From patchwork Wed Jul 20 03:41:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Pronin X-Patchwork-Id: 9238735 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 99F61602F0 for ; Wed, 20 Jul 2016 03:41:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87243200F5 for ; Wed, 20 Jul 2016 03:41:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7BCA22756B; Wed, 20 Jul 2016 03:41:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 88C12200F5 for ; Wed, 20 Jul 2016 03:41:39 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-1.v29.ch3.sourceforge.com) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bPiOA-0002uK-5f; Wed, 20 Jul 2016 03:41:38 +0000 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bPiO9-0002uA-8P for tpmdd-devel@lists.sourceforge.net; Wed, 20 Jul 2016 03:41:37 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of chromium.org designates 209.85.220.47 as permitted sender) client-ip=209.85.220.47; envelope-from=apronin@chromium.org; helo=mail-pa0-f47.google.com; Received: from mail-pa0-f47.google.com ([209.85.220.47]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1bPiO7-0002tb-Qa for tpmdd-devel@lists.sourceforge.net; Wed, 20 Jul 2016 03:41:37 +0000 Received: by mail-pa0-f47.google.com with SMTP id pp5so13495877pac.3 for ; Tue, 19 Jul 2016 20:41:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=JjGyyq3qb3ye4UkRQXw2N9CTX9iu1etr9ZXcGUiJeVc=; b=V80DaaE66JUuY4V6ok1cAPz0v8/SBUvTxZGqjigbAMZTcN5ka1i0nMCUMB63eQnd8q 1y/E6CLADTuVypY5H6PV8oMJx1YSPLot3rbIpiXiyNjxnR7KQMvj1//g/hrmQ6w8Zb4m AmPbsmEiGKSzr9XwUc2U2L4zMXVH2hPbB3pix6iCxhKWjVRcqw4jcuKIS6fjlPUO1SZT SwsPY7+WMi4Sfc2mdHFImEtD5cpofykwBDNLE239JUpPydiQzOT0KZ2f3kg+o9lSWyHD 3RvWM6YGagwAhBuiF4rSNGZltK+L7rcrTNvmaBYF6eGeKhSDW1fznE4p/6US0pe7KzT7 5mhQ== X-Gm-Message-State: ALyK8tKcs4Q62CckjpIJKXATDYPb77Hk9Ef+fbwqNEmO7Kt7UaLzd7GRd3Ti71oZ4D6hpNTU X-Received: by 10.66.8.37 with SMTP id o5mr72307865paa.100.1468986089942; Tue, 19 Jul 2016 20:41:29 -0700 (PDT) Received: from apronin0.mtv.corp.google.com ([172.22.64.136]) by smtp.gmail.com with ESMTPSA id 132sm584930pfu.6.2016.07.19.20.41.29 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 19 Jul 2016 20:41:29 -0700 (PDT) From: Andrey Pronin To: Jarkko Sakkinen Date: Tue, 19 Jul 2016 20:41:25 -0700 Message-Id: X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: References: <1468549218-19215-1-git-send-email-apronin@chromium.org> In-Reply-To: References: <1468549218-19215-1-git-send-email-apronin@chromium.org> X-Headers-End: 1bPiO7-0002tb-Qa Cc: Christophe Ricard , linux-kernel@vger.kernel.org, tpmdd-devel@lists.sourceforge.net Subject: [tpmdd-devel] [PATCH v2 2/2] tpm: add driver for cr50 on SPI X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: tpmdd-devel-bounces@lists.sourceforge.net X-Virus-Scanned: ClamAV using ClamSMTP Add TPM2.0 PTP FIFO compatible SPI interface for chips with Cr50 firmware. The firmware running on the currently supported H1 Secure Microcontroller requires a special driver to handle its specifics: - need to ensure a certain delay between spi transactions, or else the chip may miss some part of the next transaction; - if there is no spi activity for some time, it may go to sleep, and needs to be waken up before sending further commands; - access to vendor-specific registers. Signed-off-by: Andrey Pronin --- drivers/char/tpm/Kconfig | 9 + drivers/char/tpm/Makefile | 1 + drivers/char/tpm/cr50_spi.c | 388 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 398 insertions(+) create mode 100644 drivers/char/tpm/cr50_spi.c diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index 9faa0b1..3320acc 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -100,6 +100,15 @@ config TCG_ATMEL will be accessible from within Linux. To compile this driver as a module, choose M here; the module will be called tpm_atmel. +config TCG_CR50_SPI + tristate "TCG PTP FIFO Interface over SPI - Chips with Cr50 Firmware" + depends on SPI + select TCG_TIS_CORE + ---help--- + If you have a chip running Cr50 firmware on SPI bus, 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 cr50_spi. + config TCG_INFINEON tristate "Infineon Technologies TPM Interface" depends on PNP diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index a385fb8..b346306 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o obj-$(CONFIG_TCG_NSC) += tpm_nsc.o obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o +obj-$(CONFIG_TCG_CR50_SPI) += cr50_spi.o obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/ diff --git a/drivers/char/tpm/cr50_spi.c b/drivers/char/tpm/cr50_spi.c new file mode 100644 index 0000000..be10d75 --- /dev/null +++ b/drivers/char/tpm/cr50_spi.c @@ -0,0 +1,388 @@ +/* + * Copyright (C) 2016 Google, Inc + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2, as published by + * the Free Software Foundation. + * + * This device driver implements a TCG PTP FIFO compliant interface over SPI + * for Cr50 devices. + * It is based on cr50_spi driver by Peter Huewe and Christophe Ricard. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include "tpm.h" +#include "tpm_tis_core.h" + +#define MAX_SPI_FRAMESIZE 64 + +/* Cr50 default timing constants: + * - can go to sleep not earlier than after CR50_SLEEP_DELAY_MSEC + * - needs up to CR50_WAKE_START_DELAY_MSEC to wake after sleep + * - requires at least CR50_ACCESS_DELAY_MSEC between transactions + */ +#define CR50_DFT_SLEEP_DELAY_MSEC 1000 +#define CR50_DFT_WAKE_START_DELAY_MSEC 60 +#define CR50_DFT_ACCESS_DELAY_MSEC 2 + +#define TPM_CR50_FW_VER(l) (0x0F90 | ((l) << 12)) +#define TPM_CR50_MAX_FW_VER_LEN 64 + +struct cr50_spi_phy { + struct tpm_tis_data priv; + struct spi_device *spi_device; + + struct mutex time_track_mutex; + unsigned long last_access_jiffies; + unsigned long wake_after_jiffies; + + unsigned long access_delay_jiffies; + unsigned long sleep_delay_jiffies; + unsigned int wake_start_delay_msec; +}; + +static inline struct cr50_spi_phy *to_cr50_spi_phy(struct tpm_tis_data *data) +{ + return container_of(data, struct cr50_spi_phy, priv); +} + +/* Cr50 needs to have at least some delay between consecutive + * transactions. Make sure we wait. + */ +static inline void cr50_ensure_access_delay(struct cr50_spi_phy *phy) +{ + /* Note: There is a small chance, if Cr50 is not accessed in a few days, + * that time_in_range will not provide the correct result after the wrap + * around for jiffies. In this case, we'll have an unneeded short delay, + * which is fine. + */ + unsigned long allowed_access = + phy->last_access_jiffies + phy->access_delay_jiffies; + unsigned long time_now = jiffies; + + if (time_in_range_open(time_now, + phy->last_access_jiffies, allowed_access)) + mdelay(jiffies_to_msecs(allowed_access - time_now)); +} + +/* Cr50 might go to sleep if there is no SPI activity for some time and + * miss the first few bits/bytes on the bus. In such case, wake it up + * by asserting CS and give it time to start up. + */ +static inline bool cr50_needs_waking(struct cr50_spi_phy *phy) +{ + /* Note: There is a small chance, if Cr50 is not accessed in a few days, + * that time_in_range will not provide the correct result after the wrap + * around for jiffies. In this case, we'll probably timeout or read + * incorrect value from TPM_STS and just retry the operation. + */ + return !time_in_range_open(jiffies, + phy->last_access_jiffies, + phy->wake_after_jiffies); +} + +static inline void cr50_wake_if_needed(struct cr50_spi_phy *phy) +{ + if (cr50_needs_waking(phy)) { + /* assert CS, wait 1 msec, deassert CS */ + struct spi_transfer spi_cs_wake = { .delay_usecs = 1000 }; + + spi_sync_transfer(phy->spi_device, &spi_cs_wake, 1); + /* wait for it to fully wake */ + msleep(phy->wake_start_delay_msec); + } + /* Reset the time when we need to wake Cr50 again */ + phy->wake_after_jiffies = jiffies + phy->sleep_delay_jiffies; +} + +/* Flow control: clock the bus and wait for cr50 to set LSB before + * sending/receiving data. TCG PTP spec allows it to happen during + * the last byte of header, but cr50 never does that in practice, + * and earlier versions had a bug when it was set too early, so don't + * check for it during header transfer. + */ +static int cr50_spi_flow_control(struct cr50_spi_phy *phy) +{ + unsigned long timeout_jiffies = + jiffies + msecs_to_jiffies(TPM_RETRY * TPM_TIMEOUT_RETRY); + struct spi_message m; + int ret; + u8 rx = 0; + struct spi_transfer spi_xfer = { + .rx_buf = &rx, + .len = 1, + .cs_change = 1, + }; + + do { + spi_message_init(&m); + spi_message_add_tail(&spi_xfer, &m); + ret = spi_sync_locked(phy->spi_device, &m); + if (ret < 0) + return ret; + if (time_after(jiffies, timeout_jiffies)) + return -EBUSY; + } while (!(rx & 0x01)); + return 0; +} + +static int cr50_spi_xfer_bytes(struct tpm_tis_data *data, u32 addr, + u16 len, u8 *buf, bool do_write) +{ + struct cr50_spi_phy *phy = to_cr50_spi_phy(data); + struct spi_message m; + u8 tx_buf[4]; + u8 rx_buf[4]; + struct spi_transfer spi_xfer = { + .tx_buf = tx_buf, + .rx_buf = rx_buf, + .len = 4, + .cs_change = 1, + }; + int ret; + + if (len > MAX_SPI_FRAMESIZE) + return -EINVAL; + + /* Do this outside of spi_bus_lock in case cr50 is not the + * only device on that spi bus. + */ + mutex_lock(&phy->time_track_mutex); + cr50_ensure_access_delay(phy); + cr50_wake_if_needed(phy); + mutex_unlock(&phy->time_track_mutex); + + tx_buf[0] = (do_write ? 0x00 : 0x80) | (len - 1); + tx_buf[1] = 0xD4; + tx_buf[2] = (addr >> 8) & 0xFF; + tx_buf[3] = addr & 0xFF; + + spi_message_init(&m); + spi_message_add_tail(&spi_xfer, &m); + + spi_bus_lock(phy->spi_device->master); + ret = spi_sync_locked(phy->spi_device, &m); + if (ret < 0) + goto exit; + + ret = cr50_spi_flow_control(phy); + if (ret < 0) + goto exit; + + spi_xfer.cs_change = 0; + spi_xfer.len = len; + if (do_write) { + spi_xfer.tx_buf = buf; + spi_xfer.rx_buf = NULL; + } else { + spi_xfer.tx_buf = NULL; + spi_xfer.rx_buf = buf; + } + + spi_message_init(&m); + spi_message_add_tail(&spi_xfer, &m); + ret = spi_sync_locked(phy->spi_device, &m); + +exit: + spi_bus_unlock(phy->spi_device->master); + + mutex_lock(&phy->time_track_mutex); + phy->last_access_jiffies = jiffies; + mutex_unlock(&phy->time_track_mutex); + + return ret; +} + +static int cr50_spi_read_bytes(struct tpm_tis_data *data, u32 addr, + u16 len, u8 *result) +{ + return cr50_spi_xfer_bytes(data, addr, len, result, false); +} + +static int cr50_spi_write_bytes(struct tpm_tis_data *data, u32 addr, + u16 len, u8 *value) +{ + return cr50_spi_xfer_bytes(data, addr, len, value, true); +} + +static int cr50_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result) +{ + int rc; + + rc = data->phy_ops->read_bytes(data, addr, sizeof(u16), (u8 *)result); + if (!rc) + *result = le16_to_cpu(*result); + return rc; +} + +static int cr50_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result) +{ + int rc; + + rc = data->phy_ops->read_bytes(data, addr, sizeof(u32), (u8 *)result); + if (!rc) + *result = le32_to_cpu(*result); + return