tmp/tpm_crb: implement runtime pm for tpm_crb

Utilize runtime_pm for driving tpm crb idle states.
The framework calls cmd_ready from the pm_runtime_resume handler
and go idle from the pm_runtime_suspend handler.
The TPM framework should wake the device before transmit and receive.
In case the runtime_pm framework is not enabled, the device will be in
ready state.

[[e-mail]: changed pm_runtime_put_sync()
to pm_runtime_put()]

Signed-off-by: Tomas Winkler <[e-mail]>
Reviewed-by: Jarkko Sakkinen <[e-mail]>
Tested-by: Jarkko Sakkinen <[e-mail]>

drivers/char/tpm/tpm-interface.c

···
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
+#include <linux/pm_runtime.h>
 
 #include "tpm.h"
 #include "tpm_eventlog.h"
···
 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
 		mutex_lock(&chip->tpm_mutex);
 
+	pm_runtime_get_sync(chip->dev.parent);
+
 	rc = chip->ops->send(chip, (u8 *) buf, count);
 	if (rc < 0) {
 		dev_err(&chip->dev,
···
 		dev_err(&chip->dev,
 			"tpm_transmit: tpm_recv: error %zd\n", rc);
 out:
+	pm_runtime_put(chip->dev.parent);
+
 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
 		mutex_unlock(&chip->tpm_mutex);
 	return rc;

drivers/char/tpm/tpm_crb.c

···
 #include <linux/highmem.h>
 #include <linux/rculist.h>
 #include <linux/module.h>
+#include <linux/pm_runtime.h>
 #include "tpm.h"
 
 #define ACPI_SIG_TPM2 "TPM2"
···
 
 	return 0;
 }
-
-static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
 
 static u8 crb_status(struct tpm_chip *chip)
 {
···
 	if (rc)
 		return rc;
 
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
 	rc = tpm_chip_register(chip);
-	if (rc)
+	if (rc) {
 		crb_go_idle(dev, priv);
+		pm_runtime_disable(dev);
+	}
+
+	pm_runtime_put(dev);
 
 	return rc;
 }
···
 
 	tpm_chip_unregister(chip);
 
+	pm_runtime_disable(dev);
+
 	return 0;
 }
+
+#ifdef CONFIG_PM
+static int crb_pm_runtime_suspend(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+	return crb_go_idle(dev, priv);
+}
+
+static int crb_pm_runtime_resume(struct device *dev)
+{
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+
+	return crb_cmd_ready(dev, priv);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops crb_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
+	SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend, crb_pm_runtime_resume, NULL)
+};
 
 static struct acpi_device_id crb_device_ids[] = {
 	{"MSFT0101", 0},