1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2015 Google, Inc 4 * Written by Simon Glass <sjg@chromium.org> 5 */ 6 7 #include <common.h> 8 #include <syscon.h> 9 #include <dm.h> 10 #include <errno.h> 11 #include <regmap.h> 12 #include <dm/device-internal.h> 13 #include <dm/lists.h> 14 #include <dm/root.h> 15 #include <linux/err.h> 16 17 /* 18 * Caution: 19 * This API requires the given device has alerady been bound to syscon driver. 20 * For example, 21 * compatible = "syscon", "simple-mfd"; 22 * works, but 23 * compatible = "simple-mfd", "syscon"; 24 * does not. The behavior is different from Linux. 25 */ 26 struct regmap *syscon_get_regmap(struct udevice *dev) 27 { 28 struct syscon_uc_info *priv; 29 30 if (device_get_uclass_id(dev) != UCLASS_SYSCON) 31 return ERR_PTR(-ENOEXEC); 32 priv = dev_get_uclass_priv(dev); 33 return priv->regmap; 34 } 35 36 static int syscon_pre_probe(struct udevice *dev) 37 { 38 struct syscon_uc_info *priv = dev_get_uclass_priv(dev); 39 40 /* 41 * With OF_PLATDATA we really have no way of knowing the format of 42 * the device-specific platform data. So we assume that it starts with 43 * a 'reg' member, and this holds a single address and size. Drivers 44 * using OF_PLATDATA will need to ensure that this is true. 45 */ 46 #if CONFIG_IS_ENABLED(OF_PLATDATA) 47 struct syscon_base_platdata *plat = dev_get_platdata(dev); 48 49 return regmap_init_mem_platdata(dev, plat->reg, ARRAY_SIZE(plat->reg), 50 &priv->regmap); 51 #else 52 return regmap_init_mem(dev_ofnode(dev), &priv->regmap); 53 #endif 54 } 55 56 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp) 57 { 58 struct udevice *dev; 59 struct uclass *uc; 60 int ret; 61 62 *devp = NULL; 63 ret = uclass_get(UCLASS_SYSCON, &uc); 64 if (ret) 65 return ret; 66 uclass_foreach_dev(dev, uc) { 67 if (dev->driver_data == driver_data) { 68 *devp = dev; 69 return device_probe(dev); 70 } 71 } 72 73 return -ENODEV; 74 } 75 76 struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data) 77 { 78 struct syscon_uc_info *priv; 79 struct udevice *dev; 80 int ret; 81 82 ret = syscon_get_by_driver_data(driver_data, &dev); 83 if (ret) 84 return ERR_PTR(ret); 85 priv = dev_get_uclass_priv(dev); 86 87 return priv->regmap; 88 } 89 90 void *syscon_get_first_range(ulong driver_data) 91 { 92 struct regmap *map; 93 94 map = syscon_get_regmap_by_driver_data(driver_data); 95 if (IS_ERR(map)) 96 return map; 97 return regmap_get_range(map, 0); 98 } 99 100 UCLASS_DRIVER(syscon) = { 101 .id = UCLASS_SYSCON, 102 .name = "syscon", 103 .per_device_auto_alloc_size = sizeof(struct syscon_uc_info), 104 .pre_probe = syscon_pre_probe, 105 }; 106 107 static const struct udevice_id generic_syscon_ids[] = { 108 { .compatible = "syscon" }, 109 { } 110 }; 111 112 U_BOOT_DRIVER(generic_syscon) = { 113 .name = "syscon", 114 .id = UCLASS_SYSCON, 115 #if !CONFIG_IS_ENABLED(OF_PLATDATA) 116 .bind = dm_scan_fdt_dev, 117 #endif 118 .of_match = generic_syscon_ids, 119 }; 120 121 /* 122 * Linux-compatible syscon-to-regmap 123 * The syscon node can be bound to another driver, but still works 124 * as a syscon provider. 125 */ 126 static LIST_HEAD(syscon_list); 127 128 struct syscon { 129 ofnode node; 130 struct regmap *regmap; 131 struct list_head list; 132 }; 133 134 static struct syscon *of_syscon_register(ofnode node) 135 { 136 struct syscon *syscon; 137 int ret; 138 139 if (!ofnode_device_is_compatible(node, "syscon")) 140 return ERR_PTR(-EINVAL); 141 142 syscon = malloc(sizeof(*syscon)); 143 if (!syscon) 144 return ERR_PTR(-ENOMEM); 145 146 ret = regmap_init_mem(node, &syscon->regmap); 147 if (ret) { 148 free(syscon); 149 return ERR_PTR(ret); 150 } 151 152 list_add_tail(&syscon->list, &syscon_list); 153 154 return syscon; 155 } 156 157 struct regmap *syscon_node_to_regmap(ofnode node) 158 { 159 struct syscon *entry, *syscon = NULL; 160 161 list_for_each_entry(entry, &syscon_list, list) 162 if (ofnode_equal(entry->node, node)) { 163 syscon = entry; 164 break; 165 } 166 167 if (!syscon) 168 syscon = of_syscon_register(node); 169 170 if (IS_ERR(syscon)) 171 return ERR_CAST(syscon); 172 173 return syscon->regmap; 174 } 175