1 files changed, 835 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
new file mode 100644
index 000000000000..d66f51b3648e
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -0,0 +1,835 @@
+/*
+ * Copyright (C) 2005, 2006 IBM Corporation
+ * Copyright (C) 2014, 2015 Intel Corporation
+ *
+ * Authors:
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG TPM Interface Spec version 1.2, revision 1.0.
+ *
+ * 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, version 2 of the
+ * License.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/pnp.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/acpi.h>
+#include <linux/freezer.h>
+#include "tpm.h"
+#include "tpm_tis_core.h"
+
+/* Before we attempt to access the TPM we must see that the valid bit is set.
+ * The specification says that this bit is 0 at reset and remains 0 until the
+ * 'TPM has gone through its self test and initialization and has established
+ * correct values in the other bits.'
+ */
+static int wait_startup(struct tpm_chip *chip, int l)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	unsigned long stop = jiffies + chip->timeout_a;
+
+	do {
+		int rc;
+		u8 access;
+
+		rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
+		if (rc < 0)
+			return rc;
+
+		if (access & TPM_ACCESS_VALID)
+			return 0;
+		msleep(TPM_TIMEOUT);
+	} while (time_before(jiffies, stop));
+	return -1;
+}
+
+static int check_locality(struct tpm_chip *chip, int l)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc;
+	u8 access;
+
+	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
+	if (rc < 0)
+		return rc;
+
+	if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+	    (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
+		return priv->locality = l;
+
+	return -1;
+}
+
+static void release_locality(struct tpm_chip *chip, int l, int force)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc;
+	u8 access;
+
+	rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
+	if (rc < 0)
+		return;
+
+	if (force || (access &
+		      (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
+	    (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
+		tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
+
+}
+
+static int request_locality(struct tpm_chip *chip, int l)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	unsigned long stop, timeout;
+	long rc;
+
+	if (check_locality(chip, l) >= 0)
+		return l;
+
+	rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
+	if (rc < 0)
+		return rc;
+
+	stop = jiffies + chip->timeout_a;
+
+	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
+again:
+		timeout = stop - jiffies;
+		if ((long)timeout <= 0)
+			return -1;
+		rc = wait_event_interruptible_timeout(priv->int_queue,
+						      (check_locality
+						       (chip, l) >= 0),
+						      timeout);
+		if (rc > 0)
+			return l;
+		if (rc == -ERESTARTSYS && freezing(current)) {
+			clear_thread_flag(TIF_SIGPENDING);
+			goto again;
+		}
+	} else {
+		/* wait for burstcount */
+		do {
+			if (check_locality(chip, l) >= 0)
+				return l;
+			msleep(TPM_TIMEOUT);
+		} while (time_before(jiffies, stop));
+	}
+	return -1;
+}
+
+static u8 tpm_tis_status(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc;
+	u8 status;
+
+	rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
+	if (rc < 0)
+		return 0;
+
+	return status;
+}
+
+static void tpm_tis_ready(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+
+	/* this causes the current command to be aborted */
+	tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
+}
+
+static int get_burstcount(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	unsigned long stop;
+	int burstcnt, rc;
+	u32 value;
+
+	/* wait for burstcount */
+	/* which timeout value, spec has 2 answers (c & d) */
+	stop = jiffies + chip->timeout_d;
+	do {
+		rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
+		if (rc < 0)
+			return rc;
+
+		burstcnt = (value >> 8) & 0xFFFF;
+		if (burstcnt)
+			return burstcnt;
+		msleep(TPM_TIMEOUT);
+	} while (time_before(jiffies, stop));
+	return -EBUSY;
+}
+
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int size = 0, burstcnt, rc;
+
+	while (size < count &&
+	       wait_for_tpm_stat(chip,
