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>

src/drivers/i2c/tpm/Kconfig

@@ -2,24 +2,38 @@ config I2C_TPM
 	bool "I2C TPM"
 	depends on TPM || TPM2
 
+config MAINBOARD_HAS_I2C_TPM_ATMEL
+	bool
+	default n
+
 config MAINBOARD_HAS_I2C_TPM_CR50
 	bool
 	default n
 
 choice
 	prompt "I2C TPM Driver"
+	default I2C_TPM_ATMEL if MAINBOARD_HAS_I2C_TPM_ATMEL
 	default I2C_TPM_CR50 if MAINBOARD_HAS_I2C_TPM_CR50
-	default I2C_TPM_GENERIC if !MAINBOARD_HAS_I2C_TPM_CR50
+	default I2C_TPM_GENERIC if !MAINBOARD_HAS_I2C_TPM_CR50 && !MAINBOARD_HAS_I2C_TPM_ATMEL
 	depends on I2C_TPM
 
 config I2C_TPM_GENERIC
 	bool "Generic I2C TPM Driver"
 
+config I2C_TPM_ATMEL
+	bool "ATMEL I2C TPM Driver"
+
 config I2C_TPM_CR50
 	bool "CR50 I2C TPM Driver"
 
 endchoice
 
+config DRIVER_TIS_DEFAULT
+	bool
+	depends on I2C_TPM
+	default n if MAINBOARD_HAS_I2C_TPM_ATMEL
+	default y
+
 config DRIVER_TPM_I2C_BUS
 	hex "I2C TPM chip bus"
 	default 0x9 # FIXME, workaround for Kconfig BS

src/drivers/i2c/tpm/Makefile.inc

@@ -1,8 +1,13 @@
 
-ramstage-$(CONFIG_I2C_TPM) += tis.c
-romstage-$(CONFIG_I2C_TPM) += tis.c
-verstage-$(CONFIG_I2C_TPM) += tis.c
-bootblock-$(CONFIG_I2C_TPM) += tis.c
+ramstage-$(CONFIG_DRIVER_TIS_DEFAULT) += tis.c
+romstage-$(CONFIG_DRIVER_TIS_DEFAULT) += tis.c
+verstage-$(CONFIG_DRIVER_TIS_DEFAULT) += tis.c
+bootblock-$(CONFIG_DRIVER_TIS_DEFAULT) += tis.c
+
+ramstage-$(CONFIG_MAINBOARD_HAS_I2C_TPM_ATMEL) += tis_atmel.c
+romstage-$(CONFIG_MAINBOARD_HAS_I2C_TPM_ATMEL) += tis_atmel.c
+verstage-$(CONFIG_MAINBOARD_HAS_I2C_TPM_ATMEL) += tis_atmel.c
+bootblock-$(CONFIG_MAINBOARD_HAS_I2C_TPM_ATMEL) += tis_atmel.c
 
 ramstage-$(CONFIG_I2C_TPM_GENERIC) += tpm.c
 romstage-$(CONFIG_I2C_TPM_GENERIC) += tpm.c

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;
+}