drivers/bus/vexpress-config.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *
0004  * Copyright (C) 2014 ARM Limited
0005  */
0006
0007 #include <linux/err.h>
0008 #include <linux/init.h>
0009 #include <linux/io.h>
0010 #include <linux/module.h>
0011 #include <linux/of.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/of_device.h>
0014 #include <linux/sched/signal.h>
0015 #include <linux/slab.h>
0016 #include <linux/vexpress.h>
0017
0018 #define SYS_MISC        0x0
0019 #define SYS_MISC_MASTERSITE (1 << 14)
0020
0021 #define SYS_PROCID0     0x24
0022 #define SYS_PROCID1     0x28
0023 #define SYS_HBI_MASK        0xfff
0024 #define SYS_PROCIDx_HBI_SHIFT   0
0025
0026 #define SYS_CFGDATA     0x40
0027
0028 #define SYS_CFGCTRL     0x44
0029 #define SYS_CFGCTRL_START   (1 << 31)
0030 #define SYS_CFGCTRL_WRITE   (1 << 30)
0031 #define SYS_CFGCTRL_DCC(n)  (((n) & 0xf) << 26)
0032 #define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20)
0033 #define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16)
0034 #define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12)
0035 #define SYS_CFGCTRL_DEVICE(n)   (((n) & 0xfff) << 0)
0036
0037 #define SYS_CFGSTAT     0x48
0038 #define SYS_CFGSTAT_ERR     (1 << 1)
0039 #define SYS_CFGSTAT_COMPLETE    (1 << 0)
0040
0041 #define VEXPRESS_SITE_MB        0
0042 #define VEXPRESS_SITE_DB1       1
0043 #define VEXPRESS_SITE_DB2       2
0044 #define VEXPRESS_SITE_MASTER        0xf
0045
0046 struct vexpress_syscfg {
0047     struct device *dev;
0048     void __iomem *base;
0049     struct list_head funcs;
0050 };
0051
0052 struct vexpress_syscfg_func {
0053     struct list_head list;
0054     struct vexpress_syscfg *syscfg;
0055     struct regmap *regmap;
0056     int num_templates;
0057     u32 template[]; /* Keep it last! */
0058 };
0059
0060 struct vexpress_config_bridge_ops {
0061     struct regmap * (*regmap_init)(struct device *dev, void *context);
0062     void (*regmap_exit)(struct regmap *regmap, void *context);
0063 };
0064
0065 struct vexpress_config_bridge {
0066     struct vexpress_config_bridge_ops *ops;
0067     void *context;
0068 };
0069
0070
0071 static DEFINE_MUTEX(vexpress_config_mutex);
0072 static u32 vexpress_config_site_master = VEXPRESS_SITE_MASTER;
0073
0074
0075 static void vexpress_config_set_master(u32 site)
0076 {
0077     vexpress_config_site_master = site;
0078 }
0079
0080 static void vexpress_config_lock(void *arg)
0081 {
0082     mutex_lock(&vexpress_config_mutex);
0083 }
0084
0085 static void vexpress_config_unlock(void *arg)
0086 {
0087     mutex_unlock(&vexpress_config_mutex);
0088 }
0089
0090
0091 static void vexpress_config_find_prop(struct device_node *node,
0092         const char *name, u32 *val)
0093 {
0094     /* Default value */
0095     *val = 0;
0096
0097     of_node_get(node);
0098     while (node) {
0099         if (of_property_read_u32(node, name, val) == 0) {
0100             of_node_put(node);
0101             return;
0102         }
0103         node = of_get_next_parent(node);
0104     }
0105 }
0106
0107 static int vexpress_config_get_topo(struct device_node *node, u32 *site,
0108         u32 *position, u32 *dcc)
0109 {
0110     vexpress_config_find_prop(node, "arm,vexpress,site", site);
0111     if (*site == VEXPRESS_SITE_MASTER)
0112         *site = vexpress_config_site_master;
0113     if (WARN_ON(vexpress_config_site_master == VEXPRESS_SITE_MASTER))
0114         return -EINVAL;
0115     vexpress_config_find_prop(node, "arm,vexpress,position", position);
0116     vexpress_config_find_prop(node, "arm,vexpress,dcc", dcc);
0117
0118     return 0;
0119 }
0120
0121
0122 static void vexpress_config_devres_release(struct device *dev, void *res)
0123 {
0124     struct vexpress_config_bridge *bridge = dev_get_drvdata(dev->parent);
0125     struct regmap *regmap = res;
0126
0127     bridge->ops->regmap_exit(regmap, bridge->context);
0128 }
0129
0130 struct regmap *devm_regmap_init_vexpress_config(struct device *dev)
0131 {
0132     struct vexpress_config_bridge *bridge;
0133     struct regmap *regmap;
0134     struct regmap **res;
0135
0136     bridge = dev_get_drvdata(dev->parent);
0137     if (WARN_ON(!bridge))
0138         return ERR_PTR(-EINVAL);
0139
0140     res = devres_alloc(vexpress_config_devres_release, sizeof(*res),
0141             GFP_KERNEL);
0142     if (!res)
0143         return ERR_PTR(-ENOMEM);
0144
0145     regmap = (bridge->ops->regmap_init)(dev, bridge->context);
