platform/x86/intel: Move intel_pmt from MFD to Auxiliary Bus

Intel Platform Monitoring Technology (PMT) support is indicated by presence
of an Intel defined PCIe Designated Vendor Specific Extended Capabilities
(DVSEC) structure with a PMT specific ID. The current MFD implementation
creates child devices for each PMT feature, currently telemetry, watcher,
and crashlog. However DVSEC structures may also be used by Intel to
indicate support for other features. The Out Of Band Management Services
Module (OOBMSM) uses DVSEC to enumerate several features, including PMT.
In order to support them it is necessary to modify the intel_pmt driver to
handle the creation of the child devices more generically. To that end,
modify the driver to create child devices for any VSEC/DVSEC features on
supported devices (indicated by PCI ID).  Additionally, move the
implementation from MFD to the Auxiliary bus.  VSEC/DVSEC features are
really multifunctional PCI devices, not platform devices as MFD was
designed for. Auxiliary bus gives more flexibility by allowing the
definition of custom structures that can be shared between associated
auxiliary devices and the parent device. Also, rename the driver from
intel_pmt to intel_vsec to better reflect the purpose.

This series also removes the current runtime pm support which was not
complete to begin with. None of the current devices require runtime pm.
However the support will be replaced when a device is added that requires
it.

Reviewed-by: Mark Gross <markgross@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20211208015015.891275-4-david.e.box@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 25 insertions, 22 deletions

diff --git a/drivers/platform/x86/intel/pmt/crashlog.c b/drivers/platform/x86/intel/pmt/crashlog.c
index 1c1021f04d3c..34daf9df168b 100644
--- a/drivers/platform/x86/intel/pmt/crashlog.c
+++ b/drivers/platform/x86/intel/pmt/crashlog.c
@@ -8,6 +8,7 @@
  * Author: "Alexander Duyck" <alexander.h.duyck@linux.intel.com>
  */
 
+#include <linux/auxiliary_bus.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -15,10 +16,9 @@
 #include <linux/uaccess.h>
 #include <linux/overflow.h>
 
+#include "../vsec.h"
 #include "class.h"
 
-#define DRV_NAME		"pmt_crashlog"
-
 /* Crashlog discovery header types */
 #define CRASH_TYPE_OOBMSM	1
 
@@ -257,34 +257,34 @@ static struct intel_pmt_namespace pmt_crashlog_ns = {
 /*
  * initialization
  */
-static int pmt_crashlog_remove(struct platform_device *pdev)
+static void pmt_crashlog_remove(struct auxiliary_device *auxdev)
 {
-	struct pmt_crashlog_priv *priv = platform_get_drvdata(pdev);
+	struct pmt_crashlog_priv *priv = auxiliary_get_drvdata(auxdev);
 	int i;
 
 	for (i = 0; i < priv->num_entries; i++)
 		intel_pmt_dev_destroy(&priv->entry[i].entry, &pmt_crashlog_ns);
-
-	return 0;
 }
 
-static int pmt_crashlog_probe(struct platform_device *pdev)
+static int pmt_crashlog_probe(struct auxiliary_device *auxdev,
+			      const struct auxiliary_device_id *id)
 {
+	struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
 	struct pmt_crashlog_priv *priv;
 	size_t size;
 	int i, ret;
 
-	size = struct_size(priv, entry, pdev->num_resources);
-	priv = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+	size = struct_size(priv, entry, intel_vsec_dev->num_resources);
+	priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, priv);
+	auxiliary_set_drvdata(auxdev, priv);
 
-	for (i = 0; i < pdev->num_resources; i++) {
+	for (i = 0; i < intel_vsec_dev->num_resources; i++) {
 		struct intel_pmt_entry *entry = &priv->entry[i].entry;
 
-		ret = intel_pmt_dev_create(entry, &pmt_crashlog_ns, pdev, i);
+		ret = intel_pmt_dev_create(entry, &pmt_crashlog_ns, intel_vsec_dev, i);
 		if (ret < 0)
 			goto abort_probe;
 		if (ret)
@@ -295,26 +295,30 @@ static int pmt_crashlog_probe(struct platform_device *pdev)
 
 	return 0;
 abort_probe:
-	pmt_crashlog_remove(pdev);
+	pmt_crashlog_remove(auxdev);
 	return ret;
 }
 
-static struct platform_driver pmt_crashlog_driver = {
-	.driver = {
-		.name   = DRV_NAME,
-	},
-	.remove = pmt_crashlog_remove,
-	.probe  = pmt_crashlog_probe,
+static const struct auxiliary_device_id pmt_crashlog_id_table[] = {
+	{ .name = "intel_vsec.crashlog" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, pmt_crashlog_id_table);
+
+static struct auxiliary_driver pmt_crashlog_aux_driver = {
+	.id_table	= pmt_crashlog_id_table,
+	.remove		= pmt_crashlog_remove,
+	.probe		= pmt_crashlog_probe,
 };
 
 static int __init pmt_crashlog_init(void)
 {
-	return platform_driver_register(&pmt_crashlog_driver);
+	return auxiliary_driver_register(&pmt_crashlog_aux_driver);
 }
 
 static void __exit pmt_crashlog_exit(void)
 {
-	platform_driver_unregister(&pmt_crashlog_driver);
+	auxiliary_driver_unregister(&pmt_crashlog_aux_driver);
 	xa_destroy(&crashlog_array);
 }
 
@@ -323,5 +327,4 @@ module_exit(pmt_crashlog_exit);
 
 MODULE_AUTHOR("Alexander Duyck <alexander.h.duyck@linux.intel.com>");
 MODULE_DESCRIPTION("Intel PMT Crashlog driver");
-MODULE_ALIAS("platform:" DRV_NAME);
 MODULE_LICENSE("GPL v2");