[PATCH 3/4] platform/x86: amd-pmc: Move to later in the suspend process

[Mario Limonciello <mario.limonciello@amd.com>]

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: 8d89835b0467 ("PM: suspend: Do not pause cpuidle in the suspend-to-idle path")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/platform/x86/amd-pmc.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
index 971aaabaa9c8..c13fd93f2662 100644
--- a/drivers/platform/x86/amd-pmc.c
+++ b/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 int amd_pmc_suspend(void *context, bool constraints_met)
 {
-	struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+	struct amd_pmc_dev *pdev = dev_get_drvdata((struct device *)context);
 	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) {
@@ -681,28 +681,28 @@ static int __maybe_unused amd_pmc_suspend(struct device *dev)
 	return rc;
 }
 
-static int __maybe_unused amd_pmc_resume(struct device *dev)
+static void amd_pmc_resume(void *context)
 {
-	struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+	struct amd_pmc_dev *pdev = dev_get_drvdata((struct device *)context);
 	int rc;
 	u8 msg;
 
 	msg = amd_pmc_get_os_hint(pdev);
 	rc = amd_pmc_send_cmd(pdev, 0, NULL, msg, 0);
 	if (rc)
-		dev_err(pdev->dev, "resume failed\n");
+		dev_err(pdev->dev, "resume failed: %d\n", rc);
 
 	/* Let SMU know that we are looking for stats */
 	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)
 		rc = amd_pmc_write_stb(pdev, AMD_PMC_STB_PREDEF + 1);
 	if (rc)
-		dev_err(pdev->dev, "error writing to STB\n");
+		dev_err(pdev->dev, "error writing to STB: %d\n", rc);
 
 	/* Restore the QoS request back to defaults if it was set */
 	if (pdev->cpu_id == AMD_CPU_ID_CZN)
@@ -711,15 +711,8 @@ 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 const struct pci_device_id pmc_pci_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_YC) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_CZN) },
@@ -884,6 +877,12 @@ static int amd_pmc_probe(struct platform_device *pdev)
 
 	amd_pmc_get_smu_version(dev);
 	platform_set_drvdata(pdev, dev);
+	err = acpi_register_lps0_callbacks(amd_pmc_suspend,
+					   amd_pmc_resume,
+					   &pdev->dev);
+	if (err)
+		goto err_pci_dev_put;
+
 	amd_pmc_dbgfs_register(dev);
 	cpu_latency_qos_add_request(&dev->amd_pmc_pm_qos_req, PM_QOS_DEFAULT_VALUE);
 	return 0;
@@ -897,6 +896,9 @@ static int amd_pmc_remove(struct platform_device *pdev)
 {
 	struct amd_pmc_dev *dev = platform_get_drvdata(pdev);
 
+	acpi_unregister_lps0_callbacks(amd_pmc_suspend,
+					amd_pmc_resume,
+					&pdev->dev);
 	amd_pmc_dbgfs_unregister(dev);
 	pci_dev_put(dev->rdev);
 	mutex_destroy(&dev->lock);
@@ -917,7 +919,6 @@ 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,
-- 
2.34.1