[mirror_ubuntu-hirsute-kernel.git] / drivers / char / tpm / tpm_tis.c

/*
 * 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"

enum tis_access {
        TPM_ACCESS_VALID = 0x80,
        TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
        TPM_ACCESS_REQUEST_PENDING = 0x04,
        TPM_ACCESS_REQUEST_USE = 0x02,
};

enum tis_status {
        TPM_STS_VALID = 0x80,
        TPM_STS_COMMAND_READY = 0x40,
        TPM_STS_GO = 0x20,
        TPM_STS_DATA_AVAIL = 0x10,
        TPM_STS_DATA_EXPECT = 0x08,
};

enum tis_int_flags {
        TPM_GLOBAL_INT_ENABLE = 0x80000000,
        TPM_INTF_BURST_COUNT_STATIC = 0x100,
        TPM_INTF_CMD_READY_INT = 0x080,
        TPM_INTF_INT_EDGE_FALLING = 0x040,
        TPM_INTF_INT_EDGE_RISING = 0x020,
        TPM_INTF_INT_LEVEL_LOW = 0x010,
        TPM_INTF_INT_LEVEL_HIGH = 0x008,
        TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
        TPM_INTF_STS_VALID_INT = 0x002,
        TPM_INTF_DATA_AVAIL_INT = 0x001,
};

enum tis_defaults {
        TIS_MEM_LEN = 0x5000,
        TIS_SHORT_TIMEOUT = 750,        /* ms */
        TIS_LONG_TIMEOUT = 2000,        /* 2 sec */
};

struct tpm_info {
        struct resource res;
        /* irq > 0 means: use irq $irq;
         * irq = 0 means: autoprobe for an irq;
         * irq = -1 means: no irq support
         */
        int irq;
};

/* Some timeout values are needed before it is known whether the chip is
 * TPM 1.0 or TPM 2.0.
 */
#define TIS_TIMEOUT_A_MAX       max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_A)
#define TIS_TIMEOUT_B_MAX       max(TIS_LONG_TIMEOUT, TPM2_TIMEOUT_B)
#define TIS_TIMEOUT_C_MAX       max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_C)
#define TIS_TIMEOUT_D_MAX       max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_D)

#define TPM_ACCESS(l)                   (0x0000 | ((l) << 12))
#define TPM_INT_ENABLE(l)               (0x0008 | ((l) << 12))
#define TPM_INT_VECTOR(l)               (0x000C | ((l) << 12))
#define TPM_INT_STATUS(l)               (0x0010 | ((l) << 12))
#define TPM_INTF_CAPS(l)                (0x0014 | ((l) << 12))
#define TPM_STS(l)                      (0x0018 | ((l) << 12))
#define TPM_STS3(l)                     (0x001b | ((l) << 12))
#define TPM_DATA_FIFO(l)                (0x0024 | ((l) << 12))

#define TPM_DID_VID(l)                  (0x0F00 | ((l) << 12))
#define TPM_RID(l)                      (0x0F04 | ((l) << 12))

struct priv_data {
        void __iomem *iobase;
        u16 manufacturer_id;
        bool irq_tested;
        wait_queue_head_t int_queue;
};

#if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
static int has_hid(struct acpi_device *dev, const char *hid)
{
        struct acpi_hardware_id *id;

        list_for_each_entry(id, &dev->pnp.ids, list)
                if (!strcmp(hid, id->id))
                        return 1;

        return 0;
}

static inline int is_itpm(struct acpi_device *dev)
{
        return has_hid(dev, "INTC0102");
}
#else
static inline int is_itpm(struct acpi_device *dev)
{
        return 0;
}
#endif

