treewide: convert to tpm_result_t

Convert TPM functions to return TPM error codes(referred to as
tpm_result_t) values to match the TCG standard.

BUG=b:296439237
TEST=build and boot to Skyrim
BRANCH=None

Change-Id: Ifdf9ff6c2a1f9b938dbb04d245799391115eb6b1
Signed-off-by: Jon Murphy <jpmurphy@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77666
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

12 files changed, 314 insertions, 268 deletions

diff --git a/src/drivers/crb/tis.c b/src/drivers/crb/tis.c
index 40a3513511cd..cdb0dbb612e2 100644
--- a/src/drivers/crb/tis.c
+++ b/src/drivers/crb/tis.c
@@ -35,50 +35,52 @@ static const char *tis_get_dev_name(struct tpm2_info *info)
 	return "Unknown";
 }
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	if (tpm_is_open) {
 		printk(BIOS_ERR, "%s called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if (CONFIG(HAVE_INTEL_PTT)) {
 		if (!ptt_active()) {
 			printk(BIOS_ERR, "%s: Intel PTT is not active.\n", __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 		printk(BIOS_DEBUG, "%s: Intel PTT is active.\n", __func__);
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	struct tpm2_info info;
 
 	// Wake TPM up (if necessary)
-	if (tpm2_init() != 0)
-		return -1;
+	tpm_result_t rc = tpm2_init();
+	if (rc)
+		return rc;
 
 	tpm2_get_info(&info);
 
 	printk(BIOS_INFO, "Initialized TPM device %s revision %d\n", tis_get_dev_name(&info),
 	       info.revision);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size, uint8_t *recvbuf, size_t *rbuf_len)
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+					uint8_t *recvbuf, size_t *rbuf_len)
 {
 	int len = tpm2_process_command(sendbuf, sbuf_size, recvbuf, *rbuf_len);
 
 	if (len == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	*rbuf_len = len;
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void crb_tpm_fill_ssdt(const struct device *dev)
@@ -118,28 +120,28 @@ static const char *crb_tpm_acpi_name(const struct device *dev)
 }
 
 #if CONFIG(GENERATE_SMBIOS_TABLES) && CONFIG(TPM2)
-static int tpm_get_cap(uint32_t property, uint32_t *value)
+static tpm_result_t tpm_get_cap(uint32_t property, uint32_t *value)
 {
 	TPMS_CAPABILITY_DATA cap_data;
 	int i;
-	uint32_t rc;
+	tpm_result_t rc;
 
 	if (!value)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 
 	rc = tlcl_get_capability(TPM_CAP_TPM_PROPERTIES, property, 1, &cap_data);
 
 	if (rc)
-		return -1;
+		return rc;
 
 	for (i = 0 ; i < cap_data.data.tpmProperties.count; i++) {
 		if (cap_data.data.tpmProperties.tpmProperty[i].property == property) {
 			*value = cap_data.data.tpmProperties.tpmProperty[i].value;
-			return 0;
+			return TPM_SUCCESS;
 		}
 	}
 
-	return -1;
+	return TPM_CB_FAIL;
 }
 
 static int smbios_write_type43_tpm(struct device *dev, int *handle, unsigned long *current)
diff --git a/src/drivers/crb/tpm.c b/src/drivers/crb/tpm.c
index e919137ea473..4e9f6f2d2b23 100644
--- a/src/drivers/crb/tpm.c
+++ b/src/drivers/crb/tpm.c
@@ -67,7 +67,7 @@ static void crb_readControlArea(void)
 }
 
 /* Wait for Reg to be expected Value  */
-static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mask,
+static tpm_result_t crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mask,
 			      uint32_t expectedValue)
 {
 	uint32_t regValue;
@@ -81,13 +81,13 @@ static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mas
 		regValue = read32(addr);
 
 		if ((regValue & mask) == expectedValue)
-			return 0;
+			return TPM_SUCCESS;
 
 		if (stopwatch_expired(&sw)) {
 			printk(BIOS_ERR,
 			       "CRB_WAIT: Error - Timed out with RegValue: %08x, Mask: %08x, Expected: %08x\n",
 			       regValue, mask, expectedValue);
-			return -1;
+			return TPM_CB_TIMEOUT;
 		}
 	}
 }
@@ -96,27 +96,27 @@ static int crb_wait_for_reg32(const void *addr, uint32_t timeoutMs, uint32_t mas
  *
  * Checks if the CRB Interface is ready
  */
-static int crb_probe(void)
+static tpm_result_t crb_probe(void)
 {
 	uint64_t tpmStatus = read64(CRB_REG(cur_loc, CRB_REG_INTF_ID));
 	printk(BIOS_SPEW, "Interface ID Reg. %llx\n", tpmStatus);
 
 	if ((tpmStatus & CRB_INTF_REG_CAP_CRB) == 0) {
 		printk(BIOS_DEBUG, "TPM: CRB Interface is not supported.\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if ((tpmStatus & (0xf)) != 1) {
 		printk(BIOS_DEBUG,
 		       "TPM: CRB Interface is not active. System needs reboot in order to active TPM.\n");
 		write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_SEL);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_SEL);
 	write32(CRB_REG(cur_loc, CRB_REG_INTF_ID), CRB_INTF_REG_INTF_LOCK);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -129,7 +129,7 @@ static uint8_t crb_activate_locality(void)
 	uint8_t locality = (read8(CRB_REG(0, CRB_REG_LOC_STATE)) >> 2) & 0x07;
 	printk(BIOS_SPEW, "Active locality: %i\n", locality);
 
-	int rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750,
+	tpm_result_t rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750,
 				    LOC_STATE_LOC_ASSIGN, LOC_STATE_LOC_ASSIGN);
 
 	if (!rc && (locality == 0))
@@ -141,15 +141,15 @@ static uint8_t crb_activate_locality(void)
 	rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750, LOC_STATE_LOC_ASSIGN,
 				LOC_STATE_LOC_ASSIGN);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - No Locality has been assigned TPM-wise.\n");
+		printk(BIOS_ERR, "TPM: Error (%#x) - No Locality has been assigned TPM-wise.\n", rc);
 		return 0;
 	}
 
 	rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 1500,
 				LOC_STATE_REG_VALID_STS, LOC_STATE_REG_VALID_STS);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - LOC_STATE Register %u contains errors.\n",
-		       locality);
+		printk(BIOS_ERR, "TPM: Error (%#x) - LOC_STATE Register %u contains errors.\n",
+		       rc, locality);
 		return 0;
 	}
 
