Messages in this thread Patch in this message | | | From | Enric Balletbo i Serra <> | Subject | [PATCH] tpm: do not suspend/resume if power stays on | Date | Wed, 1 Mar 2017 12:51:16 +0100 |
| |
From: Sonny Rao <sonnyrao@chromium.org>
The suspend/resume behavior of the TPM can be controlled by setting "powered-while-suspended" in the DTS.
Signed-off-by: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> --- Documentation/devicetree/bindings/tpm/tpm.txt | 25 +++++++++++++++++++++++++ drivers/char/tpm/tpm_i2c_infineon.c | 25 ++++++++++++++++++++++++- 2 files changed, 49 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/tpm/tpm.txt
diff --git a/Documentation/devicetree/bindings/tpm/tpm.txt b/Documentation/devicetree/bindings/tpm/tpm.txt new file mode 100644 index 0000000..af4de0d --- /dev/null +++ b/Documentation/devicetree/bindings/tpm/tpm.txt @@ -0,0 +1,25 @@ +TPM (Trusted Platform Module) + +A TPM on the I2C bus is a child of the node for the bus. + +Required properties: +- compatible: should be "infineon,<chip>" +- reg: the I2C address + +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: + i2c@12C90000 { + samsung,i2c-sda-delay = <100>; + samsung,i2c-max-bus-freq = <66000>; + gpios = <&gpa1 2 3 3 0>, + <&gpa1 3 3 3 0>; + + tpm { + compatible = "infineon,slb9635tt"; + reg = <0x20>; + powered-while-suspended; + }; + }; diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c index 62ee44e..19d9522 100644 --- a/drivers/char/tpm/tpm_i2c_infineon.c +++ b/drivers/char/tpm/tpm_i2c_infineon.c @@ -70,6 +70,7 @@ struct tpm_inf_dev { u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ struct tpm_chip *chip; enum i2c_chip_type chip_type; + bool powered_while_suspended; }; static struct tpm_inf_dev tpm_dev; @@ -599,6 +600,11 @@ static int tpm_tis_i2c_init(struct device *dev) goto out_err; } + if (dev->of_node && + of_get_property(dev->of_node, "powered-while-suspended", NULL)) { + tpm_dev.powered_while_suspended = true; + } + /* read four bytes from DID_VID register */ if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) { dev_err(dev, "could not read vendor id\n"); @@ -662,7 +668,24 @@ static const struct of_device_id tpm_tis_i2c_of_match[] = { MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match); #endif -static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume); +static int __maybe_unused tpm_tis_i2c_suspend(struct device *dev) +{ + if (tpm_dev.powered_while_suspended) + return 0; + + return tpm_pm_suspend(dev); +} + +static int __maybe_unused tpm_tis_i2c_resume(struct device *dev) +{ + if (tpm_dev.powered_while_suspended) + return 0; + + return tpm_pm_resume(dev); +} + +static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_tis_i2c_suspend, + tpm_tis_i2c_resume); static int tpm_tis_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) -- 2.9.3
| |