/* 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 priv_data *priv = chip->vendor.priv;
        unsigned long stop = jiffies + chip->vendor.timeout_a;
        do {
                if (ioread8(priv->iobase + TPM_ACCESS(l)) &
                    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 priv_data *priv = chip->vendor.priv;

        if ((ioread8(priv->iobase + TPM_ACCESS(l)) &
             (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
            (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
                return chip->vendor.locality = l;

        return -1;
}

static void release_locality(struct tpm_chip *chip, int l, int force)
{
        struct priv_data *priv = chip->vendor.priv;

        if (force || (ioread8(priv->iobase + TPM_ACCESS(l)) &
                      (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
            (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID))
                iowrite8(TPM_ACCESS_ACTIVE_LOCALITY,
                         priv->iobase + TPM_ACCESS(l));
}

static int request_locality(struct tpm_chip *chip, int l)
{
        struct priv_data *priv = chip->vendor.priv;
        unsigned long stop, timeout;
        long rc;

        if (check_locality(chip, l) >= 0)
                return l;

        iowrite8(TPM_ACCESS_REQUEST_USE,
                 priv->iobase + TPM_ACCESS(l));

        stop = jiffies + chip->vendor.timeout_a;

        if (chip->vendor.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 priv_data *priv = chip->vendor.priv;

        return ioread8(priv->iobase +
                       TPM_STS(chip->vendor.locality));
}

static void tpm_tis_ready(struct tpm_chip *chip)
{
        struct priv_data *priv = chip->vendor.priv;

        /* this causes the current command to be aborted */
        iowrite8(TPM_STS_COMMAND_READY,
                 priv->iobase + TPM_STS(chip->vendor.locality));
}

static int get_burstcount(struct tpm_chip *chip)
{
        struct priv_data *priv = chip->vendor.priv;
        unsigned long stop;
        int burstcnt;

        /* wait for burstcount */
        /* which timeout value, spec has 2 answers (c & d) */
        stop = jiffies + chip->vendor.timeout_d;
        do {
                burstcnt = ioread8(priv->iobase +
                                   TPM_STS(chip->vendor.locality) + 1);
                burstcnt += ioread8(priv->iobase +
                                    TPM_STS(chip->vendor.locality) +
                                    2) << 8;
                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 priv_data *priv = chip->vendor.priv;
        int size = 0, burstcnt;
        while (size < count &&
               wait_for_tpm_stat(chip,
                                 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
                                 chip->vendor.timeout_c,
                                 &chip->vendor.read_queue, true)
               == 0) {
                burstcnt = get_burstcount(chip);
                for (; burstcnt > 0 && size < count; burstcnt--)
                        buf[size++] = ioread8(priv->iobase +
                                              TPM_DATA_FIFO(chip->vendor.
                                                            locality));
        }
        return size;
}

static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
        struct priv_data *priv = chip->vendor.priv;
        int size = 0;
        int expected, status;

        if (count < TPM_HEADER_SIZE) {
                size = -EIO;
                goto out;
        }

        /* read first 10 bytes, including tag, paramsize, and result */
        if ((size =
             recv_data(chip, buf, TPM_HEADER_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;
        }

        if ((size +=
             recv_data(chip, &buf[TPM_HEADER_SIZE],
                       expected - TPM_HEADER_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->vendor.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, chip->vendor.locality, 0);
        return size;
}

static bool itpm;
module_param(itpm, bool, 0444);
MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");

/*
 * 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 priv_data *priv = chip->vendor.priv;
        int rc, status, burstcnt;
        size_t count = 0;

        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->vendor.timeout_b,
                     &priv->int_queue, false) < 0) {
                        rc = -ETIME;
                        goto out_err;
                }
        }

        while (count < len - 1) {
                burstcnt = get_burstcount(chip);
                for (; burstcnt > 0 && count < len - 1; burstcnt--) {
                        iowrite8(buf[count], priv->iobase +
                                 TPM_DATA_FIFO(chip->vendor.locality));
                        count++;
                }

                wait_for_tpm_stat(chip, TPM_STS_VALID, chip->vendor.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 */
        iowrite8(buf[count],
                 priv->iobase + TPM_DATA_FIFO(chip->vendor.locality));
        wait_for_tpm_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c,
                          &priv->int_queue, false);
        status = tpm_tis_status(chip);
        if ((status & TPM_STS_DATA_EXPECT) != 0) {
                rc = -EIO;
                goto out_err;
        }

        return 0;

out_err:
        tpm_tis_ready(chip);
        release_locality(chip, chip->vendor.locality, 0);
        return rc;
}

static void disable_interrupts(struct tpm_chip *chip)
{
        struct priv_data *priv = chip->vendor.priv;
        u32 intmask;

        intmask =
            ioread32(priv->iobase +
                     TPM_INT_ENABLE(chip->vendor.locality));
        intmask &= ~TPM_GLOBAL_INT_ENABLE;
        iowrite32(intmask,
                  priv->iobase + TPM_INT_ENABLE(chip->vendor.locality));
        devm_free_irq(&chip->dev, chip->vendor.irq, chip);
        chip->vendor.irq = 0;
}

