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 */
syscon_get_regmap(struct udevice * dev)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
syscon_pre_probe(struct udevice * dev)36 static int syscon_pre_probe(struct udevice *dev)
37 {
38 struct syscon_uc_info *priv = dev_get_uclass_priv(dev);
39
40 /* Special case for PCI devices, which don't have a regmap */
41 if (device_get_uclass_id(dev->parent) == UCLASS_PCI)
42 return 0;
43
44 /*
45 * With OF_PLATDATA we really have no way of knowing the format of
46 * the device-specific platform data. So we assume that it starts with
47 * a 'reg' member, and this holds a single address and size. Drivers
48 * using OF_PLATDATA will need to ensure that this is true.
49 */
50 #if CONFIG_IS_ENABLED(OF_PLATDATA)
51 struct syscon_base_platdata *plat = dev_get_platdata(dev);
52
53 return regmap_init_mem_platdata(dev, plat->reg, ARRAY_SIZE(plat->reg),
54 &priv->regmap);
55 #else
56 return regmap_init_mem(dev_ofnode(dev), &priv->regmap);
57 #endif
58 }
59
syscon_regmap_lookup_by_phandle(struct udevice * dev,const char * name)60 struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev,
61 const char *name)
62 {
63 struct udevice *syscon;
64 struct regmap *r;
65 int err;
66
67 err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
68 name, &syscon);
69 if (err) {
70 dev_dbg(dev, "unable to find syscon device\n");
71 return ERR_PTR(err);
72 }
73
74 r = syscon_get_regmap(syscon);
75 if (!r) {
76 dev_dbg(dev, "unable to find regmap\n");
77 return ERR_PTR(-ENODEV);
78 }
79
80 return r;
81 }
82
syscon_get_by_driver_data(ulong driver_data,struct udevice ** devp)83 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp)
84 {
85 struct udevice *dev;
86 struct uclass *uc;
87 int ret;
88
89 *devp = NULL;
90 ret = uclass_get(UCLASS_SYSCON, &uc);
91 if (ret)
92 return ret;
93 uclass_foreach_dev(dev, uc) {
94 if (dev->driver_data == driver_data) {
95 *devp = dev;
96 return device_probe(dev);
97 }
98 }
99
100 return -ENODEV;
101 }
102
syscon_get_regmap_by_driver_data(ulong driver_data)103 struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data)
104 {
105 struct syscon_uc_info *priv;
106 struct udevice *dev;
107 int ret;
108
109 ret = syscon_get_by_driver_data(driver_data, &dev);
110 if (ret)
111 return ERR_PTR(ret);
112 priv = dev_get_uclass_priv(dev);
113
114 return priv->regmap;
115 }
116
syscon_get_first_range(ulong driver_data)117 void *syscon_get_first_range(ulong driver_data)
118 {
119 struct regmap *map;
120
121 map = syscon_get_regmap_by_driver_data(driver_data);
122 if (IS_ERR(map))
123 return map;
124 return regmap_get_range(map, 0);
125 }
126
127 UCLASS_DRIVER(syscon) = {
128 .id = UCLASS_SYSCON,
129 .name = "syscon",
130 .per_device_auto_alloc_size = sizeof(struct syscon_uc_info),
131 .pre_probe = syscon_pre_probe,
132 };
133
134 static const struct udevice_id generic_syscon_ids[] = {
135 { .compatible = "syscon" },
136 { }
137 };
138
139 U_BOOT_DRIVER(generic_syscon) = {
140 .name = "syscon",
141 .id = UCLASS_SYSCON,
142 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
143 .bind = dm_scan_fdt_dev,
144 #endif
145 .of_match = generic_syscon_ids,
146 };
147
148 /*
149 * Linux-compatible syscon-to-regmap
150 * The syscon node can be bound to another driver, but still works
151 * as a syscon provider.
152 */
syscon_node_to_regmap(ofnode node)153 struct regmap *syscon_node_to_regmap(ofnode node)
154 {
155 struct udevice *dev, *parent;
156 int ret;
157
158 if (!uclass_get_device_by_ofnode(UCLASS_SYSCON, node, &dev))
159 return syscon_get_regmap(dev);
160
161 if (!ofnode_device_is_compatible(node, "syscon"))
162 return ERR_PTR(-EINVAL);
163
164 /* bound to driver with same ofnode or to root if not found */
165 if (device_find_global_by_ofnode(node, &parent))
166 parent = dm_root();
167
168 /* force bound to syscon class */
169 ret = device_bind_driver_to_node(parent, "syscon",
170 ofnode_get_name(node),
171 node, &dev);
172 if (ret)
173 return ERR_PTR(ret);
174
175 ret = device_probe(dev);
176 if (ret)
177 return ERR_PTR(ret);
178
179 return syscon_get_regmap(dev);
180 }
181