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| 3 | * CPU idle Marvell Kirkwood SoCs
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| 4 | *
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| 5 | * The cpu idle uses wait-for-interrupt and DDR self refresh in order
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| 6 | * to implement two idle states -
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| 7 | * #1 wait-for-interrupt
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| 8 | * #2 wait-for-interrupt and DDR self refresh
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| 9 | *
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| 10 | * Maintainer: Jason Cooper <[email protected]>
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| 11 | * Maintainer: Andrew Lunn <[email protected]>
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| 12 |
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| 13 |
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| 14 | #include <linux/kernel.h>
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| 15 | #include <linux/module.h>
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| 16 | #include <linux/init.h>
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| 17 | #include <linux/platform_device.h>
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| 18 | #include <linux/cpuidle.h>
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| 19 | #include <linux/io.h>
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| 20 | #include <linux/export.h>
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| 21 | #include <asm/cpuidle.h>
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| 22 |
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| 23 | #define KIRKWOOD_MAX_STATES 2
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| 24 |
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| 25 | static void __iomem *ddr_operation_base;
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| 26 |
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| 27 |
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| 28 | static int kirkwood_enter_idle(struct cpuidle_device *dev,
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| 29 | struct cpuidle_driver *drv,
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| 30 | int index)
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| 31 | {
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| 32 | writel(0x7, ddr_operation_base);
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| 33 | cpu_do_idle();
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| 34 |
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| 35 | return index;
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| 36 | }
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| 37 |
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| 38 | static struct cpuidle_driver kirkwood_idle_driver = {
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| 39 | .name = "kirkwood_idle",
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| 40 | .owner = THIS_MODULE,
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| 41 | .states[0] = ARM_CPUIDLE_WFI_STATE,
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| 42 | .states[1] = {
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| 43 | .enter = kirkwood_enter_idle,
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| 44 | .exit_latency = 10,
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| 45 | .target_residency = 100000,
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| 46 | .name = "DDR SR",
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| 47 | .desc = "WFI and DDR Self Refresh",
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| 48 | },
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| 49 | .state_count = KIRKWOOD_MAX_STATES,
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| 50 | };
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| 51 |
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| 52 |
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| 53 | static int kirkwood_cpuidle_probe(struct platform_device *pdev)
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| 54 | {
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| 55 | ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
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| 56 | if (IS_ERR(ddr_operation_base))
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| 57 | return PTR_ERR(ddr_operation_base);
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| 58 |
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| 59 | return cpuidle_register(&kirkwood_idle_driver, NULL);
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| 60 | }
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| 61 |
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| 62 | static void kirkwood_cpuidle_remove(struct platform_device *pdev)
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| 63 | {
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| 64 | cpuidle_unregister(&kirkwood_idle_driver);
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| 65 | }
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| 66 |
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| 67 | static struct platform_driver kirkwood_cpuidle_driver = {
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| 68 | .probe = kirkwood_cpuidle_probe,
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| 69 | .remove = kirkwood_cpuidle_remove,
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| 70 | .driver = {
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| 71 | .name = "kirkwood_cpuidle",
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| 72 | },
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| 73 | };
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| 74 |
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| 75 | module_platform_driver(kirkwood_cpuidle_driver);
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| 76 |
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| 77 | MODULE_AUTHOR("Andrew Lunn <[email protected]>");
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| 78 | MODULE_DESCRIPTION("Kirkwood cpu idle driver");
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| 79 | MODULE_LICENSE("GPL v2");
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| 80 | MODULE_ALIAS("platform:kirkwood-cpuidle");
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