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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2014 ARM Limited
12 */
13
14#include <linux/delay.h>
15#include <linux/err.h>
16#include <linux/io.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include <linux/syscore_ops.h>
22#include <linux/vexpress.h>
23
24
25#define SYS_CFGDATA 0x0
26
27#define SYS_CFGCTRL 0x4
28#define SYS_CFGCTRL_START (1 << 31)
29#define SYS_CFGCTRL_WRITE (1 << 30)
30#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
31#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
32#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
33#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
34#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
35
36#define SYS_CFGSTAT 0x8
37#define SYS_CFGSTAT_ERR (1 << 1)
38#define SYS_CFGSTAT_COMPLETE (1 << 0)
39
40
41struct vexpress_syscfg {
42 struct device *dev;
43 void __iomem *base;
44 struct list_head funcs;
45};
46
47struct vexpress_syscfg_func {
48 struct list_head list;
49 struct vexpress_syscfg *syscfg;
50 struct regmap *regmap;
51 int num_templates;
52 u32 template[0]; /* Keep it last! */
53};
54
55
56static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
57 int index, bool write, u32 *data)
58{
59 struct vexpress_syscfg *syscfg = func->syscfg;
60 u32 command, status;
61 int tries;
62 long timeout;
63
64 if (WARN_ON(index > func->num_templates))
65 return -EINVAL;
66
67 command = readl(syscfg->base + SYS_CFGCTRL);
68 if (WARN_ON(command & SYS_CFGCTRL_START))
69 return -EBUSY;
70
71 command = func->template[index];
72 command |= SYS_CFGCTRL_START;
73 command |= write ? SYS_CFGCTRL_WRITE : 0;
74
75 /* Use a canary for reads */
76 if (!write)
77 *data = 0xdeadbeef;
78
79 dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
80 func, command, *data);
81 writel(*data, syscfg->base + SYS_CFGDATA);
82 writel(0, syscfg->base + SYS_CFGSTAT);
83 writel(command, syscfg->base + SYS_CFGCTRL);
84 mb();
85
86 /* The operation can take ages... Go to sleep, 100us initially */
87 tries = 100;
88 timeout = 100;
89 do {
90 if (!irqs_disabled()) {
91 set_current_state(TASK_INTERRUPTIBLE);
92 schedule_timeout(usecs_to_jiffies(timeout));
93 if (signal_pending(current))
94 return -EINTR;
95 } else {
96 udelay(timeout);
97 }
98
99 status = readl(syscfg->base + SYS_CFGSTAT);
100 if (status & SYS_CFGSTAT_ERR)
101 return -EFAULT;
102
103 if (timeout > 20)
104 timeout -= 20;
105 } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
106 if (WARN_ON_ONCE(!tries))
107 return -ETIMEDOUT;
108
109 if (!write) {
110 *data = readl(syscfg->base + SYS_CFGDATA);
111 dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
112 }
113
114 return 0;
115}
116
117static int vexpress_syscfg_read(void *context, unsigned int index,
118 unsigned int *val)
119{
120 struct vexpress_syscfg_func *func = context;
121
122 return vexpress_syscfg_exec(func, index, false, val);
123}
124
125static int vexpress_syscfg_write(void *context, unsigned int index,
126 unsigned int val)
127{
128 struct vexpress_syscfg_func *func = context;
129
130 return vexpress_syscfg_exec(func, index, true, &val);
131}
132
133static struct regmap_config vexpress_syscfg_regmap_config = {
134 .lock = vexpress_config_lock,
135 .unlock = vexpress_config_unlock,
136 .reg_bits = 32,
137 .val_bits = 32,
138 .reg_read = vexpress_syscfg_read,
139 .reg_write = vexpress_syscfg_write,
140 .reg_format_endian = REGMAP_ENDIAN_LITTLE,
141 .val_format_endian = REGMAP_ENDIAN_LITTLE,
142};
143
144
145static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
146 void *context)
147{
148 int err;
149 struct vexpress_syscfg *syscfg = context;
150 struct vexpress_syscfg_func *func;
