/* * STMicroelectronics TPM ST33ZP24 SPI UBOOT driver * * Copyright (C) 2016 STMicroelectronics * * Description: Device driver for ST33ZP24 SPI TPM TCG. * * This device driver implements the TPM interface as defined in * the TCG TPM Interface Spec version 1.21, revision 1.0 and the * STMicroelectronics Protocol Stack Specification version 1.2.0. * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #include #include #include #include #include #include "tpm_tis.h" #include "tpm_internal.h" #define TPM_ACCESS 0x0 #define TPM_STS 0x18 #define TPM_DATA_FIFO 0x24 #define LOCALITY0 0 #define TPM_DATA_FIFO 0x24 #define TPM_INTF_CAPABILITY 0x14 #define TPM_DUMMY_BYTE 0x00 #define TPM_WRITE_DIRECTION 0x80 #define MAX_SPI_LATENCY 15 #define LOCALITY0 0 #define ST33ZP24_OK 0x5A #define ST33ZP24_UNDEFINED_ERR 0x80 #define ST33ZP24_BADLOCALITY 0x81 #define ST33ZP24_TISREGISTER_UKNOWN 0x82 #define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83 #define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84 #define ST33ZP24_BAD_COMMAND_ORDER 0x85 #define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86 #define ST33ZP24_TPM_FIFO_OVERFLOW 0x89 #define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A #define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B #define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90 #define ST33ZP24_DUMMY_BYTES 0x00 /* * TPM command can be up to 2048 byte, A TPM response can be up to * 1024 byte. * Between command and response, there are latency byte (up to 15 * usually on st33zp24 2 are enough). * * Overall when sending a command and expecting an answer we need if * worst case: * 2048 (for the TPM command) + 1024 (for the TPM answer). We need * some latency byte before the answer is available (max 15). * We have 2048 + 1024 + 15. */ #define ST33ZP24_SPI_BUFFER_SIZE (TPM_BUFSIZE + (TPM_BUFSIZE / 2) +\ MAX_SPI_LATENCY) struct st33zp24_spi_phy { int latency; u8 tx_buf[ST33ZP24_SPI_BUFFER_SIZE]; u8 rx_buf[ST33ZP24_SPI_BUFFER_SIZE]; }; static int st33zp24_spi_status_to_errno(u8 code) { switch (code) { case ST33ZP24_OK: return 0; case ST33ZP24_UNDEFINED_ERR: case ST33ZP24_BADLOCALITY: case ST33ZP24_TISREGISTER_UKNOWN: case ST33ZP24_LOCALITY_NOT_ACTIVATED: case ST33ZP24_HASH_END_BEFORE_HASH_START: case ST33ZP24_BAD_COMMAND_ORDER: case ST33ZP24_UNEXPECTED_READ_FIFO: case ST33ZP24_UNEXPECTED_WRITE_FIFO: case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END: return -EPROTO; case ST33ZP24_INCORECT_RECEIVED_LENGTH: case ST33ZP24_TPM_FIFO_OVERFLOW: return -EMSGSIZE; case ST33ZP24_DUMMY_BYTES: return -ENOSYS; } return code; } /* * st33zp24_spi_send * Send byte to TPM register according to the ST33ZP24 SPI protocol. * @param: tpm, the chip description * @param: tpm_register, the tpm tis register where the data should be written * @param: tpm_data, the tpm_data to write inside the tpm_register * @param: tpm_size, The length of the data * @return: should be zero if success else a negative error code. */ static int st33zp24_spi_write(struct udevice *dev, u8 tpm_register, const u8 *tpm_data, size_t tpm_size) { int total_length = 0, ret; struct spi_slave *slave = dev_get_parent_priv(dev); struct st33zp24_spi_phy *phy = dev_get_platdata(dev); u8 *tx_buf = (u8 *)phy->tx_buf; u8 *rx_buf = phy->rx_buf; tx_buf[total_length++] = TPM_WRITE_DIRECTION | LOCALITY0; tx_buf[total_length++] = tpm_register; if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) { tx_buf[total_length++] = tpm_size >> 8; tx_buf[total_length++] = tpm_size; } memcpy(tx_buf + total_length, tpm_data, tpm_size); total_length += tpm_size; memset(tx_buf + total_length, TPM_DUMMY_BYTE, phy->latency); total_length += phy->latency; ret = spi_claim_bus(slave); if (ret < 0) return ret; ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf, SPI_XFER_BEGIN | SPI_XFER_END); if (ret < 0) return ret; spi_release_bus(slave); if (ret == 0) ret = rx_buf[total_length - 1]; return