drivers/bus/vexpress-config.c

   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
  46 struct vexpress_syscfg {
  47         struct device *dev;
  48         void __iomem *base;
  49         struct list_head funcs;
  50 };
  51
  52 struct vexpress_syscfg_func {
  53         struct list_head list;
  54         struct vexpress_syscfg *syscfg;
  55         struct regmap *regmap;
  56         int num_templates;
  57         u32 template[]; /* Keep it last! */
  58 };
  59
  60 struct 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
  65 struct vexpress_config_bridge {
  66         struct vexpress_config_bridge_ops *ops;
  67         void *context;
  68 };
  69
  70
  71 static DEFINE_MUTEX(vexpress_config_mutex);
  72 static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
  73
  74
  75 static void vexpress_config_set_master(u32 site)
  76 {
  77         vexpress_config_site_master = site;
  78 }
  79
  80 static void vexpress_config_lock(void *arg)
  81 {
  82         mutex_lock(&vexpress_config_mutex);
  83 }
  84
  85 static void vexpress_config_unlock(void *arg)
  86 {
  87         mutex_unlock(&vexpress_config_mutex);
  88 }
  89
  90
  91 static 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
 107 static 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
 122 static 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
 130 struct 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 }
 156 EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
 157
 158 static 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
 219 static 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
 227 static 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
 235 static 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
 247 static 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
 328 static 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
 344 static 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
 350 static 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
 405 static const struct platform_device_id vexpress_syscfg_id_table[] = {
 406         { "vexpress-syscfg", },
 407         {},
 408 };
 409 MODULE_DEVICE_TABLE(platform, vexpress_syscfg_id_table);
 410
 411 static struct platform_driver vexpress_syscfg_driver = {
 412         .driver.name = "vexpress-syscfg",
 413         .id_table = vexpress_syscfg_id_table,
 414         .probe = vexpress_syscfg_probe,
 415 };
 416 module_platform_driver(vexpress_syscfg_driver);
 417 MODULE_LICENSE("GPL v2");