diff options
Diffstat (limited to 'drivers/tpm/tpm2_tis_core.c')
| -rw-r--r-- | drivers/tpm/tpm2_tis_core.c | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/drivers/tpm/tpm2_tis_core.c b/drivers/tpm/tpm2_tis_core.c new file mode 100644 index 0000000000..ec8c730fe9 --- /dev/null +++ b/drivers/tpm/tpm2_tis_core.c @@ -0,0 +1,463 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020, Linaro Limited + * + * Based on the Linux TIS core interface and U-Boot original SPI TPM driver + */ + +#include <common.h> +#include <dm.h> +#include <tpm-v2.h> +#include <linux/delay.h> +#include <linux/unaligned/be_byteshift.h> +#include "tpm_tis.h" + +int tpm_tis_get_desc(struct udevice *dev, char *buf, int size) +{ + struct tpm_chip *chip = dev_get_priv(dev); + + if (size < 80) + return -ENOSPC; + + return snprintf(buf, size, + "%s v2.0: VendorID 0x%04x, DeviceID 0x%04x, RevisionID 0x%02x [%s]", + dev->name, chip->vend_dev & 0xFFFF, + chip->vend_dev >> 16, chip->rid, + (chip->is_open ? "open" : "closed")); +} + +/** + * tpm_tis_check_locality - Check the current TPM locality + * + * @dev: TPM device + * @loc: locality + * + * Return: True if the tested locality matches + */ +static bool tpm_tis_check_locality(struct udevice *dev, int loc) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + u8 locality; + + phy_ops->read_bytes(dev, TPM_ACCESS(loc), 1, &locality); + if ((locality & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID | + TPM_ACCESS_REQUEST_USE)) == + (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) { + chip->locality = loc; + return true; + } + + return false; +} + +/** + * tpm_tis_request_locality - Request a locality from the TPM + * + * @dev: TPM device + * @loc: requested locality + * + * Return: 0 on success -1 on failure + */ +int tpm_tis_request_locality(struct udevice *dev, int loc) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + u8 buf = TPM_ACCESS_REQUEST_USE; + unsigned long start, stop; + + if (tpm_tis_check_locality(dev, loc)) + return 0; + + phy_ops->write_bytes(dev, TPM_ACCESS(loc), 1, &buf); + start = get_timer(0); + stop = chip->timeout_a; + do { + if (tpm_tis_check_locality(dev, loc)) + return 0; + mdelay(TPM_TIMEOUT_MS); + } while (get_timer(start) < stop); + + return -1; +} + +/** + * tpm_tis_status - Check the current device status + * + * @dev: TPM device + * @status: return value of status + * + * Return: 0 on success, negative on failure + */ +static int tpm_tis_status(struct udevice *dev, u8 *status) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + + if (chip->locality < 0) + return -EINVAL; + + phy_ops->read_bytes(dev, TPM_STS(chip->locality), 1, status); + + if ((*status & TPM_STS_READ_ZERO)) { + log_err("TPM returned invalid status\n"); + return -EINVAL; + } + + return 0; +} + +/** + * tpm_tis_release_locality - Release the requested locality + * + * @dev: TPM device + * @loc: requested locality + * + * Return: 0 on success, negative on failure + */ +int tpm_tis_release_locality(struct udevice *dev, int loc) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + u8 buf = TPM_ACCESS_ACTIVE_LOCALITY; + int ret; + + if (chip->locality < 0) + return 0; + + ret = phy_ops->write_bytes(dev, TPM_ACCESS(loc), 1, &buf); + chip->locality = -1; + + return ret; +} + +/** + * tpm_tis_wait_for_stat - Wait for TPM to become ready + * + * @dev: TPM device + * @mask: mask to match + * @timeout: timeout for retries + * @status: current status + * + * Return: 0 on success, negative on failure + */ +static int