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