drivers/hwtracing/coresight/coresight-tmc.c

   1 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
   2  *
   3  * Description: CoreSight Trace Memory Controller driver
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 and
   7  * only version 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/types.h>
  18 #include <linux/device.h>
  19 #include <linux/io.h>
  20 #include <linux/err.h>
  21 #include <linux/fs.h>
  22 #include <linux/miscdevice.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/slab.h>
  25 #include <linux/dma-mapping.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/of.h>
  29 #include <linux/coresight.h>
  30 #include <linux/amba/bus.h>
  31
  32 #include "coresight-priv.h"
  33 #include "coresight-tmc.h"
  34
  35 void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata)
  36 {
  37         /* Ensure formatter, unformatter and hardware fifo are empty */
  38         if (coresight_timeout(drvdata->base,
  39                               TMC_STS, TMC_STS_TMCREADY_BIT, 1)) {
  40                 dev_err(drvdata->dev,
  41                         "timeout observed when probing at offset %#x\n",
  42                         TMC_STS);
  43         }
  44 }
  45
  46 void tmc_flush_and_stop(struct tmc_drvdata *drvdata)
  47 {
  48         u32 ffcr;
  49
  50         ffcr = readl_relaxed(drvdata->base + TMC_FFCR);
  51         ffcr |= TMC_FFCR_STOP_ON_FLUSH;
  52         writel_relaxed(ffcr, drvdata->base + TMC_FFCR);
  53         ffcr |= BIT(TMC_FFCR_FLUSHMAN_BIT);
  54         writel_relaxed(ffcr, drvdata->base + TMC_FFCR);
  55         /* Ensure flush completes */
  56         if (coresight_timeout(drvdata->base,
  57                               TMC_FFCR, TMC_FFCR_FLUSHMAN_BIT, 0)) {
  58                 dev_err(drvdata->dev,
  59                         "timeout observed when probing at offset %#x\n",
  60                         TMC_FFCR);
  61         }
  62
  63         tmc_wait_for_tmcready(drvdata);
  64 }
  65
  66 void tmc_enable_hw(struct tmc_drvdata *drvdata)
  67 {
  68         writel_relaxed(TMC_CTL_CAPT_EN, drvdata->base + TMC_CTL);
  69 }
  70
  71 void tmc_disable_hw(struct tmc_drvdata *drvdata)
  72 {
  73         writel_relaxed(0x0, drvdata->base + TMC_CTL);
  74 }
  75
  76 static int tmc_read_prepare(struct tmc_drvdata *drvdata)
  77 {
  78         int ret = 0;
  79         unsigned long flags;
  80         enum tmc_mode mode;
  81
  82         spin_lock_irqsave(&drvdata->spinlock, flags);
  83         if (!drvdata->enable)
  84                 goto out;
  85
  86         switch (drvdata->config_type) {
  87         case TMC_CONFIG_TYPE_ETB:
  88                 tmc_etb_disable_hw(drvdata);
  89                 break;
  90         case TMC_CONFIG_TYPE_ETF:
  91                 /* There is no point in reading a TMC in HW FIFO mode */
  92                 mode = readl_relaxed(drvdata->base + TMC_MODE);
  93                 if (mode != TMC_MODE_CIRCULAR_BUFFER) {
  94                         ret = -EINVAL;
  95                         goto err;
  96                 }
  97
  98                 tmc_etb_disable_hw(drvdata);
  99                 break;
 100         case TMC_CONFIG_TYPE_ETR:
 101                 tmc_etr_disable_hw(drvdata);
 102                 break;
 103         default:
 104                 ret = -EINVAL;
 105                 goto err;
 106         }
 107
 108 out:
 109         drvdata->reading = true;
 110         dev_info(drvdata->dev, "TMC read start\n");
 111 err:
 112         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 113         return ret;
 114 }
 115
 116 static void tmc_read_unprepare(struct tmc_drvdata *drvdata)
 117 {
 118         unsigned long flags;
 119         enum tmc_mode mode;
 120
 121         spin_lock_irqsave(&drvdata->spinlock, flags);
 122         if (!drvdata->enable)
 123                 goto out;
 124
 125         switch (drvdata->config_type) {
 126         case TMC_CONFIG_TYPE_ETB:
 127                 tmc_etb_enable_hw(drvdata);
 128                 break;
 129         case TMC_CONFIG_TYPE_ETF:
 130                 /* Make sure we don't re-enable a TMC in HW FIFO mode */
 131                 mode = readl_relaxed(drvdata->base + TMC_MODE);
 132                 if (mode != TMC_MODE_CIRCULAR_BUFFER)
 133                         goto err;
 134
 135                 tmc_etb_enable_hw(drvdata);
