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 struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev, 57 const char *name) 58 { 59 struct udevice *syscon; 60 struct regmap *r; 61 int err; 62 63 err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev, 64 name, &syscon); 65 if (err) { 66 dev_dbg(dev, "unable to find syscon device\n"); 67 return ERR_PTR(err); 68 } 69 70 r = syscon_get_regmap(syscon); 71 if (!r) { 72 dev_dbg(dev, "unable to find regmap\n"); 73 return ERR_PTR(-ENODEV); 74 } 75 76 return r; 77 } 78 79 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp) 80 { 81 struct udevice *dev; 82 struct uclass *uc; 83 int ret; 84 85 *devp = NULL; 86 ret = uclass_get(UCLASS_SYSCON, &uc); 87 if (ret) 88 return ret; 89 uclass_foreach_dev(dev, uc) { 90 if (dev->driver_data == driver_data) { 91 *devp = dev; 92 return device_probe(dev); 93 } 94 } 95 96 return -ENODEV; 97 } 98 99 struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data) 100 { 101 struct syscon_uc_info *priv; 102 struct udevice *dev; 103 int ret; 104 105 ret = syscon_get_by_driver_data(driver_data, &dev); 106 if (ret) 107 return ERR_PTR(ret); 108 priv = dev_get_uclass_priv(dev); 109 110 return priv->regmap; 111 } 112 113 void *syscon_get_first_range(ulong driver_data) 114 { 115 struct regmap *map; 116 117 map = syscon_get_regmap_by_driver_data(driver_data); 118 if (IS_ERR(map)) 119 return map; 120 return regmap_get_range(map, 0); 121 } 122 123 UCLASS_DRIVER(syscon) = { 124 .id = UCLASS_SYSCON, 125 .name = "syscon", 126 .per_device_auto_alloc_size = sizeof(struct syscon_uc_info), 127 .pre_probe = syscon_pre_probe, 128 }; 129 130 static const struct udevice_id generic_syscon_ids[] = { 131 { .compatible = "syscon" }, 132 { } 133 }; 134 135 U_BOOT_DRIVER(generic_syscon) = { 136 .name = "syscon", 137 .id = UCLASS_SYSCON, 138 #if !CONFIG_IS_ENABLED(OF_PLATDATA) 139 .bind = dm_scan_fdt_dev, 140 #endif 141 .of_match = generic_syscon_ids, 142 }; 143 144 /* 145 * Linux-compatible syscon-to-regmap 146 * The syscon node can be bound to another driver, but still works 147 * as a syscon provider. 148 */ 149 static LIST_HEAD(syscon_list); 150 151 struct syscon { 152 ofnode node; 153 struct regmap *regmap; 154 struct list_head list; 155 }; 156 157 static struct syscon *of_syscon_register(ofnode node) 158 { 159 struct syscon *syscon; 160 int ret; 161 162 if (!ofnode_device_is_compatible(node, "syscon")) 163 return ERR_PTR(-EINVAL); 164 165 syscon = malloc(sizeof(*syscon)); 166 if (!syscon) 167 return ERR_PTR(-ENOMEM); 168 169 ret = regmap_init_mem(node, &syscon->regmap); 170 if (ret) { 171 free(syscon); 172 return ERR_PTR(ret); 173 } 174 175 list_add_tail(&syscon->list, &syscon_list); 176 177 return syscon; 178 } 179 180 struct regmap *syscon_node_to_regmap(ofnode node) 181 { 182 struct syscon *entry, *syscon = NULL; 183 184 list_for_each_entry(entry, &syscon_list, list) 185 if (ofnode_equal(entry->node, node)) { 186 syscon = entry; 187 break; 188 } 189 190 if (!syscon) 191 syscon = of_syscon_register(node); 192 193 if (IS_ERR(syscon)) 194 return ERR_CAST(syscon); 195 196 return syscon->regmap; 197 } 198