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      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_UTILS_H
      8 #define __TPM_UTILS_H
      9 
     10 #define COMMAND_BUFFER_SIZE 256
     11 
     12 /* Internal error of TPM command library */
     13 #define TPM_LIB_ERROR ((u32)~0u)
     14 
     15 /* To make strings of commands more easily */
     16 #define __MSB(x) ((x) >> 8)
     17 #define __LSB(x) ((x) & 0xFF)
     18 #define tpm_u16(x) __MSB(x), __LSB(x)
     19 #define tpm_u32(x) tpm_u16((x) >> 16), tpm_u16((x) & 0xFFFF)
     20 
     21 /**
     22  * tpm_open() - Request access to locality 0 for the caller
     23  *
     24  * After all commands have been completed the caller is supposed to
     25  * call tpm_close().
     26  *
     27  * Returns 0 on success, -ve on failure.
     28  */
     29 int tpm_open(struct udevice *dev);
     30 
     31 /**
     32  * tpm_close() - Close the current session
     33  *
     34  * Releasing the locked locality. Returns 0 on success, -ve 1 on
     35  * failure (in case lock removal did not succeed).
     36  */
     37 int tpm_close(struct udevice *dev);
     38 
     39 /**
     40  * Pack data into a byte string.  The data types are specified in
     41  * the format string: 'b' means unsigned byte, 'w' unsigned word,
     42  * 'd' unsigned double word, and 's' byte string.  The data are a
     43  * series of offsets and values (for type byte string there are also
     44  * lengths).  The data values are packed into the byte string
     45  * sequentially, and so a latter value could over-write a former
     46  * value.
     47  *
     48  * @param str		output string
     49  * @param size		size of output string
     50  * @param format	format string
     51  * @param ...		data points
     52  * @return 0 on success, non-0 on error
     53  */
     54 int pack_byte_string(u8 *str, size_t size, const char *format, ...);
     55 
     56 /**
     57  * Unpack data from a byte string.  The data types are specified in
     58  * the format string: 'b' means unsigned byte, 'w' unsigned word,
     59  * 'd' unsigned double word, and 's' byte string.  The data are a
     60  * series of offsets and pointers (for type byte string there are also
     61  * lengths).
     62  *
     63  * @param str		output string
     64  * @param size		size of output string
     65  * @param format	format string
     66  * @param ...		data points
     67  * @return 0 on success, non-0 on error
     68  */
     69 int unpack_byte_string(const u8 *str, size_t size, const char *format, ...);
     70 
     71 /**
     72  * Get TPM command size.
     73  *
     74  * @param command	byte string of TPM command
     75  * @return command size of the TPM command
     76  */
     77 u32 tpm_command_size(const void *command);
     78 
     79 /**
     80  * Get TPM response return code, which is one of TPM_RESULT values.
     81  *
     82  * @param response	byte string of TPM response
     83  * @return return code of the TPM response
     84  */
     85 u32 tpm_return_code(const void *response);
     86 
     87 /**
     88  * Send a TPM command and return response's return code, and optionally
     89  * return response to caller.
     90  *
     91  * @param command	byte string of TPM command
     92  * @param response	output buffer for TPM response, or NULL if the
     93  *			caller does not care about it
     94  * @param size_ptr	output buffer size (input parameter) and TPM
     95  *			response length (output parameter); this parameter
     96  *			is a bidirectional
     97  * @return return code of the TPM response
     98  */
     99 u32 tpm_sendrecv_command(const void *command, void *response, size_t *size_ptr);
    100 
    101 #endif /* __TPM_UTILS_H */
    102