+				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+				 chip->timeout_c,
+				 &priv->read_queue, true) == 0) {
+		burstcnt = min_t(int, get_burstcount(chip), count - size);
+
+		rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
+					burstcnt, buf + size);
+		if (rc < 0)
+			return rc;
+
+		size += burstcnt;
+	}
+	return size;
+}
+
+static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int size = 0;
+	int expected, status;
+
+	if (count < TPM_HEADER_SIZE) {
+		size = -EIO;
+		goto out;
+	}
+
+	size = recv_data(chip, buf, TPM_HEADER_SIZE);
+	/* read first 10 bytes, including tag, paramsize, and result */
+	if (size < TPM_HEADER_SIZE) {
+		dev_err(&chip->dev, "Unable to read header\n");
+		goto out;
+	}
+
+	expected = be32_to_cpu(*(__be32 *) (buf + 2));
+	if (expected > count) {
+		size = -EIO;
+		goto out;
+	}
+
+	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
+			  expected - TPM_HEADER_SIZE);
+	if (size < expected) {
+		dev_err(&chip->dev, "Unable to read remainder of result\n");
+		size = -ETIME;
+		goto out;
+	}
+
+	wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+			  &priv->int_queue, false);
+	status = tpm_tis_status(chip);
+	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
+		dev_err(&chip->dev, "Error left over data\n");
+		size = -EIO;
+		goto out;
+	}
+
+out:
+	tpm_tis_ready(chip);
+	release_locality(chip, priv->locality, 0);
+	return size;
+}
+
+/*
+ * If interrupts are used (signaled by an irq set in the vendor structure)
+ * tpm.c can skip polling for the data to be available as the interrupt is
+ * waited for here
+ */
+static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc, status, burstcnt;
+	size_t count = 0;
+	bool itpm = priv->flags & TPM_TIS_ITPM_POSSIBLE;
+
+	if (request_locality(chip, 0) < 0)
+		return -EBUSY;
+
+	status = tpm_tis_status(chip);
+	if ((status & TPM_STS_COMMAND_READY) == 0) {
+		tpm_tis_ready(chip);
+		if (wait_for_tpm_stat
+		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
+		     &priv->int_queue, false) < 0) {
+			rc = -ETIME;
+			goto out_err;
+		}
+	}
+
+	while (count < len - 1) {
+		burstcnt = min_t(int, get_burstcount(chip), len - count - 1);
+		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
+					 burstcnt, buf + count);
+		if (rc < 0)
+			goto out_err;
+
+		count += burstcnt;
+
+		wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+				  &priv->int_queue, false);
+		status = tpm_tis_status(chip);
+		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
+			rc = -EIO;
+			goto out_err;
+		}
+	}
+
+	/* write last byte */
+	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
+	if (rc < 0)
+		goto out_err;
+
+	wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+			  &priv->int_queue, false);
+	status = tpm_tis_status(chip);
+	if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
+		rc = -EIO;
+		goto out_err;
+	}
+
+	return 0;
+
+out_err:
+	tpm_tis_ready(chip);
+	release_locality(chip, priv->locality, 0);
+	return rc;
+}
+
+static void disable_interrupts(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u32 intmask;
+	int rc;
+
+	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
+	if (rc < 0)
+		intmask = 0;
+
+	intmask &= ~TPM_GLOBAL_INT_ENABLE;
+	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
+
+	devm_free_irq(chip->dev.parent, priv->irq, chip);
+	priv->irq = 0;
+	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
+}
+
+/*
+ * If interrupts are used (signaled by an irq set in the vendor structure)
+ * tpm.c can skip polling for the data to be available as the interrupt is
+ * waited for here
+ */
+static int tpm_tis_send_main(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc;
+	u32 ordinal;
+	unsigned long dur;
+
+	rc = tpm_tis_send_data(chip, buf, len);
+	if (rc < 0)
+		return rc;
+
+	/* go and do it */
+	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
+	if (rc < 0)
+		goto out_err;
+
+	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
+		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+
+		if (chip->flags & TPM_CHIP_FLAG_TPM2)
+			dur = tpm2_calc_ordinal_duration(chip, ordinal);
+		else
+			dur = tpm_calc_ordinal_duration(chip, ordinal);
+
+		if (wait_for_tpm_stat
