tpm2: add SPI TPM driver

This introduces a SPI TPM driver compliant with the TCG issued "TPM
Profile (PTP) Specification Revision 00.43" which can be found by
googling its title.

The driver implements both the hardware flow control protocol and the
TPM state machine.

The hardware flow control allows to map SPI based TPM devices to the
LPC address space on x86 platforms, on all other platforms it needs to
be implemented in the driver software.

The tis layer is somewhat superficial, it might have to be expanded
later.

A lot more implementation details can be found in the code comments.

Also, it is worth mentioning that this is not a complete version of
the driver: its robustness needs to be improved, delay loops need to
be bound, error conditions need to propagate up the call stack.

BRANCH=none
BUG=chrome-os-partner:52132, chrome-os-partner:50645, chrome-os-partner:54141
TEST=with the rest of the patches applied coreboot is able complete
     Chrome OS factory initialization of the TPM2 device.

Change-Id: I967bc5c689f6e6f345755f08cb088ad37abd5d1c
Signed-off-by: Martin Roth <martinroth@chromium.org>
Original-Commit-Id: 5611c6f7d7fe6d37da668f337f0e70263913d63e
Original-Change-Id: I17d732e66bd231c2289ec289994dd819c6276855
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/350124
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/15298
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@googlemail.com>
Tested-by: build bot (Jenkins)

1 files changed, 84 insertions, 0 deletions

diff --git a/src/drivers/spi/tpm/tis.c b/src/drivers/spi/tpm/tis.c
new file mode 100644
index 0000000000..9facb5208b
--- /dev/null
+++ b/src/drivers/spi/tpm/tis.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <arch/early_variables.h>
+#include <console/console.h>
+#include <string.h>
+#include <tpm.h>
+
+#include "tpm.h"
+
+static unsigned tpm_is_open CAR_GLOBAL;
+
+static const struct {
+	uint16_t vid;
+	uint16_t did;
+	const char *device_name;
+} dev_map[] = {
+	{ 0x15d1, 0x001b, "SLB9670" },
+	{ 0x1ae0, 0x0028, "CR50" },
+};
+
+static const char *tis_get_dev_name(struct tpm2_info *info)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(dev_map); i++)
+		if ((dev_map[i].vid == info->vendor_id) &&
+		    (dev_map[i].did == info->device_id))
+			return dev_map[i].device_name;
+	return "Unknown";
+}
+
+int tis_open(void)
+{
+	if (car_get_var(tpm_is_open)) {
+		printk(BIOS_ERR, "tis_open() called twice.\n");
+		return -1;
+	}
+	return 0;
+}
+
+int tis_close(void)
+{
+	if (car_get_var(tpm_is_open)) {
+
+		/*
+		 * Do we need to do something here, like waiting for a
+		 * transaction to stop?
+		 */
+		car_set_var(tpm_is_open, 0);
+	}
+
+	return 0;
+}
+
+int tis_init(void)
+{
+	struct tpm2_info info;
+
+	if (tpm2_init(spi_setup_slave(CONFIG_DRIVER_TPM_SPI_BUS,
+				      CONFIG_DRIVER_TPM_SPI_CHIP))) {
+		printk(BIOS_ERR, "Failed to initialize TPM SPI intierface\n");
+		return -1;
+	}
+
+	tpm2_get_info(&info);
+
+	printk(BIOS_INFO, "Initialized TPM device %s revision %d\n",
+	       tis_get_dev_name(&info), info.revision);
+
+	return 0;
+}
+
+
+int 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);
+	*rbuf_len = len;
+	return 0;
+}