platform/x86: amd-pmc: Move to later in the suspend process

The `OS_HINT` message is supposed to indicate that everything else
that is supposed to go into the deepest state has done so.

This assumption is invalid as:
1) The CPUs will still go in and out of the deepest state
2) Other devices may still run their `noirq` suspend routines
3) The LPS0 ACPI device will still run

To more closely mirror how this works on other operating systems,
move the `amd-pmc` suspend to the very last thing before the s2idle
loop via an lps0 callback.

Fixes: 8d89835 ("PM: suspend: Do not pause cpuidle in the suspend-to-idle path")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20220317141445.6498-2-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/amd-pmc.c

@@ -639,9 +639,9 @@ static int amd_pmc_verify_czn_rtc(struct amd_pmc_dev *pdev, u32 *arg)
 	return rc;
 }
 
-static int __maybe_unused amd_pmc_suspend(struct device *dev)
+static void amd_pmc_s2idle_prepare(void)
 {
-	struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+	struct amd_pmc_dev *pdev = &pmc;
 	int rc;
 	u8 msg;
 	u32 arg = 1;
@@ -658,7 +658,7 @@ static int __maybe_unused amd_pmc_suspend(struct device *dev)
 	}
 
 	/* Dump the IdleMask before we send hint to SMU */
-	amd_pmc_idlemask_read(pdev, dev, NULL);
+	amd_pmc_idlemask_read(pdev, pdev->dev, NULL);
 	msg = amd_pmc_get_os_hint(pdev);
 	rc = amd_pmc_send_cmd(pdev, arg, NULL, msg, 0);
 	if (rc) {
@@ -672,18 +672,16 @@ static int __maybe_unused amd_pmc_suspend(struct device *dev)
 		dev_err(pdev->dev, "error writing to STB\n");
 		goto fail;
 	}
-
-	return 0;
+	return;
 fail:
 	if (pdev->cpu_id == AMD_CPU_ID_CZN)
 		cpu_latency_qos_update_request(&pdev->amd_pmc_pm_qos_req,
 						PM_QOS_DEFAULT_VALUE);
-	return rc;
 }
 
-static int __maybe_unused amd_pmc_resume(struct device *dev)
+static void amd_pmc_s2idle_restore(void)
 {
-	struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+	struct amd_pmc_dev *pdev = &pmc;
 	int rc;
 	u8 msg;
 
@@ -696,7 +694,7 @@ static int __maybe_unused amd_pmc_resume(struct device *dev)
 	amd_pmc_send_cmd(pdev, 0, NULL, SMU_MSG_LOG_DUMP_DATA, 0);
 
 	/* Dump the IdleMask to see the blockers */
-	amd_pmc_idlemask_read(pdev, dev, NULL);
+	amd_pmc_idlemask_read(pdev, pdev->dev, NULL);
 
 	/* Write data incremented by 1 to distinguish in stb_read */
 	if (enable_stb)
@@ -711,13 +709,11 @@ static int __maybe_unused amd_pmc_resume(struct device *dev)
 
 	/* Notify on failed entry */
 	amd_pmc_validate_deepest(pdev);
-
-	return rc;
 }
 
-static const struct dev_pm_ops amd_pmc_pm_ops = {
-	.suspend_noirq = amd_pmc_suspend,
-	.resume_noirq = amd_pmc_resume,
+static struct acpi_s2idle_dev_ops amd_pmc_s2idle_dev_ops = {
+	.prepare = amd_pmc_s2idle_prepare,
+	.restore = amd_pmc_s2idle_restore,
 };
 
 static const struct pci_device_id pmc_pci_ids[] = {
@@ -884,6 +880,10 @@ static int amd_pmc_probe(struct platform_device *pdev)
 
 	amd_pmc_get_smu_version(dev);
 	platform_set_drvdata(pdev, dev);
+	err = acpi_register_lps0_dev(&amd_pmc_s2idle_dev_ops);
+	if (err)
+		dev_warn(dev->dev, "failed to register LPS0 sleep handler, expect increased power consumption\n");
+
 	amd_pmc_dbgfs_register(dev);
 	cpu_latency_qos_add_request(&dev->amd_pmc_pm_qos_req, PM_QOS_DEFAULT_VALUE);
 	return 0;
@@ -897,6 +897,7 @@ static int amd_pmc_remove(struct platform_device *pdev)
 {
 	struct amd_pmc_dev *dev = platform_get_drvdata(pdev);
 
+	acpi_unregister_lps0_dev(&amd_pmc_s2idle_dev_ops);
 	amd_pmc_dbgfs_unregister(dev);
 	pci_dev_put(dev->rdev);
 	mutex_destroy(&dev->lock);
@@ -917,7 +918,6 @@ static struct platform_driver amd_pmc_driver = {
 	.driver = {
 		.name = "amd_pmc",
 		.acpi_match_table = amd_pmc_acpi_ids,
-		.pm = &amd_pmc_pm_ops,
 	},
 	.probe = amd_pmc_probe,
 	.remove = amd_pmc_remove,