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/platform_device.h> 15 #include <linux/slab.h> 16 #include <linux/pm_domain.h> 17 #include <linux/delay.h> 18 #include <linux/of.h> 19 #include <linux/of_address.h> 20 #include <linux/pm_runtime.h> 21 22 struct exynos_pm_domain_config { 23 /* Value for LOCAL_PWR_CFG and STATUS fields for each domain */ 24 u32 local_pwr_cfg; 25 }; 26 27 /* 28 * Exynos specific wrapper around the generic power domain 29 */ 30 struct exynos_pm_domain { 31 void __iomem *base; 32 struct generic_pm_domain pd; 33 u32 local_pwr_cfg; 34 }; 35 36 static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) 37 { 38 struct exynos_pm_domain *pd; 39 void __iomem *base; 40 u32 timeout, pwr; 41 char *op; 42 43 pd = container_of(domain, struct exynos_pm_domain, pd); 44 base = pd->base; 45 46 pwr = power_on ? pd->local_pwr_cfg : 0; 47 writel_relaxed(pwr, base); 48 49 /* Wait max 1ms */ 50 timeout = 10; 51 52 while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) { 53 if (!timeout) { 54 op = (power_on) ? "enable" : "disable"; 55 pr_err("Power domain %s %s failed\n", domain->name, op); 56 return -ETIMEDOUT; 57 } 58 timeout--; 59 cpu_relax(); 60 usleep_range(80, 100); 61 } 62 63 return 0; 64 } 65 66 static int exynos_pd_power_on(struct generic_pm_domain *domain) 67 { 68 return exynos_pd_power(domain, true); 69 } 70 71 static int exynos_pd_power_off(struct generic_pm_domain *domain) 72 { 73 return exynos_pd_power(domain, false); 74 } 75 76 static const struct exynos_pm_domain_config exynos4210_cfg = { 77 .local_pwr_cfg = 0x7, 78 }; 79 80 static const struct exynos_pm_domain_config exynos5433_cfg = { 81 .local_pwr_cfg = 0xf, 82 }; 83 84 static const struct of_device_id exynos_pm_domain_of_match[] = { 85 { 86 .compatible = "samsung,exynos4210-pd", 87 .data = &exynos4210_cfg, 88 }, { 89 .compatible = "samsung,exynos5433-pd", 90 .data = &exynos5433_cfg, 91 }, 92 { }, 93 }; 94 95 static const char *exynos_get_domain_name(struct device_node *node) 96 { 97 const char *name; 98 99 if (of_property_read_string(node, "label", &name) < 0) 100 name = kbasename(node->full_name); 101 return kstrdup_const(name, GFP_KERNEL); 102 } 103 104 static int exynos_pd_probe(struct platform_device *pdev) 105 { 106 const struct exynos_pm_domain_config *pm_domain_cfg; 107 struct device *dev = &pdev->dev; 108 struct device_node *np = dev->of_node; 109 struct of_phandle_args child, parent; 110 struct exynos_pm_domain *pd; 111 int on, ret; 112 113 pm_domain_cfg = of_device_get_match_data(dev); 114 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); 115 if (!pd) 116 return -ENOMEM; 117 118 pd->pd.name = exynos_get_domain_name(np); 119 if (!pd->pd.name) 120 return -ENOMEM; 121 122 pd->base = of_iomap(np, 0); 123 if (!pd->base) { 124 kfree_const(pd->pd.name); 125 return -ENODEV; 126 } 127 128 pd->pd.power_off = exynos_pd_power_off; 129 pd->pd.power_on = exynos_pd_power_on; 130 pd->local_pwr_cfg = pm_domain_cfg->local_pwr_cfg; 131 132 on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg; 133 134 pm_genpd_init(&pd->pd, NULL, !on); 135 ret = of_genpd_add_provider_simple(np, &pd->pd); 136 137 if (ret == 0 && of_parse_phandle_with_args(np, "power-domains", 138 "#power-domain-cells", 0, &parent) == 0) { 139 child.np = np; 140 child.args_count = 0; 141 142 if (of_genpd_add_subdomain(&parent, &child)) 143 pr_warn("%pOF failed to add subdomain: %pOF\n", 144 parent.np, child.np); 145 else 146 pr_info("%pOF has as child subdomain: %pOF.\n", 147 parent.np, child.np); 148 } 149 150 pm_runtime_enable(dev); 151 return ret; 152 } 153 154 static struct platform_driver exynos_pd_driver = { 155 .probe = exynos_pd_probe, 156 .driver = { 157 .name = "exynos-pd", 158 .of_match_table = exynos_pm_domain_of_match, 159 .suppress_bind_attrs = true, 160 } 161 }; 162 163 static __init int exynos4_pm_init_power_domain(void) 164 { 165 return platform_driver_register(&exynos_pd_driver); 166 } 167 core_initcall(exynos4_pm_init_power_domain); 168