/*
 * 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 priv_data *priv = chip->vendor.priv;
        int rc;
        u32 ordinal;
        unsigned long dur;

        rc = tpm_tis_send_data(chip, buf, len);
        if (rc < 0)
                return rc;

        /* go and do it */
        iowrite8(TPM_STS_GO,
                 priv->iobase + TPM_STS(chip->vendor.locality));

        if (chip->vendor.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,
                     &chip->vendor.read_queue, false) < 0) {
                        rc = -ETIME;
                        goto out_err;
                }
        }
        return len;
out_err:
        tpm_tis_ready(chip);
        release_locality(chip, chip->vendor.locality, 0);
        return rc;
}

static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
{
        int rc, irq;
        struct priv_data *priv = chip->vendor.priv;

        if (!chip->vendor.irq || priv->irq_tested)
                return tpm_tis_send_main(chip, buf, len);

        /* Verify receipt of the expected IRQ */
        irq = chip->vendor.irq;
        chip->vendor.irq = 0;
        rc = tpm_tis_send_main(chip, buf, len);
        chip->vendor.irq = 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 priv_data *priv = chip->vendor.priv;
        int i;
        u32 did_vid;

        did_vid = ioread32(priv->iobase + TPM_DID_VID(0));

        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 priv_data *priv = chip->vendor.priv;
        int rc = 0;
        u8 cmd_getticks[] = {
                0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
                0x00, 0x00, 0x00, 0xf1
        };
        size_t len = sizeof(cmd_getticks);
        bool rem_itpm = itpm;
        u16 vendor = ioread16(priv->iobase + TPM_DID_VID(0));

        /* 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, chip->vendor.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:
        itpm = rem_itpm;
        tpm_tis_ready(chip);
        release_locality(chip, chip->vendor.locality, 0);

        return rc;
}

static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
{
        struct priv_data *priv = chip->vendor.priv;

        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 const struct tpm_class_ops tpm_tis = {
        .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,
};

static irqreturn_t tis_int_handler(int dummy, void *dev_id)
{
        struct tpm_chip *chip = dev_id;
        struct priv_data *priv = chip->vendor.priv;
        u32 interrupt;
        int i;

        interrupt = ioread32(priv->iobase +
                             TPM_INT_STATUS(chip->vendor.locality));

        if (interrupt == 0)
                return IRQ_NONE;

        ((struct priv_data *)chip->vendor.priv)->irq_tested = true;
        if (interrupt & TPM_INTF_DATA_AVAIL_INT)
                wake_up_interruptible(&chip->vendor.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 */
        iowrite32(interrupt,
                  priv->iobase +
                  TPM_INT_STATUS(chip->vendor.locality));
        ioread32(priv->iobase + TPM_INT_STATUS(chip->vendor.locality));
        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 priv_data *priv = chip->vendor.priv;
        u8 original_int_vec;

        if (devm_request_irq(&chip->dev, 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;
        }
        chip->vendor.irq = irq;

        original_int_vec = ioread8(priv->iobase +
                                   TPM_INT_VECTOR(chip->vendor.locality));
        iowrite8(irq,
                 priv->iobase + TPM_INT_VECTOR(chip->vendor.locality));

        /* Clear all existing */
        iowrite32(ioread32(priv->iobase +
                           TPM_INT_STATUS(chip->vendor.locality)),
                  priv->iobase + TPM_INT_STATUS(chip->vendor.locality));

        /* Turn on */
        iowrite32(intmask | TPM_GLOBAL_INT_ENABLE,
                  priv->iobase + TPM_INT_ENABLE(chip->vendor.locality));

        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->vendor.irq) {
                iowrite8(original_int_vec,
                         priv->iobase + TPM_INT_VECTOR(chip->vendor.locality));
                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 priv_data *priv = chip->vendor.priv;
        u8 original_int_vec;
        int i;

        original_int_vec = ioread8(priv->iobase +
                                   TPM_INT_VECTOR(chip->vendor.locality));