0146     if (IS_ERR(regmap)) {
0147         devres_free(res);
0148         return regmap;
0149     }
0150
0151     *res = regmap;
0152     devres_add(dev, res);
0153
0154     return regmap;
0155 }
0156 EXPORT_SYMBOL_GPL(devm_regmap_init_vexpress_config);
0157
0158 static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func,
0159         int index, bool write, u32 *data)
0160 {
0161     struct vexpress_syscfg *syscfg = func->syscfg;
0162     u32 command, status;
0163     int tries;
0164     long timeout;
0165
0166     if (WARN_ON(index >= func->num_templates))
0167         return -EINVAL;
0168
0169     command = readl(syscfg->base + SYS_CFGCTRL);
0170     if (WARN_ON(command & SYS_CFGCTRL_START))
0171         return -EBUSY;
0172
0173     command = func->template[index];
0174     command |= SYS_CFGCTRL_START;
0175     command |= write ? SYS_CFGCTRL_WRITE : 0;
0176
0177     /* Use a canary for reads */
0178     if (!write)
0179         *data = 0xdeadbeef;
0180
0181     dev_dbg(syscfg->dev, "func %p, command %x, data %x\n",
0182             func, command, *data);
0183     writel(*data, syscfg->base + SYS_CFGDATA);
0184     writel(0, syscfg->base + SYS_CFGSTAT);
0185     writel(command, syscfg->base + SYS_CFGCTRL);
0186     mb();
0187
0188     /* The operation can take ages... Go to sleep, 100us initially */
0189     tries = 100;
0190     timeout = 100;
0191     do {
0192         if (!irqs_disabled()) {
0193             set_current_state(TASK_INTERRUPTIBLE);
0194             schedule_timeout(usecs_to_jiffies(timeout));
0195             if (signal_pending(current))
0196                 return -EINTR;
0197         } else {
0198             udelay(timeout);
0199         }
0200
0201         status = readl(syscfg->base + SYS_CFGSTAT);
0202         if (status & SYS_CFGSTAT_ERR)
0203             return -EFAULT;
0204
0205         if (timeout > 20)
0206             timeout -= 20;
0207     } while (--tries && !(status & SYS_CFGSTAT_COMPLETE));
0208     if (WARN_ON_ONCE(!tries))
0209         return -ETIMEDOUT;
0210
0211     if (!write) {
0212         *data = readl(syscfg->base + SYS_CFGDATA);
0213         dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data);
0214     }
0215
0216     return 0;
0217 }
0218
0219 static int vexpress_syscfg_read(void *context, unsigned int index,
0220         unsigned int *val)
0221 {
0222     struct vexpress_syscfg_func *func = context;
0223
0224     return vexpress_syscfg_exec(func, index, false, val);
0225 }
0226
0227 static int vexpress_syscfg_write(void *context, unsigned int index,
0228         unsigned int val)
0229 {
0230     struct vexpress_syscfg_func *func = context;
0231
0232     return vexpress_syscfg_exec(func, index, true, &val);
0233 }
0234
0235 static struct regmap_config vexpress_syscfg_regmap_config = {
0236     .lock = vexpress_config_lock,
0237     .unlock = vexpress_config_unlock,
0238     .reg_bits = 32,
0239     .val_bits = 32,
0240     .reg_read = vexpress_syscfg_read,
0241     .reg_write = vexpress_syscfg_write,
0242     .reg_format_endian = REGMAP_ENDIAN_LITTLE,
0243     .val_format_endian = REGMAP_ENDIAN_LITTLE,
0244 };
0245
0246
0247 static struct regmap *vexpress_syscfg_regmap_init(struct device *dev,
0248         void *context)
0249 {
0250     int err;
0251     struct vexpress_syscfg *syscfg = context;
0252     struct vexpress_syscfg_func *func;
0253     struct property *prop;
0254     const __be32 *val = NULL;
0255     __be32 energy_quirk[4];
0256     int num;
0257     u32 site, position, dcc;
0258     int i;
0259
0260     err = vexpress_config_get_topo(dev->of_node, &site,
0261                 &position, &dcc);
0262     if (err)
0263         return ERR_PTR(err);
0264
0265     prop = of_find_property(dev->of_node,
0266             "arm,vexpress-sysreg,func", NULL);
0267     if (!prop)
0268         return ERR_PTR(-EINVAL);
0269
0270     num = prop->length / sizeof(u32) / 2;
0271     val = prop->value;
0272
0273     /*
0274      * "arm,vexpress-energy" function used to be described
0275      * by its first device only, now it requires both
0276      */
0277     if (num == 1 && of_device_is_compatible(dev->of_node,
0278             "arm,vexpress-energy")) {
0279         num = 2;
0280         energy_quirk[0] = *val;
0281         energy_quirk[2] = *val++;
0282         energy_quirk[1] = *val;
0283         energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1);
0284         val = energy_quirk;
0285     }
0286
