From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/powerpc/platforms/pasemi/idle.c | 93 ++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 arch/powerpc/platforms/pasemi/idle.c

(limited to 'arch/powerpc/platforms/pasemi/idle.c')

diff --git a/arch/powerpc/platforms/pasemi/idle.c b/arch/powerpc/platforms/pasemi/idle.c
new file mode 100644
index 000000000..6087c70ed
--- /dev/null
+++ b/arch/powerpc/platforms/pasemi/idle.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2006-2007 PA Semi, Inc
+ *
+ * Maintained by: Olof Johansson <olof@lixom.net>
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/irq.h>
+
+#include <asm/machdep.h>
+#include <asm/reg.h>
+#include <asm/smp.h>
+
+#include "pasemi.h"
+
+struct sleep_mode {
+	char *name;
+	void (*entry)(void);
+};
+
+static struct sleep_mode modes[] = {
+	{ .name = "spin", .entry = &idle_spin },
+	{ .name = "doze", .entry = &idle_doze },
+};
+
+static int current_mode = 0;
+
+static int pasemi_system_reset_exception(struct pt_regs *regs)
+{
+	/* If we were woken up from power savings, we need to return
+	 * to the calling function, since nip is not saved across
+	 * all modes.
+	 */
+
+	if (regs->msr & SRR1_WAKEMASK)
+		regs_set_return_ip(regs, regs->link);
+
+	switch (regs->msr & SRR1_WAKEMASK) {
+	case SRR1_WAKEDEC:
+		set_dec(1);
+		break;
+	case SRR1_WAKEEE:
+		/*
+		 * Handle these when interrupts get re-enabled and we take
+		 * them as regular exceptions. We are in an NMI context
+		 * and can't handle these here.
+		 */
+		break;
+	default:
+		/* do system reset */
+		return 0;
+	}
+
+	/* Set higher astate since we come out of power savings at 0 */
+	restore_astate(hard_smp_processor_id());
+
+	/* everything handled */
+	regs_set_recoverable(regs);
+	return 1;
+}
+
+static int __init pasemi_idle_init(void)
+{
+#ifndef CONFIG_PPC_PASEMI_CPUFREQ
+	pr_warn("No cpufreq driver, powersavings modes disabled\n");
+	current_mode = 0;
+#endif
+
+	ppc_md.system_reset_exception = pasemi_system_reset_exception;
+	ppc_md.power_save = modes[current_mode].entry;
+	pr_info("Using PA6T idle loop (%s)\n", modes[current_mode].name);
+
+	return 0;
+}
+machine_late_initcall(pasemi, pasemi_idle_init);
+
+static int __init idle_param(char *p)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(modes); i++) {
+		if (!strcmp(modes[i].name, p)) {
+			current_mode = i;
+			break;
+		}
+	}
+	return 0;
+}
+
+early_param("idle", idle_param);
-- 
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