pm_domains.c (3966B)
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 21struct 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 */ 29struct exynos_pm_domain { 30 void __iomem *base; 31 struct generic_pm_domain pd; 32 u32 local_pwr_cfg; 33}; 34 35static 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 65static int exynos_pd_power_on(struct generic_pm_domain *domain) 66{ 67 return exynos_pd_power(domain, true); 68} 69 70static int exynos_pd_power_off(struct generic_pm_domain *domain) 71{ 72 return exynos_pd_power(domain, false); 73} 74 75static const struct exynos_pm_domain_config exynos4210_cfg = { 76 .local_pwr_cfg = 0x7, 77}; 78 79static const struct exynos_pm_domain_config exynos5433_cfg = { 80 .local_pwr_cfg = 0xf, 81}; 82 83static 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 94static 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 103static 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 153static 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 162static __init int exynos4_pm_init_power_domain(void) 163{ 164 return platform_driver_register(&exynos_pd_driver); 165} 166core_initcall(exynos4_pm_init_power_domain);