diff options
Diffstat (limited to 'drivers/tpm/tpm_tis_infineon.c')
| -rw-r--r-- | drivers/tpm/tpm_tis_infineon.c | 623 |
1 files changed, 623 insertions, 0 deletions
diff --git a/drivers/tpm/tpm_tis_infineon.c b/drivers/tpm/tpm_tis_infineon.c new file mode 100644 index 0000000..88eb786 --- /dev/null +++ b/drivers/tpm/tpm_tis_infineon.c @@ -0,0 +1,623 @@ +/* + * Copyright (C) 2011 Infineon Technologies + * + * Authors: + * Peter Huewe <huewe.external@infineon.com> + * + * 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 <common.h> +#include <dm.h> +#include <fdtdec.h> +#include <i2c.h> +#include <tis.h> +#include <tpm.h> +#include <asm-generic/errno.h> +#include <linux/compiler.h> +#include <linux/types.h> +#include <linux/unaligned/be_byteshift.h> + +#include "tpm_tis_infineon.h" +#include "tpm_internal.h" + +DECLARE_GLOBAL_DATA_PTR; + +static const char * const chip_name[] = { + [SLB9635] = "slb9635tt", + [SLB9645] = "slb9645tt", + [UNKNOWN] = "unknown/fallback to slb9635", +}; + +/* + * 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), +}; |