+		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
+		     &priv->read_queue, false) < 0) {
+			rc = -ETIME;
+			goto out_err;
+		}
+	}
+	return len;
+out_err:
+	tpm_tis_ready(chip);
+	release_locality(chip, priv->locality, 0);
+	return rc;
+}
+
+static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	int rc, irq;
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+
+	if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
+		return tpm_tis_send_main(chip, buf, len);
+
+	/* Verify receipt of the expected IRQ */
+	irq = priv->irq;
+	priv->irq = 0;
+	chip->flags &= ~TPM_CHIP_FLAG_IRQ;
+	rc = tpm_tis_send_main(chip, buf, len);
+	priv->irq = irq;
+	chip->flags |= TPM_CHIP_FLAG_IRQ;
+	if (!priv->irq_tested)
+		msleep(1);
+	if (!priv->irq_tested)
+		disable_interrupts(chip);
+	priv->irq_tested = true;
+	return rc;
+}
+
+struct tis_vendor_timeout_override {
+	u32 did_vid;
+	unsigned long timeout_us[4];
+};
+
+static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
+	/* Atmel 3204 */
+	{ 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
+			(TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
+};
+
+static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
+				    unsigned long *timeout_cap)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int i, rc;
+	u32 did_vid;
+
+	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
+	if (rc < 0)
+		return rc;
+
+	for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
+		if (vendor_timeout_overrides[i].did_vid != did_vid)
+			continue;
+		memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
+		       sizeof(vendor_timeout_overrides[i].timeout_us));
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Early probing for iTPM with STS_DATA_EXPECT flaw.
+ * Try sending command without itpm flag set and if that
+ * fails, repeat with itpm flag set.
+ */
+static int probe_itpm(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	int rc = 0;
+	u8 cmd_getticks[] = {
+		0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
+		0x00, 0x00, 0x00, 0xf1
+	};
+	size_t len = sizeof(cmd_getticks);
+	bool itpm;
+	u16 vendor;
+
+	rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
+	if (rc < 0)
+		return rc;
+
+	/* probe only iTPMS */
+	if (vendor != TPM_VID_INTEL)
+		return 0;
+
+	itpm = false;
+
+	rc = tpm_tis_send_data(chip, cmd_getticks, len);
+	if (rc == 0)
+		goto out;
+
+	tpm_tis_ready(chip);
+	release_locality(chip, priv->locality, 0);
+
+	itpm = true;
+
+	rc = tpm_tis_send_data(chip, cmd_getticks, len);
+	if (rc == 0) {
+		dev_info(&chip->dev, "Detected an iTPM.\n");
+		rc = 1;
+	} else
+		rc = -EFAULT;
+
+out:
+	tpm_tis_ready(chip);
+	release_locality(chip, priv->locality, 0);
+
+	return rc;
+}
+
+static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+
+	switch (priv->manufacturer_id) {
+	case TPM_VID_WINBOND:
+		return ((status == TPM_STS_VALID) ||
+			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
+	case TPM_VID_STM:
+		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
+	default:
+		return (status == TPM_STS_COMMAND_READY);
+	}
+}
+
+static irqreturn_t tis_int_handler(int dummy, void *dev_id)
+{
+	struct tpm_chip *chip = dev_id;
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u32 interrupt;
+	int i, rc;
+
+	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
+	if (rc < 0)
+		return IRQ_NONE;
+
+	if (interrupt == 0)
+		return IRQ_NONE;
+
+	priv->irq_tested = true;
+	if (interrupt & TPM_INTF_DATA_AVAIL_INT)
+		wake_up_interruptible(&priv->read_queue);
+	if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
+		for (i = 0; i < 5; i++)
+			if (check_locality(chip, i) >= 0)
+				break;
+	if (interrupt &
+	    (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
+	     TPM_INTF_CMD_READY_INT))
+		wake_up_interruptible(&priv->int_queue);
+
+	/* Clear interrupts handled with TPM_EOI */
+	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
+	if (rc < 0)
+		return IRQ_NONE;
+
+	tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
+	return IRQ_HANDLED;
+}
+
+/* Register the IRQ and issue a command that will cause an interrupt. If an
+ * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
+ * everything and leave in polling mode. Returns 0 on success.
