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-rw-r--r--arch/arm/mach-shmobile/pm_runtime.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/pm_runtime.c b/arch/arm/mach-shmobile/pm_runtime.c
new file mode 100644
index 000000000000..94912d3944d3
--- /dev/null
+++ b/arch/arm/mach-shmobile/pm_runtime.c
@@ -0,0 +1,169 @@
1/*
2 * arch/arm/mach-shmobile/pm_runtime.c
3 *
4 * Runtime PM support code for SuperH Mobile ARM
5 *
6 * Copyright (C) 2009-2010 Magnus Damm
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/io.h>
16#include <linux/pm_runtime.h>
17#include <linux/platform_device.h>
18#include <linux/clk.h>
19#include <linux/sh_clk.h>
20#include <linux/bitmap.h>
21
22#ifdef CONFIG_PM_RUNTIME
23#define BIT_ONCE 0
24#define BIT_ACTIVE 1
25#define BIT_CLK_ENABLED 2
26
27struct pm_runtime_data {
28 unsigned long flags;
29 struct clk *clk;
30};
31
32static void __devres_release(struct device *dev, void *res)
33{
34 struct pm_runtime_data *prd = res;
35
36 dev_dbg(dev, "__devres_release()\n");
37
38 if (test_bit(BIT_CLK_ENABLED, &prd->flags))
39 clk_disable(prd->clk);
40
41 if (test_bit(BIT_ACTIVE, &prd->flags))
42 clk_put(prd->clk);
43}
44
45static struct pm_runtime_data *__to_prd(struct device *dev)
46{
47 return devres_find(dev, __devres_release, NULL, NULL);
48}
49
50static void platform_pm_runtime_init(struct device *dev,
51 struct pm_runtime_data *prd)
52{
53 if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags)) {
54 prd->clk = clk_get(dev, NULL);
55 if (!IS_ERR(prd->clk)) {
56 set_bit(BIT_ACTIVE, &prd->flags);
57 dev_info(dev, "clocks managed by runtime pm\n");
58 }
59 }
60}
61
62static void platform_pm_runtime_bug(struct device *dev,
63 struct pm_runtime_data *prd)
64{
65 if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags))
66 dev_err(dev, "runtime pm suspend before resume\n");
67}
68
69int platform_pm_runtime_suspend(struct device *dev)
70{
71 struct pm_runtime_data *prd = __to_prd(dev);
72
73 dev_dbg(dev, "platform_pm_runtime_suspend()\n");
74
75 platform_pm_runtime_bug(dev, prd);
76
77 if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
78 clk_disable(prd->clk);
79 clear_bit(BIT_CLK_ENABLED, &prd->flags);
80 }
81
82 return 0;
83}
84
85int platform_pm_runtime_resume(struct device *dev)
86{
87 struct pm_runtime_data *prd = __to_prd(dev);
88
89 dev_dbg(dev, "platform_pm_runtime_resume()\n");
90
91 platform_pm_runtime_init(dev, prd);
92
93 if (prd && test_bit(BIT_ACTIVE, &prd->flags)) {
94 clk_enable(prd->clk);
95 set_bit(BIT_CLK_ENABLED, &prd->flags);
96 }
97
98 return 0;
99}
100
101int platform_pm_runtime_idle(struct device *dev)
102{
103 /* suspend synchronously to disable clocks immediately */
104 return pm_runtime_suspend(dev);
105}
106
107static int platform_bus_notify(struct notifier_block *nb,
108 unsigned long action, void *data)
109{
110 struct device *dev = data;
111 struct pm_runtime_data *prd;
112
113 dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
114
115 if (action == BUS_NOTIFY_BIND_DRIVER) {
116 prd = devres_alloc(__devres_release, sizeof(*prd), GFP_KERNEL);
117 if (prd)
118 devres_add(dev, prd);
119 else
120 dev_err(dev, "unable to alloc memory for runtime pm\n");
121 }
122
123 return 0;
124}
125
126#else /* CONFIG_PM_RUNTIME */
127
128static int platform_bus_notify(struct notifier_block *nb,
129 unsigned long action, void *data)
130{
131 struct device *dev = data;
132 struct clk *clk;
133
134 dev_dbg(dev, "platform_bus_notify() %ld !\n", action);
135
136 switch (action) {
137 case BUS_NOTIFY_BIND_DRIVER:
138 clk = clk_get(dev, NULL);
139 if (!IS_ERR(clk)) {
140 clk_enable(clk);
141 clk_put(clk);
142 dev_info(dev, "runtime pm disabled, clock forced on\n");
143 }
144 break;
145 case BUS_NOTIFY_UNBOUND_DRIVER:
146 clk = clk_get(dev, NULL);
147 if (!IS_ERR(clk)) {
148 clk_disable(clk);
149 clk_put(clk);
150 dev_info(dev, "runtime pm disabled, clock forced off\n");
151 }
152 break;
153 }
154
155 return 0;
156}
157
158#endif /* CONFIG_PM_RUNTIME */
159
160static struct notifier_block platform_bus_notifier = {
161 .notifier_call = platform_bus_notify
162};
163
164static int __init sh_pm_runtime_init(void)
165{
166 bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
167 return 0;
168}
169core_initcall(sh_pm_runtime_init);