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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 2014 ARM Limited
5 */
6
7#include <linux/err.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/of_platform.h>
14#include <linux/sched/signal.h>
15#include <linux/slab.h>
16#include <linux/vexpress.h>
17
18#define SYS_MISC 0x0
19#define SYS_MISC_MASTERSITE (1 << 14)
20
21#define SYS_PROCID0 0x24
22#define SYS_PROCID1 0x28
23#define SYS_HBI_MASK 0xfff
24#define SYS_PROCIDx_HBI_SHIFT 0
25
26#define SYS_CFGDATA 0x40
27
28#define SYS_CFGCTRL 0x44
29#define SYS_CFGCTRL_START (1 << 31)
30#define SYS_CFGCTRL_WRITE (1 << 30)
31#define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26)
32#define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
33#define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
34#define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
35#define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0)
36
37#define SYS_CFGSTAT 0x48
38#define SYS_CFGSTAT_ERR (1 << 1)
39#define SYS_CFGSTAT_COMPLETE (1 << 0)
40
41#define VEXPRESS_SITE_MB 0
42#define VEXPRESS_SITE_DB1 1
43#define VEXPRESS_SITE_DB2 2
44#define VEXPRESS_SITE_MASTER 0xf
45
46struct vexpress_syscfg {
47 struct device *dev;
48 void __iomem *base;
49 struct list_head funcs;
50};
51
52struct vexpress_syscfg_func {
53 struct list_head list;
54 struct vexpress_syscfg *syscfg;
55 struct regmap *regmap;
56 int num_templates;
57 u32 template[] __counted_by(num_templates); /* Keep it last! */
58};
59
60struct vexpress_config_bridge_ops {
61 struct regmap * (*regmap_init)(struct device *dev, void *context);
62 void (*regmap_exit)(struct regmap *regmap, void *context);
63};
64
65struct vexpress_config_bridge {
66 struct vexpress_config_bridge_ops *ops;
67 void *context;
68};
69
70
71static DEFINE_MUTEX(vexpress_config_mutex);
72static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
73
74
75static void vexpress_config_set_master(u32 site)
76{
77 vexpress_config_site_master = site;
78}
79
80static void vexpress_config_lock(void *arg)
81{
82 mutex_lock(&vexpress_config_mutex);
83}
84
85static void vexpress_config_unlock(void *arg)
86{
87 mutex_unlock(&vexpress_config_mutex);
88}
89
90
91static void vexpress_config_find_prop(struct device_node *node,
92 const char *name, u32 *val)
93{
94 /* Default value */
95 *val = 0;
96
97 of_node_get(node);
98 while (node) {
99 if (of_property_read_u32(node, name, val) == 0) {
100 of_node_put(node);
101 return;
102 }
103 node = of_get_next_parent(node);
104 }
105}
106
107static int vexpress_config_get_topo(struct device_node *node, u32 *site,
108 u32 *position, u32 *dcc)
109{
110 vexpress_config_find_prop(node, "arm,vexpress,site", site);
111 if (*site == VEXPRESS_SITE_MASTER)
112 *site = vexpress_config_site_master;
113 if (WARN_ON(vexpress_config_site_master == VEXPRESS_SITE_MASTER))
114 return -EINVAL;
115 vexpress_config_find_prop(node, "arm,vexpress,position", position);
116 vexpress_config_find_prop(node, "arm,vexpress,dcc", dcc);
117
118 return 0;
119}
120
121
122static void vexpress_config_devres_release(struct device *dev, void *res)
123{
124 struct vexpress_config_bridge *bridge = dev_get_drvdata(dev->parent);
125 struct regmap *regmap = res;
126
127 bridge->ops->regmap_exit(regmap, bridge->context);
128}
129
130struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
131{
132 struct vexpress_config_bridge *bridge;
133 struct regmap *regmap;
134 struct regmap **res;
135
136 bridge = dev_get_drvdata(dev->parent);
137 if (WARN_ON(!bridge))
138 return ERR_PTR(-EINVAL);
139
140 res = devres_alloc(vexpress_config_devres_release, sizeof(*res),
141 GFP_KERNEL);
142 if (!res)
143 return ERR_PTR(-ENOMEM);
144
