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>
28 #define MAX_CLK_PER_DOMAIN 4
31 * Exynos specific wrapper around the generic power domain
33 struct exynos_pm_domain {
37 struct generic_pm_domain pd;
39 struct clk *clk[MAX_CLK_PER_DOMAIN];
40 struct clk *pclk[MAX_CLK_PER_DOMAIN];
43 static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
45 struct exynos_pm_domain *pd;
50 pd = container_of(domain, struct exynos_pm_domain, pd);
53 /* Set oscclk before powering off a domain*/
57 for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
58 if (IS_ERR(pd->clk[i]))
60 if (clk_set_parent(pd->clk[i], pd->oscclk))
61 pr_err("%s: error setting oscclk as parent to clock %d\n",
66 pwr = power_on ? S5P_INT_LOCAL_PWR_EN : 0;
67 __raw_writel(pwr, base);
72 while ((__raw_readl(base + 0x4) & S5P_INT_LOCAL_PWR_EN) != pwr) {
74 op = (power_on) ? "enable" : "disable";
75 pr_err("Power domain %s %s failed\n", domain->name, op);
80 usleep_range(80, 100);
83 /* Restore clocks after powering on a domain*/
87 for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
88 if (IS_ERR(pd->clk[i]))
90 if (clk_set_parent(pd->clk[i], pd->pclk[i]))
91 pr_err("%s: error setting parent to clock%d\n",
99 static int exynos_pd_power_on(struct generic_pm_domain *domain)
101 return exynos_pd_power(domain, true);
104 static int exynos_pd_power_off(struct generic_pm_domain *domain)
106 return exynos_pd_power(domain, false);
109 static void exynos_add_device_to_domain(struct exynos_pm_domain *pd,
114 dev_dbg(dev, "adding to power domain %s\n", pd->pd.name);
117 ret = pm_genpd_add_device(&pd->pd, dev);
123 pm_genpd_dev_need_restore(dev, true);
126 static void exynos_remove_device_from_domain(struct device *dev)
128 struct generic_pm_domain *genpd = dev_to_genpd(dev);
131 dev_dbg(dev, "removing from power domain %s\n", genpd->name);
134 ret = pm_genpd_remove_device(genpd, dev);
141 static void exynos_read_domain_from_dt(struct device *dev)
143 struct platform_device *pd_pdev;
144 struct exynos_pm_domain *pd;
145 struct device_node *node;
147 node = of_parse_phandle(dev->of_node, "samsung,power-domain", 0);
150 pd_pdev = of_find_device_by_node(node);
153 pd = platform_get_drvdata(pd_pdev);
154 exynos_add_device_to_domain(pd, dev);
157 static int exynos_pm_notifier_call(struct notifier_block *nb,
158 unsigned long event, void *data)
160 struct device *dev = data;
163 case BUS_NOTIFY_BIND_DRIVER:
165 exynos_read_domain_from_dt(dev);
169 case BUS_NOTIFY_UNBOUND_DRIVER:
170 exynos_remove_device_from_domain(dev);
177 static struct notifier_block platform_nb = {
178 .notifier_call = exynos_pm_notifier_call,
181 static __init int exynos4_pm_init_power_domain(void)
183 struct platform_device *pdev;
184 struct device_node *np;
186 for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
187 struct exynos_pm_domain *pd;
191 pdev = of_find_device_by_node(np);
194 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
196 pr_err("%s: failed to allocate memory for domain\n",
201 pd->pd.name = kstrdup(np->name, GFP_KERNEL);
202 pd->name = pd->pd.name;
203 pd->base = of_iomap(np, 0);
204 pd->pd.power_off = exynos_pd_power_off;
205 pd->pd.power_on = exynos_pd_power_on;
208 pd->oscclk = clk_get(dev, "oscclk");
209 if (IS_ERR(pd->oscclk))
212 for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
215 snprintf(clk_name, sizeof(clk_name), "clk%d", i);
216 pd->clk[i] = clk_get(dev, clk_name);
217 if (IS_ERR(pd->clk[i]))
219 snprintf(clk_name, sizeof(clk_name), "pclk%d", i);
220 pd->pclk[i] = clk_get(dev, clk_name);
221 if (IS_ERR(pd->pclk[i])) {
223 pd->clk[i] = ERR_PTR(-EINVAL);
228 if (IS_ERR(pd->clk[0]))
232 platform_set_drvdata(pdev, pd);
234 on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;
236 pm_genpd_init(&pd->pd, NULL, !on);
239 bus_register_notifier(&platform_bus_type, &platform_nb);
243 arch_initcall(exynos4_pm_init_power_domain);