2 * CPU idle Marvell Kirkwood SoCs
4 * This file is licensed under the terms of the GNU General Public
5 * License version 2. This program is licensed "as is" without any
6 * warranty of any kind, whether express or implied.
8 * The cpu idle uses wait-for-interrupt and DDR self refresh in order
9 * to implement two idle states -
10 * #1 wait-for-interrupt
11 * #2 wait-for-interrupt and DDR self refresh
13 * Maintainer: Jason Cooper <jason@lakedaemon.net>
14 * Maintainer: Andrew Lunn <andrew@lunn.ch>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/cpuidle.h>
23 #include <linux/export.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,
50 .desc
= "WFI and DDR Self Refresh",
52 .state_count
= KIRKWOOD_MAX_STATES
,
55 /* Initialize CPU idle by registering the idle states */
56 static int kirkwood_cpuidle_probe(struct platform_device
*pdev
)
58 ddr_operation_base
= devm_platform_ioremap_resource(pdev
, 0);
59 if (IS_ERR(ddr_operation_base
))
60 return PTR_ERR(ddr_operation_base
);
62 return cpuidle_register(&kirkwood_idle_driver
, NULL
);
65 static int kirkwood_cpuidle_remove(struct platform_device
*pdev
)
67 cpuidle_unregister(&kirkwood_idle_driver
);
71 static struct platform_driver kirkwood_cpuidle_driver
= {
72 .probe
= kirkwood_cpuidle_probe
,
73 .remove
= kirkwood_cpuidle_remove
,
75 .name
= "kirkwood_cpuidle",
79 module_platform_driver(kirkwood_cpuidle_driver
);
81 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
82 MODULE_DESCRIPTION("Kirkwood cpu idle driver");
83 MODULE_LICENSE("GPL v2");
84 MODULE_ALIAS("platform:kirkwood-cpuidle");