tpm: Rename generic_lpc_tpm to tpm_tis_lpc

The new name is more aligned with Linux kernel's naming of TPM driver.

Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Che-Liang Chiou <clchiou@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>

1 files changed, 495 insertions, 0 deletions

diff --git a/drivers/tpm/tpm_tis_lpc.c b/drivers/tpm/tpm_tis_lpc.c
new file mode 100644
index 000000000..04ad41897
--- /dev/null
+++ b/drivers/tpm/tpm_tis_lpc.c
@@ -0,0 +1,495 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * The code in this file is based on the article "Writing a TPM Device Driver"
+ * published on http://ptgmedia.pearsoncmg.com.
+ *
+ * One principal difference is that in the simplest config the other than 0
+ * TPM localities do not get mapped by some devices (for instance, by Infineon
+ * slb9635), so this driver provides access to locality 0 only.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <tpm.h>
+
+#define PREFIX "lpc_tpm: "
+
+struct tpm_locality {
+	u32 access;
+	u8 padding0[4];
+	u32 int_enable;
+	u8 vector;
+	u8 padding1[3];
+	u32 int_status;
+	u32 int_capability;
+	u32 tpm_status;
+	u8 padding2[8];
+	u8 data;
+	u8 padding3[3803];
+	u32 did_vid;
+	u8 rid;
+	u8 padding4[251];
+};
+
+/*
+ * This pointer refers to the TPM chip, 5 of its localities are mapped as an
+ * array.
+ */
+#define TPM_TOTAL_LOCALITIES	5
+static struct tpm_locality *lpc_tpm_dev =
+	(struct tpm_locality *)CONFIG_TPM_TIS_BASE_ADDRESS;
+
+/* Some registers' bit field definitions */
+#define TIS_STS_VALID                  (1 << 7) /* 0x80 */
+#define TIS_STS_COMMAND_READY          (1 << 6) /* 0x40 */
+#define TIS_STS_TPM_GO                 (1 << 5) /* 0x20 */
+#define TIS_STS_DATA_AVAILABLE         (1 << 4) /* 0x10 */
+#define TIS_STS_EXPECT                 (1 << 3) /* 0x08 */
+#define TIS_STS_RESPONSE_RETRY         (1 << 1) /* 0x02 */
+
+#define TIS_ACCESS_TPM_REG_VALID_STS   (1 << 7) /* 0x80 */
+#define TIS_ACCESS_ACTIVE_LOCALITY     (1 << 5) /* 0x20 */
+#define TIS_ACCESS_BEEN_SEIZED         (1 << 4) /* 0x10 */
+#define TIS_ACCESS_SEIZE               (1 << 3) /* 0x08 */
+#define TIS_ACCESS_PENDING_REQUEST     (1 << 2) /* 0x04 */
+#define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
+#define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */
+
+#define TIS_STS_BURST_COUNT_MASK       (0xffff)
+#define TIS_STS_BURST_COUNT_SHIFT      (8)
+
+/*
+ * Error value returned if a tpm register does not enter the expected state
+ * after continuous polling. No actual TPM register reading ever returns -1,
+ * so this value is a safe error indication to be mixed with possible status
+ * register values.
+ */
+#define TPM_TIMEOUT_ERR			(-1)
+
+/* Error value returned on various TPM driver errors. */
+#define TPM_DRIVER_ERR		(1)
+
+ /* 1 second is plenty for anything TPM does. */
+#define MAX_DELAY_US	(1000 * 1000)
+
+/* Retrieve burst count value out of the status register contents. */
+static u16 burst_count(u32 status)
+{
+	return (status >> TIS_STS_BURST_COUNT_SHIFT) & TIS_STS_BURST_COUNT_MASK;
+}
+
+/*
+ * Structures defined below allow creating descriptions of TPM vendor/device
+ * ID information for run time discovery. The only device the system knows
+ * about at this time is Infineon slb9635.
