2 * Exynos Generic power domain support.
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com
7 * Implementation of Exynos specific power domain control which is used in
8 * conjunction with runtime-pm. Support for both device-tree and non-device-tree
9 * based power domain support is included.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/pm_domain.h>
20 #include <linux/clk.h>
21 #include <linux/delay.h>
22 #include <linux/of_address.h>
23 #include <linux/of_platform.h>
24 #include <linux/sched.h>
26 #define INT_LOCAL_PWR_EN 0x7
27 #define MAX_CLK_PER_DOMAIN 4
30 * Exynos specific wrapper around the generic power domain
32 struct exynos_pm_domain
{
36 struct generic_pm_domain pd
;
38 struct clk
*clk
[MAX_CLK_PER_DOMAIN
];
39 struct clk
*pclk
[MAX_CLK_PER_DOMAIN
];
42 static int exynos_pd_power(struct generic_pm_domain
*domain
, bool power_on
)
44 struct exynos_pm_domain
*pd
;
49 pd
= container_of(domain
, struct exynos_pm_domain
, pd
);
52 /* Set oscclk before powering off a domain*/
56 for (i
= 0; i
< MAX_CLK_PER_DOMAIN
; i
++) {
57 if (IS_ERR(pd
->clk
[i
]))
59 if (clk_set_parent(pd
->clk
[i
], pd
->oscclk
))
60 pr_err("%s: error setting oscclk as parent to clock %d\n",
65 pwr
= power_on
? INT_LOCAL_PWR_EN
: 0;
66 __raw_writel(pwr
, base
);
71 while ((__raw_readl(base
+ 0x4) & INT_LOCAL_PWR_EN
) != pwr
) {
73 op
= (power_on
) ? "enable" : "disable";
74 pr_err("Power domain %s %s failed\n", domain
->name
, op
);
79 usleep_range(80, 100);
82 /* Restore clocks after powering on a domain*/
86 for (i
= 0; i
< MAX_CLK_PER_DOMAIN
; i
++) {
87 if (IS_ERR(pd
->clk
[i
]))
89 if (clk_set_parent(pd
->clk
[i
], pd
->pclk
[i
]))
90 pr_err("%s: error setting parent to clock%d\n",
98 static int exynos_pd_power_on(struct generic_pm_domain
*domain
)
100 return exynos_pd_power(domain
, true);
103 static int exynos_pd_power_off(struct generic_pm_domain
*domain
)
105 return exynos_pd_power(domain
, false);
108 static void exynos_add_device_to_domain(struct exynos_pm_domain
*pd
,
113 dev_dbg(dev
, "adding to power domain %s\n", pd
->pd
.name
);
116 ret
= pm_genpd_add_device(&pd
->pd
, dev
);
122 pm_genpd_dev_need_restore(dev
, true);
125 static void exynos_remove_device_from_domain(struct device
*dev
)
127 struct generic_pm_domain
*genpd
= dev_to_genpd(dev
);
130 dev_dbg(dev
, "removing from power domain %s\n", genpd
->name
);
133 ret
= pm_genpd_remove_device(genpd
, dev
);
140 static void exynos_read_domain_from_dt(struct device
*dev
)
142 struct platform_device
*pd_pdev
;
143 struct exynos_pm_domain
*pd
;
144 struct device_node
*node
;
146 node
= of_parse_phandle(dev
->of_node
, "samsung,power-domain", 0);
149 pd_pdev
= of_find_device_by_node(node
);
152 pd
= platform_get_drvdata(pd_pdev
);
153 exynos_add_device_to_domain(pd
, dev
);
156 static int exynos_pm_notifier_call(struct notifier_block
*nb
,
157 unsigned long event
, void *data
)
159 struct device
*dev
= data
;
162 case BUS_NOTIFY_BIND_DRIVER
:
164 exynos_read_domain_from_dt(dev
);
168 case BUS_NOTIFY_UNBOUND_DRIVER
:
169 exynos_remove_device_from_domain(dev
);
176 static struct notifier_block platform_nb
= {
177 .notifier_call
= exynos_pm_notifier_call
,
180 static __init
int exynos4_pm_init_power_domain(void)
182 struct platform_device
*pdev
;
183 struct device_node
*np
;
185 for_each_compatible_node(np
, NULL
, "samsung,exynos4210-pd") {
186 struct exynos_pm_domain
*pd
;
190 pdev
= of_find_device_by_node(np
);
193 pd
= kzalloc(sizeof(*pd
), GFP_KERNEL
);
195 pr_err("%s: failed to allocate memory for domain\n",
200 pd
->pd
.name
= kstrdup(np
->name
, GFP_KERNEL
);
201 pd
->name
= pd
->pd
.name
;
202 pd
->base
= of_iomap(np
, 0);
203 pd
->pd
.power_off
= exynos_pd_power_off
;
204 pd
->pd
.power_on
= exynos_pd_power_on
;
207 pd
->oscclk
= clk_get(dev
, "oscclk");
208 if (IS_ERR(pd
->oscclk
))
211 for (i
= 0; i
< MAX_CLK_PER_DOMAIN
; i
++) {
214 snprintf(clk_name
, sizeof(clk_name
), "clk%d", i
);
215 pd
->clk
[i
] = clk_get(dev
, clk_name
);
216 if (IS_ERR(pd
->clk
[i
]))
218 snprintf(clk_name
, sizeof(clk_name
), "pclk%d", i
);
219 pd
->pclk
[i
] = clk_get(dev
, clk_name
);
220 if (IS_ERR(pd
->pclk
[i
])) {
222 pd
->clk
[i
] = ERR_PTR(-EINVAL
);
227 if (IS_ERR(pd
->clk
[0]))
231 platform_set_drvdata(pdev
, pd
);
233 on
= __raw_readl(pd
->base
+ 0x4) & INT_LOCAL_PWR_EN
;
235 pm_genpd_init(&pd
->pd
, NULL
, !on
);
238 bus_register_notifier(&platform_bus_type
, &platform_nb
);
242 arch_initcall(exynos4_pm_init_power_domain
);