151 struct property *prop;
152 const __be32 *val = NULL;
153 __be32 energy_quirk[4];
154 int num;
155 u32 site, position, dcc;
156 int i;
157
158 err = vexpress_config_get_topo(dev->of_node, &site,
159 &position, &dcc);
160 if (err)
161 return ERR_PTR(err);
162
163 prop = of_find_property(dev->of_node,
164 "arm,vexpress-sysreg,func", NULL);
165 if (!prop)
166 return ERR_PTR(-EINVAL);
167
168 num = prop->length / sizeof(u32) / 2;
169 val = prop->value;
170
171 /*
172 * "arm,vexpress-energy" function used to be described
173 * by its first device only, now it requires both
174 */
175 if (num == 1 && of_device_is_compatible(dev->of_node,
176 "arm,vexpress-energy")) {
177 num = 2;
178 energy_quirk[0] = *val;
179 energy_quirk[2] = *val++;
180 energy_quirk[1] = *val;
181 energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
182 val = energy_quirk;
183 }
184
185 func = kzalloc(sizeof(*func) + sizeof(*func->template) * num,
186 GFP_KERNEL);
187 if (!func)
188 return ERR_PTR(-ENOMEM);
189
190 func->syscfg = syscfg;
191 func->num_templates = num;
192
193 for (i = 0; i < num; i++) {
194 u32 function, device;
195
196 function = be32_to_cpup(val++);
197 device = be32_to_cpup(val++);
198
199 dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
200 func, site, position, dcc,
201 function, device);
202
203 func->template[i] = SYS_CFGCTRL_DCC(dcc);
204 func->template[i] |= SYS_CFGCTRL_SITE(site);
205 func->template[i] |= SYS_CFGCTRL_POSITION(position);
206 func->template[i] |= SYS_CFGCTRL_FUNC(function);
207 func->template[i] |= SYS_CFGCTRL_DEVICE(device);
208 }
209
210 vexpress_syscfg_regmap_config.max_register = num - 1;
211
212 func->regmap = regmap_init(dev, NULL, func,
213 &vexpress_syscfg_regmap_config);
214
215 if (IS_ERR(func->regmap)) {
216 void *err = func->regmap;
217
218 kfree(func);
219 return err;
220 }
221
222 list_add(&func->list, &syscfg->funcs);
223
224 return func->regmap;
225}
226
227static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
228{
229 struct vexpress_syscfg *syscfg = context;
230 struct vexpress_syscfg_func *func, *tmp;
231
232 regmap_exit(regmap);
233
234 list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
235 if (func->regmap == regmap) {
236 list_del(&syscfg->funcs);
237 kfree(func);
238 break;
239 }
240 }
241}
242
243static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
244 .regmap_init = vexpress_syscfg_regmap_init,
245 .regmap_exit = vexpress_syscfg_regmap_exit,
246};
247
248
249static int vexpress_syscfg_probe(struct platform_device *pdev)
250{
251 struct vexpress_syscfg *syscfg;
252 struct resource *res;
253 struct device *bridge;
254
255 syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
256 if (!syscfg)
257 return -ENOMEM;
258 syscfg->dev = &pdev->dev;
259 INIT_LIST_HEAD(&syscfg->funcs);
260
261 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
262 if (!devm_request_mem_region(&pdev->dev, res->start,
263 resource_size(res), pdev->name))
264 return -EBUSY;
265
266 syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
267 if (!syscfg->base)
268 return -EFAULT;
269
270 /* Must use dev.parent (MFD), as that's where DT phandle points at... */
271 bridge = vexpress_config_bridge_register(pdev->dev.parent,
272 &vexpress_syscfg_bridge_ops, syscfg);
273 if (IS_ERR(bridge))
274 return PTR_ERR(bridge);
275
276 return 0;
277}
278
279static const struct platform_device_id vexpress_syscfg_id_table[] = {
280 { "vexpress-syscfg", },
281 {},
282};
283
284static struct platform_driver vexpress_syscfg_driver = {
285 .driver.name = "vexpress-syscfg",
286 .id_table = vexpress_syscfg_id_table,
287 .probe = vexpress_syscfg_probe,
288};
289
290static int __init vexpress_syscfg_init(void)
291{