st33zp24_spi_status_to_errno(ret); } /* * spi_st33zp24_spi_read8_reg * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. * @param: tpm, the chip description * @param: tpm_loc, the locality to read register from * @param: tpm_register, the tpm tis register where the data should be read * @param: tpm_data, the TPM response * @param: tpm_size, tpm TPM response size to read. * @return: should be zero if success else a negative error code. */ static u8 st33zp24_spi_read8_reg(struct udevice *dev, u8 tpm_register, u8 *tpm_data, size_t tpm_size) { int total_length = 0, ret; struct spi_slave *slave = dev_get_parent_priv(dev); struct st33zp24_spi_phy *phy = dev_get_platdata(dev); u8 *tx_buf = (u8 *)phy->tx_buf; u8 *rx_buf = phy->rx_buf; /* Pre-Header */ tx_buf[total_length++] = LOCALITY0; tx_buf[total_length++] = tpm_register; memset(&tx_buf[total_length], TPM_DUMMY_BYTE, phy->latency + tpm_size); total_length += phy->latency + tpm_size; ret = spi_claim_bus(slave); if (ret < 0) return 0; ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf, SPI_XFER_BEGIN | SPI_XFER_END); if (ret < 0) return 0; spi_release_bus(slave); if (tpm_size > 0 && ret == 0) { ret = rx_buf[total_length - tpm_size - 1]; memcpy(tpm_data, rx_buf + total_length - tpm_size, tpm_size); } return ret; } /* * st33zp24_spi_recv * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. * @param: phy_id, the phy description * @param: tpm_register, the tpm tis register where the data should be read * @param: tpm_data, the TPM response * @param: tpm_size, tpm TPM response size to read. * @return: number of byte read successfully: should be one if success. */ static int st33zp24_spi_read(struct udevice *dev, u8 tpm_register, u8 *tpm_data, size_t tpm_size) { int ret; ret = st33zp24_spi_read8_reg(dev, tpm_register, tpm_data, tpm_size); if (!st33zp24_spi_status_to_errno(ret)) return tpm_size; return ret; } static int st33zp24_spi_evaluate_latency(struct udevice *dev) { int latency = 1, status = 0; u8 data = 0; struct st33zp24_spi_phy *phy = dev_get_platdata(dev); while (!status && latency < MAX_SPI_LATENCY) { phy->latency = latency; status = st33zp24_spi_read8_reg(dev, TPM_INTF_CAPABILITY, &data, 1); latency++; } if (status < 0) return status; if (latency == MAX_SPI_LATENCY) return -ENODEV; return latency - 1; } /* * st33zp24_spi_release_locality release the active locality * @param: chip, the tpm chip description. */ static void st33zp24_spi_release_locality(struct udevice *dev) { u8 data = TPM_ACCESS_ACTIVE_LOCALITY; st33zp24_spi_write(dev, TPM_ACCESS, &data, 1); } /* * st33zp24_spi_check_locality if the locality is active * @param: chip, the tpm chip description * @return: the active locality or -EACCES. */ static int st33zp24_spi_check_locality(struct udevice *dev) { u8 data; u8 status; struct tpm_chip *chip = dev_get_priv(dev); status = st33zp24_spi_read(dev, TPM_ACCESS, &data, 1); if (status && (data & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) return chip->locality; return -EACCES; } /* * st33zp24_spi_request_locality request the TPM locality * @param: chip, the chip description * @return: the active locality or negative value. */ static int st33zp24_spi_request_locality(struct udevice *dev) { unsigned long start, stop; long ret; u8 data; struct tpm_chip *chip = dev_get_priv(dev); if (st33zp24_spi_check_locality(dev) == chip->locality) return chip->locality; data = TPM_ACCESS_REQUEST_USE; ret = st33zp24_spi_write(dev, TPM_ACCESS, &data, 1); if (ret < 0) return ret; /* wait for locality activated */ start = get_timer(0); stop = chip->timeout_a; do { if (st33zp24_spi_check_locality(dev) >= 0) return chip->locality; udelay(TPM_TIMEOUT_MS * 1000); } while (get_timer(start) < stop); return -EACCES; } /* * st33zp24_spi_status return the TPM_STS register * @param: chip, the tpm chip description * @return: the TPM_STS register value. */ static u8 st33zp24_spi_status(struct udevice *dev) { u8 data; st33zp24_spi_read(dev, TPM_STS, &data, 