2 * arch/arm/mach-kirkwood/cpuidle.c
4 * CPU idle Marvell Kirkwood SoCs
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
10 * The cpu idle uses wait-for-interrupt and DDR self refresh in order
11 * to implement two idle states -
12 * #1 wait-for-interrupt
13 * #2 wait-for-interrupt and DDR self refresh
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/platform_device.h>
20 #include <linux/cpuidle.h>
22 #include <linux/export.h>
23 #include <asm/proc-fns.h>
24 #include <asm/cpuidle.h>
26 #define KIRKWOOD_MAX_STATES 2
28 static void __iomem
*ddr_operation_base
;
30 /* Actual code that puts the SoC in different idle states */
31 static int kirkwood_enter_idle(struct cpuidle_device
*dev
,
32 struct cpuidle_driver
*drv
,
35 writel(0x7, ddr_operation_base
);
41 static struct cpuidle_driver kirkwood_idle_driver
= {
42 .name
= "kirkwood_idle",
44 .states
[0] = ARM_CPUIDLE_WFI_STATE
,
46 .enter
= kirkwood_enter_idle
,
48 .target_residency
= 100000,
49 .flags
= CPUIDLE_FLAG_TIME_VALID
,
51 .desc
= "WFI and DDR Self Refresh",
53 .state_count
= KIRKWOOD_MAX_STATES
,
55 static struct cpuidle_device
*device
;
57 static DEFINE_PER_CPU(struct cpuidle_device
, kirkwood_cpuidle_device
);
59 /* Initialize CPU idle by registering the idle states */
60 static int kirkwood_cpuidle_probe(struct platform_device
*pdev
)
64 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
68 ddr_operation_base
= devm_ioremap_resource(&pdev
->dev
, res
);
69 if (IS_ERR(ddr_operation_base
))
70 return PTR_ERR(ddr_operation_base
);
72 device
= &per_cpu(kirkwood_cpuidle_device
, smp_processor_id());
73 device
->state_count
= KIRKWOOD_MAX_STATES
;
75 cpuidle_register_driver(&kirkwood_idle_driver
);
76 if (cpuidle_register_device(device
)) {
77 pr_err("kirkwood_init_cpuidle: Failed registering\n");
83 int kirkwood_cpuidle_remove(struct platform_device
*pdev
)
85 cpuidle_unregister_device(device
);
86 cpuidle_unregister_driver(&kirkwood_idle_driver
);
91 static struct platform_driver kirkwood_cpuidle_driver
= {
92 .probe
= kirkwood_cpuidle_probe
,
93 .remove
= kirkwood_cpuidle_remove
,
95 .name
= "kirkwood_cpuidle",
100 module_platform_driver(kirkwood_cpuidle_driver
);
102 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
103 MODULE_DESCRIPTION("Kirkwood cpu idle driver");
104 MODULE_LICENSE("GPL v2");
105 MODULE_ALIAS("platform:kirkwood-cpuidle");