drivers/i2c/tpm: Add support for Atmel TPM (AT97SC3204)

The I2C interface for the Atmel AT97SC3204 TPM varies greatly from the
existing I2C TPM support.  The Atmel part just passes the commands and
responses from the TIS layer across the I2C interface.

TEST=Build and run on Galileo Gen2 with Crypto Shield and vboot enabled

Change-Id: Ib2ef0ffdfc12b2fc11fe4c55b6414924d4b676dd
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/18800
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 132 insertions, 0 deletions

diff --git a/src/drivers/i2c/tpm/tis_atmel.c b/src/drivers/i2c/tpm/tis_atmel.c
new file mode 100644
index 0000000000..7d8b7a17b8
--- /dev/null
+++ b/src/drivers/i2c/tpm/tis_atmel.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but without any warranty; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/early_variables.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+#include <commonlib/endian.h>
+#include <console/console.h>
+#include <delay.h>
+#include <device/i2c.h>
+#include <endian.h>
+#include <lib.h>
+#include <tpm.h>
+#include <timer.h>
+
+#define RECV_TIMEOUT            (1 * 1000)  /* 1 second */
+#define XMIT_TIMEOUT            (1 * 1000)  /* 1 second */
+#define SLEEP_DURATION          1000        /* microseconds */
+
+struct tpm_output_header {
+	uint16_t tag;
+	uint32_t length;
+	uint32_t return_code;
+} __attribute__ ((packed));
+
+int tis_open(void)
+{
+	return 0;
+}
+
+int tis_close(void)
+{
+	return 0;
+}
+
+int tis_init(void)
+{
+	return 0;
+}
+
+int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+		uint8_t *recvbuf, size_t *rbuf_len)
+{
+	size_t hdr_bytes;
+	struct tpm_output_header *header;
+	size_t max_recv_bytes;
+	size_t recv_bytes;
+	int status;
+	struct stopwatch sw;
+
+	ASSERT(sbuf_size >= 10);
+	if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES)) {
+		/* Display the TPM command */
+		if (sbuf_size >= 10)
+			printk(BIOS_DEBUG, "TPM Command: 0x%08x\n",
+				read_at_be32(sendbuf, sizeof(uint16_t)
+				+ sizeof(uint32_t)));
+		hexdump(sendbuf, sbuf_size);
+	}
+
+	/* Send the command to the TPM */
+	stopwatch_init_msecs_expire(&sw, XMIT_TIMEOUT);
+	while (1) {
+		status = i2c_write_raw(CONFIG_DRIVER_TPM_I2C_BUS,
+			CONFIG_DRIVER_TPM_I2C_ADDR, (uint8_t *)sendbuf,
+			sbuf_size);
+		if ((status < 0) && (!stopwatch_expired(&sw)))
+			continue;
+		if (status < 0)
+			return status;
+		break;
+	}
+
+	/* Read the TPM response header */
+	max_recv_bytes = *rbuf_len;
+	ASSERT(max_recv_bytes >= sizeof(*header));
+	hdr_bytes = sizeof(*header);
+	header = (struct tpm_output_header *)recvbuf;
+	stopwatch_init_msecs_expire(&sw, RECV_TIMEOUT);
+	do {
+		status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
+			CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, hdr_bytes);
+		if (status > 0)
+			break;
+		udelay(SLEEP_DURATION);
+	} while (!stopwatch_expired(&sw));
+	if (status != sizeof(*header))
+		return -1;
+
+	/* Determine the number of bytes remaining */
+	recv_bytes = min(be32_to_cpu(*(uint32_t *)&header->length),
+		max_recv_bytes);
+
+	/* Determine if there is additional response data */
+	if (recv_bytes > hdr_bytes) {
+		/* Display the TPM response */
+		if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES))
+			hexdump(recvbuf, hdr_bytes);
+
+		/* 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;
+	}
+
+	/* Return the number of bytes received */
+	*rbuf_len = status;
+
+	/* Display the TPM response */
+	if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES)) {
+		printk(BIOS_DEBUG, "TPM Response: 0x%08x\n",
+			read_at_be32(recvbuf, sizeof(uint16_t)
+				+ sizeof(uint32_t)));
+		hexdump(recvbuf, *rbuf_len);
+	}
+
+	/* Successful transfer */
+	return 0;
+}