1); return data; } /* * st33zp24_spi_get_burstcount return the burstcount address 0x19 0x1A * @param: chip, the chip description * return: the burstcount or -TPM_DRIVER_ERR in case of error. */ static int st33zp24_spi_get_burstcount(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); unsigned long start, stop; int burstcnt, status; u8 tpm_reg, temp; /* wait for burstcount */ start = get_timer(0); stop = chip->timeout_d; do { tpm_reg = TPM_STS + 1; status = st33zp24_spi_read(dev, tpm_reg, &temp, 1); if (status < 0) return -EBUSY; tpm_reg = TPM_STS + 2; burstcnt = temp; status = st33zp24_spi_read(dev, tpm_reg, &temp, 1); if (status < 0) return -EBUSY; burstcnt |= temp << 8; if (burstcnt) return burstcnt; udelay(TIS_SHORT_TIMEOUT_MS * 1000); } while (get_timer(start) < stop); return -EBUSY; } /* * st33zp24_spi_cancel, cancel the current command execution or * set STS to COMMAND READY. * @param: chip, tpm_chip description. */ static void st33zp24_spi_cancel(struct udevice *dev) { u8 data; data = TPM_STS_COMMAND_READY; st33zp24_spi_write(dev, TPM_STS, &data, 1); } /* * st33zp24_spi_wait_for_stat wait for a TPM_STS value * @param: chip, the tpm chip description * @param: mask, the value mask to wait * @param: timeout, the timeout * @param: status, * @return: the tpm status, 0 if success, -ETIME if timeout is reached. */ static int st33zp24_spi_wait_for_stat(struct udevice *dev, u8 mask, unsigned long timeout, int *status) { unsigned long start, stop; /* Check current status */ *status = st33zp24_spi_status(dev); if ((*status & mask) == mask) return 0; start = get_timer(0); stop = timeout; do { udelay(TPM_TIMEOUT_MS * 1000); *status = st33zp24_spi_status(dev); if ((*status & mask) == mask) return 0; } while (get_timer(start) < stop); return -ETIME; } /* * st33zp24_spi_recv_data receive data * @param: chip, the tpm chip description * @param: buf, the buffer where the data are received * @param: count, the number of data to receive * @return: the number of bytes read from TPM FIFO. */ static int st33zp24_spi_recv_data(struct udevice *dev, u8 *buf, size_t count) { struct tpm_chip *chip = dev_get_priv(dev); int size = 0, burstcnt, len, ret, status; while (size < count && st33zp24_spi_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID, chip->timeout_c, &status) == 0) { burstcnt = st33zp24_spi_get_burstcount(dev); if (burstcnt < 0) return burstcnt; len = min_t(int, burstcnt, count - size); ret = st33zp24_spi_read(dev, TPM_DATA_FIFO, buf + size, len); if (ret < 0) return ret; size += len; } return size; } /* * st33zp24_spi_recv received TPM response through TPM phy. * @param: chip, tpm_chip description. * @param: buf, the buffer to store data. * @param: count, the number of bytes that can received (sizeof buf). * @return: Returns zero in case of success else -EIO. */ static int st33zp24_spi_recv(struct udevice *dev, u8 *buf, size_t count) { struct tpm_chip *chip = dev_get_priv(dev); int size, expected; if (!chip) return -ENODEV; if (count < TPM_HEADER_SIZE) { size = -EIO; goto out; } size = st33zp24_spi_recv_data(dev, buf, TPM_HEADER_SIZE); if (size < TPM_HEADER_SIZE) { debug("TPM error, unable to read header\n"); goto out; } expected = get_unaligned_be32(buf + 2); if (expected > count) { size = -EIO; goto out; } size += st33zp24_spi_recv_data(dev, &buf[TPM_HEADER_SIZE], expected - TPM_HEADER_SIZE); if (size < expected) { debug("TPM error, unable to read remaining bytes of result\n"); size = -EIO; goto out; } out: st33zp24_spi_cancel(dev); st33zp24_spi_release_locality(dev); return size; } /* * st33zp24_spi_send send TPM commands through TPM phy. * @param: chip, tpm_chip description. * @param: buf, the buffer to send. * @param: len, the number of bytes to send. * @return: Returns zero in case of success else the negative error code. */ static int st33zp24_spi_send(struct udevice *dev, const u8 *buf, size_t len) { struct tpm_chip *chip = dev_get_priv(dev); u32 