@@ -157,27 +157,27 @@ static uint8_t crb_activate_locality(void)
 }
 
 /* Switch Device into a Ready State */
-static int crb_switch_to_ready(void)
+static tpm_result_t crb_switch_to_ready(void)
 {
 	/* Transition into ready state */
 	write8(CRB_REG(cur_loc, CRB_REG_REQUEST), 0x1);
-	int rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_REQUEST), 200,
+	tpm_result_t rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_REQUEST), 200,
 					CRB_REG_REQUEST_CMD_RDY, 0x0);
 	if (rc) {
 		printk(BIOS_ERR,
-		       "TPM: Error - TPM did not transition into ready state in time.\n");
-		return -1;
+		       "TPM Error (%#x): TPM did not transition into ready state in time.\n", rc);
+		return rc;
 	}
 
 	/* Check TPM_CRB_CTRL_STS[0] to be "0" - no unrecoverable error */
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_STATUS), 500, CRB_REG_STATUS_ERROR,
 				0x0);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Fatal Error - Could not recover.\n");
-		return -1;
+		printk(BIOS_ERR, "TPM Error (%#x): Could not recover.\n", rc);
+		return rc;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -188,11 +188,12 @@ static int crb_switch_to_ready(void)
  * normal bring up mode.
  *
  */
-int tpm2_init(void)
+tpm_result_t tpm2_init(void)
 {
-	if (crb_probe()) {
+	tpm_result_t rc = crb_probe();
+	if (rc) {
 		printk(BIOS_ERR, "TPM: Probe failed.\n");
-		return -1;
+		return rc;
 	}
 
 	/* Read back control area structure */
@@ -211,7 +212,7 @@ int tpm2_init(void)
 	/* Good to go. */
 	printk(BIOS_SPEW, "TPM: CRB TPM initialized successfully\n");
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void set_ptt_cmd_resp_buffers(void)
@@ -231,7 +232,7 @@ static void set_ptt_cmd_resp_buffers(void)
 size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void *tpm2_response,
 			    size_t max_response)
 {
-	int rc;
+	tpm_result_t rc;
 
 	if (command_size > control_area.command_size) {
 		printk(BIOS_ERR, "TPM: Command size is too big.\n");
@@ -248,12 +249,15 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Check if CMD bit is cleared.
 	rc = crb_wait_for_reg32(CRB_REG(0, CRB_REG_START), 250, CRB_REG_START_START, 0x0);
 	if (rc) {
-		printk(BIOS_ERR, "TPM: Error - Cmd Bit not cleared.\n");
+		printk(BIOS_ERR, "TPM Error (%#x): Cmd Bit not cleared.\n", rc);
 		return -1;
 	}
 
-	if (crb_switch_to_ready())
+	rc = crb_switch_to_ready();
+	if (rc) {
+		printk(BIOS_DEBUG, "TPM Error (%#x): Can not transition into ready state.\n", rc);
 		return -1;
+	}
 
 	// Write to Command Buffer
 	memcpy(control_area.command_bfr, tpm2_command, command_size);
@@ -272,14 +276,14 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Poll for Response
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_START), 3500, CRB_REG_START_START, 0);
 	if (rc) {
-		printk(BIOS_DEBUG, "TPM: Command Timed out.\n");
+		printk(BIOS_DEBUG, "TPM Error (%#x): Command Timed out.\n", rc);
 		return -1;
 	}
 
 	// Check for errors
 	rc = crb_wait_for_reg32(CRB_REG(cur_loc, CRB_REG_STATUS), 200, CRB_REG_STATUS_ERROR, 0);
 	if (rc) {
-		printk(BIOS_DEBUG, "TPM: Command errored.\n");
+		printk(BIOS_DEBUG, "TPM Error (%#x): Command errored.\n", rc);
 		return -1;
 	}
 
@@ -293,8 +297,9 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
 	// Copy Response
 	memcpy(tpm2_response, control_area.response_bfr, length);
 
-	if (crb_switch_to_ready()) {
-		printk(BIOS_DEBUG, "TPM: Can not transition into ready state again.\n");
+	rc = crb_switch_to_ready();
+	if (rc) {
+		printk(BIOS_DEBUG, "TPM Error (%#x): Can not transition into ready state again.\n", rc);
 		return -1;
 	}
 
diff --git a/src/drivers/crb/tpm.h b/src/drivers/crb/tpm.h
index be26be2d24ff..7b25e78b3b4b 100644
--- a/src/drivers/crb/tpm.h
+++ b/src/drivers/crb/tpm.h
@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: BSD-3-Clause */
 /* This is a driver for a Command Response Buffer Interface */
 
+#include <security/tpm/tss_errors.h>
+
 /* CRB driver */
 /* address of locality 0 (CRB) */
 #define TPM_CRB_BASE_ADDRESS        CONFIG_CRB_TPM_BASE_ADDRESS
@@ -58,7 +60,7 @@ struct tpm2_info {
 	uint16_t revision;
 };
 
-int tpm2_init(void);
+tpm_result_t tpm2_init(void);
 void tpm2_get_info(struct tpm2_info *tpm2_info);
 size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
 			    void *tpm2_response, size_t max_response);
diff --git a/src/drivers/i2c/tpm/cr50.c b/src/drivers/i2c/tpm/cr50.c
index 929628407dee..d207f2b20bfa 100644
--- a/src/drivers/i2c/tpm/cr50.c
+++ b/src/drivers/i2c/tpm/cr50.c
@@ -56,12 +56,12 @@ static struct tpm_inf_dev tpm_dev;
  * 2) wait for TPM to indicate it is ready
  * 3) read 'len' bytes of TPM response into the provided 'buffer'
  *
- * Return -1 on error, 0 on success.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
+static tpm_result_t cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
 {
 	if (tpm_dev.addr == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Clear interrupt before starting transaction */
 	cr50_plat_irq_status();
@@ -69,20 +69,20 @@ static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
 	/* Send the register address byte to the TPM */
 	if (i2c_write_raw(tpm_dev.bus, tpm_dev.addr, &addr, 1)) {
 		printk(BIOS_ERR, "%s: Address write failed\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/* Wait for TPM to be ready with response data */
 	if (cr50_wait_tpm_ready() != CB_SUCCESS)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Read response data from the TPM */
 	if (i2c_read_raw(tpm_dev.bus, tpm_dev.addr, buffer, len)) {
 		printk(BIOS_ERR, "%s: Read response failed\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -96,14 +96,14 @@ static int cr50_i2c_read(uint8_t addr, uint8_t *buffer, size_t len)
  * 2) send the address+data to the TPM
  * 3) wait for TPM to indicate it is done writing
  *
- * Returns -1 on error, 0 on success.
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
+static tpm_result_t cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
 {
 	if (tpm_dev.addr == 0)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 	if (len > CR50_MAX_BUFSIZE)
-		return -1;
+		return TPM_CB_INVALID_ARG;
 
