Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752462AbdCCQK2 (ORCPT ); Fri, 3 Mar 2017 11:10:28 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:51800 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752453AbdCCQKZ (ORCPT ); Fri, 3 Mar 2017 11:10:25 -0500 From: Enric Balletbo i Serra To: Rob Herring , Peter Huewe Cc: Mark Rutland , Jarkko Sakkinen , Jason Gunthorpe , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, Sonny Rao Subject: [PATCH v3] tpm: do not suspend/resume if power stays on Date: Fri, 3 Mar 2017 17:09:59 +0100 Message-Id: <20170303160959.27422-1-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3045 Lines: 82 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 --- 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