+ */
+static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
+				    int flags, int irq)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u8 original_int_vec;
+	int rc;
+	u32 int_status;
+
+	if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
+			     dev_name(&chip->dev), chip) != 0) {
+		dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
+			 irq);
+		return -1;
+	}
+	priv->irq = irq;
+
+	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
+			   &original_int_vec);
+	if (rc < 0)
+		return rc;
+
+	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
+	if (rc < 0)
+		return rc;
+
+	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
+	if (rc < 0)
+		return rc;
+
+	/* Clear all existing */
+	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
+	if (rc < 0)
+		return rc;
+
+	/* Turn on */
+	rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
+			     intmask | TPM_GLOBAL_INT_ENABLE);
+	if (rc < 0)
+		return rc;
+
+	priv->irq_tested = false;
+
+	/* Generate an interrupt by having the core call through to
+	 * tpm_tis_send
+	 */
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		tpm2_gen_interrupt(chip);
+	else
+		tpm_gen_interrupt(chip);
+
+	/* tpm_tis_send will either confirm the interrupt is working or it
+	 * will call disable_irq which undoes all of the above.
+	 */
+	if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
+		rc = tpm_tis_write8(priv, original_int_vec,
+				TPM_INT_VECTOR(priv->locality));
+		if (rc < 0)
+			return rc;
+
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
+ * do not have ACPI/etc. We typically expect the interrupt to be declared if
+ * present.
+ */
+static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u8 original_int_vec;
+	int i, rc;
+
+	rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
+			   &original_int_vec);
+	if (rc < 0)
+		return;
+
+	if (!original_int_vec) {
+		if (IS_ENABLED(CONFIG_X86))
+			for (i = 3; i <= 15; i++)
+				if (!tpm_tis_probe_irq_single(chip, intmask, 0,
+							      i))
+					return;
+	} else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
+					     original_int_vec))
+		return;
+}
+
+void tpm_tis_remove(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u32 reg = TPM_INT_ENABLE(priv->locality);
+	u32 interrupt;
+	int rc;
+
+	rc = tpm_tis_read32(priv, reg, &interrupt);
+	if (rc < 0)
+		interrupt = 0;
+
+	tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
+	release_locality(chip, priv->locality, 1);
+}
+EXPORT_SYMBOL_GPL(tpm_tis_remove);
+
+static const struct tpm_class_ops tpm_tis = {
+	.flags = TPM_OPS_AUTO_STARTUP,
+	.status = tpm_tis_status,
+	.recv = tpm_tis_recv,
+	.send = tpm_tis_send,
+	.cancel = tpm_tis_ready,
+	.update_timeouts = tpm_tis_update_timeouts,
+	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_canceled = tpm_tis_req_canceled,
+};
+
+int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
+		      const struct tpm_tis_phy_ops *phy_ops,
+		      acpi_handle acpi_dev_handle)
+{
+	u32 vendor, intfcaps, intmask;
+	u8 rid;
+	int rc, probe;
+	struct tpm_chip *chip;
+
+	chip = tpmm_chip_alloc(dev, &tpm_tis);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+
+#ifdef CONFIG_ACPI
+	chip->acpi_dev_handle = acpi_dev_handle;
+#endif
+
+	/* Maximum timeouts */
+	chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
+	chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
+	chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
+	chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
+	priv->phy_ops = phy_ops;
+	dev_set_drvdata(&chip->dev, priv);
+
+	if (wait_startup(chip, 0) != 0) {
+		rc = -ENODEV;
+		goto out_err;
+	}
+
+	/* Take control of the TPM's interrupt hardware and shut it off */
+	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
+	if (rc < 0)
+		goto out_err;
+
+	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
+		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
+	intmask &= ~TPM_GLOBAL_INT_ENABLE;
