Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754261AbdCFOrK (ORCPT ); Mon, 6 Mar 2017 09:47:10 -0500 Received: from mga09.intel.com ([134.134.136.24]:32150 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754711AbdCFOqr (ORCPT ); Mon, 6 Mar 2017 09:46:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="232823796" Date: Mon, 6 Mar 2017 16:43:08 +0200 From: Jarkko Sakkinen To: Enric Balletbo i Serra Cc: Rob Herring , Peter Huewe , Mark Rutland , Jason Gunthorpe , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, Sonny Rao Subject: Re: [PATCH v3] tpm: do not suspend/resume if power stays on Message-ID: <20170306144308.xpvnipto2cyj7pox@intel.com> References: <20170303160959.27422-1-enric.balletbo@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170303160959.27422-1-enric.balletbo@collabora.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3385 Lines: 91 On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote: > From: Sonny Rao > > The suspend/resume behavior of the TPM can be controlled by setting > "powered-while-suspended" in the DTS. This is useful for the cases > when hardware does not power-off the TPM. > > Signed-off-by: Sonny Rao > Signed-off-by: Enric Balletbo i Serra Thanks. Looks good to me. Reviewed-by: Jarkko Sakkinen /Jarkko > --- > Changes since v2: > Jarkko Sakkinen > - Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean variable. > - Remove a trailing newline. > Changes since v1: > Jason Gunthorpe : > - Move the code to handle suspend/resume in the common chip code. > > Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt | 6 ++++++ > drivers/char/tpm/tpm-interface.c | 3 +++ > drivers/char/tpm/tpm.h | 1 + > drivers/char/tpm/tpm_of.c | 3 +++ > 4 files changed, 13 insertions(+) > > diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt > index 8cb638b..85c8216 100644 > --- a/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt > +++ b/Documentation/devicetree/bindings/security/tpm/tpm-i2c.txt > @@ -8,6 +8,12 @@ Required properties: > the firmware event log > - linux,sml-size : size of the memory allocated for the firmware event log > > +Optional properties: > + > +- powered-while-suspended: present when the TPM is left powered on between > + suspend and resume (makes the suspend/resume > + callbacks do nothing). > + > Example (for OpenPower Systems with Nuvoton TPM 2.0 on I2C) > ---------------------------------------------------------- > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index a2688ac..6869093 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -944,6 +944,9 @@ int tpm_pm_suspend(struct device *dev) > if (chip == NULL) > return -ENODEV; > > + if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED) > + return 0; > + > if (chip->flags & TPM_CHIP_FLAG_TPM2) { > tpm2_shutdown(chip, TPM2_SU_STATE); > return 0; > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h > index 1ae9768..0ce379c 100644 > --- a/drivers/char/tpm/tpm.h > +++ b/drivers/char/tpm/tpm.h > @@ -146,6 +146,7 @@ enum tpm_chip_flags { > TPM_CHIP_FLAG_IRQ = BIT(2), > TPM_CHIP_FLAG_VIRTUAL = BIT(3), > TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4), > + TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5), > }; > > struct tpm_chip_seqops { > diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c > index 7dee42d7..e89276c 100644 > --- a/drivers/char/tpm/tpm_of.c > +++ b/drivers/char/tpm/tpm_of.c > @@ -34,6 +34,9 @@ int tpm_read_log_of(struct tpm_chip *chip) > else > return -ENODEV; > > + if (of_property_read_bool(np, "powered-while-suspended")) > + chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED; > + > sizep = of_get_property(np, "linux,sml-size", NULL); > basep = of_get_property(np, "linux,sml-base", NULL); > if (sizep == NULL && basep == NULL) > -- > 2.9.3 >