ARM: mach-shmobile: sh7372 Core Standby Suspend-to-RAM

Add sh7372 Core Standby sleep mode support and tie it
in with the shared SH-Mobile ARM suspend code.

The Core Standby mode is the lightest sh7372-specific
sleep mode, cutting power to the ARM core excluding the
L2 cache. Any interrupt source can be used for wakeups.

The low level portion of this code is based on the
TI OMAP sleep code in sleep34xx.S, thanks to them.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/pm-sh7372.c b/arch/arm/mach-shmobile/pm-sh7372.c
new file mode 100644
index 0000000..92c374d
--- /dev/null
+++ b/arch/arm/mach-shmobile/pm-sh7372.c
@@ -0,0 +1,79 @@
+/*
+ * sh7372 Power management support
+ *
+ *  Copyright (C) 2011 Magnus Damm
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/pm.h>
+#include <linux/suspend.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/tlbflush.h>
+#include <mach/common.h>
+
+#define SMFRAM 0xe6a70000
+#define SYSTBCR 0xe6150024
+#define SBAR 0xe6180020
+#define APARMBAREA 0xe6f10020
+
+#ifdef CONFIG_SUSPEND
+static void sh7372_enter_core_standby(void)
+{
+	void __iomem *smfram = (void __iomem *)SMFRAM;
+
+	__raw_writel(0, APARMBAREA); /* translate 4k */
+	__raw_writel(__pa(sh7372_cpu_resume), SBAR); /* set reset vector */
+	__raw_writel(0x10, SYSTBCR); /* enable core standby */
+
+	__raw_writel(0, smfram + 0x3c); /* clear page table address */
+
+	sh7372_cpu_suspend();
+	cpu_init();
+
+	/* if page table address is non-NULL then we have been powered down */
+	if (__raw_readl(smfram + 0x3c)) {
+		__raw_writel(__raw_readl(smfram + 0x40),
+			     __va(__raw_readl(smfram + 0x3c)));
+
+		flush_tlb_all();
+		set_cr(__raw_readl(smfram + 0x38));
+	}
+
+	__raw_writel(0, SYSTBCR); /* disable core standby */
+	__raw_writel(0, SBAR); /* disable reset vector translation */
+}
+
+static int sh7372_enter_suspend(suspend_state_t suspend_state)
+{
+	sh7372_enter_core_standby();
+	return 0;
+}
+
+static void sh7372_suspend_init(void)
+{
+	shmobile_suspend_ops.enter = sh7372_enter_suspend;
+}
+#else
+static void sh7372_suspend_init(void) {}
+#endif
+
+#define DBGREG1 0xe6100020
+#define DBGREG9 0xe6100040
+
+void __init sh7372_pm_init(void)
+{
+	/* enable DBG hardware block to kick SYSC */
+	__raw_writel(0x0000a500, DBGREG9);
+	__raw_writel(0x0000a501, DBGREG9);
+	__raw_writel(0x00000000, DBGREG1);
+
+	sh7372_suspend_init();
+}