+	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
+
+	if (request_locality(chip, 0) != 0) {
+		rc = -ENODEV;
+		goto out_err;
+	}
+
+	rc = tpm2_probe(chip);
+	if (rc)
+		goto out_err;
+
+	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
+	if (rc < 0)
+		goto out_err;
+
+	priv->manufacturer_id = vendor;
+
+	rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
+	if (rc < 0)
+		goto out_err;
+
+	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
+		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
+		 vendor >> 16, rid);
+
+	if (!(priv->flags & TPM_TIS_ITPM_POSSIBLE)) {
+		probe = probe_itpm(chip);
+		if (probe < 0) {
+			rc = -ENODEV;
+			goto out_err;
+		}
+
+		if (!!probe)
+			priv->flags |= TPM_TIS_ITPM_POSSIBLE;
+	}
+
+	/* Figure out the capabilities */
+	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
+	if (rc < 0)
+		goto out_err;
+
+	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
+		intfcaps);
+	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
+		dev_dbg(dev, "\tBurst Count Static\n");
+	if (intfcaps & TPM_INTF_CMD_READY_INT)
+		dev_dbg(dev, "\tCommand Ready Int Support\n");
+	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
+		dev_dbg(dev, "\tInterrupt Edge Falling\n");
+	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
+		dev_dbg(dev, "\tInterrupt Edge Rising\n");
+	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
+		dev_dbg(dev, "\tInterrupt Level Low\n");
+	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
+		dev_dbg(dev, "\tInterrupt Level High\n");
+	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
+		dev_dbg(dev, "\tLocality Change Int Support\n");
+	if (intfcaps & TPM_INTF_STS_VALID_INT)
+		dev_dbg(dev, "\tSts Valid Int Support\n");
+	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
+		dev_dbg(dev, "\tData Avail Int Support\n");
+
+	/* Very early on issue a command to the TPM in polling mode to make
+	 * sure it works. May as well use that command to set the proper
+	 *  timeouts for the driver.
+	 */
+	if (tpm_get_timeouts(chip)) {
+		dev_err(dev, "Could not get TPM timeouts and durations\n");
+		rc = -ENODEV;
+		goto out_err;
+	}
+
+	/* INTERRUPT Setup */
+	init_waitqueue_head(&priv->read_queue);
+	init_waitqueue_head(&priv->int_queue);
+	if (irq != -1) {
+		if (irq) {
+			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
+						 irq);
+			if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
+				dev_err(&chip->dev, FW_BUG
+					"TPM interrupt not working, polling instead\n");
+		} else {
+			tpm_tis_probe_irq(chip, intmask);
+		}
+	}
+
+	return tpm_chip_register(chip);
+out_err:
+	tpm_tis_remove(chip);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_tis_core_init);
+
+#ifdef CONFIG_PM_SLEEP
+static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	u32 intmask;
+	int rc;
+
+	/* reenable interrupts that device may have lost or
+	 * BIOS/firmware may have disabled
+	 */
+	rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
+	if (rc < 0)
+		return;
+
+	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
+	if (rc < 0)
+		return;
+
+	intmask |= TPM_INTF_CMD_READY_INT
+	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
+	    | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
+
+	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
+}
+
+int tpm_tis_resume(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	int ret;
+
+	if (chip->flags & TPM_CHIP_FLAG_IRQ)
+		tpm_tis_reenable_interrupts(chip);
+
+	ret = tpm_pm_resume(dev);
+	if (ret)
+		return ret;
+
+	/* TPM 1.2 requires self-test on resume. This function actually returns
+	 * an error code but for unknown reason it isn't handled.
+	 */
+	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
+		tpm_do_selftest(chip);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tpm_tis_resume);
+#endif
+
+MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
+MODULE_DESCRIPTION("TPM Driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");