        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;
}

static bool interrupts = true;
module_param(interrupts, bool, 0444);
MODULE_PARM_DESC(interrupts, "Enable interrupts");

static void tpm_tis_remove(struct tpm_chip *chip)
{
        struct priv_data *priv = chip->vendor.priv;
        void __iomem *reg = priv->iobase +
                TPM_INT_ENABLE(chip->vendor.locality);

        iowrite32(~TPM_GLOBAL_INT_ENABLE & ioread32(reg), reg);
        release_locality(chip, chip->vendor.locality, 1);
}

static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
                        acpi_handle acpi_dev_handle)
{
        u32 vendor, intfcaps, intmask;
        int rc, probe;
        struct tpm_chip *chip;
        struct priv_data *priv;

        priv = devm_kzalloc(dev, sizeof(struct priv_data), GFP_KERNEL);
        if (priv == NULL)
                return -ENOMEM;

        chip = tpmm_chip_alloc(dev, &tpm_tis);
        if (IS_ERR(chip))
                return PTR_ERR(chip);

        chip->vendor.priv = priv;
#ifdef CONFIG_ACPI
        chip->acpi_dev_handle = acpi_dev_handle;
#endif

        priv->iobase = devm_ioremap_resource(dev, &tpm_info->res);
        if (IS_ERR(priv->iobase))
                return PTR_ERR(priv->iobase);

        /* Maximum timeouts */
        chip->vendor.timeout_a = TIS_TIMEOUT_A_MAX;
        chip->vendor.timeout_b = TIS_TIMEOUT_B_MAX;
        chip->vendor.timeout_c = TIS_TIMEOUT_C_MAX;
        chip->vendor.timeout_d = TIS_TIMEOUT_D_MAX;

        if (wait_startup(chip, 0) != 0) {
                rc = -ENODEV;
                goto out_err;
        }

        /* Take control of the TPM's interrupt hardware and shut it off */
        intmask = ioread32(priv->iobase +
                           TPM_INT_ENABLE(chip->vendor.locality));
        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;
        iowrite32(intmask,
                  priv->iobase + TPM_INT_ENABLE(chip->vendor.locality));

        if (request_locality(chip, 0) != 0) {
                rc = -ENODEV;
                goto out_err;
        }

        rc = tpm2_probe(chip);
        if (rc)
                goto out_err;

        vendor = ioread32(priv->iobase + TPM_DID_VID(0));
        priv->manufacturer_id = vendor;

        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, ioread8(priv->iobase + TPM_RID(0)));

        if (!itpm) {
                probe = probe_itpm(chip);
                if (probe < 0) {
                        rc = -ENODEV;
                        goto out_err;
                }
                itpm = !!probe;
        }

        if (itpm)
                dev_info(dev, "Intel iTPM workaround enabled\n");


        /* Figure out the capabilities */
        intfcaps =
            ioread32(priv->iobase +
                     TPM_INTF_CAPS(chip->vendor.locality));
        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(&chip->vendor.read_queue);
        init_waitqueue_head(&priv->int_queue);
        if (interrupts && tpm_info->irq != -1) {
                if (tpm_info->irq) {
                        tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
                                                 tpm_info->irq);
                        if (!chip->vendor.irq)
                                dev_err(&chip->dev, FW_BUG
                                        "TPM interrupt not working, polling instead\n");
                } else
                        tpm_tis_probe_irq(chip, intmask);
        }

        if (chip->flags & TPM_CHIP_FLAG_TPM2) {
                rc = tpm2_do_selftest(chip);
                if (rc == TPM2_RC_INITIALIZE) {
                        dev_warn(dev, "Firmware has not started TPM\n");
                        rc  = tpm2_startup(chip, TPM2_SU_CLEAR);
                        if (!rc)
                                rc = tpm2_do_selftest(chip);
                }

                if (rc) {
                        dev_err(dev, "TPM self test failed\n");
                        if (rc > 0)
                                rc = -ENODEV;
                        goto out_err;
                }
        } else {
                if (tpm_do_selftest(chip)) {
                        dev_err(dev, "TPM self test failed\n");
                        rc = -ENODEV;
                        goto out_err;
                }
        }

        return tpm_chip_register(chip);
out_err:
        tpm_tis_remove(chip);
        return rc;
}

