Commit | Line | Data |
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a6c0f6ec SN |
1 | /* |
2 | * CPU idle for DaVinci SoCs | |
3 | * | |
4 | * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/ | |
5 | * | |
6 | * Derived from Marvell Kirkwood CPU idle code | |
7 | * (arch/arm/mach-kirkwood/cpuidle.c) | |
8 | * | |
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. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/cpuidle.h> | |
18 | #include <linux/io.h> | |
dc28094b | 19 | #include <linux/export.h> |
a6c0f6ec SN |
20 | #include <asm/proc-fns.h> |
21 | ||
22 | #include <mach/cpuidle.h> | |
0020afb3 | 23 | #include <mach/ddr2.h> |
a6c0f6ec SN |
24 | |
25 | #define DAVINCI_CPUIDLE_MAX_STATES 2 | |
26 | ||
27 | struct davinci_ops { | |
28 | void (*enter) (u32 flags); | |
29 | void (*exit) (u32 flags); | |
30 | u32 flags; | |
31 | }; | |
32 | ||
33 | /* fields in davinci_ops.flags */ | |
34 | #define DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN BIT(0) | |
35 | ||
36 | static struct cpuidle_driver davinci_idle_driver = { | |
37 | .name = "cpuidle-davinci", | |
38 | .owner = THIS_MODULE, | |
39 | }; | |
40 | ||
41 | static DEFINE_PER_CPU(struct cpuidle_device, davinci_cpuidle_device); | |
42 | static void __iomem *ddr2_reg_base; | |
43 | ||
a6c0f6ec SN |
44 | static void davinci_save_ddr_power(int enter, bool pdown) |
45 | { | |
46 | u32 val; | |
47 | ||
48 | val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET); | |
49 | ||
50 | if (enter) { | |
51 | if (pdown) | |
52 | val |= DDR2_SRPD_BIT; | |
53 | else | |
54 | val &= ~DDR2_SRPD_BIT; | |
55 | val |= DDR2_LPMODEN_BIT; | |
56 | } else { | |
57 | val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT); | |
58 | } | |
59 | ||
60 | __raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET); | |
61 | } | |
62 | ||
63 | static void davinci_c2state_enter(u32 flags) | |
64 | { | |
65 | davinci_save_ddr_power(1, !!(flags & DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN)); | |
66 | } | |
67 | ||
68 | static void davinci_c2state_exit(u32 flags) | |
69 | { | |
70 | davinci_save_ddr_power(0, !!(flags & DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN)); | |
71 | } | |
72 | ||
73 | static struct davinci_ops davinci_states[DAVINCI_CPUIDLE_MAX_STATES] = { | |
74 | [1] = { | |
75 | .enter = davinci_c2state_enter, | |
76 | .exit = davinci_c2state_exit, | |
77 | }, | |
78 | }; | |
79 | ||
80 | /* Actual code that puts the SoC in different idle states */ | |
81 | static int davinci_enter_idle(struct cpuidle_device *dev, | |
46bcfad7 | 82 | struct cpuidle_driver *drv, |
e978aa7d | 83 | int index) |
a6c0f6ec | 84 | { |
4202735e DD |
85 | struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; |
86 | struct davinci_ops *ops = cpuidle_get_statedata(state_usage); | |
a6c0f6ec SN |
87 | struct timeval before, after; |
88 | int idle_time; | |
89 | ||
90 | local_irq_disable(); | |
91 | do_gettimeofday(&before); | |
92 | ||
93 | if (ops && ops->enter) | |
94 | ops->enter(ops->flags); | |
95 | /* Wait for interrupt state */ | |
96 | cpu_do_idle(); | |
97 | if (ops && ops->exit) | |
