2 * CPU idle for DaVinci SoCs
4 * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/
6 * Derived from Marvell Kirkwood CPU idle code
7 * (arch/arm/mach-kirkwood/cpuidle.c)
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/platform_device.h>
17 #include <linux/cpuidle.h>
19 #include <linux/export.h>
20 #include <asm/proc-fns.h>
21 #include <asm/cpuidle.h>
23 #include <mach/cpuidle.h>
24 #include <mach/ddr2.h>
26 #define DAVINCI_CPUIDLE_MAX_STATES 2
28 static void __iomem
*ddr2_reg_base
;
29 static bool ddr2_pdown
;
31 static void davinci_save_ddr_power(int enter
, bool pdown
)
35 val
= __raw_readl(ddr2_reg_base
+ DDR2_SDRCR_OFFSET
);
41 val
&= ~DDR2_SRPD_BIT
;
42 val
|= DDR2_LPMODEN_BIT
;
44 val
&= ~(DDR2_SRPD_BIT
| DDR2_LPMODEN_BIT
);
47 __raw_writel(val
, ddr2_reg_base
+ DDR2_SDRCR_OFFSET
);
50 /* Actual code that puts the SoC in different idle states */
51 static int davinci_enter_idle(struct cpuidle_device
*dev
,
52 struct cpuidle_driver
*drv
, int index
)
54 davinci_save_ddr_power(1, ddr2_pdown
);
56 davinci_save_ddr_power(0, ddr2_pdown
);
61 static struct cpuidle_driver davinci_idle_driver
= {
62 .name
= "cpuidle-davinci",
64 .states
[0] = ARM_CPUIDLE_WFI_STATE
,
66 .enter
= davinci_enter_idle
,
68 .target_residency
= 10000,
69 .flags
= CPUIDLE_FLAG_TIME_VALID
,
71 .desc
= "WFI and DDR Self Refresh",
73 .state_count
= DAVINCI_CPUIDLE_MAX_STATES
,
76 static int __init
davinci_cpuidle_probe(struct platform_device
*pdev
)
78 struct davinci_cpuidle_config
*pdata
= pdev
->dev
.platform_data
;
81 dev_err(&pdev
->dev
, "cannot get platform data\n");
85 ddr2_reg_base
= pdata
->ddr2_ctlr_base
;
87 ddr2_pdown
= pdata
->ddr2_pdown
;
89 return cpuidle_register(&davinci_idle_driver
, NULL
);
92 static struct platform_driver davinci_cpuidle_driver
= {
94 .name
= "cpuidle-davinci",
99 static int __init
davinci_cpuidle_init(void)
101 return platform_driver_probe(&davinci_cpuidle_driver
,
102 davinci_cpuidle_probe
);
104 device_initcall(davinci_cpuidle_init
);