On Fri, Mar 03, 2017 at 05:09:59PM +0100, Enric Balletbo i Serra wrote:
> From: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
>
> 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 <sonnyrao@xxxxxxxxxxxx>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Thanks. Looks good to me.
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
/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
>
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