/* * Copyright (C) 2011 Infineon Technologies * * Authors: * Peter Huewe * * Description: * Device driver for TCG/TCPA TPM (trusted platform module). * Specifications at www.trustedcomputinggroup.org * * This device driver implements the TPM interface as defined in * the TCG TPM Interface Spec version 1.2, revision 1.0 and the * Infineon I2C Protocol Stack Specification v0.20. * * It is based on the Linux kernel driver tpm.c from Leendert van * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall. * * Version: 2.1.1 * * SPDX-License-Identifier: GPL-2.0 */ #include #include #include #include #include #include #include #include #include #include "tpm_tis.h" #include "tpm_internal.h" DECLARE_GLOBAL_DATA_PTR; enum i2c_chip_type { SLB9635, SLB9645, UNKNOWN, }; /* expected value for DIDVID register */ #define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L #define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L static const char * const chip_name[] = { [SLB9635] = "slb9635tt", [SLB9645] = "slb9645tt", [UNKNOWN] = "unknown/fallback to slb9635", }; #define TPM_ACCESS(l) (0x0000 | ((l) << 4)) #define TPM_STS(l) (0x0001 | ((l) << 4)) #define TPM_DATA_FIFO(l) (0x0005 | ((l) << 4)) #define TPM_DID_VID(l) (0x0006 | ((l) << 4)) /* * tpm_tis_i2c_read() - read from TPM register * @addr: register address to read from * @buffer: provided by caller * @len: number of bytes to read * * Read len bytes from TPM register and put them into * buffer (little-endian format, i.e. first byte is put into buffer[0]). * * NOTE: TPM is big-endian for multi-byte values. Multi-byte * values have to be swapped. * * Return -EIO on error, 0 on success. */ static int tpm_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer, size_t len) { struct tpm_chip *chip = dev_get_priv(dev); int rc; int count; uint32_t addrbuf = addr; if ((chip->chip_type == SLB9635) || (chip->chip_type == UNKNOWN)) { /* slb9635 protocol should work in both cases */ for (count = 0; count < MAX_COUNT; count++) { rc = dm_i2c_write(dev, 0, (uchar *)&addrbuf, 1); if (rc == 0) break; /* Success, break to skip sleep */ udelay(SLEEP_DURATION_US); } if (rc) return rc; /* After the TPM has successfully received the register address * it needs some time, thus we're sleeping here again, before * retrieving the data */ for (count = 0; count < MAX_COUNT; count++) { udelay(SLEEP_DURATION_US); rc = dm_i2c_read(dev, 0, buffer, len); if (rc == 0) break; /* success, break to skip sleep */ } } else { /* * Use a combined read for newer chips. * Unfortunately the smbus functions are not suitable due to * the 32 byte limit of the smbus. * Retries should usually not be needed, but are kept just to * be safe on the safe side. */ for (count = 0; count < MAX_COUNT; count++) { rc = dm_i2c_read(dev, addr, buffer, len); if (rc == 0) break; /* break here to skip sleep */ udelay(SLEEP_DURATION_US); } } /* Take care of 'guard time' */ udelay(SLEEP_DURATION_US); if (rc) return rc; return 0; } static int tpm_tis_i2c_write_generic(struct udevice *dev, u8 addr, const u8 *buffer, size_t len, unsigned int sleep_time_us, u8 max_count) { struct tpm_chip_priv *priv = dev_get_uclass_priv(dev); struct tpm_chip *chip = dev_get_priv(dev); int rc = 0; int count; if (chip->chip_type == SLB9635) { /* Prepare send buffer to include the address */ priv->buf[0] = addr; memcpy(&(priv->buf[1]), buffer, len); buffer = priv->buf; len++; addr = 0; } for (count = 0; count < max_count; count++) { rc = dm_i2c_write(dev, addr, buffer, len); if (rc == 0) break; /* Success, break to skip sleep */ udelay(sleep_time_us); } /* take care of 'guard time' */ udelay(sleep_time_us); if (rc) return rc; return 0; } /* * tpm_tis_i2c_write() - write to TPM register * @addr: register address to write to * @buffer: containing data to be written * @len: number of bytes to write * * Write len bytes from provided buffer to TPM register (little * endian format, i.e. buffer[0] is written as first byte). * * NOTE: TPM is big-endian for multi-byte values. Multi-byte * values have to be swapped. * * NOTE: use this function instead of the tpm_tis_i2c_write_generic function. * * Return -EIO on error, 0 on success */ static int tpm_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer, size_t len) { return tpm_tis_i2c_write_generic(dev, addr, buffer, len, SLEEP_DURATION_US, MAX_COUNT); } /* * This function is needed especially for the cleanup situation after * sending TPM_READY */ static int tpm_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer, size_t len) { return tpm_tis_i2c_write_generic(dev, addr, buffer, len, SLEEP_DURATION_LONG_US, MAX_COUNT_LONG); } static