allwinner: Use CPUIDLE hardware when available

This works even on SoCs that do not have an ARISC, and it avoids
clobbering whatever ARISC firmware might be running.

Change-Id: I9f2fed597189bb387de79e8e76a7da3375e1ee91
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

plat/allwinner/common/sunxi_cpu_ops.c

@@ -15,11 +15,14 @@
 #include <lib/utils_def.h>
 #include <plat/common/platform.h>
 
-#include <core_off_arisc.h>
 #include <sunxi_cpucfg.h>
 #include <sunxi_mmap.h>
 #include <sunxi_private.h>
 
+#ifndef SUNXI_CPUIDLE_EN_REG
+#include <core_off_arisc.h>
+#endif
+
 static void sunxi_cpu_disable_power(unsigned int cluster, unsigned int core)
 {
 	if (mmio_read_32(SUNXI_CPU_POWER_CLAMP_REG(cluster, core)) == 0xff)
@@ -72,6 +75,14 @@ void sunxi_cpu_power_off_self(void)
 	/* Simplifies assembly, all SoCs so far are single cluster anyway. */
 	assert(MPIDR_AFFLVL1_VAL(mpidr) == 0);
 
+#ifdef SUNXI_CPUIDLE_EN_REG
+	/* Enable the CPUIDLE hardware (only really needs to be done once). */
+	mmio_write_32(SUNXI_CPUIDLE_EN_REG, 0x16aa0000);
+	mmio_write_32(SUNXI_CPUIDLE_EN_REG, 0xaa160001);
+
+	/* Trigger power off for this core. */
+	mmio_write_32(SUNXI_CORE_CLOSE_REG, BIT_32(core));
+#else
 	/*
 	 * If we are supposed to turn ourself off, tell the arisc SCP
 	 * to do that work for us. The code expects the core mask to be
@@ -79,6 +90,7 @@ void sunxi_cpu_power_off_self(void)
 	 */
 	sunxi_execute_arisc_code(arisc_core_off, sizeof(arisc_core_off),
 				 BIT_32(core));
+#endif
 }
 
 void sunxi_cpu_on(u_register_t mpidr)

plat/allwinner/sun50i_h6/include/sunxi_cpucfg.h

 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -24,4 +24,9 @@
 #define SUNXI_CPU_POWER_CLAMP_REG(c, n)	(SUNXI_R_CPUCFG_BASE + 0x0050 + \
 					(c) * 0x10 + (n) * 4)
 
+#define SUNXI_CPUIDLE_EN_REG		(SUNXI_R_CPUCFG_BASE + 0x0100)
+#define SUNXI_CORE_CLOSE_REG		(SUNXI_R_CPUCFG_BASE + 0x0104)
+#define SUNXI_PWR_SW_DELAY_REG		(SUNXI_R_CPUCFG_BASE + 0x0140)
+#define SUNXI_CONFIG_DELAY_REG		(SUNXI_R_CPUCFG_BASE + 0x0144)
+
 #endif /* SUNXI_CPUCFG_H */