[PATCH v4 1/2] MIPS: Loongson64: Add Loongson-2K1000 reset platform driver

[Qing Zhang]

Add power management register operations to support reboot and poweroff.

Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx>
---

v2-v3:
-make reset support as a driver

v3-v4:
-Modify patch title

Signed-off-by: Qing Zhang <zhangqing@xxxxxxxxxxx>
---
 drivers/platform/mips/Kconfig      |  6 +++
 drivers/platform/mips/Makefile     |  1 +
 drivers/platform/mips/ls2k-reset.c | 60 ++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 drivers/platform/mips/ls2k-reset.c

diff --git a/drivers/platform/mips/Kconfig b/drivers/platform/mips/Kconfig
index 8ac149173c64..d421e1482395 100644
--- a/drivers/platform/mips/Kconfig
+++ b/drivers/platform/mips/Kconfig
@@ -30,4 +30,10 @@ config RS780E_ACPI
 	help
 	  Loongson RS780E PCH ACPI Controller driver.
 
+config LS2K_RESET
+	bool "Loongson-2K1000 Reset Controller"
+	depends on MACH_LOONGSON64 || COMPILE_TEST
+	help
+	  Loongson-2K1000 Reset Controller driver.
+
 endif # MIPS_PLATFORM_DEVICES
diff --git a/drivers/platform/mips/Makefile b/drivers/platform/mips/Makefile
index 178149098777..4c71444e453a 100644
--- a/drivers/platform/mips/Makefile
+++ b/drivers/platform/mips/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_CPU_HWMON) += cpu_hwmon.o
 obj-$(CONFIG_RS780E_ACPI) += rs780e-acpi.o
+obj-$(CONFIG_LS2K_RESET) += ls2k-reset.o
diff --git a/drivers/platform/mips/ls2k-reset.c b/drivers/platform/mips/ls2k-reset.c
new file mode 100644
index 000000000000..c5f073c82c5e
--- /dev/null
+++ b/drivers/platform/mips/ls2k-reset.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2021, Qing Zhang <zhangqing@xxxxxxxxxxx>
+ *  Loongson-2K1000 reset support
+ */
+
+#include <linux/of_address.h>
+#include <linux/pm.h>
+#include <asm/reboot.h>
+
+static char *pm_reg_name[] = {"pm1_sts", "pm1_cnt", "rst_cnt"};
+
+static void __iomem *get_reg_byname(struct device_node *node, const char *name)
+{
+	int index = of_property_match_string(node, "reg-names", name);
+
+	if (index < 0)
+		return NULL;
+
+	return of_iomap(node, index);
+}
+
+static void ls2k_restart(char *command)
+{
+	writel(0x1, (void *)pm_reg_name[2]);
+}
+
+static void ls2k_poweroff(void)
+{
+	/* Clear */
+	writel((readl((void *)pm_reg_name[0]) & 0xffffffff), (void *)pm_reg_name[0]);
+	/* Sleep Enable | Soft Off*/
+	writel(GENMASK(12, 10)|BIT(13), (void *)pm_reg_name[1]);
+}
+
+static int ls2k_reset_init(void)
+{
+	struct device_node *np;
+	int i;
+
+	np = of_find_node_by_type(NULL, "power management");
+	if (!np) {
+		pr_info("Failed to get PM node\n");
+		return -ENODEV;
+	}
+
+	for (i = 0; i < sizeof(pm_reg_name)/sizeof(char *); i++) {
+		pm_reg_name[i] = get_reg_byname(np, pm_reg_name[i]);
+		if (!pm_reg_name[i])
+			iounmap(pm_reg_name[i]);
+	}
+
+	_machine_restart = ls2k_restart;
+	pm_power_off = ls2k_poweroff;
+
+	of_node_put(np);
+	return 0;
+}
+
+arch_initcall(ls2k_reset_init);
-- 
2.31.0