platform/x86/amd/pmf: Use existing input event codes to update system states

At present, the PMF driver employs custom system state codes to update
system states. It is recommended to replace these with existing input
event codes (KEY_SLEEP, KEY_SUSPEND, and KEY_SCREENLOCK) to align system
updates with the PMF-TA output actions.

Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20240711052047.1531957-1-Shyam-sundar.S-k@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: Shyam Sundar S K

drivers/platform/x86/amd/pmf/pmf.h

@@ -12,6 +12,7 @@
 #define PMF_H
 
 #include <linux/acpi.h>
+#include <linux/input.h>
 #include <linux/platform_profile.h>
 
 #define POLICY_BUF_MAX_SZ		0x4b000
@@ -300,6 +301,7 @@ struct amd_pmf_dev {
 	void __iomem *policy_base;
 	bool smart_pc_enabled;
 	u16 pmf_if_version;
+	struct input_dev *pmf_idev;
 };
 
 struct apmf_sps_prop_granular_v2 {

drivers/platform/x86/amd/pmf/tee-if.c

@@ -62,18 +62,12 @@ static void amd_pmf_prepare_args(struct amd_pmf_dev *dev, int cmd,
 	param[0].u.memref.shm_offs = 0;
 }
 
-static int amd_pmf_update_uevents(struct amd_pmf_dev *dev, u16 event)
+static void amd_pmf_update_uevents(struct amd_pmf_dev *dev, u16 event)
 {
-	char *envp[2] = {};
-
-	envp[0] = kasprintf(GFP_KERNEL, "EVENT_ID=%d", event);
-	if (!envp[0])
-		return -EINVAL;
-
-	kobject_uevent_env(&dev->dev->kobj, KOBJ_CHANGE, envp);
-
-	kfree(envp[0]);
-	return 0;
+	input_report_key(dev->pmf_idev, event, 1); /* key press */
+	input_sync(dev->pmf_idev);
+	input_report_key(dev->pmf_idev, event, 0); /* key release */
+	input_sync(dev->pmf_idev);
 }
 
 static void amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_result *out)
@@ -149,7 +143,20 @@ static void amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_
 			break;
 
 		case PMF_POLICY_SYSTEM_STATE:
-			amd_pmf_update_uevents(dev, val);
+			switch (val) {
+			case 0:
+				amd_pmf_update_uevents(dev, KEY_SLEEP);
+				break;
+			case 1:
+				amd_pmf_update_uevents(dev, KEY_SUSPEND);
+				break;
+			case 2:
+				amd_pmf_update_uevents(dev, KEY_SCREENLOCK);
+				break;
+			default:
+				dev_err(dev->dev, "Invalid PMF policy system state: %d\n", val);
+			}
+
 			dev_dbg(dev->dev, "update SYSTEM_STATE: %s\n",
 				amd_pmf_uevent_as_str(val));
 			break;
@@ -363,6 +370,30 @@ static int amd_pmf_ta_open_session(struct tee_context *ctx, u32 *id)
 	return rc;
 }
 
+static int amd_pmf_register_input_device(struct amd_pmf_dev *dev)
+{
+	int err;
+
+	dev->pmf_idev = devm_input_allocate_device(dev->dev);
+	if (!dev->pmf_idev)
+		return -ENOMEM;
+
+	dev->pmf_idev->name = "PMF-TA output events";
+	dev->pmf_idev->phys = "amd-pmf/input0";
+
+	input_set_capability(dev->pmf_idev, EV_KEY, KEY_SLEEP);
+	input_set_capability(dev->pmf_idev, EV_KEY, KEY_SCREENLOCK);
+	input_set_capability(dev->pmf_idev, EV_KEY, KEY_SUSPEND);
+
+	err = input_register_device(dev->pmf_idev);
+	if (err) {
+		dev_err(dev->dev, "Failed to register input device: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static int amd_pmf_tee_init(struct amd_pmf_dev *dev)
 {
 	u32 size;
@@ -470,6 +501,10 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev)
 	if (pb_side_load)
 		amd_pmf_open_pb(dev, dev->dbgfs_dir);
 
+	ret = amd_pmf_register_input_device(dev);
+	if (ret)
+		goto error;
+
 	return 0;
 
 error:
@@ -480,6 +515,9 @@ int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev)
 
 void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev)
 {
+	if (dev->pmf_idev)
+		input_unregister_device(dev->pmf_idev);
+
 	if (pb_side_load && dev->esbin)
 		amd_pmf_remove_pb(dev);