98 | ops->exit(ops->flags); | |
99 | ||
100 | do_gettimeofday(&after); | |
101 | local_irq_enable(); | |
102 | idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC + | |
103 | (after.tv_usec - before.tv_usec); | |
e978aa7d DD |
104 | |
105 | dev->last_residency = idle_time; | |
106 | ||
107 | return index; | |
a6c0f6ec SN |
108 | } |
109 | ||
110 | static int __init davinci_cpuidle_probe(struct platform_device *pdev) | |
111 | { | |
112 | int ret; | |
113 | struct cpuidle_device *device; | |
46bcfad7 | 114 | struct cpuidle_driver *driver = &davinci_idle_driver; |
a6c0f6ec | 115 | struct davinci_cpuidle_config *pdata = pdev->dev.platform_data; |
a6c0f6ec SN |
116 | |
117 | device = &per_cpu(davinci_cpuidle_device, smp_processor_id()); | |
118 | ||
119 | if (!pdata) { | |
120 | dev_err(&pdev->dev, "cannot get platform data\n"); | |
121 | return -ENOENT; | |
122 | } | |
123 | ||
948c66df | 124 | ddr2_reg_base = pdata->ddr2_ctlr_base; |
a6c0f6ec | 125 | |
a6c0f6ec | 126 | /* Wait for interrupt state */ |
46bcfad7 DD |
127 | driver->states[0].enter = davinci_enter_idle; |
128 | driver->states[0].exit_latency = 1; | |
129 | driver->states[0].target_residency = 10000; | |
130 | driver->states[0].flags = CPUIDLE_FLAG_TIME_VALID; | |
131 | strcpy(driver->states[0].name, "WFI"); | |
132 | strcpy(driver->states[0].desc, "Wait for interrupt"); | |
a6c0f6ec SN |
133 | |
134 | /* Wait for interrupt and DDR self refresh state */ | |
46bcfad7 DD |
135 | driver->states[1].enter = davinci_enter_idle; |
136 | driver->states[1].exit_latency = 10; | |
137 | driver->states[1].target_residency = 10000; | |
138 | driver->states[1].flags = CPUIDLE_FLAG_TIME_VALID; | |
139 | strcpy(driver->states[1].name, "DDR SR"); | |
140 | strcpy(driver->states[1].desc, "WFI and DDR Self Refresh"); | |
a6c0f6ec SN |
141 | if (pdata->ddr2_pdown) |
142 | davinci_states[1].flags |= DAVINCI_CPUIDLE_FLAGS_DDR2_PWDN; | |
4202735e | 143 | cpuidle_set_statedata(&device->states_usage[1], &davinci_states[1]); |
a6c0f6ec SN |
144 | |
145 | device->state_count = DAVINCI_CPUIDLE_MAX_STATES; | |
46bcfad7 DD |
146 | driver->state_count = DAVINCI_CPUIDLE_MAX_STATES; |
147 | ||
148 | ret = cpuidle_register_driver(&davinci_idle_driver); | |
149 | if (ret) { | |
150 | dev_err(&pdev->dev, "failed to register driver\n"); | |
151 | return ret; | |
152 | } | |
a6c0f6ec SN |
153 | |
154 | ret = cpuidle_register_device(device); | |
155 | if (ret) { | |
156 | dev_err(&pdev->dev, "failed to register device\n"); | |
948c66df SN |
157 | cpuidle_unregister_driver(&davinci_idle_driver); |
158 | return ret; | |
a6c0f6ec SN |
159 | } |
160 | ||
161 | return 0; | |
a6c0f6ec SN |
162 | } |
163 | ||
164 | static struct platform_driver davinci_cpuidle_driver = { | |
165 | .driver = { | |
166 | .name = "cpuidle-davinci", | |
167 | .owner = THIS_MODULE, | |
168 | }, | |
169 | }; | |
170 | ||
171 | static int __init davinci_cpuidle_init(void) | |
172 | { | |
173 | return platform_driver_probe(&davinci_cpuidle_driver, | |
174 | davinci_cpuidle_probe); | |
175 | } | |
176 | device_initcall(davinci_cpuidle_init); | |
177 |