--- /dev/null
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG CRB 2.0 TPM specification.
+ *
+ * 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/acpi.h>
+#include <linux/highmem.h>
+#include <linux/rculist.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include "tpm.h"
+
+#define ACPI_SIG_TPM2 "TPM2"
+
+static const u8 CRB_ACPI_START_UUID[] = {
+ /* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47,
+ /* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4
+};
+
+enum crb_defaults {
+ CRB_ACPI_START_REVISION_ID = 1,
+ CRB_ACPI_START_INDEX = 1,
+};
+
+enum crb_start_method {
+ CRB_SM_ACPI_START = 2,
+ CRB_SM_CRB = 7,
+ CRB_SM_CRB_WITH_ACPI_START = 8,
+};
+
+struct acpi_tpm2 {
+ struct acpi_table_header hdr;
+ u16 platform_class;
+ u16 reserved;
+ u64 control_area_pa;
+ u32 start_method;
+} __packed;
+
+enum crb_ca_request {
+ CRB_CA_REQ_GO_IDLE = BIT(0),
+ CRB_CA_REQ_CMD_READY = BIT(1),
+};
+
+enum crb_ca_status {
+ CRB_CA_STS_ERROR = BIT(0),
+ CRB_CA_STS_TPM_IDLE = BIT(1),
+};
+
+enum crb_start {
+ CRB_START_INVOKE = BIT(0),
+};
+
+enum crb_cancel {
+ CRB_CANCEL_INVOKE = BIT(0),
+};
+
+struct crb_control_area {
+ u32 req;
+ u32 sts;
+ u32 cancel;
+ u32 start;
+ u32 int_enable;
+ u32 int_sts;
+ u32 cmd_size;
+ u64 cmd_pa;
+ u32 rsp_size;
+ u64 rsp_pa;
+} __packed;
+
+enum crb_status {
+ CRB_STS_COMPLETE = BIT(0),
+};
+
+enum crb_flags {
+ CRB_FL_ACPI_START = BIT(0),
+ CRB_FL_CRB_START = BIT(1),
+};
+
+struct crb_priv {
+ unsigned int flags;
+ struct crb_control_area __iomem *cca;
+ u8 __iomem *cmd;
+ u8 __iomem *rsp;
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int crb_resume(struct device *dev)
+{
+ int rc;
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ rc = tpm2_shutdown(chip, TPM2_SU_STATE);
+ if (!rc)
+ rc = tpm2_do_selftest(chip);
+
+ return rc;
+}
+
+static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, crb_resume);
+#endif
+
+static u8 crb_status(struct tpm_chip *chip)
+{
+ struct crb_priv *priv = chip->vendor.priv;
+ u8 sts = 0;
+
+ if ((le32_to_cpu(ioread32(&priv->cca->start)) & CRB_START_INVOKE) !=
+ CRB_START_INVOKE)
+ sts |= CRB_STS_COMPLETE;
+
+ return sts;
+}
+
+static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+ struct crb_priv *priv = chip->vendor.priv;
+ unsigned int expected;
+
+ /* sanity check */
+ if (count < 6)
+ return -EIO;
+
+ if (le32_to_cpu(ioread32(&priv->cca->sts)) & CRB_CA_STS_ERROR)
+ return -EIO;
+
+ memcpy_fromio(buf, priv->rsp, 6);
+ expected = be32_to_cpup((__be32 *) &buf[2]);
+
+ if (expected > count)
+ return -EIO;
+
+ memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
+
+ return expected;
+}
+
+static int crb_do_acpi_start(struct tpm_chip *chip)
+{
+ union acpi_object *obj;
+ int rc;
+
+ obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
+ CRB_ACPI_START_UUID,
+ CRB_ACPI_START_REVISION_ID,
+ CRB_ACPI_START_INDEX,
+ NULL);
+ if (!obj)
+ return -ENXIO;
+ rc = obj->integer.value == 0 ? 0 : -ENXIO;
+ ACPI_FREE(obj);
+ return rc;
+}
+
+static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+ struct crb_priv *priv = chip->vendor.priv;
+ int rc = 0;
+
+ if (len > le32_to_cpu(ioread32(&priv->cca->cmd_size))) {
+ dev_err(&chip->dev,
+ "invalid command count value %x %zx\n",
+ (unsigned int) len,
+ (size_t) le32_to_cpu(ioread32(&priv->cca->cmd_size)));
+ return -E2BIG;
+ }
+
+ memcpy_toio(priv->cmd, buf, len);
+
+ /* Make sure that cmd is populated before issuing start. */
+ wmb();
+
+ if (priv->flags & CRB_FL_CRB_START)
+ iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start);
+
+ if (priv->flags & CRB_FL_ACPI_START)
+ rc = crb_do_acpi_start(chip);
+
+ return rc;
+}
+
+static void crb_cancel(struct tpm_chip *chip)
+{
+ struct crb_priv *priv = chip->vendor.priv;
+
+ iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel);
+
+ /* Make sure that cmd is populated before issuing cancel. */
+ wmb();
+
+ if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
+ dev_err(&chip->dev, "ACPI Start failed\n");
+
+ iowrite32(0, &priv->cca->cancel);
