The register TPM_CRB_CTRL_REQ_0 contains bits goIdle and cmdReady for invoking the chip to suspend and resume. This commit implements runtime PM for tpm_crb by using these bits.
The legacy ACPI start (SMI + DMA) based devices do not support these bits. Thus this functionality only is enabled only for CRB start (MMIO) based devices. Signed-off-by: Jarkko Sakkinen <[email protected]> --- drivers/char/tpm/tpm-interface.c | 3 +++ drivers/char/tpm/tpm_crb.c | 50 ++++++++++++++++++++++++++++++++++++++-- 2 files changed, 51 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 5e3c1b6..3b85648 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -29,6 +29,7 @@ #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/freezer.h> +#include <linux/pm_runtime.h> #include "tpm.h" #include "tpm_eventlog.h" @@ -350,6 +351,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf, return -E2BIG; } + pm_runtime_get_sync(chip->dev.parent); mutex_lock(&chip->tpm_mutex); rc = chip->ops->send(chip, (u8 *) buf, count); @@ -394,6 +396,7 @@ out_recv: "tpm_transmit: tpm_recv: error %zd\n", rc); out: mutex_unlock(&chip->tpm_mutex); + pm_runtime_put_sync(chip->dev.parent); return rc; } diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 0c8ed7f..ef545eb 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -20,6 +20,7 @@ #include <linux/rculist.h> #include <linux/module.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include "tpm.h" #define ACPI_SIG_TPM2 "TPM2" @@ -41,7 +42,6 @@ enum crb_ca_request { enum crb_ca_status { CRB_CA_STS_ERROR = BIT(0), - CRB_CA_STS_TPM_IDLE = BIT(1), }; enum crb_start { @@ -83,7 +83,50 @@ struct crb_priv { u8 __iomem *rsp; }; -static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume); +/* CONFIG_PM */ +static int __maybe_unused crb_runtime_suspend(struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + struct crb_priv *priv = dev_get_drvdata(&chip->dev); + u32 req; + + if (priv->flags & CRB_FL_ACPI_START) + return 0; + + req = ioread32(&priv->cca->req); + iowrite32(cpu_to_le32(req | CRB_CA_REQ_GO_IDLE), &priv->cca->req); + msleep(chip->timeout_c); + + if (ioread32(&priv->cca->req) & CRB_CA_REQ_GO_IDLE) + return -ETIME; + + return 0; +} + +/* CONFIG_PM */ +static int __maybe_unused crb_runtime_resume(struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + struct crb_priv *priv = dev_get_drvdata(&chip->dev); + u32 req; + + if (priv->flags & CRB_FL_ACPI_START) + return 0; + + req = ioread32(&priv->cca->req); + iowrite32(cpu_to_le32(req | CRB_CA_REQ_CMD_READY), &priv->cca->req); + msleep(chip->timeout_c); + + if (ioread32(&priv->cca->req) & CRB_CA_REQ_CMD_READY) + return -ETIME; + + return 0; +} + +static const struct dev_pm_ops crb_pm = { + SET_RUNTIME_PM_OPS(crb_runtime_suspend, crb_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume) +}; static u8 crb_status(struct tpm_chip *chip) { @@ -206,6 +249,8 @@ static int crb_init(struct acpi_device *device, struct crb_priv *priv) if (IS_ERR(chip)) return PTR_ERR(chip); + pm_runtime_set_active(&device->dev); + pm_runtime_enable(&device->dev); dev_set_drvdata(&chip->dev, priv); chip->acpi_dev_handle = device->handle; chip->flags = TPM_CHIP_FLAG_TPM2; @@ -366,6 +411,7 @@ static int crb_acpi_remove(struct acpi_device *device) tpm_chip_unregister(chip); + pm_runtime_disable(dev); return 0; } -- 2.7.4
