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From: Stephen Boyd <swboyd@chromium.org>
To: Peter Huewe <peterhuewe@gmx.de>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org,
	Andrey Pronin <apronin@chromium.org>,
	Duncan Laurie <dlaurie@chromium.org>,
	Jason Gunthorpe <jgg@ziepe.ca>, Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Guenter Roeck <groeck@chromium.org>,
	Alexander Steffen <Alexander.Steffen@infineon.com>,
	Heiko Stuebner <heiko@sntech.de>
Subject: [PATCH v6 2/4] tpm: Add a flag to indicate TPM power is managed by firmware
Date: Thu, 29 Aug 2019 15:41:08 -0700	[thread overview]
Message-ID: <20190829224110.91103-3-swboyd@chromium.org> (raw)
In-Reply-To: <20190829224110.91103-1-swboyd@chromium.org>

On some platforms, the TPM power is managed by firmware and therefore we
don't need to stop the TPM on suspend when going to a light version of
suspend such as S0ix ("freeze" suspend state). Add a chip flag,
TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED, to indicate this so that certain
platforms can probe for the usage of this light suspend and avoid
touching the TPM state across suspend/resume.

Cc: Andrey Pronin <apronin@chromium.org>
Cc: Duncan Laurie <dlaurie@chromium.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Alexander Steffen <Alexander.Steffen@infineon.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/char/tpm/tpm-interface.c | 8 +++++++-
 drivers/char/tpm/tpm.h           | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1b4f95c13e00..0b3def8e8186 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
+#include <linux/suspend.h>
 #include <linux/freezer.h>
 #include <linux/tpm_eventlog.h>
 
@@ -395,7 +396,11 @@ int tpm_pm_suspend(struct device *dev)
 		return -ENODEV;
 
 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
-		return 0;
+		goto suspended;
+
+	if ((chip->flags & TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED) &&
+	    !pm_suspend_via_firmware())
+		goto suspended;
 
 	if (!tpm_chip_start(chip)) {
 		if (chip->flags & TPM_CHIP_FLAG_TPM2)
@@ -406,6 +411,7 @@ int tpm_pm_suspend(struct device *dev)
 		tpm_chip_stop(chip);
 	}
 
+suspended:
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index e503ffc3aa39..28f73331aa2e 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -162,6 +162,7 @@ enum tpm_chip_flags {
 	TPM_CHIP_FLAG_VIRTUAL		= BIT(3),
 	TPM_CHIP_FLAG_HAVE_TIMEOUTS	= BIT(4),
 	TPM_CHIP_FLAG_ALWAYS_POWERED	= BIT(5),
+	TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED	= BIT(6),
 };
 
 #define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
-- 
Sent by a computer through tubes


  parent reply	other threads:[~2019-08-29 22:41 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-29 22:41 [PATCH v6 0/4] tpm: Add driver for cr50 Stephen Boyd
2019-08-29 22:41 ` [PATCH v6 1/4] dt-bindings: tpm: document properties " Stephen Boyd
2019-08-29 22:41 ` Stephen Boyd [this message]
2019-08-29 22:41 ` [PATCH v6 3/4] tpm: tpm_tis_spi: Introduce a flow control callback Stephen Boyd
2019-08-29 22:41 ` [PATCH v6 4/4] tpm: tpm_tis_spi: Support cr50 devices Stephen Boyd
2019-08-30 15:33   ` Heiko Stuebner
2019-08-30 15:40     ` Stephen Boyd
2019-09-02 16:53   ` kbuild test robot
2019-09-02 18:19   ` kbuild test robot
2019-09-03 16:39   ` Jarkko Sakkinen
2019-09-03 16:52     ` Stephen Boyd
2019-09-07 17:04       ` Jarkko Sakkinen
2019-09-07 17:20         ` Heiko Stübner

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