From patchwork Sat Oct 8 11:59:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winkler, Tomas" X-Patchwork-Id: 9368115 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 392E3608A6 for ; Sat, 8 Oct 2016 12:01:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2C860298B3 for ; Sat, 8 Oct 2016 12:01:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 21A9D29986; Sat, 8 Oct 2016 12:01:55 +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 49846298B3 for ; Sat, 8 Oct 2016 12:01:54 +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 1bsqK8-0006El-A3; Sat, 08 Oct 2016 12:01:52 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bsqK6-0006Ef-MV for tpmdd-devel@lists.sourceforge.net; Sat, 08 Oct 2016 12:01:50 +0000 Received-SPF: fail (sog-mx-1.v43.ch3.sourceforge.com: domain of intel.com does not designate 192.55.52.120 as permitted sender) client-ip=192.55.52.120; envelope-from=tomas.winkler@intel.com; helo=mga04.intel.com; Received: from mga04.intel.com ([192.55.52.120]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1bsqK5-0002zy-OF for tpmdd-devel@lists.sourceforge.net; Sat, 08 Oct 2016 12:01:50 +0000 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP; 08 Oct 2016 05:01:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,460,1473145200"; d="scan'208";a="177833732" Received: from twinkler-lnx.jer.intel.com ([10.12.87.167]) by fmsmga004.fm.intel.com with ESMTP; 08 Oct 2016 05:01:41 -0700 From: Tomas Winkler To: tpmdd-devel@lists.sourceforge.net, Jason Gunthorpe , Jarkko Sakkinen Date: Sat, 8 Oct 2016 14:59:36 +0300 Message-Id: <1475927979-23484-2-git-send-email-tomas.winkler@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1475927979-23484-1-git-send-email-tomas.winkler@intel.com> References: <1475927979-23484-1-git-send-email-tomas.winkler@intel.com> X-Headers-End: 1bsqK5-0002zy-OF Cc: linux-kernel@vger.kernel.org Subject: [tpmdd-devel] [PATCH v4 1/4] tpm/tpm_crb: implement tpm crb idle state 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 From: "Winkler, Tomas" The register TPM_CRB_CTRL_REQ_x contains bits goIdle and cmdReady for SW to indicate that the device can enter or should exit the idle state. The legacy ACPI-start (SMI + DMA) based devices do not support these bits and the idle state management is not exposed to the host SW. Thus, this functionality only is enabled only for a CRB start (MMIO) based devices. Based on Jarkko Sakkinen original patch: 'tpm_crb: implement power tpm crb power management' To keep the implementation local to the hw we don't use wait_for_tpm_stat for polling the TPM_CRB_CTRL_REQ. Signed-off-by: Tomas Winkler Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- V2: do not export the functions via tpm ops V3: fix lower case corruption; adjust function documentation V4: resend drivers/char/tpm/tpm_crb.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index a7c870af916c..0f3b3f3d12d3 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -83,6 +83,76 @@ struct crb_priv { u32 cmd_size; }; +/** + * crb_go_idle - request tpm crb device to go the idle state + * + * @dev: crb device + * @priv: crb private data + * + * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ + * The device should respond within TIMEOUT_C by clearing the bit. + * Anyhow, we do not wait here as a consequent CMD_READY request + * will be handled correctly even if idle was not completed. + * + * The function does nothing for devices with ACPI-start method. + * + * Return: 0 always + */ +static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv) +{ + if (priv->flags & CRB_FL_ACPI_START) + return 0; + + iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req); + /* we don't really care when this settles */ + dev_dbg(dev, "goIdle\n"); + + return 0; +} + +/** + * crb_cmd_ready - request tpm crb device to enter ready state + * + * @dev: crb device + * @priv: crb private data + * + * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ + * and poll till the device acknowledge it by clearing the bit. + * The device should respond within TIMEOUT_C. + * + * The function does nothing for devices with ACPI-start method + * + * Return: 0 on success -ETIME on timeout; + */ +static int __maybe_unused crb_cmd_ready(struct device *dev, + struct crb_priv *priv) +{ + ktime_t stop, start; + + if (priv->flags & CRB_FL_ACPI_START) + return 0; + + iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req); + + start = ktime_get(); + stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C)); + do { + if (!(ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY)) { + dev_dbg(dev, "cmdReady in %lld usecs\n", + ktime_to_us(ktime_sub(ktime_get(), start))); + return 0; + } + usleep_range(50, 100); + } while (ktime_before(ktime_get(), stop)); + + if (ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY) { + dev_warn(dev, "cmdReady timed out\n"); + return -ETIME; + } + + return 0; +} + static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume); static u8 crb_status(struct tpm_chip *chip)