 	/* Prepend the 'register address' to the buffer */
 	tpm_dev.buf[0] = addr;
@@ -115,11 +115,11 @@ static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
 	/* Send write request buffer with address */
 	if (i2c_write_raw(tpm_dev.bus, tpm_dev.addr, tpm_dev.buf, len + 1)) {
 		printk(BIOS_ERR, "%s: Error writing to TPM\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/* Wait for TPM to be ready */
-	return cr50_wait_tpm_ready() == CB_SUCCESS ? 0 : -1;
+	return cr50_wait_tpm_ready() == CB_SUCCESS ? TPM_SUCCESS : TPM_CB_FAIL;
 }
 
 /*
@@ -128,11 +128,13 @@ static int cr50_i2c_write(uint8_t addr, const uint8_t *buffer, size_t len)
  *
  * This function will make sure that the AP does not proceed with boot until
  * TPM finished reset processing.
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int process_reset(void)
+static tpm_result_t process_reset(void)
 {
 	struct stopwatch sw;
-	int rc = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 	uint8_t access;
 
 	/*
@@ -162,59 +164,72 @@ static int process_reset(void)
 		printk(BIOS_INFO, "TPM ready after %lld ms\n",
 		       stopwatch_duration_msecs(&sw));
 
-		return 0;
+		return TPM_SUCCESS;
 	} while (!stopwatch_expired(&sw));
 
-	if (rc)
-		printk(BIOS_ERR, "Failed to read TPM\n");
-	else
+	if (rc) {
+		printk(BIOS_ERR, "Failed to read TPM with error %d\n", rc);
+		return rc;
+	} else
 		printk(BIOS_ERR,
 			"TPM failed to reset after %lld ms, status: %#x\n",
 			stopwatch_duration_msecs(&sw), access);
-
-	return -1;
+	return TPM_CB_FAIL;
 }
 
 /*
  * Locality could be already claimed (if this is a later coreboot stage and
  * the RO did not release it), or not yet claimed, if this is verstage or the
  * older RO did release it.
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
  */
-static int claim_locality(void)
+static tpm_result_t claim_locality(void)
 {
 	uint8_t access;
 	const uint8_t mask = TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY;
+	tpm_result_t rc = TPM_SUCCESS;
 
-	if (cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access));
+	if (rc)
+		return rc;
 
 	if ((access & mask) == mask) {
 		printk(BIOS_INFO, "Locality already claimed\n");
-		return 0;
+		return TPM_SUCCESS;
 	}
 
 	access = TPM_ACCESS_REQUEST_USE;
-	if (cr50_i2c_write(TPM_ACCESS(0),
-			   &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_write(TPM_ACCESS(0),
+			   &access, sizeof(access));
+	if (rc)
+		return rc;
 
-	if (cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access)))
-		return -1;
+	rc = cr50_i2c_read(TPM_ACCESS(0), &access, sizeof(access));
+	if (rc)
+		return rc;
 
 	if ((access & mask) != mask) {
 		printk(BIOS_INFO, "Failed to claim locality.\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-/* cr50 requires all 4 bytes of status register to be read */
+/*
+ * cr50 requires all 4 bytes of status register to be read
+ *
+ * Returns lowest 8-bits of the TIS Status register value
+ * see tis_status bit mask enumerated type in tis.h.
+ * Return 0 on error.
+ */
 static uint8_t cr50_i2c_tis_status(void)
 {
 	uint8_t buf[4];
-	if (cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf)) < 0) {
-		printk(BIOS_ERR, "%s: Failed to read status\n", __func__);
+	tpm_result_t rc = cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf));
+	if (rc) {
+		printk(BIOS_ERR, "%s: Failed to read status with error %#x\n", __func__, rc);
 		return 0;
 	}
 	return buf[0];
@@ -229,16 +244,21 @@ static void cr50_i2c_tis_ready(void)
 }
 
 /* cr50 uses bytes 3:2 of status register for burst count and
- * all 4 bytes must be read */
-static int cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
+ * all 4 bytes must be read
+ *
+ * Returns TSS Return Code from TCG TPM Structures.  See tss_errors.h
+ */
+static tpm_result_t cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
 {
 	uint8_t buf[4];
 	struct stopwatch sw;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS);
 
 	while (!stopwatch_expired(&sw)) {
-		if (cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf)) != 0) {
+		rc = cr50_i2c_read(TPM_STS(tpm_dev.locality), buf, sizeof(buf));
+		if (rc) {
 			mdelay(CR50_TIMEOUT_SHORT_MS);
 			continue;
 		}
@@ -249,13 +269,14 @@ static int cr50_i2c_wait_burststs(uint8_t mask, size_t *burst, int *status)
 		/* Check if mask matches and burst is valid */
 		if ((*status & mask) == mask &&
 		    *burst > 0 && *burst <= CR50_MAX_BUFSIZE)
-			return 0;
+			return TPM_SUCCESS;
 
 		mdelay(CR50_TIMEOUT_SHORT_MS);
 	}
-
-	printk(BIOS_ERR, "%s: Timeout reading burst and status\n", __func__);
-	return -1;
+	printk(BIOS_ERR, "%s: Timeout reading burst and status with error %#x\n", __func__, rc);
+	if (rc)
+		return rc;
+	return TPM_CB_TIMEOUT;
 }
 
 static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
@@ -264,18 +285,21 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	uint8_t addr = TPM_DATA_FIFO(tpm_dev.locality);
 	uint8_t mask = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
 	int status;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (buf_len < TPM_HEADER_SIZE)
 		goto out_err;
 
-	if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0) {
-		printk(BIOS_ERR, "%s: First chunk not available\n", __func__);
+	rc = cr50_i2c_wait_burststs(mask, &burstcnt, &status);
+	if (rc) {
+		printk(BIOS_ERR, "%s: First chunk not available with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 
 	/* Read first chunk of burstcnt bytes */
-	if (cr50_i2c_read(addr, buf, burstcnt) != 0) {
-		printk(BIOS_ERR, "%s: Read failed\n", __func__);
+	rc = cr50_i2c_read(addr, buf, burstcnt);
+	if (rc) {
+		printk(BIOS_ERR, "%s: Read failed with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 
@@ -291,12 +315,13 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	current = burstcnt;
 	while (current < expected) {
 		/* Read updated burst count and check status */
-		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0)
+		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status))
 			goto out_err;
 
 		len = MIN(burstcnt, expected - current);
-		if (cr50_i2c_read(addr, buf + current, len) != 0) {
-			printk(BIOS_ERR, "%s: Read failed\n", __func__);
+		rc = cr50_i2c_read(addr, buf + current, len);
+		if (rc) {
+			printk(BIOS_ERR, "%s: Read failed with error %#x\n", __func__, rc);
 			goto out_err;
 		}
 
