MIPS: JZ4740: Add power-management and system reset support

Add support for suspend/resume and poweroff/reboot on a JZ4740 SoC.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1398/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/arch/mips/jz4740/reset.c b/arch/mips/jz4740/reset.c
new file mode 100644
index 000000000000..5f1fb95c0d0d
--- /dev/null
+++ b/arch/mips/jz4740/reset.c
@@ -0,0 +1,79 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/pm.h>
+
+#include <asm/reboot.h>
+
+#include <asm/mach-jz4740/base.h>
+#include <asm/mach-jz4740/timer.h>
+
+static void jz4740_halt(void)
+{
+        while (1) {
+                __asm__(".set push;\n"
+                        ".set mips3;\n"
+                        "wait;\n"
+                        ".set pop;\n"
+                );
+        }
+}
+
+#define JZ_REG_WDT_DATA 0x00
+#define JZ_REG_WDT_COUNTER_ENABLE 0x04
+#define JZ_REG_WDT_COUNTER 0x08
+#define JZ_REG_WDT_CTRL 0x0c
+
+static void jz4740_restart(char *command)
+{
+        void __iomem *wdt_base = ioremap(JZ4740_WDT_BASE_ADDR, 0x0f);
+
+        jz4740_timer_enable_watchdog();
+
+        writeb(0, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
+
+        writew(0, wdt_base + JZ_REG_WDT_COUNTER);
+        writew(0, wdt_base + JZ_REG_WDT_DATA);
+        writew(BIT(2), wdt_base + JZ_REG_WDT_CTRL);
+
+        writeb(1, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
+        jz4740_halt();
+}
+
+#define JZ_REG_RTC_CTRL         0x00
+#define JZ_REG_RTC_HIBERNATE    0x20
+
+#define JZ_RTC_CTRL_WRDY        BIT(7)
+
+static void jz4740_power_off(void)
+{
+        void __iomem *rtc_base = ioremap(JZ4740_RTC_BASE_ADDR, 0x24);
+        uint32_t ctrl;
+
+        do {
+                ctrl = readl(rtc_base + JZ_REG_RTC_CTRL);
+        } while (!(ctrl & JZ_RTC_CTRL_WRDY));
+
+        writel(1, rtc_base + JZ_REG_RTC_HIBERNATE);
+        jz4740_halt();
+}
+
+void jz4740_reset_init(void)
+{
+        _machine_restart = jz4740_restart;
+        _machine_halt = jz4740_halt;
+        pm_power_off = jz4740_power_off;
+}