+ */
+struct device_name {
+	u16 dev_id;
+	const char * const dev_name;
+};
+
+struct vendor_name {
+	u16 vendor_id;
+	const char *vendor_name;
+	const struct device_name *dev_names;
+};
+
+static const struct device_name infineon_devices[] = {
+	{0xb, "SLB9635 TT 1.2"},
+	{0}
+};
+
+static const struct vendor_name vendor_names[] = {
+	{0x15d1, "Infineon", infineon_devices},
+};
+
+/*
+ * Cached vendor/device ID pair to indicate that the device has been already
+ * discovered.
+ */
+static u32 vendor_dev_id;
+
+/* TPM access wrappers to support tracing */
+static u8 tpm_read_byte(const u8 *ptr)
+{
+	u8  ret = readb(ptr);
+	debug(PREFIX "Read reg 0x%4.4x returns 0x%2.2x\n",
+	      (u32)(uintptr_t)ptr - (u32)(uintptr_t)lpc_tpm_dev, ret);
+	return ret;
+}
+
+static u32 tpm_read_word(const u32 *ptr)
+{
+	u32  ret = readl(ptr);
+	debug(PREFIX "Read reg 0x%4.4x returns 0x%8.8x\n",
+	      (u32)(uintptr_t)ptr - (u32)(uintptr_t)lpc_tpm_dev, ret);
+	return ret;
+}
+
+static void tpm_write_byte(u8 value, u8 *ptr)
+{
+	debug(PREFIX "Write reg 0x%4.4x with 0x%2.2x\n",
+	      (u32)(uintptr_t)ptr - (u32)(uintptr_t)lpc_tpm_dev, value);
+	writeb(value, ptr);
+}
+
+static void tpm_write_word(u32 value, u32 *ptr)
+{
+	debug(PREFIX "Write reg 0x%4.4x with 0x%8.8x\n",
+	      (u32)(uintptr_t)ptr - (u32)(uintptr_t)lpc_tpm_dev, value);
+	writel(value, ptr);
+}
+
+/*
+ * tis_wait_reg()
+ *
+ * Wait for at least a second for a register to change its state to match the
+ * expected state. Normally the transition happens within microseconds.
+ *
+ * @reg - pointer to the TPM register
+ * @mask - bitmask for the bitfield(s) to watch
+ * @expected - value the field(s) are supposed to be set to
+ *
+ * Returns the register contents in case the expected value was found in the
+ * appropriate register bits, or TPM_TIMEOUT_ERR on timeout.
+ */
+static u32 tis_wait_reg(u32 *reg, u8 mask, u8 expected)
+{
+	u32 time_us = MAX_DELAY_US;
+
+	while (time_us > 0) {
+		u32 value = tpm_read_word(reg);
+		if ((value & mask) == expected)
+			return value;
+		udelay(1); /* 1 us */
+		time_us--;
+	}
+	return TPM_TIMEOUT_ERR;
+}
+
+/*
+ * 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.
+ */
+int tis_init(void)
+{
+	u32 didvid = tpm_read_word(&lpc_tpm_dev[0].did_vid);
+	int i;
+	const char *device_name = "unknown";
+	const char *vendor_name = device_name;
+	u16 vid, did;
+
+	if (vendor_dev_id)
+		return 0;  /* Already probed. */
+
+	if (!didvid || (didvid == 0xffffffff)) {
+		printf("%s: No TPM device found\n", __func__);
+		return TPM_DRIVER_ERR;
+	}
+
+	vendor_dev_id = didvid;
+
+	vid = didvid & 0xffff;
+	did = (didvid >> 16) & 0xffff;
+	for (i = 0; i < ARRAY_SIZE(vendor_names); i++) {
+		int j = 0;
+		u16 known_did;
+
+		if (vid == vendor_names[i].vendor_id)
+			vendor_name = vendor_names[i].vendor_name;
+
+		while ((known_did = vendor_names[i].dev_names[j].dev_id) != 0) {
+			if (known_did == did) {
+				device_name =
+					vendor_names[i].dev_names[j].dev_name;
+				break;
+			}
+			j++;
+		}
+		break;
+	}
+
+	printf("Found TPM %s by %s\n", device_name, vendor_name);
+	return 0;
+}
+
+/*
+ * tis_senddata()
+ *
+ * send the passed in data to the TPM device.