145 regmap = (bridge->ops->regmap_init)(dev, bridge->context);
146 if (IS_ERR(regmap)) {
147 devres_free(res);
148 return regmap;
149 }
150
151 *res = regmap;
152 devres_add(dev, res);
153
154 return regmap;
155}
156EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
157
158static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
159 int index, bool write, u32 *data)
160{
161 struct vexpress_syscfg *syscfg = func->syscfg;
162 u32 command, status;
163 int tries;
164 long timeout;
165
166 if (WARN_ON(index >= func->num_templates))
167 return -EINVAL;
168
169 command = readl(syscfg->base + SYS_CFGCTRL);
170 if (WARN_ON(command & SYS_CFGCTRL_START))
171 return -EBUSY;
172
173 command = func->template[index];
174 command |= SYS_CFGCTRL_START;
175 command |= write ? SYS_CFGCTRL_WRITE : 0;
176
177 /* Use a canary for reads */
178 if (!write)
179 *data = 0xdeadbeef;
180
181 dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
182 func, command, *data);
183 writel(*data, syscfg->base + SYS_CFGDATA);
184 writel(0, syscfg->base + SYS_CFGSTAT);
185 writel(command, syscfg->base + SYS_CFGCTRL);
186 mb();
187
188 /* The operation can take ages... Go to sleep, 100us initially */
189 tries = 100;
190 timeout = 100;
191 do {
192 if (!irqs_disabled()) {
193 set_current_state(TASK_INTERRUPTIBLE);
194 schedule_timeout(usecs_to_jiffies(timeout));
195 if (signal_pending(current))
196 return -EINTR;
197 } else {
198 udelay(timeout);
199 }
200
201 status = readl(syscfg->base + SYS_CFGSTAT);
202 if (status & SYS_CFGSTAT_ERR)
203 return -EFAULT;
204
205 if (timeout > 20)
206 timeout -= 20;
207 } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
208 if (WARN_ON_ONCE(!tries))
209 return -ETIMEDOUT;
210
211 if (!write) {
212 *data = readl(syscfg->base + SYS_CFGDATA);
213 dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
214 }
215
216 return 0;
217}
218
219static int vexpress_syscfg_read(void *context, unsigned int index,
220 unsigned int *val)
221{
222 struct vexpress_syscfg_func *func = context;
223
224 return vexpress_syscfg_exec(func, index, false, val);
225}
226
227static int vexpress_syscfg_write(void *context, unsigned int index,
228 unsigned int val)
229{
230 struct vexpress_syscfg_func *func = context;
231
232 return vexpress_syscfg_exec(func, index, true, &val);
233}
234
235static struct regmap_config vexpress_syscfg_regmap_config = {
236 .lock = vexpress_config_lock,
237 .unlock = vexpress_config_unlock,
238 .reg_bits = 32,
239 .val_bits = 32,
240 .reg_read = vexpress_syscfg_read,
241 .reg_write = vexpress_syscfg_write,
242 .reg_format_endian = REGMAP_ENDIAN_LITTLE,
243 .val_format_endian = REGMAP_ENDIAN_LITTLE,
244};
245
246
247static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
248 void *context)
249{
250 int err;
251 struct vexpress_syscfg *syscfg = context;
252 struct vexpress_syscfg_func *func;
253 struct property *prop;
254 const __be32 *val = NULL;
255 __be32 energy_quirk[4];
256 int num;
257 u32 site, position, dcc;
258 int i;
259
260 err = vexpress_config_get_topo(dev->of_node, &site,
261 &position, &dcc);
262 if (err)
263 return ERR_PTR(err);
264
265 prop = of_find_property(dev->of_node,
266 "arm,vexpress-sysreg,func", NULL);
267 if (!prop)
268 return ERR_PTR(-EINVAL);
269
270 num = prop->length / sizeof(u32) / 2;
271 val = prop->value;
272
273 /*
274 * "arm,vexpress-energy" function used to be described
275 * by its first device only, now it requires both
276 */
277 if (num == 1 && of_device_is_compatible(dev->of_node,
278 "arm,vexpress-energy")) {
279 num = 2;
280 energy_quirk[0] = *val;
281 energy_quirk[2] = *val++;
282 energy_quirk[1] = *val;
283 energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
284 val = energy_quirk;
285 }
286