#ifdef CONFIG_PM_SLEEP
static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
{
        struct priv_data *priv = chip->vendor.priv;
        u32 intmask;

        /* reenable interrupts that device may have lost or
           BIOS/firmware may have disabled */
        iowrite8(chip->vendor.irq, priv->iobase +
                 TPM_INT_VECTOR(chip->vendor.locality));

        intmask =
            ioread32(priv->iobase + TPM_INT_ENABLE(chip->vendor.locality));

        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;

        iowrite32(intmask,
                  priv->iobase + TPM_INT_ENABLE(chip->vendor.locality));
}

static int tpm_tis_resume(struct device *dev)
{
        struct tpm_chip *chip = dev_get_drvdata(dev);
        int ret;

        if (chip->vendor.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;
}
#endif

static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);

static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
                            const struct pnp_device_id *pnp_id)
{
        struct tpm_info tpm_info = {};
        acpi_handle acpi_dev_handle = NULL;
        struct resource *res;

        res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;
        tpm_info.res = *res;

        if (pnp_irq_valid(pnp_dev, 0))
                tpm_info.irq = pnp_irq(pnp_dev, 0);
        else
                tpm_info.irq = -1;

        if (pnp_acpi_device(pnp_dev)) {
                if (is_itpm(pnp_acpi_device(pnp_dev)))
                        itpm = true;

                acpi_dev_handle = ACPI_HANDLE(&pnp_dev->dev);
        }

        return tpm_tis_init(&pnp_dev->dev, &tpm_info, acpi_dev_handle);
}

static struct pnp_device_id tpm_pnp_tbl[] = {
        {"PNP0C31", 0},         /* TPM */
        {"ATM1200", 0},         /* Atmel */
        {"IFX0102", 0},         /* Infineon */
        {"BCM0101", 0},         /* Broadcom */
        {"BCM0102", 0},         /* Broadcom */
        {"NSC1200", 0},         /* National */
        {"ICO0102", 0},         /* Intel */
        /* Add new here */
        {"", 0},                /* User Specified */
        {"", 0}                 /* Terminator */
};
MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);

static void tpm_tis_pnp_remove(struct pnp_dev *dev)
{
        struct tpm_chip *chip = pnp_get_drvdata(dev);

        tpm_chip_unregister(chip);
        tpm_tis_remove(chip);
}

static struct pnp_driver tis_pnp_driver = {
        .name = "tpm_tis",
        .id_table = tpm_pnp_tbl,
        .probe = tpm_tis_pnp_init,
        .remove = tpm_tis_pnp_remove,
        .driver = {
                .pm = &tpm_tis_pm,
        },
};

#define TIS_HID_USR_IDX sizeof(tpm_pnp_tbl)/sizeof(struct pnp_device_id) -2
module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
                    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");

#ifdef CONFIG_ACPI
static int tpm_check_resource(struct acpi_resource *ares, void *data)
{
        struct tpm_info *tpm_info = (struct tpm_info *) data;
        struct resource res;

        if (acpi_dev_resource_interrupt(ares, 0, &res))
                tpm_info->irq = res.start;
        else if (acpi_dev_resource_memory(ares, &res)) {
                tpm_info->res = res;
                tpm_info->res.name = NULL;
        }

        return 1;
}

static int tpm_tis_acpi_init(struct acpi_device *acpi_dev)
{
        struct acpi_table_tpm2 *tbl;
        acpi_status st;
        struct list_head resources;
        struct tpm_info tpm_info = {};
        int ret;

        st = acpi_get_table(ACPI_SIG_TPM2, 1,
                            (struct acpi_table_header **) &tbl);
        if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
                dev_err(&acpi_dev->dev,
                        FW_BUG "failed to get TPM2 ACPI table\n");
                return -EINVAL;
        }

        if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
                return -ENODEV;

