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 #define LOG_CATEGORY UCLASS_SYSCON
8
9 #include <common.h>
10 #include <log.h>
11 #include <syscon.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <regmap.h>
15 #include <dm/device-internal.h>
16 #include <dm/device_compat.h>
17 #include <dm/lists.h>
18 #include <dm/root.h>
19 #include <linux/err.h>
20
21 /*
22 * Caution:
23 * This API requires the given device has already been bound to the syscon
24 * driver. For example,
25 *
26 * compatible = "syscon", "simple-mfd";
27 *
28 * works, but
29 *
30 * compatible = "simple-mfd", "syscon";
31 *
32 * does not. The behavior is different from Linux.
33 */
syscon_get_regmap(struct udevice * dev)34 struct regmap *syscon_get_regmap(struct udevice *dev)
35 {
36 struct syscon_uc_info *priv;
37
38 if (device_get_uclass_id(dev) != UCLASS_SYSCON)
39 return ERR_PTR(-ENOEXEC);
40 priv = dev_get_uclass_priv(dev);
41 return priv->regmap;
42 }
43
syscon_pre_probe(struct udevice * dev)44 static int syscon_pre_probe(struct udevice *dev)
45 {
46 struct syscon_uc_info *priv = dev_get_uclass_priv(dev);
47
48 /* Special case for PCI devices, which don't have a regmap */
49 if (device_get_uclass_id(dev->parent) == UCLASS_PCI)
50 return 0;
51
52 /*
53 * With OF_PLATDATA we really have no way of knowing the format of
54 * the device-specific platform data. So we assume that it starts with
55 * a 'reg' member, and this holds a single address and size. Drivers
56 * using OF_PLATDATA will need to ensure that this is true.
57 */
58 #if CONFIG_IS_ENABLED(OF_PLATDATA)
59 struct syscon_base_plat *plat = dev_get_plat(dev);
60
61 return regmap_init_mem_plat(dev, plat->reg, ARRAY_SIZE(plat->reg),
62 &priv->regmap);
63 #else
64 return regmap_init_mem(dev_ofnode(dev), &priv->regmap);
65 #endif
66 }
67
syscon_probe_by_ofnode(ofnode node,struct udevice ** devp)68 static int syscon_probe_by_ofnode(ofnode node, struct udevice **devp)
69 {
70 struct udevice *dev, *parent;
71 int ret;
72
73 /* found node with "syscon" compatible, not bounded to SYSCON UCLASS */
74 if (!ofnode_device_is_compatible(node, "syscon")) {
75 log_debug("invalid compatible for syscon device\n");
76 return -EINVAL;
77 }
78
79 /* bound to driver with same ofnode or to root if not found */
80 if (device_find_global_by_ofnode(node, &parent))
81 parent = dm_root();
82
83 /* force bound to syscon class */
84 ret = device_bind_driver_to_node(parent, "syscon",
85 ofnode_get_name(node),
86 node, &dev);
87 if (ret) {
88 dev_dbg(dev, "unable to bound syscon device\n");
89 return ret;
90 }
91 ret = device_probe(dev);
92 if (ret) {
93 dev_dbg(dev, "unable to probe syscon device\n");
94 return ret;
95 }
96
97 *devp = dev;
98 return 0;
99 }
100
syscon_regmap_lookup_by_phandle(struct udevice * dev,const char * name)101 struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev,
102 const char *name)
103 {
104 struct udevice *syscon;
105 struct regmap *r;
106 u32 phandle;
107 ofnode node;
108 int err;
109
110 err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
111 name, &syscon);
112 if (err) {
113 /* found node with "syscon" compatible, not bounded to SYSCON */
114 err = ofnode_read_u32(dev_ofnode(dev), name, &phandle);
115 if (err)
116 return ERR_PTR(err);
117
118 node = ofnode_get_by_phandle(phandle);
119 if (!ofnode_valid(node)) {
120 dev_dbg(dev, "unable to find syscon device\n");
121 return ERR_PTR(-EINVAL);
122 }
123 err = syscon_probe_by_ofnode(node, &syscon);
124 if (err)
125 return ERR_PTR(-ENODEV);
126 }
127
128 r = syscon_get_regmap(syscon);
129 if (!r) {
130 dev_dbg(dev, "unable to find regmap\n");
131 return ERR_PTR(-ENODEV);
132 }
133
134 return r;
135 }
136
syscon_get_by_driver_data(ulong driver_data,struct udevice ** devp)137 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp)
138 {
139 int ret;
140
141 *devp = NULL;
142
143 ret = uclass_first_device_drvdata(UCLASS_SYSCON, driver_data, devp);
144 if (ret)
145 return ret;
146
147 return 0;
148 }
149
syscon_get_regmap_by_driver_data(ulong driver_data)150 struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data)
151 {
152 struct syscon_uc_info *priv;
153 struct udevice *dev;
154 int ret;
155
156 ret = syscon_get_by_driver_data(driver_data, &dev);
157 if (ret)
158 return ERR_PTR(ret);
159 priv = dev_get_uclass_priv(dev);
160
161 return priv->regmap;
162 }
163
syscon_get_first_range(ulong driver_data)164 void *syscon_get_first_range(ulong driver_data)
165 {
166 struct regmap *map;
167
168 map = syscon_get_regmap_by_driver_data(driver_data);
169 if (IS_ERR(map))
170 return map;
171 return regmap_get_range(map, 0);
172 }
173
174 UCLASS_DRIVER(syscon) = {
175 .id = UCLASS_SYSCON,
176 .name = "syscon",
177 .per_device_auto = sizeof(struct syscon_uc_info),
178 .pre_probe = syscon_pre_probe,
179 };
180
181 static const struct udevice_id generic_syscon_ids[] = {
182 { .compatible = "syscon" },
183 { }
184 };
185
186 U_BOOT_DRIVER(generic_syscon) = {
187 .name = "syscon",
188 .id = UCLASS_SYSCON,
189 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
190 .bind = dm_scan_fdt_dev,
191 #endif
192 .of_match = generic_syscon_ids,
193 };
194
195 /*
196 * Linux-compatible syscon-to-regmap
197 * The syscon node can be bound to another driver, but still works
198 * as a syscon provider.
199 */
syscon_node_to_regmap(ofnode node)200 struct regmap *syscon_node_to_regmap(ofnode node)
201 {
202 struct udevice *dev;
203 struct regmap *r;
204
205 if (uclass_get_device_by_ofnode(UCLASS_SYSCON, node, &dev))
206 if (syscon_probe_by_ofnode(node, &dev))
207 return ERR_PTR(-ENODEV);
208
209 r = syscon_get_regmap(dev);
210 if (!r) {
211 dev_dbg(dev, "unable to find regmap\n");
212 return ERR_PTR(-ENODEV);
213 }
214
215 return r;
216 }
217