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84 lines
2.2 KiB
84 lines
2.2 KiB
/* |
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* CPU idle Marvell Kirkwood SoCs |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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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 <[email protected]> |
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* Maintainer: Andrew Lunn <[email protected]> |
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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 <[email protected]>"); |
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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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