soc: intel_adsp: cavs: start using zephyr power management

Start using zephyr power management in cavs platform in a similar way
that is already done in ace. This commit only addresses the power off/on
sequence. Runtime power management is not implemented.

Signed-off-by: Jaska Uimonen <jaska.uimonen@linux.intel.com>

dts/xtensa/intel/intel_adsp_cavs25.dtsi

@@ -16,6 +16,7 @@
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <0>;
+			cpu-power-states = <&d3>;
 			i-cache-line-size = <64>;
 			d-cache-line-size = <64>;
 		};
@@ -24,18 +25,33 @@
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <1>;
+			cpu-power-states = <&d3>;
 		};
 
 		cpu2: cpu@2 {
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <2>;
+			cpu-power-states = <&d3>;
 		};
 
 		cpu3: cpu@3 {
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <3>;
+			cpu-power-states = <&d3>;
+		};
+	};
+
+	power-states {
+		/* PM_STATE_SOFT_OFF can be entered only by calling pm_state_force.
+		 * The procedure is triggered by IPC from the HOST (SET_DX).
+		 */
+		d3: off {
+			compatible = "zephyr,power-state";
+			power-state-name = "soft-off";
+			min-residency-us = <2147483647>;
+			exit-latency-us = <0>;
 		};
 	};
 

dts/xtensa/intel/intel_adsp_cavs25_tgph.dtsi

@@ -16,6 +16,7 @@
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <0>;
+			cpu-power-states = <&d3>;
 			i-cache-line-size = <64>;
 			d-cache-line-size = <64>;
 		};
@@ -24,6 +25,19 @@
 			device_type = "cpu";
 			compatible = "cdns,tensilica-xtensa-lx6";
 			reg = <1>;
+			cpu-power-states = <&d3>;
+		};
+	};
+
+	power-states {
+		/* PM_STATE_SOFT_OFF can be entered only by calling pm_state_force.
+		 * The procedure is triggered by IPC from the HOST (SET_DX).
+		 */
+		d3: off {
+			compatible = "zephyr,power-state";
+			power-state-name = "soft-off";
+			min-residency-us = <2147483647>;
+			exit-latency-us = <0>;
 		};
 	};
 

soc/xtensa/intel_adsp/cavs/CMakeLists.txt

@@ -9,6 +9,7 @@ zephyr_library_include_directories(${ZEPHYR_BASE}/drivers)
 zephyr_library_sources(
     sram.c
     power.c
+    power_down_cavs.S
     )
 
 if(CONFIG_SMP OR CONFIG_MP_MAX_NUM_CPUS GREATER 1)