i, size; int burstcnt, ret, status; u8 data, tpm_stat; if (!chip) return -ENODEV; if (len < TPM_HEADER_SIZE) return -EIO; ret = st33zp24_spi_request_locality(dev); if (ret < 0) return ret; tpm_stat = st33zp24_spi_status(dev); if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) { st33zp24_spi_cancel(dev); if (st33zp24_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY, chip->timeout_b, &status) < 0) { ret = -ETIME; goto out_err; } } for (i = 0; i < len - 1;) { burstcnt = st33zp24_spi_get_burstcount(dev); if (burstcnt < 0) return burstcnt; size = min_t(int, len - i - 1, burstcnt); ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + i, size); if (ret < 0) goto out_err; i += size; } tpm_stat = st33zp24_spi_status(dev); if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) { ret = -EIO; goto out_err; } ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + len - 1, 1); if (ret < 0) goto out_err; tpm_stat = st33zp24_spi_status(dev); if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) { ret = -EIO; goto out_err; } data = TPM_STS_GO; ret = st33zp24_spi_write(dev, TPM_STS, &data, 1); if (ret < 0) goto out_err; return len; out_err: st33zp24_spi_cancel(dev); st33zp24_spi_release_locality(dev); return ret; } static int st33zp24_spi_cleanup(struct udevice *dev) { st33zp24_spi_cancel(dev); /* * The TPM needs some time to clean up here, * so we sleep rather than keeping the bus busy */ mdelay(2); st33zp24_spi_release_locality(dev); return 0; } static int st33zp24_spi_init(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); struct st33zp24_spi_phy *phy = dev_get_platdata(dev); chip->is_open = 1; /* Default timeouts - these could move to the device tree */ chip->timeout_a = TIS_SHORT_TIMEOUT_MS; chip->timeout_b = TIS_LONG_TIMEOUT_MS; chip->timeout_c = TIS_SHORT_TIMEOUT_MS; chip->timeout_d = TIS_SHORT_TIMEOUT_MS; chip->locality = LOCALITY0; phy->latency = st33zp24_spi_evaluate_latency(dev); if (phy->latency <= 0) return -ENODEV; /* * A timeout query to TPM can be placed here. * Standard timeout values are used so far */ return 0; } static int st33zp24_spi_open(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); int rc; debug("%s: start\n", __func__); if (chip->is_open) return -EBUSY; rc = st33zp24_spi_init(dev); if (rc < 0) chip->is_open = 0; return rc; } static int st33zp24_spi_close(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); if (chip->is_open) { st33zp24_spi_release_locality(dev); chip->is_open = 0; chip->vend_dev = 0; } return 0; } static int st33zp24_spi_get_desc(struct udevice *dev, char *buf, int size) { struct tpm_chip *chip = dev_get_priv(dev); if (size < 50) return -ENOSPC; return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)", chip->is_open ? "open" : "closed", dev->name, chip->vend_dev >> 16); } const struct tpm_ops st33zp24_spi_tpm_ops = { .open = st33zp24_spi_open, .close = st33zp24_spi_close, .recv = st33zp24_spi_recv, .send = st33zp24_spi_send, .cleanup = st33zp24_spi_cleanup, .get_desc = st33zp24_spi_get_desc, }; static int st33zp24_spi_probe(struct udevice *dev) { struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev); uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS; uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS; uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS; uc_priv->retry_time_ms = TPM_TIMEOUT_MS; debug("ST33ZP24 SPI TPM from STMicroelectronics found\n"); return 0; } static int st33zp24_spi_remove(struct udevice *dev) { st33zp24_spi_release_locality(dev); return 0; } static const struct udevice_id st33zp24_spi_ids[] = { { .compatible = "st,st33zp24-spi" }, { } }; U_BOOT_DRIVER(st33zp24_spi_spi) = { .name = "st33zp24-spi", .id = UCLASS_TPM, .of_match = of_match_ptr(st33zp24_spi_ids), .probe = st33zp24_spi_probe, .remove = st33zp24_spi_remove, .ops = &st33zp24_spi_tpm_ops, .priv_auto_alloc_size = sizeof(struct tpm_chip), .platdata_auto_alloc_size = sizeof(struct st33zp24_spi_phy), };