From patchwork Sun Nov 10 16:21:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Amir Mizinski X-Patchwork-Id: 11236259 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 55AB8139A for ; Sun, 10 Nov 2019 16:33:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2AF6F214E0 for ; Sun, 10 Nov 2019 16:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727159AbfKJQdg (ORCPT ); Sun, 10 Nov 2019 11:33:36 -0500 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:44397 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727151AbfKJQdg (ORCPT ); Sun, 10 Nov 2019 11:33:36 -0500 X-Greylist: delayed 642 seconds by postgrey-1.27 at vger.kernel.org; Sun, 10 Nov 2019 11:33:15 EST Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id xAAGMRng013912; Sun, 10 Nov 2019 18:22:27 +0200 Received: by taln60.nuvoton.co.il (Postfix, from userid 10140) id 2AB9C60275; Sun, 10 Nov 2019 18:22:27 +0200 (IST) From: amirmizi6@gmail.com To: Eyal.Cohen@nuvoton.com, jarkko.sakkinen@linux.intel.com, oshrialkoby85@gmail.com, alexander.steffen@infineon.com, robh+dt@kernel.org, mark.rutland@arm.com, peterhuewe@gmx.de, jgg@ziepe.ca, arnd@arndb.de, gregkh@linuxfoundation.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, oshri.alkoby@nuvoton.com, tmaimon77@gmail.com, gcwilson@us.ibm.com, kgoldman@us.ibm.com, ayna@linux.vnet.ibm.com, Dan.Morav@nuvoton.com, oren.tanami@nuvoton.com, shmulik.hagar@nuvoton.com, amir.mizinski@nuvoton.com, Amir Mizinski Subject: [PATCH v1 5/5] char: tpm: add tpm_tis_i2c driver Date: Sun, 10 Nov 2019 18:21:37 +0200 Message-Id: <20191110162137.230913-6-amirmizi6@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20191110162137.230913-1-amirmizi6@gmail.com> References: <20191110162137.230913-1-amirmizi6@gmail.com> MIME-Version: 1.0 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Amir Mizinski Implements the functionality needed to communicate with an I2C TPM according to the TCG TPM I2C Interface Specification. Limitations: * No IRQ support * No support for updating GUARD_TIME Signed-off-by: Amir Mizinski --- drivers/char/tpm/Kconfig | 12 ++ drivers/char/tpm/Makefile | 1 + drivers/char/tpm/tpm_tis_i2c.c | 272 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 285 insertions(+) create mode 100644 drivers/char/tpm/tpm_tis_i2c.c diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index 88a3c06..b731a80 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -67,6 +67,18 @@ config TCG_TIS_SPI within Linux. To compile this driver as a module, choose M here; the module will be called tpm_tis_spi. +config TCG_TIS_I2C + tristate "TPM I2C Interface Specification" + depends on I2C + depends on CRC_CCITT + select TCG_TIS_CORE + ---help--- + If you have a TPM security chip which is connected to a regular + I2C master (i.e. most embedded platforms) that is compliant with the + TCG TPM I2C Interface Specification say Yes and it will be accessible from + within Linux. To compile this driver as a module, choose M here; + the module will be called tpm_tis_i2c. + config TCG_TIS_I2C_ATMEL tristate "TPM Interface Specification 1.2 Interface (I2C - Atmel)" depends on I2C diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index a01c4ca..15a0010 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -22,6 +22,7 @@ tpm-$(CONFIG_OF) += eventlog/of.o obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o obj-$(CONFIG_TCG_TIS) += tpm_tis.o obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o +obj-$(CONFIG_TCG_TIS_I2C) += tpm_tis_i2c.o obj-$(CONFIG_TCG_TIS_I2C_ATMEL) += tpm_i2c_atmel.o obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c new file mode 100644 index 0000000..080e82e --- /dev/null +++ b/drivers/char/tpm/tpm_tis_i2c.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2014-2019 Nuvoton Technology corporation + * + * TPM TIS I2C + * + * TPM TIS I2C Device Driver Interface for devices that implement the TPM I2C + * Interface defined by TCG PC Client Platform TPM Profile (PTP) Specification + * Revision 01.03 v22 at www.trustedcomputinggroup.org + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include "tpm.h" +#include "tpm_tis_core.h" + +#define TPM_LOC_SEL 0x04 +#define TPM_I2C_INTERFACE_CAPABILITY 0x30 +#define TPM_I2C_DEVICE_ADDRESS 0x38 +#define TPM_DATA_CSUM_ENABLE 0x40 +#define TPM_DATA_CSUM 0x44 +#define TPM_I2C_DID_VID 0x48 +#define TPM_I2C_RID 0x4C + +struct tpm_tis_i2c_phy { + struct tpm_tis_data priv; + struct i2c_client *i2c_client; + bool data_csum; + u8 *iobuf; +}; + +static inline struct tpm_tis_i2c_phy *to_tpm_tis_i2c_phy(struct tpm_tis_data *data) +{ + return container_of(data, struct tpm_tis_i2c_phy, priv); +} + +static u8 address_to_register(u32 addr) +{ + addr &= 0xFFF; + + switch (addr) { + // adapt register addresses that have changed compared to + // older TIS versions + case TPM_ACCESS(0): + return 0x04; + case TPM_LOC_SEL: + return 0x00; + case TPM_DID_VID(0): + return 0x48; + case TPM_RID(0): + return 0x4C; + default: + return addr; + } +} + +static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, + u16 len, u8 *result) +{ + struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data); + int ret; + u8 reg = address_to_register(addr); + struct i2c_msg msgs[] = { + { + .addr = phy->i2c_client->addr, + .len = sizeof(reg), + .buf = ®, + }, + { + .addr = phy->i2c_client->addr, + .len = len, + .buf = result, + .flags = I2C_M_RD, + }, + }; + + ret = i2c_transfer(phy->i2c_client->adapter, msgs, ARRAY_SIZE(msgs)); + + if (ret < 0) + return ret; + + usleep_range(250, 300); // wait default GUARD_TIME of 250µs + + return 0; +} + +static int tpm_tis_i2c_write_bytes(struct tpm_tis_data *data, u32 addr, + u16 len, const u8 *value) +{ + struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data); + int ret; + + if (phy->iobuf) { + if (len > TPM_BUFSIZE - 1) + return -EIO; + + phy->iobuf[0] = address_to_register(addr); + memcpy(phy->iobuf + 1, value, len); + + { + struct i2c_msg msgs[] = { + { + .addr = phy->i2c_client->addr, + .len = len + 1, + .buf = phy->iobuf, + }, + }; + + ret = i2c_transfer(phy->i2c_client->adapter, msgs, + ARRAY_SIZE(msgs)); + } + } else { + u8 reg = address_to_register(addr); + + struct i2c_msg msgs[] = { + { + .addr = phy->i2c_client->addr, + .len = sizeof(reg), + .buf = ®, + }, + { + .addr = phy->i2c_client->addr, + .len = len, + .buf = (u8 *)value, + .flags = I2C_M_NOSTART, + }, + }; + + ret = i2c_transfer(phy->i2c_client->adapter, msgs, + ARRAY_SIZE(msgs)); + } + + if (ret < 0) + return ret; + + usleep_range(250, 300); // wait default GUARD_TIME of 250µs + + return 0; +} + +static bool tpm_tis_i2c_check_data(struct tpm_tis_data *data, + const u8 *buf, size_t len) +{ + struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data); + u16 crc, crc_tpm; + int rc; + + if (phy->data_csum) { + crc = crc_ccitt(0x0000, buf, len); + rc = tpm_tis_read16(data, TPM_DATA_CSUM, &crc_tpm); + if (rc < 0) + return false; + + crc_tpm = be16_to_cpu(crc_tpm); + return crc == crc_tpm; + } + + return true; +} + +static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume); + +static int csum_state_store(struct tpm_tis_data *data, u8 new_state) +{ + struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data); + u8 cur_state; + int rc; + + rc = tpm_tis_i2c_write_bytes(&phy->priv, TPM_DATA_CSUM_ENABLE, + 1, &new_state); + if (rc < 0) + return rc; + + rc = tpm_tis_i2c_read_bytes(&phy->priv, TPM_DATA_CSUM_ENABLE, + 1, &cur_state); + if (rc < 0) + return rc; + + if (new_state == cur_state) + phy->data_csum = (bool)new_state; + + return rc; +} + +static const struct tpm_tis_phy_ops tpm_i2c_phy_ops = { + .read_bytes = tpm_tis_i2c_read_bytes, + .write_bytes = tpm_tis_i2c_write_bytes, + .check_data = tpm_tis_i2c_check_data, +}; + +static int tpm_tis_i2c_probe(struct i2c_client *dev, + const struct i2c_device_id *id) +{ + struct tpm_tis_i2c_phy *phy; + int rc; + const u8 loc_init = 0; + + phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_i2c_phy), + GFP_KERNEL); + if (!phy) + return -ENOMEM; + + phy->i2c_client = dev; + + if (!i2c_check_functionality(dev->adapter, I2C_FUNC_NOSTART)) { + phy->iobuf = devm_kmalloc(&dev->dev, TPM_BUFSIZE, GFP_KERNEL); + if (!phy->iobuf) + return -ENOMEM; + } + + // select locality 0 (the driver will access only via locality 0) + rc = tpm_tis_i2c_write_bytes(&phy->priv, TPM_LOC_SEL, 1, &loc_init); + if (rc < 0) + return rc; + + // enables the data checksum calculation + rc = csum_state_store(&phy->priv, 0x01); + if (rc < 0) + return rc; + + return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_i2c_phy_ops, + NULL); +} + +static const struct i2c_device_id tpm_tis_i2c_id[] = { + {"tpm_tis_i2c", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_id); + +static const struct of_device_id of_tis_i2c_match[] = { + { .compatible = "tcg,tpm_tis-i2c", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_tis_i2c_match); + +static const struct acpi_device_id acpi_tis_i2c_match[] = { + {"SMO0768", 0}, + {} +}; +MODULE_DEVICE_TABLE(acpi, acpi_tis_i2c_match); + +static struct i2c_driver tpm_tis_i2c_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "tpm_tis_i2c", + .pm = &tpm_tis_pm, + .of_match_table = of_match_ptr(of_tis_i2c_match), + .acpi_match_table = ACPI_PTR(acpi_tis_i2c_match), + }, + .probe = tpm_tis_i2c_probe, + .id_table = tpm_tis_i2c_id, +}; + +module_i2c_driver(tpm_tis_i2c_driver); + +MODULE_DESCRIPTION("TPM Driver for native I2C access"); +MODULE_LICENSE("GPL");