@@ -304,7 +329,7 @@ static int cr50_i2c_tis_recv(uint8_t *buf, size_t buf_len)
 	}
 
 	/* Ensure TPM is done reading data */
-	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status) < 0)
+	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status))
 		goto out_err;
 	if (status & TPM_STS_DATA_AVAIL) {
 		printk(BIOS_ERR, "%s: Data still available\n", __func__);
@@ -326,6 +351,7 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	size_t burstcnt, limit, sent = 0;
 	uint8_t tpm_go[4] = { TPM_STS_GO };
 	struct stopwatch sw;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS);
 
@@ -348,14 +374,15 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 			mask |= TPM_STS_DATA_EXPECT;
 
 		/* Read burst count and check status */
-		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status) < 0)
+		if (cr50_i2c_wait_burststs(mask, &burstcnt, &status))
 			goto out_err;
 
 		/* Use burstcnt - 1 to account for the address byte
 		 * that is inserted by cr50_i2c_write() */
 		limit = MIN(burstcnt - 1, len);
-		if (cr50_i2c_write(TPM_DATA_FIFO(tpm_dev.locality), &buf[sent], limit) != 0) {
-			printk(BIOS_ERR, "%s: Write failed\n", __func__);
+		rc = cr50_i2c_write(TPM_DATA_FIFO(tpm_dev.locality), &buf[sent], limit);
+		if (rc) {
+			printk(BIOS_ERR, "%s: Write failed with error %#x\n", __func__, rc);
 			goto out_err;
 		}
 
@@ -364,7 +391,7 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	}
 
 	/* Ensure TPM is not expecting more data */
-	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status) < 0)
+	if (cr50_i2c_wait_burststs(TPM_STS_VALID, &burstcnt, &status))
 		goto out_err;
 	if (status & TPM_STS_DATA_EXPECT) {
 		printk(BIOS_ERR, "%s: Data still expected\n", __func__);
@@ -372,8 +399,9 @@ static int cr50_i2c_tis_send(uint8_t *buf, size_t len)
 	}
 
 	/* Start the TPM command */
-	if (cr50_i2c_write(TPM_STS(tpm_dev.locality), tpm_go, sizeof(tpm_go)) < 0) {
-		printk(BIOS_ERR, "%s: Start command failed\n", __func__);
+	rc = cr50_i2c_write(TPM_STS(tpm_dev.locality), tpm_go, sizeof(tpm_go));
+	if (rc) {
+		printk(BIOS_ERR, "%s: Start command failed with error %#x\n", __func__, rc);
 		goto out_err;
 	}
 	return sent;
@@ -396,14 +424,15 @@ static void cr50_vendor_init(struct tpm_chip *chip)
 	chip->cancel = &cr50_i2c_tis_ready;
 }
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr)
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-static int cr50_i2c_probe(uint32_t *did_vid)
+static tpm_result_t cr50_i2c_probe(uint32_t *did_vid)
 {
 	int retries;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/*
 	 * 1s should be enough to synchronize with the TPM even under the
@@ -414,14 +443,13 @@ static int cr50_i2c_probe(uint32_t *did_vid)
 	printk(BIOS_INFO, "Probing TPM I2C: ");
 
 	for (retries = 100; retries > 0; retries--) {
-		int rc;
 
 		rc = cr50_i2c_read(TPM_DID_VID(0), (uint8_t *)did_vid, 4);
 
 		/* Exit once DID and VID verified */
 		if (!rc && (*did_vid == CR50_DID_VID || *did_vid == TI50_DID_VID)) {
 			printk(BIOS_INFO, "done! DID_VID 0x%08x\n", *did_vid);
-			return 0;
+			return TPM_SUCCESS;
 		}
 
 		/* TPM might be resetting, let's retry in a bit. */
@@ -432,17 +460,21 @@ static int cr50_i2c_probe(uint32_t *did_vid)
 	/*
 	 * I2C reads failed, or the DID and VID didn't match
 	 */
-	printk(BIOS_ERR, "DID_VID 0x%08x not recognized\n", *did_vid);
-	return -1;
+	if (!rc) {
+		printk(BIOS_ERR, "DID_VID 0x%08x not recognized\n", *did_vid);
+		return TPM_CB_FAIL;
+	}
+	return rc;
 }
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 {
 	uint32_t did_vid = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (dev_addr == 0) {
 		printk(BIOS_ERR, "%s: missing device address\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	tpm_dev.bus = bus;
@@ -450,15 +482,19 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 
 	cr50_vendor_init(chip);
 
-	if (cr50_i2c_probe(&did_vid))
-		return -1;
+	rc = cr50_i2c_probe(&did_vid);
+	if (rc)
+		return rc;
 
-	if (ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK)
-		if (process_reset())
-			return -1;
+	if (ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK) {
+		rc = process_reset();
+		if (rc)
+			return rc;
+	}
 
-	if (claim_locality())
-		return -1;
+	rc = claim_locality();
+	if (rc)
+		return rc;
 
 	printk(BIOS_DEBUG, "cr50 TPM 2.0 (i2c %u:0x%02x id %#x)\n",
 	       bus, dev_addr, did_vid >> 16);
@@ -470,7 +506,7 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	}
 
 	chip->is_open = 1;
-	return 0;
+	return TPM_SUCCESS;
 }
 
 enum cb_err tis_vendor_write(unsigned int addr, const void *buffer, size_t bytes)
diff --git a/src/drivers/i2c/tpm/tis.c b/src/drivers/i2c/tpm/tis.c
index 25b7f40801a2..a5c3b8fdf3ef 100644
--- a/src/drivers/i2c/tpm/tis.c
+++ b/src/drivers/i2c/tpm/tis.c
@@ -19,27 +19,24 @@ static struct tpm_chip chip;
 #define TPM_CMD_COUNT_BYTE 2
 #define TPM_CMD_ORDINAL_BYTE 6
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
-	int rc;
+	tpm_result_t rc;
 
 	if (chip.is_open) {
 		printk(BIOS_DEBUG, "%s() called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	rc = tpm_vendor_init(&chip, CONFIG_DRIVER_TPM_I2C_BUS,
 			     CONFIG_DRIVER_TPM_I2C_ADDR);
-	if (rc < 0)
+	if (rc != TPM_SUCCESS)
 		chip.is_open = 0;
 