+ *
+ * @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
+ * not accept the entire command).
+ */
+static u32 tis_senddata(const u8 * const data, u32 len)
+{
+	u32 offset = 0;
+	u16 burst = 0;
+	u32 max_cycles = 0;
+	u8 locality = 0;
+	u32 value;
+
+	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
+			     TIS_STS_COMMAND_READY, TIS_STS_COMMAND_READY);
+	if (value == TPM_TIMEOUT_ERR) {
+		printf("%s:%d - failed to get 'command_ready' status\n",
+		       __FILE__, __LINE__);
+		return TPM_DRIVER_ERR;
+	}
+	burst = burst_count(value);
+
+	while (1) {
+		unsigned count;
+
+		/* Wait till the device is ready to accept more data. */
+		while (!burst) {
+			if (max_cycles++ == MAX_DELAY_US) {
+				printf("%s:%d failed to feed %d bytes of %d\n",
+				       __FILE__, __LINE__, len - offset, len);
+				return TPM_DRIVER_ERR;
+			}
+			udelay(1);
+			burst = burst_count(tpm_read_word(&lpc_tpm_dev
+						     [locality].tpm_status));
+		}
+
+		max_cycles = 0;
+
+		/*
+		 * Calculate number of bytes the TPM is ready to accept in one
+		 * shot.
+		 *
+		 * We want to send the last byte outside of the loop (hence
+		 * the -1 below) to make sure that the 'expected' status bit
+		 * changes to zero exactly after the last byte is fed into the
+		 * FIFO.
+		 */
+		count = min(burst, len - offset - 1);
+		while (count--)
+			tpm_write_byte(data[offset++],
+				  &lpc_tpm_dev[locality].data);
+
+		value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
+				     TIS_STS_VALID, TIS_STS_VALID);
+
+		if ((value == TPM_TIMEOUT_ERR) || !(value & TIS_STS_EXPECT)) {
+			printf("%s:%d TPM command feed overflow\n",
+			       __FILE__, __LINE__);
+			return TPM_DRIVER_ERR;
+		}
+
+		burst = burst_count(value);
+		if ((offset == (len - 1)) && burst) {
+			/*
+			 * We need to be able to send the last byte to the
+			 * device, so burst size must be nonzero before we
+			 * break out.
+			 */
+			break;
+		}
+	}
+
+	/* Send the last byte. */
+	tpm_write_byte(data[offset++], &lpc_tpm_dev[locality].data);
+	/*
+	 * Verify that TPM does not expect any more data as part of this
+	 * command.
+	 */
+	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
+			     TIS_STS_VALID, TIS_STS_VALID);
+	if ((value == TPM_TIMEOUT_ERR) || (value & TIS_STS_EXPECT)) {
+		printf("%s:%d unexpected TPM status 0x%x\n",
+		       __FILE__, __LINE__, value);
+		return TPM_DRIVER_ERR;
+	}
+
+	/* OK, sitting pretty, let's start the command execution. */
+	tpm_write_word(TIS_STS_TPM_GO, &lpc_tpm_dev[locality].tpm_status);
+	return 0;
+}
+
+/*
+ * tis_readresponse()
+ *
+ * read the TPM device response after a command was issued.
+ *
+ * @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.
+ */
+static u32 tis_readresponse(u8 *buffer, u32 *len)
+{
+	u16 burst;
+	u32 value;
+	u32 offset = 0;
+	u8 locality = 0;
+	const u32 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
+	u32 expected_count = *len;
+	int max_cycles = 0;
+
+	/* Wait for the TPM to process the command. */
+	value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
+			      has_data, has_data);
+	if (value == TPM_TIMEOUT_ERR) {
+		printf("%s:%d failed processing command\n",
+		       __FILE__, __LINE__);
+		return TPM_DRIVER_ERR;
+	}
+
+	do {
+		while ((burst = burst_count(value)) == 0) {
+			if (max_cycles++ == MAX_DELAY_US) {
+				printf("%s:%d TPM stuck on read\n",
+				       __FILE__, __LINE__);
+				return TPM_DRIVER_ERR;
+			}
+			udelay(1);
+			value = tpm_read_word(&lpc_tpm_dev
+					      [locality].tpm_status);
+		}
+
+		max_cycles = 0;
+
+		while (burst-- && (offset < expected_count)) {
+			buffer[offset++] = tpm_read_byte(&lpc_tpm_dev
+							 [locality].data);
+
+			if (offset == 6) {
+				/*
+				 * We got the first six bytes of the reply,
+				 * let's figure out how many bytes to expect
+				 * total - it is stored as a 4 byte number in
+				 * network order, starting with offset 2 into
+				 * the body of the reply.
