On Thu, Mar 02, 2017 at 04:42:57PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonny...@chromium.org>
>
> 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 <sonny...@chromium.org>
> Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
> ---
>
> 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 | 3 +++
> drivers/char/tpm/tpm_of.c | 3 +++
> 4 files changed, 15 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..7f60780 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->powered_while_suspended)
> + return 0;
Why there can't just be TPM_CHIP_FLAG_ALWAYS_POWERED or something similar?
> +
> 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..c8f796c 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -183,10 +183,13 @@ struct tpm_chip {
> unsigned long duration[3]; /* jiffies */
> bool duration_adjusted;
>
> + bool powered_while_suspended;
> +
> struct dentry *bios_dir[TPM_NUM_EVENT_LOG_FILES];
>
> const struct attribute_group *groups[3];
> unsigned int groups_cnt;
> +
trailing newline
> #ifdef CONFIG_ACPI
> acpi_handle acpi_dev_handle;
> char ppi_version[TPM_PPI_VERSION_LEN + 1];
> diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
> index 7dee42d7..33eddd4 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;
>
> + chip->powered_while_suspended = of_property_read_bool(np,
> + "powered-while-suspended");
> +
> 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
>
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, SlashDot.org! http://sdm.link/slashdot
> _______________________________________________
> tpmdd-devel mailing list
> tpmdd-de...@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