int tpm_tis_i2c_check_locality(struct udevice *dev, int loc) { const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID; struct tpm_chip *chip = dev_get_priv(dev); u8 buf; int rc; rc = tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1); if (rc < 0) return rc; if ((buf & mask) == mask) { chip->locality = loc; return loc; } return -ENOENT; } static void tpm_tis_i2c_release_locality(struct udevice *dev, int loc, int force) { const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID; u8 buf; if (tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1) < 0) return; if (force || (buf & mask) == mask) { buf = TPM_ACCESS_ACTIVE_LOCALITY; tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1); } } static int tpm_tis_i2c_request_locality(struct udevice *dev, int loc) { struct tpm_chip *chip = dev_get_priv(dev); unsigned long start, stop; u8 buf = TPM_ACCESS_REQUEST_USE; int rc; rc = tpm_tis_i2c_check_locality(dev, loc); if (rc >= 0) { debug("%s: Already have locality\n", __func__); return loc; /* We already have the locality */ } else if (rc != -ENOENT) { debug("%s: Failed to get locality: %d\n", __func__, rc); return rc; } rc = tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1); if (rc) { debug("%s: Failed to write to TPM: %d\n", __func__, rc); return rc; } /* Wait for burstcount */ start = get_timer(0); stop = chip->timeout_a; do { rc = tpm_tis_i2c_check_locality(dev, loc); if (rc >= 0) { debug("%s: Have locality\n", __func__); return loc; } else if (rc != -ENOENT) { debug("%s: Failed to get locality: %d\n", __func__, rc); return rc; } mdelay(TPM_TIMEOUT_MS); } while (get_timer(start) < stop); debug("%s: Timeout getting locality: %d\n", __func__, rc); return rc; } static u8 tpm_tis_i2c_status(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */ u8 buf; if (tpm_tis_i2c_read(dev, TPM_STS(chip->locality), &buf, 1) < 0) return 0; else return buf; } static int tpm_tis_i2c_ready(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); int rc; /* This causes the current command to be aborted */ u8 buf = TPM_STS_COMMAND_READY; debug("%s\n", __func__); rc = tpm_tis_i2c_write_long(dev, TPM_STS(chip->locality), &buf, 1); if (rc) debug("%s: rc=%d\n", __func__, rc); return rc; } static ssize_t tpm_tis_i2c_get_burstcount(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); unsigned long start, stop; ssize_t burstcnt; u8 addr, buf[3]; /* Wait for burstcount */ /* XXX: Which timeout value? Spec has 2 answers (c & d) */ start = get_timer(0); stop = chip->timeout_d; do { /* Note: STS is little endian */ addr = TPM_STS(chip->locality) + 1; if (tpm_tis_i2c_read(dev, addr, buf, 3) < 0) burstcnt = 0; else burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0]; if (burstcnt) return burstcnt; mdelay(TPM_TIMEOUT_MS); } while (get_timer(start) < stop); return -EBUSY; } static int tpm_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask, unsigned long timeout, int *status) { unsigned long start, stop; /* Check current status */ *status = tpm_tis_i2c_status(dev); if ((*status & mask) == mask) return 0; start = get_timer(0); stop = timeout; do { mdelay(TPM_TIMEOUT_MS); *status = tpm_tis_i2c_status(dev); if ((*status & mask) == mask) return 0; } while (get_timer(start) < stop); return -ETIMEDOUT; } static int tpm_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count) { struct tpm_chip *chip = dev_get_priv(dev); size_t size = 0; ssize_t burstcnt; int rc; while (size < count) { burstcnt = tpm_tis_i2c_get_burstcount(dev); /* burstcount < 0 -> tpm is busy */ if (burstcnt < 0) return burstcnt; /* Limit received data to max left */ if (burstcnt > (count - size)) burstcnt = count - size; rc = tpm_tis_i2c_read(dev, TPM_DATA_FIFO(chip->locality), &(buf[size]), burstcnt); if (rc == 0) size += burstcnt; } return size; } static int tpm_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count) { struct tpm_chip *chip = dev_get_priv(dev); int size = 0; int expected, status; int rc; status = tpm_tis_i2c_status(dev); if (status == TPM_STS_COMMAND_READY) return -EINTR; if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) != (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) return -EAGAIN; debug("...got it;\n"); /* Read first 10 bytes, including tag, paramsize, and result */ size = tpm_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE); if (size < TPM_HEADER_SIZE) { debug("Unable to read header\n"); return size < 0 ? size : -EIO; } expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE); if ((size_t)expected > count) { debug("Error size=%x, expected=%x, count=%x\n", size, expected, count); return -ENOSPC; } size += tpm_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE], expected - TPM_HEADER_SIZE); if (size < expected) { debug("Unable to read remainder of result\n"); return -ETIMEDOUT; } rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c, &status); if (rc) return rc; if (status & TPM_STS_DATA_AVAIL) { /* Retry? */ debug("Error left over data\n"); return -EIO; } return size; } static int tpm_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len) { struct tpm_chip *chip = dev_get_priv(dev); int rc, status; size_t burstcnt; size_t count = 0; int retry = 0; u8 sts = TPM_STS_GO; debug("%s: len=%d\n", __func__, len); if (len > TPM_DEV_BUFSIZE) return -E2BIG; /* Command is too long for our tpm, sorry */ if (tpm_tis_i2c_request_locality(dev, 0) < 0) return -EBUSY; status = tpm_tis_i2c_status(dev); if ((status & TPM_STS_COMMAND_READY) == 0) { rc = tpm_tis_i2c_ready(dev); if (rc) return rc; rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY, chip->timeout_b, &status); if (rc) return rc; } burstcnt = tpm_tis_i2c_get_burstcount(dev); /* burstcount < 0 -> tpm is busy */ if (burstcnt < 0) return burstcnt; while (count < len) { udelay(300); if (burstcnt > len - count) burstcnt = len - count; #ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN) burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN; #endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */ rc = tpm_tis_i2c_write(dev, TPM_DATA_FIFO(chip->locality), &(buf[count]), burstcnt); if (rc == 0) count += burstcnt; else { debug("%s: error\n", __func__); if (retry++ > 10) return -EIO; rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c, &status); if (rc) return rc; if ((status & TPM_STS_DATA_EXPECT) == 0) return -EIO; } } /* Go and do it */ rc = tpm_tis_i2c_write(dev, TPM_STS(chip->locality), &sts, 1); if (rc < 0) return rc; debug("%s: done, rc=%d\n", __func__, rc); return len; } static int tpm_tis_i2c_cleanup(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); tpm_tis_i2c_ready(dev); /* * The TPM needs some time to clean up here, * so we sleep rather than keeping the bus busy */ mdelay(2); tpm_tis_i2c_release_locality(dev, chip->locality, 0); return 0; } static int tpm_tis_i2c_init(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); u32 vendor; u32 expected_did_vid; int rc; 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; rc = tpm_tis_i2c_request_locality(dev, 0); if (rc < 0) return rc; /* Read four bytes from DID_VID register */ if (tpm_tis_i2c_read(dev, TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) { tpm_tis_i2c_release_locality(dev, 0, 1); return -EIO; } if (chip->chip_type == SLB9635) { vendor = be32_to_cpu(vendor); expected_did_vid = TPM_TIS_I2C_DID_VID_9635; } else { /* device id and byte order has changed for newer i2c tpms */ expected_did_vid = TPM_TIS_I2C_DID_VID_9645; } if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) { error("Vendor id did not match! ID was %08x\n", vendor); return -ENODEV; } chip->vend_dev = vendor; debug("1.2 TPM (chip type %s device-id 0x%X)\n", chip_name[chip->chip_type], vendor >> 16); /* * A timeout query to TPM can be placed here. * Standard timeout values are used so far */ return 0; } static int tpm_tis_i2c_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 = tpm_tis_i2c_init(dev); if (rc < 0) chip->is_open = 0; return rc; } static int tpm_tis_i2c_close(struct udevice *dev) { struct tpm_chip *chip = dev_get_priv(dev); if (chip->is_open) { tpm_tis_i2c_release_locality(dev, chip->locality, 1); chip->is_open = 0; chip->vend_dev = 0; } return 0; } static int tpm_tis_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", chip_name[chip->chip_type], chip->vend_dev >> 16); } static int tpm_tis_i2c_probe(struct udevice *dev) { struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev); struct tpm_chip *chip = dev_get_priv(dev); chip->chip_type = dev_get_driver_data(dev); /* TODO: These need to be checked and tuned */ 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; return 0; } static const struct tpm_ops tpm_tis_i2c_ops = { .open = tpm_tis_i2c_open, .close = tpm_tis_i2c_close, .get_desc = tpm_tis_get_desc, .send = tpm_tis_i2c_send, .recv = tpm_tis_i2c_recv, .cleanup = tpm_tis_i2c_cleanup, }; static const struct udevice_id tpm_tis_i2c_ids[] = { { .compatible = "infineon,slb9635tt", .data = SLB9635 }, { .compatible = "infineon,slb9645tt", .data = SLB9645 }, { } }; U_BOOT_DRIVER(tpm_tis_i2c) = { .name = "tpm_tis_infineon", .id = UCLASS_TPM, .of_match = tpm_tis_i2c_ids, .ops = &tpm_tis_i2c_ops, .probe = tpm_tis_i2c_probe, .priv_auto_alloc_size = sizeof(struct tpm_chip), };