-	if (rc)
-		return -1;
-
-	return 0;
+	return rc;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	return tpm_vendor_probe(CONFIG_DRIVER_TPM_I2C_BUS,
 				CONFIG_DRIVER_TPM_I2C_ADDR);
@@ -48,23 +45,23 @@ int tis_init(void)
 static ssize_t tpm_transmit(const uint8_t *sbuf, size_t sbufsiz, void *rbuf,
 			size_t rbufsiz)
 {
-	int rc;
+	int rc = -1;
 	uint32_t count;
 
 	memcpy(&count, sbuf + TPM_CMD_COUNT_BYTE, sizeof(count));
 	count = be32_to_cpu(count);
 
 	if (!chip.send || !chip.status || !chip.cancel)
-		return -1;
+		goto out;
 
 	if (count == 0) {
 		printk(BIOS_DEBUG, "%s: no data\n", __func__);
-		return -1;
+		goto out;
 	}
 	if (count > sbufsiz) {
 		printk(BIOS_DEBUG, "%s: invalid count value %#x %zx\n", __func__,
 			count, sbufsiz);
-		return -1;
+		goto out;
 	}
 
 	ASSERT(chip.send);
@@ -95,11 +92,10 @@ static ssize_t tpm_transmit(const uint8_t *sbuf, size_t sbufsiz, void *rbuf,
 	ASSERT(chip.cancel);
 	chip.cancel();
 	printk(BIOS_DEBUG, "%s: Operation Timed out\n", __func__);
-	rc = -1; //ETIME;
+	rc = -1;
 	goto out;
 
 out_recv:
-
 	rc = chip.recv((uint8_t *)rbuf, rbufsiz);
 	if (rc < 0)
 		printk(BIOS_DEBUG, "%s: tpm_recv: error %d\n", __func__, rc);
@@ -107,7 +103,7 @@ out:
 	return rc;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		uint8_t *recvbuf, size_t *rbuf_len)
 {
 	ASSERT(sbuf_size >= 10);
@@ -124,12 +120,12 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 
 	if (len < 10) {
 		*rbuf_len = 0;
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	if (len > *rbuf_len) {
 		*rbuf_len = len;
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	*rbuf_len = len;
@@ -142,5 +138,5 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		hexdump(recvbuf, *rbuf_len);
 	}
 
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/i2c/tpm/tis_atmel.c b/src/drivers/i2c/tpm/tis_atmel.c
index 669ac68f6c82..91ed6a99e363 100644
--- a/src/drivers/i2c/tpm/tis_atmel.c
+++ b/src/drivers/i2c/tpm/tis_atmel.c
@@ -22,17 +22,17 @@ struct tpm_output_header {
 	uint32_t return_code;
 } __packed;
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		uint8_t *recvbuf, size_t *rbuf_len)
 {
 	size_t hdr_bytes;
@@ -60,8 +60,10 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 			sbuf_size);
 		if ((status < 0) && (!stopwatch_expired(&sw)))
 			continue;
-		if (status < 0)
-			return status;
+		if (status < 0) {
+			printk(BIOS_ERR, "I2C write error: %d\n", status);
+			return TPM_CB_COMMUNICATION_ERROR;
+		}
 		break;
 	}
 
@@ -79,7 +81,7 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		udelay(SLEEP_DURATION);
 	} while (!stopwatch_expired(&sw));
 	if (status != sizeof(*header))
-		return -1;
+		return TPM_CB_COMMUNICATION_ERROR;
 
 	/* Determine the number of bytes remaining */
 	recv_bytes = MIN(be32_to_cpu(*(uint32_t *)&header->length),
@@ -94,8 +96,10 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		/* Read the full TPM response */
 		status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
 			CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, recv_bytes);
-		if (status < 0)
-			return status;
+		if (status < 0) {
+			printk(BIOS_ERR, "I2C read error: %d\n", status);
+			return TPM_CB_COMMUNICATION_ERROR;
+		}
 	}
 
 	/* Return the number of bytes received */
@@ -110,5 +114,5 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 	}
 
 	/* Successful transfer */
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/i2c/tpm/tpm.c b/src/drivers/i2c/tpm/tpm.c
index c88dcdd4b95c..4dbefb44f396 100644
--- a/src/drivers/i2c/tpm/tpm.c
+++ b/src/drivers/i2c/tpm/tpm.c
@@ -451,7 +451,7 @@ out_err:
 
 /* Initialization of I2C TPM */
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr)
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr)
 {
 	struct stopwatch sw;
 	uint8_t buf = 0;
@@ -487,18 +487,18 @@ int tpm_vendor_probe(unsigned int bus, uint32_t addr)
 	 * Claim failure if the ValidSts (bit 7) is clear.
 	 */
 	if (!(buf & TPM_STS_VALID))
-		return -1;
+		return TPM_CB_FAIL;
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 {
 	uint32_t vendor;
 
 	if (dev_addr == 0) {
 		printk(BIOS_ERR, "%s: missing device address\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	tpm_dev.chip_type = UNKNOWN;
@@ -518,7 +518,7 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	chip->cancel = &tpm_tis_i2c_ready;
 
 	if (request_locality(0) != 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	/* Read four bytes from DID_VID register */
 	if (iic_tpm_read(TPM_DID_VID(0), (uint8_t *)&vendor, 4) < 0)
@@ -543,9 +543,9 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr)
 	 * Standard timeout values are used so far
 	 */
 
-	return 0;
+	return TPM_SUCCESS;
 
 out_err:
 	release_locality(0, 1);
-	return -1;
+	return TPM_CB_FAIL;
 }
diff --git a/src/drivers/i2c/tpm/tpm.h b/src/drivers/i2c/tpm/tpm.h
index d4176cc5114c..fb9837789ddc 100644
--- a/src/drivers/i2c/tpm/tpm.h
+++ b/src/drivers/i2c/tpm/tpm.h
@@ -12,6 +12,7 @@
 #ifndef __DRIVERS_TPM_SLB9635_I2C_TPM_H__
 #define __DRIVERS_TPM_SLB9635_I2C_TPM_H__
 
+#include <security/tpm/tss_errors.h>
 #include <stdint.h>
 
 enum tpm_timeout {
@@ -51,8 +52,8 @@ struct tpm_chip {
 
 /* ---------- Interface for TPM vendor ------------ */
 
-int tpm_vendor_probe(unsigned int bus, uint32_t addr);
+tpm_result_t tpm_vendor_probe(unsigned int bus, uint32_t addr);
 
-int tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr);
+tpm_result_t tpm_vendor_init(struct tpm_chip *chip, unsigned int bus, uint32_t dev_addr);
 