0287     func = kzalloc(struct_size(func, template, num), GFP_KERNEL);
0288     if (!func)
0289         return ERR_PTR(-ENOMEM);
0290
0291     func->syscfg = syscfg;
0292     func->num_templates = num;
0293
0294     for (i = 0; i < num; i++) {
0295         u32 function, device;
0296
0297         function = be32_to_cpup(val++);
0298         device = be32_to_cpup(val++);
0299
0300         dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n",
0301                 func, site, position, dcc,
0302                 function, device);
0303
0304         func->template[i] = SYS_CFGCTRL_DCC(dcc);
0305         func->template[i] |= SYS_CFGCTRL_SITE(site);
0306         func->template[i] |= SYS_CFGCTRL_POSITION(position);
0307         func->template[i] |= SYS_CFGCTRL_FUNC(function);
0308         func->template[i] |= SYS_CFGCTRL_DEVICE(device);
0309     }
0310
0311     vexpress_syscfg_regmap_config.max_register = num - 1;
0312
0313     func->regmap = regmap_init(dev, NULL, func,
0314             &vexpress_syscfg_regmap_config);
0315
0316     if (IS_ERR(func->regmap)) {
0317         void *err = func->regmap;
0318
0319         kfree(func);
0320         return err;
0321     }
0322
0323     list_add(&func->list, &syscfg->funcs);
0324
0325     return func->regmap;
0326 }
0327
0328 static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context)
0329 {
0330     struct vexpress_syscfg *syscfg = context;
0331     struct vexpress_syscfg_func *func, *tmp;
0332
0333     regmap_exit(regmap);
0334
0335     list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) {
0336         if (func->regmap == regmap) {
0337             list_del(&syscfg->funcs);
0338             kfree(func);
0339             break;
0340         }
0341     }
0342 }
0343
0344 static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = {
0345     .regmap_init = vexpress_syscfg_regmap_init,
0346     .regmap_exit = vexpress_syscfg_regmap_exit,
0347 };
0348
0349
0350 static int vexpress_syscfg_probe(struct platform_device *pdev)
0351 {
0352     struct vexpress_syscfg *syscfg;
0353     struct resource *res;
0354     struct vexpress_config_bridge *bridge;
0355     struct device_node *node;
0356     int master;
0357     u32 dt_hbi;
0358
0359     syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL);
0360     if (!syscfg)
0361         return -ENOMEM;
0362     syscfg->dev = &pdev->dev;
0363     INIT_LIST_HEAD(&syscfg->funcs);
0364
0365     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0366     syscfg->base = devm_ioremap_resource(&pdev->dev, res);
0367     if (IS_ERR(syscfg->base))
0368         return PTR_ERR(syscfg->base);
0369
0370     bridge = devm_kmalloc(&pdev->dev, sizeof(*bridge), GFP_KERNEL);
0371     if (!bridge)
0372         return -ENOMEM;
0373
0374     bridge->ops = &vexpress_syscfg_bridge_ops;
0375     bridge->context = syscfg;
0376
0377     dev_set_drvdata(&pdev->dev, bridge);
0378
0379     master = readl(syscfg->base + SYS_MISC) & SYS_MISC_MASTERSITE ?
0380             VEXPRESS_SITE_DB2 : VEXPRESS_SITE_DB1;
0381     vexpress_config_set_master(master);
0382
0383     /* Confirm board type against DT property, if available */
0384     if (of_property_read_u32(of_root, "arm,hbi", &dt_hbi) == 0) {
0385         u32 id = readl(syscfg->base + (master == VEXPRESS_SITE_DB1 ?
0386                  SYS_PROCID0 : SYS_PROCID1));
0387         u32 hbi = (id >> SYS_PROCIDx_HBI_SHIFT) & SYS_HBI_MASK;
0388
0389         if (WARN_ON(dt_hbi != hbi))
0390             dev_warn(&pdev->dev, "DT HBI (%x) is not matching hardware (%x)!\n",
0391                     dt_hbi, hbi);
0392     }
0393
0394     for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
0395         struct device_node *bridge_np;
0396
0397         bridge_np = of_parse_phandle(node, "arm,vexpress,config-bridge", 0);
0398         if (bridge_np != pdev->dev.parent->of_node)
0399             continue;
0400
0401         of_platform_populate(node, NULL, NULL, &pdev->dev);
0402     }
0403
0404     return 0;
0405 }
0406
0407 static const struct platform_device_id vexpress_syscfg_id_table[] = {
0408     { "vexpress-syscfg", },
0409     {},
0410 };
0411 MODULE_DEVICE_TABLE(platform, vexpress_syscfg_id_table);
0412
0413 static struct platform_driver vexpress_syscfg_driver = {
0414     .driver.name = "vexpress-syscfg",
0415     .id_table = vexpress_syscfg_id_table,
0416     .probe = vexpress_syscfg_probe,
0417 };
0418 module_platform_driver(vexpress_syscfg_driver);
0419 MODULE_LICENSE("GPL v2");