        INIT_LIST_HEAD(&resources);
        tpm_info.irq = -1;
        ret = acpi_dev_get_resources(acpi_dev, &resources, tpm_check_resource,
                                     &tpm_info);
        if (ret < 0)
                return ret;

        acpi_dev_free_resource_list(&resources);

        if (resource_type(&tpm_info.res) != IORESOURCE_MEM) {
                dev_err(&acpi_dev->dev,
                        FW_BUG "TPM2 ACPI table does not define a memory resource\n");
                return -EINVAL;
        }

        if (is_itpm(acpi_dev))
                itpm = true;

        return tpm_tis_init(&acpi_dev->dev, &tpm_info, acpi_dev->handle);
}

static int tpm_tis_acpi_remove(struct acpi_device *dev)
{
        struct tpm_chip *chip = dev_get_drvdata(&dev->dev);

        tpm_chip_unregister(chip);
        tpm_tis_remove(chip);

        return 0;
}

static struct acpi_device_id tpm_acpi_tbl[] = {
        {"MSFT0101", 0},        /* TPM 2.0 */
        /* Add new here */
        {"", 0},                /* User Specified */
        {"", 0}                 /* Terminator */
};
MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);

static struct acpi_driver tis_acpi_driver = {
        .name = "tpm_tis",
        .ids = tpm_acpi_tbl,
        .ops = {
                .add = tpm_tis_acpi_init,
                .remove = tpm_tis_acpi_remove,
        },
        .drv = {
                .pm = &tpm_tis_pm,
        },
};
#endif

static struct platform_device *force_pdev;

static int tpm_tis_plat_probe(struct platform_device *pdev)
{
        struct tpm_info tpm_info = {};
        struct resource *res;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
                dev_err(&pdev->dev, "no memory resource defined\n");
                return -ENODEV;
        }
        tpm_info.res = *res;

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (res) {
                tpm_info.irq = res->start;
        } else {
                if (pdev == force_pdev)
                        tpm_info.irq = -1;
                else
                        /* When forcing auto probe the IRQ */
                        tpm_info.irq = 0;
        }

        return tpm_tis_init(&pdev->dev, &tpm_info, NULL);
}

static int tpm_tis_plat_remove(struct platform_device *pdev)
{
        struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);

        tpm_chip_unregister(chip);
        tpm_tis_remove(chip);

        return 0;
}

static struct platform_driver tis_drv = {
        .probe = tpm_tis_plat_probe,
        .remove = tpm_tis_plat_remove,
        .driver = {
                .name           = "tpm_tis",
                .pm             = &tpm_tis_pm,
        },
};

static bool force;
#ifdef CONFIG_X86
module_param(force, bool, 0444);
MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
#endif

static int tpm_tis_force_device(void)
{
        struct platform_device *pdev;
        static const struct resource x86_resources[] = {
                {
                        .start = 0xFED40000,
                        .end = 0xFED40000 + TIS_MEM_LEN - 1,
                        .flags = IORESOURCE_MEM,
                },
        };

        if (!force)
                return 0;

        /* The driver core will match the name tpm_tis of the device to
         * the tpm_tis platform driver and complete the setup via
         * tpm_tis_plat_probe
         */
        pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
                                               ARRAY_SIZE(x86_resources));
        if (IS_ERR(pdev))
                return PTR_ERR(pdev);
        force_pdev = pdev;

        return 0;
}

static int __init init_tis(void)
{
        int rc;

        rc = tpm_tis_force_device();
        if (rc)
                goto err_force;

        rc = platform_driver_register(&tis_drv);
        if (rc)
                goto err_platform;

#ifdef CONFIG_ACPI
        rc = acpi_bus_register_driver(&tis_acpi_driver);
        if (rc)
                goto err_acpi;
#endif

        if (IS_ENABLED(CONFIG_PNP)) {
                rc = pnp_register_driver(&tis_pnp_driver);
                if (rc)
                        goto err_pnp;
        }

        return 0;

err_pnp:
#ifdef CONFIG_ACPI
        acpi_bus_unregister_driver(&tis_acpi_driver);
err_acpi:
#endif
        platform_device_unregister(force_pdev);
err_platform:
        if (force_pdev)
                platform_device_unregister(force_pdev);
err_force:
        return rc;
}

static void __exit cleanup_tis(void)
{
        pnp_unregister_driver(&tis_pnp_driver);
#ifdef CONFIG_ACPI
        acpi_bus_unregister_driver(&tis_acpi_driver);
#endif
        platform_driver_unregister(&tis_drv);

        if (force_pdev)
                platform_device_unregister(force_pdev);
}

module_init(init_tis);
module_exit(cleanup_tis);
MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");