+}
+
+static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
+{
+ struct crb_priv *priv = chip->vendor.priv;
+ u32 cancel = le32_to_cpu(ioread32(&priv->cca->cancel));
+
+ return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
+}
+
+static const struct tpm_class_ops tpm_crb = {
+ .status = crb_status,
+ .recv = crb_recv,
+ .send = crb_send,
+ .cancel = crb_cancel,
+ .req_canceled = crb_req_canceled,
+ .req_complete_mask = CRB_STS_COMPLETE,
+ .req_complete_val = CRB_STS_COMPLETE,
+};
+
+static int crb_acpi_add(struct acpi_device *device)
+{
+ struct tpm_chip *chip;
+ struct acpi_tpm2 *buf;
+ struct crb_priv *priv;
+ struct device *dev = &device->dev;
+ acpi_status status;
+ u32 sm;
+ u64 pa;
+ int rc;
+
+ chip = tpmm_chip_alloc(dev, &tpm_crb);
+ if (IS_ERR(chip))
+ return PTR_ERR(chip);
+
+ chip->flags = TPM_CHIP_FLAG_TPM2;
+
+ status = acpi_get_table(ACPI_SIG_TPM2, 1,
+ (struct acpi_table_header **) &buf);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "failed to get TPM2 ACPI table\n");
+ return -ENODEV;
+ }
+
+ if (buf->hdr.length < sizeof(struct acpi_tpm2)) {
+ dev_err(dev, "TPM2 ACPI table has wrong size");
+ return -EINVAL;
+ }
+
+ priv = (struct crb_priv *) devm_kzalloc(dev, sizeof(struct crb_priv),
+ GFP_KERNEL);
+ if (!priv) {
+ dev_err(dev, "failed to devm_kzalloc for private data\n");
+ return -ENOMEM;
+ }
+
+ sm = le32_to_cpu(buf->start_method);
+
+ /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
+ * report only ACPI start but in practice seems to require both
+ * ACPI start and CRB start.
+ */
+ if (sm == CRB_SM_CRB || sm == CRB_SM_CRB_WITH_ACPI_START ||
+ !strcmp(acpi_device_hid(device), "MSFT0101"))
+ priv->flags |= CRB_FL_CRB_START;
+
+ if (sm == CRB_SM_ACPI_START || sm == CRB_SM_CRB_WITH_ACPI_START)
+ priv->flags |= CRB_FL_ACPI_START;
+
+ priv->cca = (struct crb_control_area __iomem *)
+ devm_ioremap_nocache(dev, buf->control_area_pa, 0x1000);
+ if (!priv->cca) {
+ dev_err(dev, "ioremap of the control area failed\n");
+ return -ENOMEM;
+ }
+
+ memcpy_fromio(&pa, &priv->cca->cmd_pa, 8);
+ pa = le64_to_cpu(pa);
+ priv->cmd = devm_ioremap_nocache(dev, le64_to_cpu(pa),
+ ioread32(&priv->cca->cmd_size));
+ if (!priv->cmd) {
+ dev_err(dev, "ioremap of the command buffer failed\n");
+ return -ENOMEM;
+ }
+
+ memcpy_fromio(&pa, &priv->cca->rsp_pa, 8);
+ pa = le64_to_cpu(pa);
+ priv->rsp = devm_ioremap_nocache(dev, le64_to_cpu(pa),
+ ioread32(&priv->cca->rsp_size));
+ if (!priv->rsp) {
+ dev_err(dev, "ioremap of the response buffer failed\n");
+ return -ENOMEM;
+ }
+
+ chip->vendor.priv = priv;
+
+ /* Default timeouts and durations */
+ chip->vendor.timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
+ chip->vendor.timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
+ chip->vendor.timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
+ chip->vendor.timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
+ chip->vendor.duration[TPM_SHORT] =
+ msecs_to_jiffies(TPM2_DURATION_SHORT);
+ chip->vendor.duration[TPM_MEDIUM] =
+ msecs_to_jiffies(TPM2_DURATION_MEDIUM);
+ chip->vendor.duration[TPM_LONG] =
+ msecs_to_jiffies(TPM2_DURATION_LONG);
+
+ chip->acpi_dev_handle = device->handle;
+
+ rc = tpm2_do_selftest(chip);
+ if (rc)
+ return rc;
+
+ return tpm_chip_register(chip);
+}
+
+static int crb_acpi_remove(struct acpi_device *device)
+{
+ struct device *dev = &device->dev;
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ tpm_chip_unregister(chip);
+ return 0;
+}
+
+static struct acpi_device_id crb_device_ids[] = {
+ {"MSFT0101", 0},
+ {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, crb_device_ids);
+
+static struct acpi_driver crb_acpi_driver = {
+ .name = "tpm_crb",
+ .ids = crb_device_ids,
+ .ops = {
+ .add = crb_acpi_add,
+ .remove = crb_acpi_remove,
+ },
+ .drv = {
+ .pm = &crb_pm,
+ },
+};
+
+module_acpi_driver(crb_acpi_driver);
+MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
+MODULE_DESCRIPTION("TPM2 Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff