mei: debugfs: add pxp mode to devstate in debugfs

Add pxp mode devstate to debugfs to monitor pxp state machine progress.
This is useful to debug issues in scenarios in which the pxp state
needs to be re-initialized, like during power transitions such as
suspend/resume. With this debugfs the state could be monitored
to ensure that pxp is in the ready state.

CC: Vitaly Lubart <vitaly.lubart@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-15-tomas.winkler@intel.com
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/misc/mei/debugfs.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (c) 2012-2016, Intel Corporation. All rights reserved
+ * Copyright (c) 2012-2022, Intel Corporation. All rights reserved
  * Intel Management Engine Interface (Intel MEI) Linux driver
  */
 
@@ -86,6 +86,20 @@ static int mei_dbgfs_active_show(struct seq_file *m, void *unused)
 }
 DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_active);
 
+static const char *mei_dev_pxp_mode_str(enum mei_dev_pxp_mode state)
+{
+#define MEI_PXP_MODE(state) case MEI_DEV_PXP_##state: return #state
+	switch (state) {
+	MEI_PXP_MODE(DEFAULT);
+	MEI_PXP_MODE(INIT);
+	MEI_PXP_MODE(SETUP);
+	MEI_PXP_MODE(READY);
+	default:
+		return "unknown";
+	}
+#undef MEI_PXP_MODE
+}
+
 static int mei_dbgfs_devstate_show(struct seq_file *m, void *unused)
 {
 	struct mei_device *dev = m->private;
@@ -112,6 +126,9 @@ static int mei_dbgfs_devstate_show(struct seq_file *m, void *unused)
 	seq_printf(m, "pg:  %s, %s\n",
 		   mei_pg_is_enabled(dev) ? "ENABLED" : "DISABLED",
 		   mei_pg_state_str(mei_pg_state(dev)));
+
+	seq_printf(m, "pxp: %s\n", mei_dev_pxp_mode_str(dev->pxp_mode));
+
 	return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(mei_dbgfs_devstate);