tpm_tis_wait_for_stat(struct udevice *dev, u8 mask, + unsigned long timeout, u8 *status) +{ + unsigned long start = get_timer(0); + unsigned long stop = timeout; + int ret; + + do { + mdelay(TPM_TIMEOUT_MS); + ret = tpm_tis_status(dev, status); + if (ret) + return ret; + + if ((*status & mask) == mask) + return 0; + } while (get_timer(start) < stop); + + return -ETIMEDOUT; +} + +/** + * tpm_tis_get_burstcount - Get the burstcount for the data FIFO + * + * @dev: TPM device + * @burstcount: current burstcount + * + * Return: 0 on success, negative on failure + */ +static int tpm_tis_get_burstcount(struct udevice *dev, size_t *burstcount) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + unsigned long start, stop; + u32 burst; + + if (chip->locality < 0) + return -EINVAL; + + /* wait for burstcount */ + start = get_timer(0); + /* + * This is the TPMv2 defined timeout. Change this in case you want to + * make the driver compatile to TPMv1 + */ + stop = chip->timeout_a; + do { + phy_ops->read32(dev, TPM_STS(chip->locality), &burst); + *burstcount = (burst >> 8) & 0xFFFF; + if (*burstcount) + return 0; + + mdelay(TPM_TIMEOUT_MS); + } while (get_timer(start) < stop); + + return -ETIMEDOUT; +} + +/** + * tpm_tis_ready - Cancel pending comands and get the device on a ready state + * + * @dev: TPM device + * + * Return: 0 on success, negative on failure + */ +static int tpm_tis_ready(struct udevice *dev) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + u8 data = TPM_STS_COMMAND_READY; + + /* This will cancel any pending commands */ + return phy_ops->write_bytes(dev, TPM_STS(chip->locality), 1, &data); +} + +int tpm_tis_send(struct udevice *dev, const u8 *buf, size_t len) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + size_t burstcnt, wr_size, sent = 0; + u8 data = TPM_STS_GO; + u8 status; + int ret; + + if (!chip) + return -ENODEV; + + ret = tpm_tis_request_locality(dev, 0); + if (ret < 0) + return -EBUSY; + + ret = tpm_tis_status(dev, &status); + if (ret) + goto release_locality; + + if (!(status & TPM_STS_COMMAND_READY)) { + ret = tpm_tis_ready(dev); + if (ret) { + log_err("Can't cancel previous TPM operation\n"); + goto release_locality; + } + ret = tpm_tis_wait_for_stat(dev, TPM_STS_COMMAND_READY, + chip->timeout_b, &status); + if (ret) { + log_err("TPM not ready\n"); + goto release_locality; + } + } + + while (len > 0) { + ret = tpm_tis_get_burstcount(dev, &burstcnt); + if (ret) + goto release_locality; + + wr_size = min(len, burstcnt); + ret = phy_ops->write_bytes(dev, TPM_DATA_FIFO(chip->locality), + wr_size, buf + sent); + if (ret < 0) + goto release_locality; + + ret = tpm_tis_wait_for_stat(dev, TPM_STS_VALID, + chip->timeout_c, &status); + if (ret) + goto release_locality; + + sent += wr_size; + len -= wr_size; + /* make sure the TPM expects more data */ + if (len && !(status & TPM_STS_DATA_EXPECT)) { + ret = -EIO; + goto release_locality; + } + } + + /* + * Make a final check ensuring everything is ok and the TPM expects no + * more data + */ + ret = tpm_tis_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c, + &status); + if (ret) + goto release_locality; + + if (status & TPM_STS_DATA_EXPECT) { + ret = -EIO; + goto release_locality; + } + + ret = phy_ops->write_bytes(dev, TPM_STS(chip->locality), 1, &data); + if (ret) + goto release_locality; + + return sent; + +release_locality: + tpm_tis_ready(dev); + tpm_tis_release_locality(dev, chip->locality); + + return ret; +} + +static int tpm_tis_recv_data(struct udevice *dev, u8 *buf, size_t count) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + int size = 0, len, ret; + size_t burstcnt; + u8 status; + + while (size < count && + tpm_tis_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID, + chip->timeout_c, &status) == 0) { + ret = tpm_tis_get_burstcount(dev, &burstcnt); + if (ret) + return ret; + + len = min_t(int, burstcnt, count - size); + ret = phy_ops->read_bytes(dev, TPM_DATA_FIFO(chip->locality), + len, buf + size); + if (ret < 0) + return ret; + + size += len; + } + + return size; +} + +/** + * tpm_tis_recv - Receive data from a device + * + * @dev: TPM device + * @buf: buffer to copy data + * @size: buffer size + * + * Return: bytes read or negative on failure + */ +int tpm_tis_recv(struct udevice *dev, u8 *buf, size_t count) +{ + struct tpm_chip *chip = dev_get_priv(dev); + int size, expected; + + if (count < TPM_HEADER_SIZE) + return -E2BIG; + + size = tpm_tis_recv_data(dev, buf, TPM_HEADER_SIZE); + if (size < TPM_HEADER_SIZE) { + log_err("TPM error, unable to read header\n"); + goto out; + } + + expected = get_unaligned_be32(buf + TPM_CMD_COUNT_OFFSET); + if (expected > count) { + size = -EIO; + log_warning("Too much data: %d > %zu\n", expected, count); + goto out; + } + + size += tpm_tis_recv_data(dev, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (size < expected) { + log(LOGC_NONE, LOGL_ERR, + "TPM error, unable to read remaining bytes of result\n"); + size = -EIO; + goto out; + } + +out: + tpm_tis_ready(dev); + /* acquired in tpm_tis_send */ + tpm_tis_release_locality(dev, chip->locality); + + return size; +} + +int tpm_tis_cleanup(struct udevice *dev) +{ + struct tpm_chip *chip = dev_get_priv(dev); + + tpm_tis_ready(dev); + tpm_tis_release_locality(dev, chip->locality); + + return 0; +} + +int tpm_tis_open(struct udevice *dev) +{ + struct tpm_chip *chip = dev_get_priv(dev); + int ret; + + if (chip->is_open) + return -EBUSY; + + ret = tpm_tis_request_locality(dev, 0); + if (!ret) + chip->is_open = 1; + + return ret; +} + +void tpm_tis_ops_register(struct udevice *dev, struct tpm_tis_phy_ops *ops) +{ + struct tpm_chip *chip = dev_get_priv(dev); + + chip->phy_ops = ops; +} + +static bool tis_check_ops(struct tpm_tis_phy_ops *phy_ops) +{ + if (!phy_ops || !phy_ops->read_bytes || !phy_ops->write_bytes || + !phy_ops->read32 || !phy_ops->write32) + return false; + + return true; +} + +int tpm_tis_init(struct udevice *dev) +{ + struct tpm_chip *chip = dev_get_priv(dev); + struct tpm_tis_phy_ops *phy_ops = chip->phy_ops; + int ret; + u32 tmp; + + if (!tis_check_ops(phy_ops)) { + log_err("Driver bug. No bus ops defined\n"); + return -1; + } + ret = tpm_tis_request_locality(dev, 0); + if (ret) + return ret; + + 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; + + /* Disable interrupts */ + phy_ops->read32(dev, TPM_INT_ENABLE(chip->locality), &tmp); + tmp |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT | + TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT; + tmp &= ~TPM_GLOBAL_INT_ENABLE; + phy_ops->write32(dev, TPM_INT_ENABLE(chip->locality), tmp); + + phy_ops->read_bytes(dev, TPM_RID(chip->locality), 1, &chip->rid); + phy_ops->read32(dev, TPM_DID_VID(chip->locality), &chip->vend_dev); + + return tpm_tis_release_locality(dev, chip->locality); +} + +int tpm_tis_close(struct udevice *dev) +{ + struct tpm_chip *chip = dev_get_priv(dev); + int ret = 0; + + if (chip->is_open) { + ret = tpm_tis_release_locality(dev, chip->locality); + chip->is_open = 0; + } + + return ret; +} |