1 /* 2 * Copyright (c) 2015 Google, Inc 3 * Written by Simon Glass <sjg@chromium.org> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <dm.h> 10 #include <tpm.h> 11 #include <linux/unaligned/be_byteshift.h> 12 #include "tpm_internal.h" 13 14 int tpm_open(struct udevice *dev) 15 { 16 struct tpm_ops *ops = tpm_get_ops(dev); 17 18 if (!ops->open) 19 return -ENOSYS; 20 21 return ops->open(dev); 22 } 23 24 int tpm_close(struct udevice *dev) 25 { 26 struct tpm_ops *ops = tpm_get_ops(dev); 27 28 if (!ops->close) 29 return -ENOSYS; 30 31 return ops->close(dev); 32 } 33 34 int tpm_get_desc(struct udevice *dev, char *buf, int size) 35 { 36 struct tpm_ops *ops = tpm_get_ops(dev); 37 38 if (!ops->get_desc) 39 return -ENOSYS; 40 41 return ops->get_desc(dev, buf, size); 42 } 43 44 /* Returns max number of milliseconds to wait */ 45 static ulong tpm_tis_i2c_calc_ordinal_duration(struct tpm_chip_priv *priv, 46 u32 ordinal) 47 { 48 int duration_idx = TPM_UNDEFINED; 49 int duration = 0; 50 51 if (ordinal < TPM_MAX_ORDINAL) { 52 duration_idx = tpm_ordinal_duration[ordinal]; 53 } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) < 54 TPM_MAX_PROTECTED_ORDINAL) { 55 duration_idx = tpm_protected_ordinal_duration[ 56 ordinal & TPM_PROTECTED_ORDINAL_MASK]; 57 } 58 59 if (duration_idx != TPM_UNDEFINED) 60 duration = priv->duration_ms[duration_idx]; 61 62 if (duration <= 0) 63 return 2 * 60 * 1000; /* Two minutes timeout */ 64 else 65 return duration; 66 } 67 68 int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size, 69 uint8_t *recvbuf, size_t *recv_size) 70 { 71 struct tpm_chip_priv *priv = dev_get_uclass_priv(dev); 72 struct tpm_ops *ops = tpm_get_ops(dev); 73 ulong start, stop; 74 uint count, ordinal; 75 int ret, ret2; 76 77 if (ops->xfer) 78 return ops->xfer(dev, sendbuf, send_size, recvbuf, recv_size); 79 80 if (!ops->send || !ops->recv) 81 return -ENOSYS; 82 83 /* switch endianess: big->little */ 84 count = get_unaligned_be32(sendbuf + TPM_CMD_COUNT_BYTE); 85 ordinal = get_unaligned_be32(sendbuf + TPM_CMD_ORDINAL_BYTE); 86 87 if (count == 0) { 88 debug("no data\n"); 89 return -ENODATA; 90 } 91 if (count > send_size) { 92 debug("invalid count value %x %zx\n", count, send_size); 93 return -E2BIG; 94 } 95 96 debug("%s: Calling send\n", __func__); 97 ret = ops->send(dev, sendbuf, send_size); 98 if (ret < 0) 99 return ret; 100 101 start = get_timer(0); 102 stop = tpm_tis_i2c_calc_ordinal_duration(priv, ordinal); 103 do { 104 ret = ops->recv(dev, priv->buf, sizeof(priv->buf)); 105 if (ret >= 0) { 106 if (ret > *recv_size) 107 return -ENOSPC; 108 memcpy(recvbuf, priv->buf, ret); 109 *recv_size = ret; 110 ret = 0; 111 break; 112 } else if (ret != -EAGAIN) { 113 return ret; 114 } 115 116 mdelay(priv->retry_time_ms); 117 if (get_timer(start) > stop) { 118 ret = -ETIMEDOUT; 119 break; 120 } 121 } while (ret); 122 123 ret2 = ops->cleanup ? ops->cleanup(dev) : 0; 124 125 return ret2 ? ret2 : ret; 126 } 127 128 UCLASS_DRIVER(tpm) = { 129 .id = UCLASS_TPM, 130 .name = "tpm", 131 .flags = DM_UC_FLAG_SEQ_ALIAS, 132 .per_device_auto_alloc_size = sizeof(struct tpm_chip_priv), 133 }; 134