soc/xtensa/intel_adsp/cavs/asm_ldo_management.h

@@ -0,0 +1,108 @@
+/* Copyright (c) 2023 Intel Corporation
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __ZEPHYR_CAVS_LIB_ASM_LDO_MANAGEMENT_H__
+#define __ZEPHYR_CAVS_LIB_ASM_LDO_MANAGEMENT_H__
+
+#ifdef _ASMLANGUAGE
+
+#define SHIM_BASE		0x00071F00
+#define SHIM_LDOCTL		0xA4
+#define SHIM_LDOCTL_HPSRAM_MASK		(3 << 0 | 3 << 16)
+#define SHIM_LDOCTL_LPSRAM_MASK		(3 << 2)
+#define SHIM_LDOCTL_HPSRAM_LDO_ON	(3 << 0 | 3 << 16)
+#define SHIM_LDOCTL_LPSRAM_LDO_ON	(3 << 2)
+#define SHIM_LDOCTL_HPSRAM_LDO_OFF	(0 << 0)
+#define SHIM_LDOCTL_LPSRAM_LDO_OFF	(0 << 2)
+#define SHIM_LDOCTL_HPSRAM_LDO_BYPASS	(BIT(0) | BIT(16))
+#define SHIM_LDOCTL_LPSRAM_LDO_BYPASS	BIT(2)
+
+.macro m_cavs_set_ldo_state state, ax
+movi \ax, (SHIM_BASE + SHIM_LDOCTL)
+s32i \state, \ax, 0
+memw
+/* wait loop > 300ns (min 100ns required) */
+movi \ax, 128
+1 :
+addi \ax, \ax, -1
+nop
+bnez \ax, 1b
+.endm
+
+.macro m_cavs_set_hpldo_state state, ax, ay
+movi \ax, (SHIM_BASE + SHIM_LDOCTL)
+l32i \ay, \ax, 0
+
+movi \ax, ~(SHIM_LDOCTL_HPSRAM_MASK)
+and \ay, \ax, \ay
+or \state, \ay, \state
+
+m_cavs_set_ldo_state \state, \ax
+.endm
+
+.macro m_cavs_set_lpldo_state state, ax, ay
+movi \ax, (SHIM_BASE + SHIM_LDOCTL)
+l32i \ay, \ax, 0
+/* LP SRAM mask */
+movi \ax, ~(SHIM_LDOCTL_LPSRAM_MASK)
+and \ay, \ax, \ay
+or \state, \ay, \state
+
+m_cavs_set_ldo_state \state, \ax
+.endm
+
+.macro m_cavs_set_ldo_on_state ax, ay, az
+movi \ay, (SHIM_BASE + SHIM_LDOCTL)
+l32i \az, \ay, 0
+
+movi \ax, ~(SHIM_LDOCTL_HPSRAM_MASK | SHIM_LDOCTL_LPSRAM_MASK)
+and \az, \ax, \az
+movi \ax, (SHIM_LDOCTL_HPSRAM_LDO_ON | SHIM_LDOCTL_LPSRAM_LDO_ON)
+or \ax, \az, \ax
+
+m_cavs_set_ldo_state \ax, \ay
+.endm
+
+.macro m_cavs_set_ldo_off_state ax, ay, az
+/* wait loop > 300ns (min 100ns required) */
+movi \ax, 128
+1 :
+		addi \ax, \ax, -1
+		nop
+		bnez \ax, 1b
+movi \ay, (SHIM_BASE + SHIM_LDOCTL)
+l32i \az, \ay, 0
+
+movi \ax, ~(SHIM_LDOCTL_HPSRAM_MASK | SHIM_LDOCTL_LPSRAM_MASK)
+and \az, \az, \ax
+
+movi \ax, (SHIM_LDOCTL_HPSRAM_LDO_OFF | SHIM_LDOCTL_LPSRAM_LDO_OFF)
+or \ax, \ax, \az
+
+s32i \ax, \ay, 0
+l32i \ax, \ay, 0
+.endm
+
+.macro m_cavs_set_ldo_bypass_state ax, ay, az
+/* wait loop > 300ns (min 100ns required) */
+movi \ax, 128
+1 :
+		addi \ax, \ax, -1
+		nop
+		bnez \ax, 1b
+movi \ay, (SHIM_BASE + SHIM_LDOCTL)
+l32i \az, \ay, 0
+
+movi \ax, ~(SHIM_LDOCTL_HPSRAM_MASK | SHIM_LDOCTL_LPSRAM_MASK)
+and \az, \az, \ax
+
+movi \ax, (SHIM_LDOCTL_HPSRAM_LDO_BYPASS | SHIM_LDOCTL_LPSRAM_LDO_BYPASS)
+or \ax, \ax, \az
+
+s32i \ax, \ay, 0
+l32i \ax, \ay, 0
+.endm
+
+#endif
+#endif /* __ZEPHYR_CAVS_LIB_ASM_LDO_MANAGEMENT_H__ */

soc/xtensa/intel_adsp/cavs/asm_memory_management.h

@@ -0,0 +1,76 @@
+/* Copyright (c) 2023 Intel Corporation
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __ZEPHYR_CAVS_LIB_ASM_MEMORY_MANAGEMENT_H__
+#define __ZEPHYR_CAVS_LIB_ASM_MEMORY_MANAGEMENT_H__
+
+#ifdef _ASMLANGUAGE
+
+#define HSPGCTL0		0x71D10
+#define HSRMCTL0		0x71D14
+#define HSPGISTS0		0x71D18
+
+#define LSPGCTL			0x71D50
+#define LSRMCTL			0x71D54
+#define LSPGISTS		0x71D58
+
+#define SHIM_HSPGCTL(x)		(HSPGCTL0 + 0x10 * (x))
+#define SHIM_HSPGISTS(x)	(HSPGISTS0 + 0x10 * (x))
+
+#define LPSRAM_MASK	0x1
+/**
+ * Macro powers down entire HPSRAM. On entry literals and code for section from
+ * where this code is executed need to be placed in memory which is not
+ * HPSRAM (in case when this code is located in HPSRAM, lock memory in L1$ or
+ * L1 SRAM)
+ */
+.macro m_cavs_hpsram_power_down_entire ax, ay, az
+	/* SEGMENT #0 */
+	movi \az, SHIM_HSPGCTL(0)
+	movi \ax, SHIM_HSPGISTS(0)
+	movi \ay, 0x1FFFFFFF /* HPSRAM_MASK(0) */
+	s32i \ay, \ax, 0
+	memw
+1 :
+	l32i \ax, \az, 0
+	bne \ax, \ay, 1b
+
+	/* SEGMENT #1 */
+	movi \az, SHIM_HSPGCTL(1)
+	movi \ax, SHIM_HSPGISTS(1)
+	movi \ay, 0x0FFFFFFF /* HPSRAM_MASK(1) */
+	s32i \ay, \ax, 0
+	memw
+1 :
+	l32i \ax, \az, 0
+	bne \ax, \ay, 1b
+.endm
+
+.macro m_cavs_hpsram_power_change segment_index, mask, ax, ay, az
+	movi \ax, SHIM_HSPGCTL(\segment_index)
+	movi \ay, SHIM_HSPGISTS(\segment_index)
+	s32i \mask, \ax, 0
+	memw
+	/* assumed that HDA shared dma buffer will be in LPSRAM */
+1 :
+	l32i \ax, \ay, 0
+	bne \ax, \mask, 1b
+.endm
+
+.macro m_cavs_lpsram_power_down_entire ax, ay, az, loop_cnt_addr
+	movi \az, LSPGISTS
+	movi \ax, LSPGCTL
+	movi \ay, LPSRAM_MASK
+	s32i \ay, \ax, 0
+	memw
+	/* assumed that HDA shared dma buffer will be in LPSRAM */
+	movi \ax, \loop_cnt_addr
+	l32i \ax, \ax, 0
+1 :
+	addi \ax, \ax, -1
+	bnez \ax, 1b
+.endm
+
+#endif
+#endif