+				 */
+				u32 real_length;
+				memcpy(&real_length,
+				       buffer + 2,
+				       sizeof(real_length));
+				expected_count = be32_to_cpu(real_length);
+
+				if ((expected_count < offset) ||
+				    (expected_count > *len)) {
+					printf("%s:%d bad response size %d\n",
+					       __FILE__, __LINE__,
+					       expected_count);
+					return TPM_DRIVER_ERR;
+				}
+			}
+		}
+
+		/* Wait for the next portion. */
+		value = tis_wait_reg(&lpc_tpm_dev[locality].tpm_status,
+				     TIS_STS_VALID, TIS_STS_VALID);
+		if (value == TPM_TIMEOUT_ERR) {
+			printf("%s:%d failed to read response\n",
+			       __FILE__, __LINE__);
+			return TPM_DRIVER_ERR;
+		}
+
+		if (offset == expected_count)
+			break;	/* We got all we needed. */
+
+	} while ((value & has_data) == has_data);
+
+	/*
+	 * Make sure we indeed read all there was. The TIS_STS_VALID bit is
+	 * known to be set.
+	 */
+	if (value & TIS_STS_DATA_AVAILABLE) {
+		printf("%s:%d wrong receive status %x\n",
+		       __FILE__, __LINE__, value);
+		return TPM_DRIVER_ERR;
+	}
+
+	/* Tell the TPM that we are done. */
+	tpm_write_word(TIS_STS_COMMAND_READY, &lpc_tpm_dev
+		  [locality].tpm_status);
+	*len = offset;
+	return 0;
+}
+
+int tis_open(void)
+{
+	u8 locality = 0; /* we use locality zero for everything. */
+
+	if (tis_close())
+		return TPM_DRIVER_ERR;
+
+	/* now request access to locality. */
+	tpm_write_word(TIS_ACCESS_REQUEST_USE, &lpc_tpm_dev[locality].access);
+
+	/* did we get a lock? */
+	if (tis_wait_reg(&lpc_tpm_dev[locality].access,
+			 TIS_ACCESS_ACTIVE_LOCALITY,
+			 TIS_ACCESS_ACTIVE_LOCALITY) == TPM_TIMEOUT_ERR) {
+		printf("%s:%d - failed to lock locality %d\n",
+		       __FILE__, __LINE__, locality);
+		return TPM_DRIVER_ERR;
+	}
+
+	tpm_write_word(TIS_STS_COMMAND_READY,
+		       &lpc_tpm_dev[locality].tpm_status);
+	return 0;
+}
+
+int tis_close(void)
+{
+	u8 locality = 0;
+
+	if (tpm_read_word(&lpc_tpm_dev[locality].access) &
+	    TIS_ACCESS_ACTIVE_LOCALITY) {
+		tpm_write_word(TIS_ACCESS_ACTIVE_LOCALITY,
+			       &lpc_tpm_dev[locality].access);
+
+		if (tis_wait_reg(&lpc_tpm_dev[locality].access,
+				 TIS_ACCESS_ACTIVE_LOCALITY, 0) ==
+		    TPM_TIMEOUT_ERR) {
+			printf("%s:%d - failed to release locality %d\n",
+			       __FILE__, __LINE__, locality);
+			return TPM_DRIVER_ERR;
+		}
+	}
+	return 0;
+}
+
+int tis_sendrecv(const u8 *sendbuf, size_t send_size,
+		 u8 *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;
+	}
+
+	return tis_readresponse(recvbuf, (u32 *)recv_len);
+}