292 return platform_driver_register(&vexpress_syscfg_driver);
293}
294core_initcall(vexpress_syscfg_init);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 2014 ARM Limited
5 */
6
7#include <linux/delay.h>
8#include <linux/err.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/sched/signal.h>
13#include <linux/slab.h>
14#include <linux/syscore_ops.h>
15#include <linux/vexpress.h>
16
17
18#define SYS_CFGDATA 0x0
19
20#define SYS_CFGCTRL 0x4
21#define SYS_CFGCTRL_START (1 << 31)
22#define SYS_CFGCTRL_WRITE (1 << 30)
23#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
24#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
25#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
26#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
27#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
28
29#define SYS_CFGSTAT 0x8
30#define SYS_CFGSTAT_ERR (1 << 1)
31#define SYS_CFGSTAT_COMPLETE (1 << 0)
32
33
34struct vexpress_syscfg {
35 struct device *dev;
36 void __iomem *base;
37 struct list_head funcs;
38};
39
40struct vexpress_syscfg_func {
41 struct list_head list;
42 struct vexpress_syscfg *syscfg;
43 struct regmap *regmap;
44 int num_templates;
45 u32 template[0]; /* Keep it last! */
46};
47
48
49static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
50 int index, bool write, u32 *data)
51{
52 struct vexpress_syscfg *syscfg = func->syscfg;
53 u32 command, status;
54 int tries;
55 long timeout;
56
57 if (WARN_ON(index >= func->num_templates))
58 return -EINVAL;
59
60 command = readl(syscfg->base + SYS_CFGCTRL);
61 if (WARN_ON(command & SYS_CFGCTRL_START))
62 return -EBUSY;
63
64 command = func->template[index];
65 command |= SYS_CFGCTRL_START;
66 command |= write ? SYS_CFGCTRL_WRITE : 0;
67
68 /* Use a canary for reads */
69 if (!write)
70 *data = 0xdeadbeef;
71
72 dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
73 func, command, *data);
74 writel(*data, syscfg->base + SYS_CFGDATA);
75 writel(0, syscfg->base + SYS_CFGSTAT);
76 writel(command, syscfg->base + SYS_CFGCTRL);
77 mb();
78
79 /* The operation can take ages... Go to sleep, 100us initially */
80 tries = 100;
81 timeout = 100;
82 do {
83 if (!irqs_disabled()) {
84 set_current_state(TASK_INTERRUPTIBLE);
85 schedule_timeout(usecs_to_jiffies(timeout));
86 if (signal_pending(current))
87 return -EINTR;
88 } else {
89 udelay(timeout);
90 }
91
92 status = readl(syscfg->base + SYS_CFGSTAT);
93 if (status & SYS_CFGSTAT_ERR)
94 return -EFAULT;
95
96 if (timeout > 20)
97 timeout -= 20;
98 } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
99 if (WARN_ON_ONCE(!tries))
100 return -ETIMEDOUT;
101
102 if (!write) {
103 *data = readl(syscfg->base + SYS_CFGDATA);
104 dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
105 }
106
107 return 0;
108}
109
110static int vexpress_syscfg_read(void *context, unsigned int index,
111 unsigned int *val)
112{
113 struct vexpress_syscfg_func *func = context;
114
115 return vexpress_syscfg_exec(func, index, false, val);
116}
117
118static int vexpress_syscfg_write(void *context, unsigned int index,
119 unsigned int val)
120{
121 struct vexpress_syscfg_func *func = context;
122
123 return vexpress_syscfg_exec(func, index, true, &val);
124}
125
126static struct regmap_config vexpress_syscfg_regmap_config = {
127 .lock = vexpress_config_lock,
128 .unlock = vexpress_config_unlock,
129 .reg_bits = 32,
130 .val_bits = 32,
131 .reg_read = vexpress_syscfg_read,
132 .reg_write = vexpress_syscfg_write,
133 .reg_format_endian = REGMAP_ENDIAN_LITTLE,
134 .val_format_endian = REGMAP_ENDIAN_LITTLE,
135};
136
137
138static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
139 void *context)
140{
141 int err;
142 struct vexpress_syscfg *syscfg = context;
