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99 lines
2.2 KiB
99 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* CPU idle for DaVinci SoCs |
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* |
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* Copyright (C) 2009 Texas Instruments Incorporated. https://www.ti.com/ |
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* |
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* Derived from Marvell Kirkwood CPU idle code |
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* (arch/arm/mach-kirkwood/cpuidle.c) |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/platform_device.h> |
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#include <linux/cpuidle.h> |
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#include <linux/io.h> |
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#include <linux/export.h> |
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#include <asm/cpuidle.h> |
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#include "cpuidle.h" |
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#include "ddr2.h" |
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#define DAVINCI_CPUIDLE_MAX_STATES 2 |
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static void __iomem *ddr2_reg_base; |
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static bool ddr2_pdown; |
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static void davinci_save_ddr_power(int enter, bool pdown) |
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{ |
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u32 val; |
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val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET); |
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if (enter) { |
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if (pdown) |
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val |= DDR2_SRPD_BIT; |
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else |
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val &= ~DDR2_SRPD_BIT; |
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val |= DDR2_LPMODEN_BIT; |
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} else { |
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val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT); |
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} |
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__raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET); |
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} |
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/* Actual code that puts the SoC in different idle states */ |
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static int davinci_enter_idle(struct cpuidle_device *dev, |
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struct cpuidle_driver *drv, int index) |
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{ |
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davinci_save_ddr_power(1, ddr2_pdown); |
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cpu_do_idle(); |
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davinci_save_ddr_power(0, ddr2_pdown); |
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return index; |
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} |
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static struct cpuidle_driver davinci_idle_driver = { |
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.name = "cpuidle-davinci", |
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.owner = THIS_MODULE, |
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.states[0] = ARM_CPUIDLE_WFI_STATE, |
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.states[1] = { |
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.enter = davinci_enter_idle, |
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.exit_latency = 10, |
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.target_residency = 10000, |
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.name = "DDR SR", |
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.desc = "WFI and DDR Self Refresh", |
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}, |
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.state_count = DAVINCI_CPUIDLE_MAX_STATES, |
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}; |
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static int __init davinci_cpuidle_probe(struct platform_device *pdev) |
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{ |
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struct davinci_cpuidle_config *pdata = pdev->dev.platform_data; |
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if (!pdata) { |
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dev_err(&pdev->dev, "cannot get platform data\n"); |
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return -ENOENT; |
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} |
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ddr2_reg_base = pdata->ddr2_ctlr_base; |
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ddr2_pdown = pdata->ddr2_pdown; |
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return cpuidle_register(&davinci_idle_driver, NULL); |
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} |
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static struct platform_driver davinci_cpuidle_driver = { |
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.driver = { |
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.name = "cpuidle-davinci", |
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}, |
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}; |
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static int __init davinci_cpuidle_init(void) |
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{ |
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return platform_driver_probe(&davinci_cpuidle_driver, |
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davinci_cpuidle_probe); |
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} |
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device_initcall(davinci_cpuidle_init); |
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