 #endif /* __DRIVERS_TPM_SLB9635_I2C_TPM_H__ */
diff --git a/src/drivers/pc80/tpm/tis.c b/src/drivers/pc80/tpm/tis.c
index a7a3e9d72d90..3f2d6bd7a294 100644
--- a/src/drivers/pc80/tpm/tis.c
+++ b/src/drivers/pc80/tpm/tis.c
@@ -74,17 +74,6 @@
 #define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
 #define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */
 
-/*
- * Error value returned if a tpm register does not enter the expected state
- * after continuous polling. No actual TPM register reading ever returns ~0,
- * so this value is a safe error indication to be mixed with possible status
- * register values.
- */
-#define TPM_TIMEOUT_ERR			(~0)
-
-/* Error value returned on various TPM driver errors */
-#define TPM_DRIVER_ERR		(~0)
-
  /* 1 second is plenty for anything TPM does.*/
 #define MAX_DELAY_US	USECS_PER_SEC
 
@@ -248,9 +237,9 @@ static inline u32 tpm_read_int_polarity(int locality)
  * @mask - bitmask for the bitfield(s) to watch
  * @expected - value the field(s) are supposed to be set to
  *
- * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
+ * Returns TPM_SUCCESS on success or TPM_CB_TIMEOUT on timeout.
  */
-static int tis_wait_sts(int locality, u8 mask, u8 expected)
+static tpm_result_t tis_wait_sts(int locality, u8 mask, u8 expected)
 {
 	struct stopwatch sw;
 
@@ -258,24 +247,24 @@ static int tis_wait_sts(int locality, u8 mask, u8 expected)
 	do {
 		u8 value = tpm_read_status(locality);
 		if ((value & mask) == expected)
-			return 0;
+			return TPM_SUCCESS;
 		udelay(1);
 	} while (!stopwatch_expired(&sw));
-	return TPM_TIMEOUT_ERR;
+	return TPM_CB_TIMEOUT;
 }
 
-static inline int tis_wait_ready(int locality)
+static inline tpm_result_t tis_wait_ready(int locality)
 {
 	return tis_wait_sts(locality, TIS_STS_COMMAND_READY,
 	                    TIS_STS_COMMAND_READY);
 }
 
-static inline int tis_wait_valid(int locality)
+static inline tpm_result_t tis_wait_valid(int locality)
 {
 	return tis_wait_sts(locality, TIS_STS_VALID, TIS_STS_VALID);
 }
 
-static inline int tis_wait_valid_data(int locality)
+static inline tpm_result_t tis_wait_valid_data(int locality)
 {
 	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
 	return tis_wait_sts(locality, has_data, has_data);
@@ -302,9 +291,9 @@ static inline int tis_expect_data(int locality)
  * @mask - bitmask for the bitfield(s) to watch
  * @expected - value the field(s) are supposed to be set to
  *
- * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
+ * Returns TPM_SUCCESS on success or TPM_CB_TIMEOUT on timeout.
  */
-static int tis_wait_access(int locality, u8 mask, u8 expected)
+static tpm_result_t tis_wait_access(int locality, u8 mask, u8 expected)
 {
 	struct stopwatch sw;
 
@@ -312,13 +301,13 @@ static int tis_wait_access(int locality, u8 mask, u8 expected)
 	do {
 		u8 value = tpm_read_access(locality);
 		if ((value & mask) == expected)
-			return 0;
+			return TPM_SUCCESS;
 		udelay(1);
 	} while (!stopwatch_expired(&sw));
-	return TPM_TIMEOUT_ERR;
+	return TPM_CB_TIMEOUT;
 }
 
-static inline int tis_wait_received_access(int locality)
+static inline tpm_result_t tis_wait_received_access(int locality)
 {
 	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY,
 	                       TIS_ACCESS_ACTIVE_LOCALITY);
@@ -345,10 +334,8 @@ static inline void tis_request_access(int locality)
  * In practice not all TPMs behave the same so it is necessary to be
  * flexible when trying to set command ready.
  *
- * Returns 0 on success if the TPM is ready for transactions.
- * Returns TPM_TIMEOUT_ERR if the command ready bit does not get set.
  */
-static int tis_command_ready(u8 locality)
+static tpm_result_t tis_command_ready(u8 locality)
 {
 	u32 status;
 
@@ -360,7 +347,7 @@ static int tis_command_ready(u8 locality)
 
 	/* Check if command ready is set yet */
 	if (status & TIS_STS_COMMAND_READY)
-		return 0;
+		return TPM_SUCCESS;
 
 	/* 2nd attempt to set command ready */
 	tpm_write_status(TIS_STS_COMMAND_READY, locality);
@@ -373,10 +360,10 @@ static int tis_command_ready(u8 locality)
  *
  * Probe the TPM device and try determining its manufacturer/device name.
  *
- * Returns 0 on success (the device is found or was found during an earlier
- * invocation) or TPM_DRIVER_ERR if the device is not found.
+ * Returns TPM_SUCCESS on success (the device is found or was found during
+ * an earlier invocation) or TPM_CB_FAIL if the device is not found.
  */
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	const char *device_name = "unknown";
 	const char *vendor_name = device_name;
@@ -386,12 +373,12 @@ int tis_init(void)
 	int i;
 
 	if (vendor_dev_id)
-		return 0;  /* Already probed. */
+		return TPM_SUCCESS;  /* Already probed. */
 
 	didvid = tpm_read_did_vid(0);
 	if (!didvid || (didvid == 0xffffffff)) {
 		printf("%s: No TPM device found\n", __func__);
-		return TPM_DRIVER_ERR;
+		return TPM_CB_FAIL;
 	}
 
 	vendor_dev_id = didvid;
@@ -419,7 +406,7 @@ int tis_init(void)
 	}
 	/* this will have to be converted into debug printout */
 	printk(BIOS_INFO, "Found TPM %s by %s\n", device_name, vendor_name);
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -430,19 +417,21 @@ int tis_init(void)
  * @data - address of the data to send, byte by byte
  * @len - length of the data to send
  *
- * Returns 0 on success, TPM_DRIVER_ERR on error (in case the device does
+ * Returns TPM_SUCCESS on success, TPM_CB_FAIL on error (in case the device does
  * not accept the entire command).
  */
-static u32 tis_senddata(const u8 *const data, u32 len)
+static tpm_result_t tis_senddata(const u8 *const data, u32 len)
 {
 	u32 offset = 0;
 	u16 burst = 0;
 	u8 locality = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
-	if (tis_wait_ready(locality)) {
-		printf("%s:%d - failed to get 'command_ready' status\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_ready(locality);
+	if (rc) {
+		printf("%s:%d - failed to get 'command_ready' status with error %#x\n",
+		       __FILE__, __LINE__, rc);
+		return rc;
 	}
 	burst = tpm_read_burst_count(locality);
 