soc/xtensa/intel_adsp/cavs/power.c

@@ -10,6 +10,9 @@
 #include <xtensa/hal.h>
 #include <zephyr/init.h>
 #include <zephyr/kernel.h>
+#include <zephyr/pm/pm.h>
+#include <zephyr/device.h>
+#include <cpu_init.h>
 
 #include <adsp_shim.h>
 #include <adsp_clk.h>
@@ -32,6 +35,84 @@ LOG_MODULE_REGISTER(soc);
 
 #endif
 
+#ifdef CONFIG_PM
+
+#define SRAM_ALIAS_BASE		0x9E000000
+#define SRAM_ALIAS_MASK		0xFF000000
+#define EBB_BANKS_IN_SEGMENT	32
+#define SRAM_ALIAS_OFFSET	0x20000000
+
+#define L2_INTERRUPT_NUMBER     4
+#define L2_INTERRUPT_MASK       (1<<L2_INTERRUPT_NUMBER)
+
+#define L3_INTERRUPT_NUMBER     6
+#define L3_INTERRUPT_MASK       (1<<L3_INTERRUPT_NUMBER)
+
+#define ALL_USED_INT_LEVELS_MASK (L2_INTERRUPT_MASK | L3_INTERRUPT_MASK)
+
+struct core_state {
+	uint32_t intenable;
+};
+
+static struct core_state core_desc[CONFIG_MP_MAX_NUM_CPUS] = {{0}};
+
+/**
+ * @brief Power down procedure.
+ *
+ * Locks its code in L1 cache and shuts down memories.
+ * NOTE: there's no return from this function.
+ *
+ * @param disable_lpsram        flag if LPSRAM is to be disabled (whole)
+ * @param hpsram_pg_mask pointer to memory segments power gating mask
+ * (each bit corresponds to one ebb)
+ */
+extern void power_down_cavs(bool disable_lpsram, uint32_t *hpsram_pg_mask);
+
+static inline void __sparse_cache *uncache_to_cache(void *address)
+{
+	return (void __sparse_cache *)((uintptr_t)(address) | SRAM_ALIAS_OFFSET);
+}
+
+__weak void pm_state_set(enum pm_state state, uint8_t substate_id)
+{
+	ARG_UNUSED(substate_id);
+	uint32_t cpu = arch_proc_id();
+
+	if (state == PM_STATE_SOFT_OFF) {
+		core_desc[cpu].intenable = XTENSA_RSR("INTENABLE");
+		z_xt_ints_off(0xffffffff);
+		soc_cpus_active[cpu] = false;
+		z_xtensa_cache_flush_inv_all();
+		if (cpu == 0) {
+			uint32_t ebb = EBB_BANKS_IN_SEGMENT;
+			/* turn off all HPSRAM banks - get a full bitmap */
+			uint32_t hpsram_mask = (1 << ebb) - 1;
+			/* do power down - this function won't return */
+			power_down_cavs(true, uncache_to_cache(&hpsram_mask));
+		} else {
+			z_xt_ints_on(core_desc[cpu].intenable);
+			k_cpu_idle();
+		}
+	} else {
+		__ASSERT(false, "invalid argument - unsupported power state");
+	}
+}
+
+/* Handle SOC specific activity after Low Power Mode Exit */
+__weak void pm_state_exit_post_ops(enum pm_state state, uint8_t substate_id)
+{
+	ARG_UNUSED(substate_id);
+	uint32_t cpu = arch_proc_id();
+
+	if (state == PM_STATE_SOFT_OFF) {
+		soc_cpus_active[cpu] = true;
+		z_xtensa_cache_flush_inv_all();
+		z_xt_ints_on(core_desc[cpu].intenable);
+	} else {
+		__ASSERT(false, "invalid argument - unsupported power state");
+	}
+}
+#endif
 
 __imr void power_init(void)
 {