[PATCH v2] ARM: rockchip: add reboot notifier

[Andy Yan <andy.yan@rock-chips.com>]

rockchip platform have a protocol to pass the kernel reboot
mode to bootloader by some special registers when system reboot.
By this way the bootloader can take different action according
to the different kernel reboot mode, for example, command
"reboot loader" will reboot the board to rockusb mode, this is
a very convenient way to get the board enter download mode.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
---

Changes in v2:
  - check cpu dt node
  - remove a unnecessary of_put_node in function rockchip_get_pmu_regmap
  - fix a align issue
  - use reboot_notifier instead of restart_handler

 arch/arm/mach-rockchip/Makefile |   2 +-
 arch/arm/mach-rockchip/loader.h |  22 ++++++++
 arch/arm/mach-rockchip/reboot.c | 111 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-rockchip/loader.h
 create mode 100644 arch/arm/mach-rockchip/reboot.c

diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 5c3a9b2..cd291e3 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -1,5 +1,5 @@
 CFLAGS_platsmp.o := -march=armv7-a
 
-obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip.o
+obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip.o reboot.o
 obj-$(CONFIG_PM_SLEEP) += pm.o sleep.o
 obj-$(CONFIG_SMP) += headsmp.o platsmp.o
diff --git a/arch/arm/mach-rockchip/loader.h b/arch/arm/mach-rockchip/loader.h
new file mode 100644
index 0000000..bf51baa
--- /dev/null
+++ b/arch/arm/mach-rockchip/loader.h
@@ -0,0 +1,22 @@
+#ifndef __MACH_ROCKCHIP_LOADER_H
+#define __MACH_ROCKCHIP_LOADER_H
+
+/*high 24 bits is tag, low 8 bits is type*/
+#define SYS_LOADER_REBOOT_FLAG   0x5242C300
+
+enum {
+	BOOT_NORMAL = 0, /* normal boot */
+	BOOT_LOADER,     /* enter loader rockusb mode */
+	BOOT_MASKROM,    /* enter maskrom rockusb mode (not support now) */
+	BOOT_RECOVER,    /* enter recover */
+	BOOT_NORECOVER,  /* do not enter recover */
+	BOOT_SECONDOS,   /* boot second OS (not support now)*/
+	BOOT_WIPEDATA,   /* enter recover and wipe data. */
+	BOOT_WIPEALL,    /* enter recover and wipe all data. */
+	BOOT_CHECKIMG,   /* check firmware img with backup part*/
+	BOOT_FASTBOOT,   /* enter fast boot mode */
+	BOOT_SECUREBOOT_DISABLE,
+	BOOT_CHARGING,   /* enter charge mode */
+	BOOT_MAX         /* MAX VALID BOOT TYPE.*/
+};
+#endif
diff --git a/arch/arm/mach-rockchip/reboot.c b/arch/arm/mach-rockchip/reboot.c
new file mode 100644
index 0000000..c29f031e
--- /dev/null
+++ b/arch/arm/mach-rockchip/reboot.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * 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.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include "loader.h"
+
+#define RK3188_PMU_SYS_REG0             0x40
+#define RK3288_PMU_SYS_REG0             0x94
+
+struct regmap *regmap;
+int flag_reg;
+
+static int rockchip_get_pmu_regmap(void)
+{
+	struct device_node *node;
+
+	node = of_find_node_by_path("/cpus");
+	if (!node)
+		return -ENODEV;
+
+	regmap = syscon_regmap_lookup_by_phandle(node, "rockchip,pmu");
+	of_node_put(node);
+	if (!IS_ERR(regmap))
+		return 0;
+
+	regmap = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu");
+	if (!IS_ERR(regmap))
+		return 0;
+
+	return -ENODEV;
+}
+
+static int rockchip_get_reboot_flag_regmap(void)
+{
+	int ret = rockchip_get_pmu_regmap();
+
+	if (ret < 0)
+		return ret;
+
+	if (of_machine_is_compatible("rockchip,rk3288")) {
+		flag_reg = RK3288_PMU_SYS_REG0;
+		return 0;
+	} else if (of_machine_is_compatible("rockchip,rk3066a") ||
+		   of_machine_is_compatible("rockchip,rk3066b") ||
+		   of_machine_is_compatible("rockchip,rk3188")) {
+		flag_reg = RK3188_PMU_SYS_REG0;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static void rockchip_get_reboot_flag(const char *cmd, u32 *flag)
+{
+	*flag = SYS_LOADER_REBOOT_FLAG + BOOT_NORMAL;
+
+	if (cmd) {
+		if (!strcmp(cmd, "loader") || !strcmp(cmd, "bootloader"))
+			*flag = SYS_LOADER_REBOOT_FLAG + BOOT_LOADER;
+		else if (!strcmp(cmd, "recovery"))
+			*flag = SYS_LOADER_REBOOT_FLAG + BOOT_RECOVER;
+		else if (!strcmp(cmd, "charge"))
+			*flag = SYS_LOADER_REBOOT_FLAG + BOOT_CHARGING;
+	}
+}
+
+static int rockchip_reboot_notify(struct notifier_block *this,
+				  unsigned long mode, void *cmd)
+{
+	u32 flag;
+
+	rockchip_get_reboot_flag(cmd, &flag);
+	regmap_write(regmap, flag_reg, flag);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block rockchip_reboot_handler = {
+	.notifier_call = rockchip_reboot_notify,
+};
+
+static int __init rockchip_reboot_init(void)
+{
+	int ret = 0;
+
+	if (!rockchip_get_reboot_flag_regmap()) {
+		ret = register_reboot_notifier(&rockchip_reboot_handler);
+		if (ret)
+			pr_err("%s: cannot register reboot handler, %d\n",
+			       __func__, ret);
+	}
+
+	return ret;
+}
+
+module_init(rockchip_reboot_init);
+MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com");
+MODULE_DESCRIPTION("Rockchip platform reboot notifier driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1