mirror of
https://github.com/revyos/thead-kernel.git
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108 lines
2.5 KiB
C
108 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2022 Alibaba Group Holding Limited.
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*/
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#include <asm/cpuidle.h>
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/suspend.h>
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#include <linux/io.h>
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#include <linux/of_address.h>
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#include <linux/of.h>
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#include <linux/types.h>
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#undef pr_fmt
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#define pr_fmt(fmt) "light-system-suspend" ": " fmt
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#ifdef CONFIG_PLIC_INT_CLEAR
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void __iomem *hart0_sbase;
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/*
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* Each hart context has a set of control registers associated with it. Right
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* now there's only two: a source priority threshold over which the hart will
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* take an interrupt, and a register to claim interrupts.
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*/
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#define CONTEXT_BASE 0x200000
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#define CONTEXT_PER_HART 0x1000
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#define CONTEXT_THRESHOLD 0x00
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#define CONTEXT_CLAIM 0x04
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#endif
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static int light_suspend_prepare_late(void)
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{
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#ifdef CONFIG_PLIC_INT_CLEAR
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void __iomem *claim = hart0_sbase + CONTEXT_CLAIM;
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irq_hw_number_t hwirq;
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pr_debug("clear plic pending interrupt\n");
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pr_debug("claim base = 0x%lx\n", (unsigned long)claim);
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while ((hwirq = readl(claim))) {
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pr_debug("claim hwirq%ld\n", hwirq);
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writel(hwirq, claim);
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}
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#endif
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/*
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* Two-level switch for interrupt control: it needs to disable interrupts in SIE, not just in SSTATUS,
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* otherwise the pending interrupts will wakup the cpu immediately after wfi.
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*/
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csr_write(CSR_IE, 0);
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return 0;
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}
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static int light_suspend_enter(suspend_state_t state)
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{
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if (!IS_ENABLED(CONFIG_PM))
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return 0;
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switch (state) {
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case PM_SUSPEND_MEM:
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pr_debug("enter platform system suspend...\n");
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cpu_do_idle();
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pr_debug("wakeup from wfi...\n");
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static const struct platform_suspend_ops light_suspend_ops = {
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.enter = light_suspend_enter,
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.valid = suspend_valid_only_mem,
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.prepare_late = light_suspend_prepare_late,
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};
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static int __init pm_light_init(void)
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{
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#ifdef CONFIG_PLIC_INT_CLEAR
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struct device_node *np;
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void __iomem *regs;
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np = of_find_node_by_path("/soc/interrupt-controller@ffd8000000");
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if (!np) {
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pr_err("no plic interrupt controller found\n");
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return -EINVAL;
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}
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regs = of_iomap(np, 0);
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if (WARN_ON(!regs)) {
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pr_err("failed to ioremap interrupt regs\n");
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return -EIO;
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}
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hart0_sbase = regs + CONTEXT_BASE + 1 * CONTEXT_PER_HART; /* 1 means s mode */
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pr_debug("hart0_sbase = 0x%lx\n", (unsigned long)hart0_sbase);
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#endif
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pr_info("set system suspend platform callbacks\n");
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suspend_set_ops(&light_suspend_ops);
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return 0;
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}
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late_initcall(pm_light_init);
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