82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* CPU idle Marvell Kirkwood SoCs
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*
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* The cpu idle uses wait-for-interrupt and DDR self refresh in order
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* to implement two idle states -
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* #1 wait-for-interrupt
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* #2 wait-for-interrupt and DDR self refresh
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*
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* Maintainer: Jason Cooper <jason@lakedaemon.net>
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* Maintainer: Andrew Lunn <andrew@lunn.ch>
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*/
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#include <linux/kernel.h>
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#include <linux/module.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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#define KIRKWOOD_MAX_STATES 2
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static void __iomem *ddr_operation_base;
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/* Actual code that puts the SoC in different idle states */
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static int kirkwood_enter_idle(struct cpuidle_device *dev,
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struct cpuidle_driver *drv,
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int index)
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{
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writel(0x7, ddr_operation_base);
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cpu_do_idle();
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return index;
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}
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static struct cpuidle_driver kirkwood_idle_driver = {
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.name = "kirkwood_idle",
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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 = kirkwood_enter_idle,
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.exit_latency = 10,
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.target_residency = 100000,
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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 = KIRKWOOD_MAX_STATES,
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};
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/* Initialize CPU idle by registering the idle states */
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static int kirkwood_cpuidle_probe(struct platform_device *pdev)
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{
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ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(ddr_operation_base))
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return PTR_ERR(ddr_operation_base);
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return cpuidle_register(&kirkwood_idle_driver, NULL);
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}
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static int kirkwood_cpuidle_remove(struct platform_device *pdev)
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{
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cpuidle_unregister(&kirkwood_idle_driver);
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return 0;
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}
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static struct platform_driver kirkwood_cpuidle_driver = {
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.probe = kirkwood_cpuidle_probe,
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.remove = kirkwood_cpuidle_remove,
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.driver = {
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.name = "kirkwood_cpuidle",
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},
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};
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module_platform_driver(kirkwood_cpuidle_driver);
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MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
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MODULE_DESCRIPTION("Kirkwood cpu idle driver");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:kirkwood-cpuidle");
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