rc; +} + +static int cr50_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value) +{ + value = cpu_to_le32(value); + return data->phy_ops->write_bytes(data, addr, sizeof(u32), + (u8 *)&value); +} + +static void cr50_get_fw_version(struct tpm_tis_data *data, char *fw_ver) +{ + int i, len = 0; + char fw_ver_block[4]; + + /* Write anything to TPM_CR50_FW_VER to start from the beg of string */ + tpm_tis_write8(data, TPM_CR50_FW_VER(data->locality), 0); + + /* Read the string, 4 bytes at a time, until we get '\0' */ + do { + tpm_tis_read_bytes(data, TPM_CR50_FW_VER(data->locality), 4, + fw_ver_block); + for (i = 0; i < 4 && fw_ver_block[i]; ) + fw_ver[len++] = fw_ver_block[i++]; + } while (i == 4 && len < TPM_CR50_MAX_FW_VER_LEN); + fw_ver[len] = 0; +} + +static const struct tpm_tis_phy_ops cr50_spi_phy_ops = { + .read_bytes = cr50_spi_read_bytes, + .write_bytes = cr50_spi_write_bytes, + .read16 = cr50_spi_read16, + .read32 = cr50_spi_read32, + .write32 = cr50_spi_write32, + .max_xfer_size = MAX_SPI_FRAMESIZE, +}; + +static int cr50_of_property_read_u32_optional(struct spi_device *dev, + const char *name, + u32 default_value, + u32 *value) +{ + struct device_node *np = dev->dev.of_node; + int rc; + + if (of_find_property(np, name, NULL)) { + rc = of_property_read_u32(np, name, value); + if (rc < 0) { + dev_err(&dev->dev, + "invalid '%s' property (%d)\n", + name, rc); + return rc; + } + } else { + *value = default_value; + } + + dev_dbg(&dev->dev, "%s = %u\n", name, *value); + return 0; +} + +static int cr50_spi_probe(struct spi_device *dev) +{ + char fw_ver[TPM_CR50_MAX_FW_VER_LEN + 1]; + struct cr50_spi_phy *phy; + int rc; + u32 value; + + phy = devm_kzalloc(&dev->dev, sizeof(struct cr50_spi_phy), + GFP_KERNEL); + if (!phy) + return -ENOMEM; + + phy->spi_device = dev; + + /* Cr50 timing properties. + */ + rc = cr50_of_property_read_u32_optional(dev, "access-delay-ms", + CR50_DFT_ACCESS_DELAY_MSEC, + &value); + if (rc < 0) + return rc; + phy->access_delay_jiffies = msecs_to_jiffies(value); + + rc = cr50_of_property_read_u32_optional(dev, "sleep-delay-ms", + CR50_DFT_SLEEP_DELAY_MSEC, + &value); + if (rc < 0) + return rc; + phy->sleep_delay_jiffies = msecs_to_jiffies(value); + + rc = cr50_of_property_read_u32_optional(dev, "wake-start-delay-ms", + CR50_DFT_WAKE_START_DELAY_MSEC, + &value); + if (rc < 0) + return rc; + phy->wake_start_delay_msec = value; + + mutex_init(&phy->time_track_mutex); + phy->wake_after_jiffies = jiffies; + phy->last_access_jiffies = jiffies; + + rc = tpm_tis_core_init(&dev->dev, &phy->priv, -1, &cr50_spi_phy_ops, + NULL); + if (rc < 0) + return rc; + + cr50_get_fw_version(&phy->priv, fw_ver); + dev_info(&dev->dev, "Cr50 firmware version: %s\n", fw_ver); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(cr50_pm, tpm_pm_suspend, tpm_tis_resume); + +static int cr50_spi_remove(struct spi_device *dev) +{ + struct tpm_chip *chip = spi_get_drvdata(dev); + + tpm_chip_unregister(chip); + tpm_tis_remove(chip); + return 0; +} + +static const struct spi_device_id cr50_spi_id[] = { + {"cr50", 0}, + {} +}; +MODULE_DEVICE_TABLE(spi, cr50_spi_id); + +static const struct of_device_id of_cr50_spi_match[] = { + { .compatible = "google,cr50", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_cr50_spi_match); + +static struct spi_driver cr50_spi_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "cr50_spi", + .pm = &cr50_pm, + .of_match_table = of_match_ptr(of_cr50_spi_match), + }, + .probe = cr50_spi_probe, + .remove = cr50_spi_remove, + .id_table = cr50_spi_id, +}; +module_spi_driver(cr50_spi_driver); + +MODULE_DESCRIPTION("Cr50 TCG PTP FIFO SPI driver"); +MODULE_LICENSE("GPL v2");