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3bb16560 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e50b6bef | 2 | /* |
e50b6bef RK |
3 | * CPU idle Marvell Kirkwood SoCs |
4 | * | |
e50b6bef RK |
5 | * The cpu idle uses wait-for-interrupt and DDR self refresh in order |
6 | * to implement two idle states - | |
7 | * #1 wait-for-interrupt | |
8 | * #2 wait-for-interrupt and DDR self refresh | |
a8e39c35 DL |
9 | * |
10 | * Maintainer: Jason Cooper <jason@lakedaemon.net> | |
11 | * Maintainer: Andrew Lunn <andrew@lunn.ch> | |
e50b6bef RK |
12 | */ |
13 | ||
14 | #include <linux/kernel.h> | |
9cfc94eb | 15 | #include <linux/module.h> |
e50b6bef RK |
16 | #include <linux/init.h> |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/cpuidle.h> | |
19 | #include <linux/io.h> | |
dc28094b | 20 | #include <linux/export.h> |
b334648d | 21 | #include <asm/cpuidle.h> |
e50b6bef RK |
22 | |
23 | #define KIRKWOOD_MAX_STATES 2 | |
24 | ||
9cfc94eb AL |
25 | static void __iomem *ddr_operation_base; |
26 | ||
e50b6bef RK |
27 | /* Actual code that puts the SoC in different idle states */ |
28 | static int kirkwood_enter_idle(struct cpuidle_device *dev, | |
9cfc94eb | 29 | struct cpuidle_driver *drv, |
e978aa7d | 30 | int index) |
e50b6bef | 31 | { |
9cfc94eb | 32 | writel(0x7, ddr_operation_base); |
b334648d | 33 | cpu_do_idle(); |
e978aa7d DD |
34 | |
35 | return index; | |
e50b6bef RK |
36 | } |
37 | ||
b334648d RL |
38 | static struct cpuidle_driver kirkwood_idle_driver = { |
39 | .name = "kirkwood_idle", | |
40 | .owner = THIS_MODULE, | |
b334648d RL |
41 | .states[0] = ARM_CPUIDLE_WFI_STATE, |
42 | .states[1] = { | |
43 | .enter = kirkwood_enter_idle, | |
44 | .exit_latency = 10, | |
45 | .target_residency = 100000, | |
b334648d RL |
46 | .name = "DDR SR", |
47 | .desc = "WFI and DDR Self Refresh", | |
48 | }, | |
49 | .state_count = KIRKWOOD_MAX_STATES, | |
50 | }; | |
b334648d | 51 | |
e50b6bef | 52 | /* Initialize CPU idle by registering the idle states */ |
9cfc94eb | 53 | static int kirkwood_cpuidle_probe(struct platform_device *pdev) |
e50b6bef | 54 | { |
85c3ebd4 | 55 | ddr_operation_base = devm_platform_ioremap_resource(pdev, 0); |
488540bf SMP |
56 | if (IS_ERR(ddr_operation_base)) |
57 | return PTR_ERR(ddr_operation_base); | |
e50b6bef | 58 | |
30dc72c6 | 59 | return cpuidle_register(&kirkwood_idle_driver, NULL); |
e50b6bef RK |
60 | } |
61 | ||
75d6137d | 62 | static int kirkwood_cpuidle_remove(struct platform_device *pdev) |
9cfc94eb | 63 | { |
30dc72c6 | 64 | cpuidle_unregister(&kirkwood_idle_driver); |
9cfc94eb AL |
65 | return 0; |
66 | } | |
67 | ||
68 | static struct platform_driver kirkwood_cpuidle_driver = { | |
69 | .probe = kirkwood_cpuidle_probe, | |
70 | .remove = kirkwood_cpuidle_remove, | |
71 | .driver = { | |
72 | .name = "kirkwood_cpuidle", | |
9cfc94eb AL |
73 | }, |
74 | }; | |
75 | ||
76 | module_platform_driver(kirkwood_cpuidle_driver); | |
77 | ||
78 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); | |
79 | MODULE_DESCRIPTION("Kirkwood cpu idle driver"); | |
80 | MODULE_LICENSE("GPL v2"); | |
81 | MODULE_ALIAS("platform:kirkwood-cpuidle"); |