@@ -456,7 +445,7 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 			if (stopwatch_expired(&sw)) {
 				printf("%s:%d failed to feed %u bytes of %u\n",
 				       __FILE__, __LINE__, len - offset, len);
-				return TPM_DRIVER_ERR;
+				return TPM_CB_TIMEOUT;
 			}
 			udelay(1);
 			burst = tpm_read_burst_count(locality);
@@ -475,10 +464,11 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 		while (count--)
 			tpm_write_data(data[offset++], locality);
 
-		if (tis_wait_valid(locality) || !tis_expect_data(locality)) {
-			printf("%s:%d TPM command feed overflow\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_valid(locality);
+		if (rc || !tis_expect_data(locality)) {
+			printf("%s:%d TPM command feed overflow with error %#x\n",
+			       __FILE__, __LINE__, rc);
+			return rc ? rc : TPM_CB_FAIL;
 		}
 
 		burst = tpm_read_burst_count(locality);
@@ -498,16 +488,17 @@ static u32 tis_senddata(const u8 *const data, u32 len)
 	 * Verify that TPM does not expect any more data as part of this
 	 * command.
 	 */
-	if (tis_wait_valid(locality) || tis_expect_data(locality)) {
-		printf("%s:%d unexpected TPM status %#x\n",
-		       __FILE__, __LINE__, tpm_read_status(locality));
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_valid(locality);
+	if (rc || tis_expect_data(locality)) {
+		printf("%s:%d unexpected TPM error %#x with status %#x\n",
+		       __FILE__, __LINE__, rc, tpm_read_status(locality));
+		return rc ? rc : TPM_CB_FAIL;
 	}
 
 	/* OK, sitting pretty, let's start the command execution. */
 	tpm_write_status(TIS_STS_TPM_GO, locality);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -518,22 +509,25 @@ static u32 tis_senddata(const u8 *const data, u32 len)
  * @buffer - address where to read the response, byte by byte.
  * @len - pointer to the size of buffer
  *
- * On success stores the number of received bytes to len and returns 0. On
- * errors (misformatted TPM data or synchronization problems) returns
- * TPM_DRIVER_ERR.
+ * On success stores the number of received bytes to len and returns
+ * TPM_SUCCESS. On errors (misformatted TPM data or synchronization
+ * problems) returns TPM_CB_FAIL.
  */
-static u32 tis_readresponse(u8 *buffer, size_t *len)
+static tpm_result_t tis_readresponse(u8 *buffer, size_t *len)
 {
 	u16 burst_count;
 	u32 offset = 0;
 	u8 locality = 0;
 	u32 expected_count = *len;
 	int max_cycles = 0;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	/* Wait for the TPM to process the command */
-	if (tis_wait_valid_data(locality)) {
-		printf("%s:%d failed processing command\n", __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	rc = tis_wait_valid_data(locality);
+	if (rc) {
+		printf("%s:%d failed processing command with error %#x\n",
+			   __FILE__, __LINE__, rc);
+		return rc;
 	}
 
 	do {
@@ -541,7 +535,7 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 			if (max_cycles++ == MAX_DELAY_US) {
 				printf("%s:%d TPM stuck on read\n",
 				       __FILE__, __LINE__);
-				return TPM_DRIVER_ERR;
+				return TPM_CB_FAIL;
 			}
 			udelay(1);
 		}
@@ -569,16 +563,17 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 					printf("%s:%d bad response size %u\n",
 					       __FILE__, __LINE__,
 					       expected_count);
-					return TPM_DRIVER_ERR;
+					return TPM_CB_FAIL;
 				}
 			}
 		}
 
 		/* Wait for the next portion */
-		if (tis_wait_valid(locality)) {
-			printf("%s:%d failed to read response\n",
-			       __FILE__, __LINE__);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_valid(locality);
+		if (rc) {
+			printf("%s:%d failed to read response with error %#x\n",
+			       __FILE__, __LINE__, rc);
+			return rc;
 		}
 
 		if (offset == expected_count)
@@ -599,15 +594,16 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
 		printf("%s:%d wrong receive status: %#x %u bytes left\n",
 		       __FILE__, __LINE__, tpm_read_status(locality),
 	               tpm_read_burst_count(locality));
-		return TPM_DRIVER_ERR;
+		return TPM_CB_FAIL;
 	}
 
 	/* Tell the TPM that we are done. */
-	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
-		return TPM_DRIVER_ERR;
+	rc = tis_command_ready(locality);
+	if (rc)
+		return rc;
 
 	*len = offset;
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
@@ -615,31 +611,30 @@ static u32 tis_readresponse(u8 *buffer, size_t *len)
  *
  * Requests access to locality 0 for the caller.
  *
- * Returns 0 on success, TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success, TSS Error on failure.
  */
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	u8 locality = 0; /* we use locality zero for everything */
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (!tis_has_access(locality)) {
 		/* request access to locality */
 		tis_request_access(locality);
 
 		/* did we get a lock? */
-		if (tis_wait_received_access(locality)) {
-			printf("%s:%d - failed to lock locality %u\n",
-			__FILE__, __LINE__, locality);
-			return TPM_DRIVER_ERR;
+		rc = tis_wait_received_access(locality);
+		if (rc) {
+			printf("%s:%d - failed to lock locality %u with error %#x\n",
+			__FILE__, __LINE__, locality, rc);
+			return rc;
 		}
 
 		/* Certain TPMs seem to need some delay here or they hang... */
 		udelay(10);
 	}
 
-	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
-		return TPM_DRIVER_ERR;
-
-	return 0;
+	return tis_command_ready(locality);
 }
 