143 struct vexpress_syscfg_func *func;
144 struct property *prop;
145 const __be32 *val = NULL;
146 __be32 energy_quirk[4];
147 int num;
148 u32 site, position, dcc;
149 int i;
150
151 err = vexpress_config_get_topo(dev->of_node, &site,
152 &position, &dcc);
153 if (err)
154 return ERR_PTR(err);
155
156 prop = of_find_property(dev->of_node,
157 "arm,vexpress-sysreg,func", NULL);
158 if (!prop)
159 return ERR_PTR(-EINVAL);
160
161 num = prop->length / sizeof(u32) / 2;
162 val = prop->value;
163
164 /*
165 * "arm,vexpress-energy" function used to be described
166 * by its first device only, now it requires both
167 */
168 if (num == 1 && of_device_is_compatible(dev->of_node,
169 "arm,vexpress-energy")) {
170 num = 2;
171 energy_quirk[0] = *val;
172 energy_quirk[2] = *val++;
173 energy_quirk[1] = *val;
174 energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
175 val = energy_quirk;
176 }
177
178 func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
179 if (!func)
180 return ERR_PTR(-ENOMEM);
181
182 func->syscfg = syscfg;
183 func->num_templates = num;
184
185 for (i = 0; i < num; i++) {
186 u32 function, device;
187
188 function = be32_to_cpup(val++);
189 device = be32_to_cpup(val++);
190
191 dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
192 func, site, position, dcc,
193 function, device);
194
195 func->template[i] = SYS_CFGCTRL_DCC(dcc);
196 func->template[i] |= SYS_CFGCTRL_SITE(site);
197 func->template[i] |= SYS_CFGCTRL_POSITION(position);
198 func->template[i] |= SYS_CFGCTRL_FUNC(function);
199 func->template[i] |= SYS_CFGCTRL_DEVICE(device);
200 }
201
202 vexpress_syscfg_regmap_config.max_register = num - 1;
203
204 func->regmap = regmap_init(dev, NULL, func,
205 &vexpress_syscfg_regmap_config);
206
207 if (IS_ERR(func->regmap)) {
208 void *err = func->regmap;
209
210 kfree(func);
211 return err;
212 }
213
214 list_add(&func->list, &syscfg->funcs);
215
216 return func->regmap;
217}
218
219static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
220{
221 struct vexpress_syscfg *syscfg = context;
222 struct vexpress_syscfg_func *func, *tmp;
223
224 regmap_exit(regmap);
225
226 list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
227 if (func->regmap == regmap) {
228 list_del(&syscfg->funcs);
229 kfree(func);
230 break;
231 }
232 }
233}
234
235static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
236 .regmap_init = vexpress_syscfg_regmap_init,
237 .regmap_exit = vexpress_syscfg_regmap_exit,
238};
239
240
241static int vexpress_syscfg_probe(struct platform_device *pdev)
242{
243 struct vexpress_syscfg *syscfg;
244 struct resource *res;
245 struct device *bridge;
246
247 syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
248 if (!syscfg)
249 return -ENOMEM;
250 syscfg->dev = &pdev->dev;
251 INIT_LIST_HEAD(&syscfg->funcs);
252
253 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
254 syscfg->base = devm_ioremap_resource(&pdev->dev, res);
255 if (IS_ERR(syscfg->base))
256 return PTR_ERR(syscfg->base);
257
258 /* Must use dev.parent (MFD), as that's where DT phandle points at... */
259 bridge = vexpress_config_bridge_register(pdev->dev.parent,
260 &vexpress_syscfg_bridge_ops, syscfg);
261
262 return PTR_ERR_OR_ZERO(bridge);
263}
264
265static const struct platform_device_id vexpress_syscfg_id_table[] = {
266 { "vexpress-syscfg", },
267 {},
268};
269
270static struct platform_driver vexpress_syscfg_driver = {
271 .driver.name = "vexpress-syscfg",
272 .id_table = vexpress_syscfg_id_table,
273 .probe = vexpress_syscfg_probe,
274};
275
276static int __init vexpress_syscfg_init(void)
277{
278 return platform_driver_register(&vexpress_syscfg_driver);
279}
280core_initcall(vexpress_syscfg_init);