drivers/soc/samsung/pm_domains.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Exynos Generic power domain support.
   4 //
   5 // Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6 //              http://www.samsung.com
   7 //
   8 // Implementation of Exynos specific power domain control which is used in
   9 // conjunction with runtime-pm. Support for both device-tree and non-device-tree
  10 // based power domain support is included.
  11
  12 #include <linux/io.h>
  13 #include <linux/err.h>
  14 #include <linux/slab.h>
  15 #include <linux/pm_domain.h>
  16 #include <linux/delay.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/pm_runtime.h>
  20
  21 struct exynos_pm_domain_config {
  22         /* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
  23         u32 local_pwr_cfg;
  24 };
  25
  26 /*
  27  * Exynos specific wrapper around the generic power domain
  28  */
  29 struct exynos_pm_domain {
  30         void __iomem *base;
  31         struct generic_pm_domain pd;
  32         u32 local_pwr_cfg;
  33 };
  34
  35 static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
  36 {
  37         struct exynos_pm_domain *pd;
  38         void __iomem *base;
  39         u32 timeout, pwr;
  40         char *op;
  41
  42         pd = container_of(domain, struct exynos_pm_domain, pd);
  43         base = pd->base;
  44
  45         pwr = power_on ? pd->local_pwr_cfg : 0;
  46         writel_relaxed(pwr, base);
  47
  48         /* Wait max 1ms */
  49         timeout = 10;
  50
  51         while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) {
  52                 if (!timeout) {
  53                         op = (power_on) ? "enable" : "disable";
  54                         pr_err("Power domain %s %s failed\n", domain->name, op);
  55                         return -ETIMEDOUT;
  56                 }
  57                 timeout--;
  58                 cpu_relax();
  59                 usleep_range(80, 100);
  60         }
  61
  62         return 0;
  63 }
  64
  65 static int exynos_pd_power_on(struct generic_pm_domain *domain)
  66 {
  67         return exynos_pd_power(domain, true);
  68 }
  69
  70 static int exynos_pd_power_off(struct generic_pm_domain *domain)
  71 {
  72         return exynos_pd_power(domain, false);
  73 }
  74
  75 static const struct exynos_pm_domain_config exynos4210_cfg = {
  76         .local_pwr_cfg          = 0x7,
  77 };
  78
  79 static const struct exynos_pm_domain_config exynos5433_cfg = {
  80         .local_pwr_cfg          = 0xf,
  81 };
  82
  83 static const struct of_device_id exynos_pm_domain_of_match[] = {
  84         {
  85                 .compatible = "samsung,exynos4210-pd",
  86                 .data = &exynos4210_cfg,
  87         }, {
  88                 .compatible = "samsung,exynos5433-pd",
  89                 .data = &exynos5433_cfg,
  90         },
  91         { },
  92 };
  93
  94 static const char *exynos_get_domain_name(struct device_node *node)
  95 {
  96         const char *name;
  97
  98         if (of_property_read_string(node, "label", &name) < 0)
  99                 name = kbasename(node->full_name);
 100         return kstrdup_const(name, GFP_KERNEL);
 101 }
 102
 103 static int exynos_pd_probe(struct platform_device *pdev)
 104 {
 105         const struct exynos_pm_domain_config *pm_domain_cfg;
 106         struct device *dev = &pdev->dev;
 107         struct device_node *np = dev->of_node;
 108         struct of_phandle_args child, parent;
 109         struct exynos_pm_domain *pd;
 110         int on, ret;
 111
 112         pm_domain_cfg = of_device_get_match_data(dev);
 113         pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
 114         if (!pd)
 115                 return -ENOMEM;
 116
 117         pd->pd.name = exynos_get_domain_name(np);
 118         if (!pd->pd.name)
 119                 return -ENOMEM;
 120
 121         pd->base = of_iomap(np, 0);
 122         if (!pd->base) {
 123                 kfree_const(pd->pd.name);
 124                 return -ENODEV;
 125         }
 126
 127         pd->pd.power_off = exynos_pd_power_off;
 128         pd->pd.power_on = exynos_pd_power_on;
 129         pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg;
 130
 131         on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;
 132
 133         pm_genpd_init(&pd->pd, NULL, !on);
 134         ret = of_genpd_add_provider_simple(np, &pd->pd);
 135
 136         if (ret == 0 && of_parse_phandle_with_args(np, "power-domains",
 137                                       "#power-domain-cells", 0, &parent) == 0) {
 138                 child.np = np;
 139                 child.args_count = 0;
 140
 141                 if (of_genpd_add_subdomain(&parent, &child))
 142                         pr_warn("%pOF failed to add subdomain: %pOF\n",
 143                                 parent.np, child.np);
 144                 else
 145                         pr_info("%pOF has as child subdomain: %pOF.\n",
 146                                 parent.np, child.np);
 147         }
 148
 149         pm_runtime_enable(dev);
 150         return ret;
 151 }
 152
 153 static struct platform_driver exynos_pd_driver = {
 154         .probe  = exynos_pd_probe,
 155         .driver = {
 156                 .name           = "exynos-pd",
 157                 .of_match_table = exynos_pm_domain_of_match,
 158                 .suppress_bind_attrs = true,
 159         }
 160 };
 161
 162 static __init int exynos4_pm_init_power_domain(void)
 163 {
 164         return platform_driver_register(&exynos_pd_driver);
 165 }
 166 core_initcall(exynos4_pm_init_power_domain);