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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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e1cb367de2
Implements standby support for Kirkwood SoC. When the SoC enters standby state the memory PM units are disabled, the DDR is set in self-refresh mode, and the CPU is set in WFI. At this point there's no clock gating, as that is considered each driver's task. Signed-off-by: Simon Guinot <sguinot@lacie.com> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
/*
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* Power Management driver for Marvell Kirkwood SoCs
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*
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* Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
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* Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License,
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* version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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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 <mach/bridge-regs.h>
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static void __iomem *ddr_operation_base;
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static void kirkwood_low_power(void)
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{
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u32 mem_pm_ctrl;
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mem_pm_ctrl = readl(MEMORY_PM_CTRL);
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/* Set peripherals to low-power mode */
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writel_relaxed(~0, MEMORY_PM_CTRL);
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/* Set DDR in self-refresh */
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writel_relaxed(0x7, ddr_operation_base);
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/*
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* Set CPU in wait-for-interrupt state.
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* This disables the CPU core clocks,
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* the array clocks, and also the L2 controller.
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*/
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cpu_do_idle();
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writel_relaxed(mem_pm_ctrl, MEMORY_PM_CTRL);
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}
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static int kirkwood_suspend_enter(suspend_state_t state)
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{
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switch (state) {
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case PM_SUSPEND_STANDBY:
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kirkwood_low_power();
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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 int kirkwood_pm_valid_standby(suspend_state_t state)
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{
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return state == PM_SUSPEND_STANDBY;
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}
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static const struct platform_suspend_ops kirkwood_suspend_ops = {
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.enter = kirkwood_suspend_enter,
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.valid = kirkwood_pm_valid_standby,
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};
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int __init kirkwood_pm_init(void)
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{
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ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
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suspend_set_ops(&kirkwood_suspend_ops);
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return 0;
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}
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