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1// SPDX-License-Identifier: GPL-2.0-only2/*3 *4 * Copyright (C) 2014 ARM Limited5 */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 0x019#define SYS_MISC_MASTERSITE (1 << 14)20 21#define SYS_PROCID0 0x2422#define SYS_PROCID1 0x2823#define SYS_HBI_MASK 0xfff24#define SYS_PROCIDx_HBI_SHIFT 025 26#define SYS_CFGDATA 0x4027 28#define SYS_CFGCTRL 0x4429#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 0x4838#define SYS_CFGSTAT_ERR (1 << 1)39#define SYS_CFGSTAT_COMPLETE (1 << 0)40 41#define VEXPRESS_SITE_MB 042#define VEXPRESS_SITE_DB1 143#define VEXPRESS_SITE_DB2 244#define VEXPRESS_SITE_MASTER 0xf45 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 described275 * by its first device only, now it requires both276 */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");419