arch/arm/mach-exynos/pm_domains.c

   1 /*
   2  * Exynos Generic power domain support.
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *              http://www.samsung.com
   6  *
   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.
  10  *
  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.
  14 */
  15
  16 #include <linux/io.h>
  17 #include <linux/err.h>
  18 #include <linux/slab.h>
  19 #include <linux/pm_domain.h>
  20 #include <linux/delay.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/sched.h>
  24
  25 #include <mach/regs-pmu.h>
  26 #include <plat/devs.h>
  27
  28 /*
  29  * Exynos specific wrapper around the generic power domain
  30  */
  31 struct exynos_pm_domain {
  32         void __iomem *base;
  33         char const *name;
  34         bool is_off;
  35         struct generic_pm_domain pd;
  36 };
  37
  38 static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
  39 {
  40         struct exynos_pm_domain *pd;
  41         void __iomem *base;
  42         u32 timeout, pwr;
  43         char *op;
  44
  45         pd = container_of(domain, struct exynos_pm_domain, pd);
  46         base = pd->base;
  47
  48         pwr = power_on ? S5P_INT_LOCAL_PWR_EN : 0;
  49         __raw_writel(pwr, base);
  50
  51         /* Wait max 1ms */
  52         timeout = 10;
  53
  54         while ((__raw_readl(base + 0x4) & S5P_INT_LOCAL_PWR_EN) != pwr) {
  55                 if (!timeout) {
  56                         op = (power_on) ? "enable" : "disable";
  57                         pr_err("Power domain %s %s failed\n", domain->name, op);
  58                         return -ETIMEDOUT;
  59                 }
  60                 timeout--;
  61                 cpu_relax();
  62                 usleep_range(80, 100);
  63         }
  64         return 0;
  65 }
  66
  67 static int exynos_pd_power_on(struct generic_pm_domain *domain)
  68 {
  69         return exynos_pd_power(domain, true);
  70 }
  71
  72 static int exynos_pd_power_off(struct generic_pm_domain *domain)
  73 {
  74         return exynos_pd_power(domain, false);
  75 }
  76
  77 static void exynos_add_device_to_domain(struct exynos_pm_domain *pd,
  78                                          struct device *dev)
  79 {
  80         int ret;
  81
  82         dev_dbg(dev, "adding to power domain %s\n", pd->pd.name);
  83
  84         while (1) {
  85                 ret = pm_genpd_add_device(&pd->pd, dev);
  86                 if (ret != -EAGAIN)
  87                         break;
  88                 cond_resched();
  89         }
  90
  91         pm_genpd_dev_need_restore(dev, true);
  92 }
  93
  94 static void exynos_remove_device_from_domain(struct device *dev)
  95 {
  96         struct generic_pm_domain *genpd = dev_to_genpd(dev);
  97         int ret;
  98
  99         dev_dbg(dev, "removing from power domain %s\n", genpd->name);
 100
 101         while (1) {
 102                 ret = pm_genpd_remove_device(genpd, dev);
 103                 if (ret != -EAGAIN)
 104                         break;
 105                 cond_resched();
 106         }
 107 }
 108
 109 static void exynos_read_domain_from_dt(struct device *dev)
 110 {
 111         struct platform_device *pd_pdev;
 112         struct exynos_pm_domain *pd;
 113         struct device_node *node;
 114
 115         node = of_parse_phandle(dev->of_node, "samsung,power-domain", 0);
 116         if (!node)
 117                 return;
 118         pd_pdev = of_find_device_by_node(node);
 119         if (!pd_pdev)
 120                 return;
 121         pd = platform_get_drvdata(pd_pdev);
 122         exynos_add_device_to_domain(pd, dev);
 123 }
 124
 125 static int exynos_pm_notifier_call(struct notifier_block *nb,
 126                                     unsigned long event, void *data)
 127 {
 128         struct device *dev = data;
 129
 130         switch (event) {
 131         case BUS_NOTIFY_BIND_DRIVER:
 132                 if (dev->of_node)
 133                         exynos_read_domain_from_dt(dev);
 134
 135                 break;
 136
 137         case BUS_NOTIFY_UNBOUND_DRIVER:
 138                 exynos_remove_device_from_domain(dev);
 139
 140                 break;
 141         }
 142         return NOTIFY_DONE;
 143 }
 144
 145 static struct notifier_block platform_nb = {
 146         .notifier_call = exynos_pm_notifier_call,
 147 };
 148
 149 static __init int exynos4_pm_init_power_domain(void)
 150 {
 151         struct platform_device *pdev;
 152         struct device_node *np;
 153
 154         for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
 155                 struct exynos_pm_domain *pd;
 156                 int on;
 157
 158                 pdev = of_find_device_by_node(np);
 159
 160                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 161                 if (!pd) {
 162                         pr_err("%s: failed to allocate memory for domain\n",
 163                                         __func__);
 164                         return -ENOMEM;
 165                 }
 166
 167                 pd->pd.name = kstrdup(np->name, GFP_KERNEL);
 168                 pd->name = pd->pd.name;
 169                 pd->base = of_iomap(np, 0);
 170                 pd->pd.power_off = exynos_pd_power_off;
 171                 pd->pd.power_on = exynos_pd_power_on;
 172                 pd->pd.of_node = np;
 173
 174                 platform_set_drvdata(pdev, pd);
 175
 176                 on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;
 177
 178                 pm_genpd_init(&pd->pd, NULL, !on);
 179         }
 180
 181         bus_register_notifier(&platform_bus_type, &platform_nb);
 182
 183         return 0;
 184 }
 185 arch_initcall(exynos4_pm_init_power_domain);
 186
 187 int __init exynos_pm_late_initcall(void)
 188 {
 189         pm_genpd_poweroff_unused();
 190         return 0;
 191 }