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https://github.com/AsahiLinux/u-boot
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60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
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/*
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* (C) Copyright 2015, Siemens AG
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* Author: Jan Kiszka <jan.kiszka@siemens.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <asm/psci.h>
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#include <asm/arch/flow.h>
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#include <asm/arch/powergate.h>
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#include <asm/arch-tegra/ap.h>
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#include <asm/arch-tegra/pmc.h>
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static void park_cpu(void)
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{
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while (1)
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asm volatile("wfi");
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}
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/**
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* Initialize power management for application processors
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*/
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void psci_board_init(void)
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{
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struct flow_ctlr *flow = (struct flow_ctlr *)NV_PA_FLOW_BASE;
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writel((u32)park_cpu, EXCEP_VECTOR_CPU_RESET_VECTOR);
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/*
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* The naturally expected order of putting these CPUs under Flow
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* Controller regime would be
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* - configure the Flow Controller
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* - power up the CPUs
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* - wait for the CPUs to hit wfi and be powered down again
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*
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* However, this doesn't work in practice. We rather need to power them
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* up first and park them in wfi. While they are waiting there, we can
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* indeed program the Flow Controller to powergate them on wfi, which
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* will then happen immediately as they are already in that state.
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*/
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tegra_powergate_power_on(TEGRA_POWERGATE_CPU1);
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tegra_powergate_power_on(TEGRA_POWERGATE_CPU2);
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tegra_powergate_power_on(TEGRA_POWERGATE_CPU3);
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writel((2 << CSR_WAIT_WFI_SHIFT) | CSR_ENABLE, &flow->cpu1_csr);
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writel((4 << CSR_WAIT_WFI_SHIFT) | CSR_ENABLE, &flow->cpu2_csr);
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writel((8 << CSR_WAIT_WFI_SHIFT) | CSR_ENABLE, &flow->cpu3_csr);
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writel(EVENT_MODE_STOP, &flow->halt_cpu1_events);
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writel(EVENT_MODE_STOP, &flow->halt_cpu2_events);
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writel(EVENT_MODE_STOP, &flow->halt_cpu3_events);
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while (!(readl(&flow->cpu1_csr) & CSR_PWR_OFF_STS) ||
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!(readl(&flow->cpu2_csr) & CSR_PWR_OFF_STS) ||
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!(readl(&flow->cpu3_csr) & CSR_PWR_OFF_STS))
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/* wait */;
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}
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