM
151	 * response is not ready, -EINTR if cancelled, or other -ve value on
152	 * failure.
153	 */
154	int (*recv)(struct udevice *dev, u8 *recvbuf, size_t max_size);
155
156	/**
157	 * cleanup() - clean up after an operation in progress
158	 *
159	 * This is called if receiving times out. The TPM may need to abort
160	 * the current transaction if it did not complete, and make itself
161	 * ready for another.
162	 *
163	 * @dev:	Device to talk to
164	 */
165	int (*cleanup)(struct udevice *dev);
166
167	/**
168	 * xfer() - send data to the TPM and get response
169	 *
170	 * This method is optional. If it exists it is used in preference
171	 * to send(), recv() and cleanup(). It should handle all aspects of
172	 * TPM communication for a single transfer.
173	 *
174	 * @dev:	Device to talk to
175	 * @sendbuf:	Buffer of the data to send
176	 * @send_size:	Size of the data to send
177	 * @recvbuf:	Buffer to save the response to
178	 * @recv_size:	Pointer to the size of the response buffer
179	 *
180	 * Returns 0 on success (and places the number of response bytes at
181	 * recv_size) or -ve on failure.
182	 */
183	int (*xfer)(struct udevice *dev, const u8 *sendbuf, size_t send_size,
184		    u8 *recvbuf, size_t *recv_size);
185};
186
187#define tpm_get_ops(dev)        ((struct tpm_ops *)device_get_ops(dev))
188
189#define MAKE_TPM_CMD_ENTRY(cmd) \
190	U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "")
191
192#define TPM_COMMAND_NO_ARG(cmd)				\
193int do_##cmd(struct cmd_tbl *cmdtp, int flag,		\
194	     int argc, char *const argv[])		\
195{							\
196	struct udevice *dev;				\
197	int rc;						\
198							\
199	rc = get_tpm(&dev);				\
200	if (rc)						\
201		return rc;				\
202	if (argc != 1)					\
203		return CMD_RET_USAGE;			\
204	return report_return_code(cmd(dev));		\
205}
206
207/**
208 * tpm_open() - Request access to locality 0 for the caller
209 *
210 * After all commands have been completed the caller is supposed to
211 * call tpm_close().
212 *
213 * @dev - TPM device
214 * Returns 0 on success, -ve on failure.
215 */
216int tpm_open(struct udevice *dev);
217
218/**
219 * tpm_close() - Close the current session
220 *
221 * Releasing the locked locality. Returns 0 on success, -ve 1 on
222 * failure (in case lock removal did not succeed).
223 *
224 * @dev - TPM device
225 * Returns 0 on success, -ve on failure.
226 */
227int tpm_close(struct udevice *dev);
228
229/**
230 * tpm_clear_and_reenable() - Force clear the TPM and reenable it
231 *
232 * @dev: TPM device
233 * Return: 0 on success, -ve on failure
234 */
235u32 tpm_clear_and_reenable(struct udevice *dev);
236
237/**
238 * tpm_get_desc() - Get a text description of the TPM
239 *
240 * @dev:	Device to check
241 * @buf:	Buffer to put the string
242 * @size:	Maximum size of buffer
243 * Return: length of string, or -ENOSPC it no space
244 */
245int tpm_get_desc(struct udevice *dev, char *buf, int size);
246
247/**
248 * tpm_report_state() - Collect information about the current TPM state
249 *
250 * @dev:	Device to check
251 * @buf:	Buffer to put the string
252 * @size:	Maximum size of buffer
253 * Return: return code of the operation (0 = success)
254 */
255int tpm_report_state(struct udevice *dev, char *buf, int size);
256
257/**
258 * tpm_xfer() - send data to the TPM and get response
259 *
260 * This first uses the device's send() method to send the bytes. Then it calls
261 * recv() to get the reply. If recv() returns -EAGAIN then it will delay a
262 * short time and then call recv() again.
263 *
264 * Regardless of whether recv() completes successfully, it will then call
265 * cleanup() to finish the transaction.
266 *
267 * Note that the outgoing data is inspected to determine command type
268 * (ordinal) and a timeout is used for that command type.
269 *
270 * @dev - TPM device
271 * @sendbuf - buffer of the data to send
272 * @send_size size of the data to send
273 * @recvbuf - memory to save the response to
274 * @recv_len - pointer to the size of the response buffer
275 *
276 * Returns 0 on success (and places the number of response bytes at
277 * recv_len) or -ve on failure.
278 */
279int tpm_xfer(struct udevice *dev, const u8 *sendbuf, size_t send_size,
280	     u8 *recvbuf, size_t *recv_size);
281
282/**
283 * Initialize TPM device.  It must be called before any TPM commands.
284 *
285 * @dev - TPM device
286 * Return: 0 on success, non-0 on error.
287 */
288int tpm_init(struct udevice *dev);
289
290/**
291 * Retrieve the array containing all the v1 (resp. v2) commands.
292 *
293 * Return: a struct cmd_tbl array.
294 */
295#if defined(CONFIG_TPM_V1)
296struct cmd_tbl *get_tpm1_commands(unsigned int *size);
297#else
298static inline struct cmd_tbl *get_tpm1_commands(unsigned int *size)
299{
300	return NULL;
301}
302#endif
303#if defined(CONFIG_TPM_V2)
304struct cmd_tbl *get_tpm2_commands(unsigned int *size);
305#else
306static inline struct cmd_tbl *get_tpm2_commands(unsigned int *size)
307{
308	return NULL;
309}
310#endif
311
312/**
313 * tpm_get_version() - Find the version of a TPM
314 *
315 * This checks the uclass data for a TPM device and returns the version number
316 * it supports.
317 *
318 * @dev: TPM device
319 * Return: version number (TPM_V1 or TPMV2)
320 */
321enum tpm_version tpm_get_version(struct udevice *dev);
322
323/* Iterate on all TPM devices */
324#define for_each_tpm_device(dev) uclass_foreach_dev_probe(UCLASS_TPM, (dev))
325
326#endif /* __TPM_COMMON_H */
327