287 func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
288 if (!func)
289 return ERR_PTR(-ENOMEM);
290
291 func->syscfg = syscfg;
292 func->num_templates = num;
293
294 for (i = 0; i < num; i++) {
295 u32 function, device;
296
297 function = be32_to_cpup(val++);
298 device = be32_to_cpup(val++);
299
300 dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
301 func, site, position, dcc,
302 function, device);
303
304 func->template[i] = SYS_CFGCTRL_DCC(dcc);
305 func->template[i] |= SYS_CFGCTRL_SITE(site);
306 func->template[i] |= SYS_CFGCTRL_POSITION(position);
307 func->template[i] |= SYS_CFGCTRL_FUNC(function);
308 func->template[i] |= SYS_CFGCTRL_DEVICE(device);
309 }
310
311 vexpress_syscfg_regmap_config.max_register = num - 1;
312
313 func->regmap = regmap_init(dev, NULL, func,
314 &vexpress_syscfg_regmap_config);
315
316 if (IS_ERR(func->regmap)) {
317 void *err = func->regmap;
318
319 kfree(func);
320 return err;
321 }
322
323 list_add(&func->list, &syscfg->funcs);
324
325 return func->regmap;
326}
327
328static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
329{
330 struct vexpress_syscfg *syscfg = context;
331 struct vexpress_syscfg_func *func, *tmp;
332
333 regmap_exit(regmap);
334
335 list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
336 if (func->regmap == regmap) {
337 list_del(&syscfg->funcs);
338 kfree(func);
339 break;
340 }
341 }
342}
343
344static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
345 .regmap_init = vexpress_syscfg_regmap_init,
346 .regmap_exit = vexpress_syscfg_regmap_exit,
347};
348
349
350static int vexpress_syscfg_probe(struct platform_device *pdev)
351{
352 struct vexpress_syscfg *syscfg;
353 struct vexpress_config_bridge *bridge;
354 struct device_node *node;
355 int master;
356 u32 dt_hbi;
357
358 syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
359 if (!syscfg)
360 return -ENOMEM;
361 syscfg->dev = &pdev->dev;
362 INIT_LIST_HEAD(&syscfg->funcs);
363
364 syscfg->base = devm_platform_ioremap_resource(pdev, 0);
365 if (IS_ERR(syscfg->base))
366 return PTR_ERR(syscfg->base);
367
368 bridge = devm_kmalloc(&pdev->dev, sizeof(*bridge), GFP_KERNEL);
369 if (!bridge)
370 return -ENOMEM;
371
372 bridge->ops = &vexpress_syscfg_bridge_ops;
373 bridge->context = syscfg;
374
375 dev_set_drvdata(&pdev->dev, bridge);
376
377 master = readl(syscfg->base + SYS_MISC) & SYS_MISC_MASTERSITE ?
378 VEXPRESS_SITE_DB2 : VEXPRESS_SITE_DB1;
379 vexpress_config_set_master(master);
380
381 /* Confirm board type against DT property, if available */
382 if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) {
383 u32 id = readl(syscfg->base + (master == VEXPRESS_SITE_DB1 ?
384 SYS_PROCID0 : SYS_PROCID1));
385 u32 hbi = (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
386
387 if (WARN_ON(dt_hbi != hbi))
388 dev_warn(&pdev->dev, "DT HBI (%x) is not matching hardware (%x)!\n",
389 dt_hbi, hbi);
390 }
391
392 for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
393 struct device_node *bridge_np;
394
395 bridge_np = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);
396 if (bridge_np != pdev->dev.parent->of_node)
397 continue;
398
399 of_platform_populate(node, NULL, NULL, &pdev->dev);
400 }
401
402 return 0;
403}
404
405static const struct platform_device_id vexpress_syscfg_id_table[] = {
406 { "vexpress-syscfg", },
407 {},
408};
409MODULE_DEVICE_TABLE(platform, vexpress_syscfg_id_table);
410
411static struct platform_driver vexpress_syscfg_driver = {
412 .driver.name = "vexpress-syscfg",
413 .id_table = vexpress_syscfg_id_table,
414 .probe = vexpress_syscfg_probe,
415};
416module_platform_driver(vexpress_syscfg_driver);
417MODULE_DESCRIPTION("Versatile Express configuration bus");
418MODULE_LICENSE("GPL v2");