cmd: Add ariscrun command for starting CPUS

CPUS is a power management co-processor on some Allwinner SoCs (H3,
A83T).

Signed-off-by: Ondrej Jirman <megous@megous.com>

cmd/Kconfig

@@ -1691,6 +1691,15 @@ endmenu
 
 source "cmd/ti/Kconfig"
 
+menu "sunxi specific command line interface"
+
+config CMD_SUNXI_ARISC
+	bool "command for starting ARISC code on sunxi platforms"
+	help
+	   Support for starting OpenRISC coprocessor on sunxi platforms.
+
+endmenu
+
 config CMD_BOOTSTAGE
 	bool "Enable the 'bootstage' command"
 	depends on BOOTSTAGE

cmd/Makefile

@@ -169,6 +169,7 @@ obj-$(CONFIG_CMD_PMIC) += pmic.o
 obj-$(CONFIG_CMD_REGULATOR) += regulator.o
 
 obj-$(CONFIG_CMD_BLOB) += blob.o
+obj-$(CONFIG_CMD_SUNXI_ARISC) += sunxi-arisc.o
 
 # Android Verified Boot 2.0
 obj-$(CONFIG_CMD_AVB) += avb.o

cmd/sunxi-arisc.c

@@ -0,0 +1,69 @@
+/*
+ * Written by Ondrej Jirman <megous@megous.com>, 2018
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/io.h>
+#include <watchdog.h>
+
+#define R_CPUCFG_BASE	0x01f01c00
+
+static void reset_cpus(int stop)
+{
+	uint32_t cpu_cfg;
+	
+	cpu_cfg = readl(R_CPUCFG_BASE);
+	cpu_cfg &= ~(1uL);
+	writel(cpu_cfg, R_CPUCFG_BASE);
+
+	mdelay(1);
+
+	if (!stop) {
+		cpu_cfg |= 1;
+		writel(cpu_cfg, R_CPUCFG_BASE);
+	}
+}
+
+static int do_arisc_start(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	reset_cpus(0);
+	return 0;
+}
+
+static int do_arisc_stop(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	reset_cpus(1);
+	return 0;
+}
+
+static int do_arisc_takeover(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	reset_cpus(0);
+
+	while (1) {
+		WATCHDOG_RESET();
+		mdelay(10);
+	}
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	arisc_start, 3, 1, do_arisc_start,
+	"reset arisc comprocessor and de-assert the reset line",
+	""
+);
+
+U_BOOT_CMD(
+	arisc_stop, 3, 1, do_arisc_stop,
+	"reset arisc comprocessor and keep it reset",
+	""
+);
+
+U_BOOT_CMD(
+	arisc_takeover, 3, 1, do_arisc_takeover,
+	"reset arisc comprocessor and de-assert the reset line, stop u-boot",
+	""
+);