1 /* 2 * Copyright (C) 2013 Guntermann & Drunck, GmbH 3 * 4 * Written by Dirk Eibach <dirk.eibach@gdsys.cc> 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <common.h> 10 #include <dm.h> 11 #include <tpm.h> 12 #include <i2c.h> 13 #include <asm/unaligned.h> 14 15 #include "tpm_internal.h" 16 17 #define ATMEL_TPM_TIMEOUT_MS 5000 /* sufficient for anything but 18 generating/exporting keys */ 19 20 /* 21 * tpm_atmel_twi_open() 22 * 23 * Requests access to locality 0 for the caller. After all commands have been 24 * completed the caller is supposed to call tis_close(). 25 * 26 * Returns 0 on success, -1 on failure. 27 */ 28 static int tpm_atmel_twi_open(struct udevice *dev) 29 { 30 return 0; 31 } 32 33 /* 34 * tpm_atmel_twi_close() 35 * 36 * terminate the currect session with the TPM by releasing the locked 37 * locality. Returns 0 on success of -1 on failure (in case lock 38 * removal did not succeed). 39 */ 40 static int tpm_atmel_twi_close(struct udevice *dev) 41 { 42 return 0; 43 } 44 45 /* 46 * tpm_atmel_twi_get_desc() 47 * 48 * @dev: Device to check 49 * @buf: Buffer to put the string 50 * @size: Maximum size of buffer 51 * @return length of string, or -ENOSPC it no space 52 */ 53 static int tpm_atmel_twi_get_desc(struct udevice *dev, char *buf, int size) 54 { 55 return 0; 56 } 57 58 /* 59 * tpm_atmel_twi_xfer() 60 * 61 * Send the requested data to the TPM and then try to get its response 62 * 63 * @sendbuf - buffer of the data to send 64 * @send_size size of the data to send 65 * @recvbuf - memory to save the response to 66 * @recv_len - pointer to the size of the response buffer 67 * 68 * Returns 0 on success (and places the number of response bytes at recv_len) 69 * or -1 on failure. 70 */ 71 static int tpm_atmel_twi_xfer(struct udevice *dev, 72 const uint8_t *sendbuf, size_t send_size, 73 uint8_t *recvbuf, size_t *recv_len) 74 { 75 int res; 76 unsigned long start; 77 78 #ifdef DEBUG 79 memset(recvbuf, 0xcc, *recv_len); 80 printf("send to TPM (%d bytes, recv_len=%d):\n", send_size, *recv_len); 81 print_buffer(0, (void *)sendbuf, 1, send_size, 0); 82 #endif 83 84 #ifndef CONFIG_DM_I2C 85 res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size); 86 #else 87 res = dm_i2c_write(dev, 0, sendbuf, send_size); 88 #endif 89 if (res) { 90 printf("i2c_write returned %d\n", res); 91 return -1; 92 } 93 94 start = get_timer(0); 95 #ifndef CONFIG_DM_I2C 96 while ((res = i2c_read(0x29, 0, 0, recvbuf, 10))) 97 #else 98 while ((res = dm_i2c_read(dev, 0, recvbuf, 10))) 99 #endif 100 { 101 /* TODO Use TIS_TIMEOUT from tpm_tis_infineon.h */ 102 if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) { 103 puts("tpm timed out\n"); 104 return -1; 105 } 106 udelay(100); 107 } 108 if (!res) { 109 unsigned int hdr_recv_len; 110 hdr_recv_len = get_unaligned_be32(recvbuf + 2); 111 if (hdr_recv_len < 10) { 112 puts("tpm response header too small\n"); 113 return -1; 114 } else if (hdr_recv_len > *recv_len) { 115 puts("tpm response length is bigger than receive buffer\n"); 116 return -1; 117 } else { 118 *recv_len = hdr_recv_len; 119 #ifndef CONFIG_DM_I2C 120 res = i2c_read(0x29, 0, 0, recvbuf, *recv_len); 121 #else 122 res = dm_i2c_read(dev, 0, recvbuf, *recv_len); 123 #endif 124 125 } 126 } 127 if (res) { 128 printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len); 129 #ifdef DEBUG 130 print_buffer(0, recvbuf, 1, *recv_len, 0); 131 #endif 132 } 133 134 #ifdef DEBUG 135 if (!res) { 136 printf("read from TPM (%d bytes):\n", *recv_len); 137 print_buffer(0, recvbuf, 1, *recv_len, 0); 138 } 139 #endif 140 141 return res; 142 } 143 144 static int tpm_atmel_twi_probe(struct udevice *dev) 145 { 146 return 0; 147 } 148 149 static const struct udevice_id tpm_atmel_twi_ids[] = { 150 { .compatible = "atmel,at97sc3204t"}, 151 { } 152 }; 153 154 static const struct tpm_ops tpm_atmel_twi_ops = { 155 .open = tpm_atmel_twi_open, 156 .close = tpm_atmel_twi_close, 157 .xfer = tpm_atmel_twi_xfer, 158 .get_desc = tpm_atmel_twi_get_desc, 159 }; 160 161 U_BOOT_DRIVER(tpm_atmel_twi) = { 162 .name = "tpm_atmel_twi", 163 .id = UCLASS_TPM, 164 .of_match = tpm_atmel_twi_ids, 165 .ops = &tpm_atmel_twi_ops, 166 .probe = tpm_atmel_twi_probe, 167 }; 168