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