 /*
@@ -652,16 +647,17 @@ int tis_open(void)
  * @recvbuf - memory to save the response to
  * @recv_len - pointer to the size of the response buffer
  *
- * Returns 0 on success (and places the number of response bytes at recv_len)
- * or TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success (and places the number of response bytes
+ * at recv_len) or TPM_CB_FAIL on failure.
  */
-int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
 		 uint8_t *recvbuf, size_t *recv_len)
 {
-	if (tis_senddata(sendbuf, send_size)) {
-		printf("%s:%d failed sending data to TPM\n",
-		       __FILE__, __LINE__);
-		return TPM_DRIVER_ERR;
+	tpm_result_t rc = tis_senddata(sendbuf, send_size);
+	if (rc) {
+		printf("%s:%d failed sending data to TPM with error %#x\n",
+		       __FILE__, __LINE__, rc);
+		return rc;
 	}
 
 	return tis_readresponse(recvbuf, recv_len);
@@ -680,14 +676,15 @@ int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
  * @vector - TPM interrupt vector
  * @polarity - TPM interrupt polarity
  *
- * Returns 0 on success, TPM_DRIVER_ERR on failure.
+ * Returns TPM_SUCCESS on success, TPM_CB_FAIL on failure.
  */
-static int tis_setup_interrupt(int vector, int polarity)
+static tpm_result_t tis_setup_interrupt(int vector, int polarity)
 {
 	u8 locality = 0;
+	tpm_result_t rc = tlcl_lib_init();
 
-	if (tlcl_lib_init())
-		return TPM_DRIVER_ERR;
+	if (rc)
+		return rc;
 
 	/* Set TPM interrupt vector */
 	tpm_write_int_vector(vector, locality);
@@ -695,7 +692,7 @@ static int tis_setup_interrupt(int vector, int polarity)
 	/* Set TPM interrupt polarity and disable interrupts */
 	tpm_write_int_polarity(polarity, locality);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
 static void lpc_tpm_read_resources(struct device *dev)
diff --git a/src/drivers/spi/tpm/tis.c b/src/drivers/spi/tpm/tis.c
index b9b2a4a5cb6a..6fa6c828483c 100644
--- a/src/drivers/spi/tpm/tis.c
+++ b/src/drivers/spi/tpm/tis.c
@@ -29,29 +29,31 @@ static const char *tis_get_dev_name(struct tpm2_info *info)
 	return "Unknown";
 }
 
-int tis_open(void)
+tpm_result_t tis_open(void)
 {
 	if (tpm_is_open) {
 		printk(BIOS_ERR, "%s() called twice.\n", __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_init(void)
+tpm_result_t tis_init(void)
 {
 	struct spi_slave spi;
 	struct tpm2_info info;
+	tpm_result_t rc = TPM_SUCCESS;
 
 	if (spi_setup_slave(CONFIG_DRIVER_TPM_SPI_BUS,
 			    CONFIG_DRIVER_TPM_SPI_CHIP, &spi)) {
 		printk(BIOS_ERR, "Failed to setup TPM SPI slave\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
-	if (tpm2_init(&spi)) {
+	rc = tpm2_init(&spi);
+	if (rc) {
 		printk(BIOS_ERR, "Failed to initialize TPM SPI interface\n");
-		return -1;
+		return rc;
 	}
 
 	tpm2_get_info(&info);
@@ -59,18 +61,18 @@ int tis_init(void)
 	printk(BIOS_INFO, "Initialized TPM device %s revision %d\n",
 	       tis_get_dev_name(&info), info.revision);
 
-	return 0;
+	return TPM_SUCCESS;
 }
 
-int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+tpm_result_t tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 		 uint8_t *recvbuf, size_t *rbuf_len)
 {
 	int len = tpm2_process_command(sendbuf, sbuf_size, recvbuf, *rbuf_len);
 
 	if (len == 0)
-		return -1;
+		return TPM_CB_FAIL;
 
 	*rbuf_len = len;
 
-	return 0;
+	return TPM_SUCCESS;
 }
diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c
index 01f04f4a36f6..13f44f9448b7 100644
--- a/src/drivers/spi/tpm/tpm.c
+++ b/src/drivers/spi/tpm/tpm.c
@@ -394,7 +394,7 @@ static const uint32_t supported_did_vids[] = {
 	0x0000104a   /* ST33HTPH2E32 */
 };
 
-int tpm2_init(struct spi_slave *spi_if)
+tpm_result_t tpm2_init(struct spi_slave *spi_if)
 {
 	uint32_t did_vid, status, intf_id;
 	uint8_t cmd;
@@ -433,7 +433,7 @@ int tpm2_init(struct spi_slave *spi_if)
 	if (!retries) {
 		printk(BIOS_ERR, "\n%s: Failed to connect to the TPM\n",
 		       __func__);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	printk(BIOS_INFO, " done!\n");
@@ -444,11 +444,11 @@ int tpm2_init(struct spi_slave *spi_if)
 		if (tpm2_read_reg(TPM_INTF_ID_REG, &intf_id, sizeof(intf_id)) != CB_SUCCESS) {
 			printk(BIOS_ERR, "\n%s: Failed to read interface ID register\n",
 			       __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 		if ((be32toh(intf_id) & 0xF) == 0xF) {
 			printk(BIOS_DEBUG, "\n%s: Not a TPM2 device\n", __func__);
-			return -1;
+			return TPM_CB_FAIL;
 		}
 	}
 
@@ -459,16 +459,16 @@ int tpm2_init(struct spi_slave *spi_if)
 		 * initialization after reset.
 		 */
 		if (tpm2_claim_locality() != CB_SUCCESS)
-			return -1;
+			return TPM_CB_FAIL;
 
 	if (read_tpm_sts(&status) != CB_SUCCESS) {
 		printk(BIOS_ERR, "Reading status reg failed\n");
-		return -1;
+		return TPM_CB_FAIL;
 	}
 	if ((status & TPM_STS_FAMILY_MASK) != TPM_STS_FAMILY_TPM_2_0) {
 		printk(BIOS_ERR, "unexpected TPM family value, status: %#x\n",
 		       status);
-		return -1;
+		return TPM_CB_FAIL;
 	}
 
 	/*
@@ -492,7 +492,7 @@ int tpm2_init(struct spi_slave *spi_if)
                         cr50_set_board_cfg();
 		}
 	}
-	return 0;
+	return TPM_SUCCESS;
 }
 
 /*
diff --git a/src/drivers/spi/tpm/tpm.h b/src/drivers/spi/tpm/tpm.h
index cb09148b1f86..da15a73bd8b1 100644
--- a/src/drivers/spi/tpm/tpm.h
+++ b/src/drivers/spi/tpm/tpm.h
@@ -4,6 +4,7 @@
 #define __COREBOOT_SRC_DRIVERS_SPI_TPM_TPM_H
 
 #include <drivers/tpm/cr50.h>
+#include <security/tpm/tss_errors.h>
 #include <stddef.h>
 #include <spi-generic.h>
 
@@ -26,7 +27,7 @@ struct tpm2_info {
  *
  * Return 0 on success, non-zero on failure.
  */
-int tpm2_init(struct spi_slave *spi_if);
+tpm_result_t tpm2_init(struct spi_slave *spi_if);
 
 /*
  * Each command processing consists of sending the command to the TPM, by