 136                 break;
 137         case TMC_CONFIG_TYPE_ETR:
 138                 tmc_etr_disable_hw(drvdata);
 139                 break;
 140         default:
 141                 goto err;
 142         }
 143
 144 out:
 145         drvdata->reading = false;
 146         dev_info(drvdata->dev, "TMC read end\n");
 147 err:
 148         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 149 }
 150
 151 static int tmc_open(struct inode *inode, struct file *file)
 152 {
 153         struct tmc_drvdata *drvdata = container_of(file->private_data,
 154                                                    struct tmc_drvdata, miscdev);
 155         int ret = 0;
 156
 157         if (drvdata->read_count++)
 158                 goto out;
 159
 160         ret = tmc_read_prepare(drvdata);
 161         if (ret)
 162                 return ret;
 163 out:
 164         nonseekable_open(inode, file);
 165
 166         dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
 167         return 0;
 168 }
 169
 170 static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
 171                         loff_t *ppos)
 172 {
 173         struct tmc_drvdata *drvdata = container_of(file->private_data,
 174                                                    struct tmc_drvdata, miscdev);
 175         char *bufp = drvdata->buf + *ppos;
 176
 177         if (*ppos + len > drvdata->size)
 178                 len = drvdata->size - *ppos;
 179
 180         if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
 181                 if (bufp == (char *)(drvdata->vaddr + drvdata->size))
 182                         bufp = drvdata->vaddr;
 183                 else if (bufp > (char *)(drvdata->vaddr + drvdata->size))
 184                         bufp -= drvdata->size;
 185                 if ((bufp + len) > (char *)(drvdata->vaddr + drvdata->size))
 186                         len = (char *)(drvdata->vaddr + drvdata->size) - bufp;
 187         }
 188
 189         if (copy_to_user(data, bufp, len)) {
 190                 dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
 191                 return -EFAULT;
 192         }
 193
 194         *ppos += len;
 195
 196         dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
 197                 __func__, len, (int)(drvdata->size - *ppos));
 198         return len;
 199 }
 200
 201 static int tmc_release(struct inode *inode, struct file *file)
 202 {
 203         struct tmc_drvdata *drvdata = container_of(file->private_data,
 204                                                    struct tmc_drvdata, miscdev);
 205
 206         if (--drvdata->read_count) {
 207                 if (drvdata->read_count < 0) {
 208                         dev_err(drvdata->dev, "mismatched close\n");
 209                         drvdata->read_count = 0;
 210                 }
 211                 goto out;
 212         }
 213
 214         tmc_read_unprepare(drvdata);
 215 out:
 216         dev_dbg(drvdata->dev, "%s: released\n", __func__);
 217         return 0;
 218 }
 219
 220 static const struct file_operations tmc_fops = {
 221         .owner          = THIS_MODULE,
 222         .open           = tmc_open,
 223         .read           = tmc_read,
 224         .release        = tmc_release,
 225         .llseek         = no_llseek,
 226 };
 227
 228 #define coresight_tmc_simple_func(name, offset)                 \
 229         coresight_simple_func(struct tmc_drvdata, name, offset)
 230
 231 coresight_tmc_simple_func(rsz, TMC_RSZ);
 232 coresight_tmc_simple_func(sts, TMC_STS);
 233 coresight_tmc_simple_func(rrp, TMC_RRP);
 234 coresight_tmc_simple_func(rwp, TMC_RWP);
 235 coresight_tmc_simple_func(trg, TMC_TRG);
 236 coresight_tmc_simple_func(ctl, TMC_CTL);
 237 coresight_tmc_simple_func(ffsr, TMC_FFSR);
 238 coresight_tmc_simple_func(ffcr, TMC_FFCR);
 239 coresight_tmc_simple_func(mode, TMC_MODE);
 240 coresight_tmc_simple_func(pscr, TMC_PSCR);
 241 coresight_tmc_simple_func(devid, CORESIGHT_DEVID);
 242
 243 static struct attribute *coresight_tmc_mgmt_attrs[] = {
 244         &dev_attr_rsz.attr,
 245         &dev_attr_sts.attr,
 246         &dev_attr_rrp.attr,
 247         &dev_attr_rwp.attr,
 248         &dev_attr_trg.attr,
 249         &dev_attr_ctl.attr,
 250         &dev_attr_ffsr.attr,
 251         &dev_attr_ffcr.attr,
 252         &dev_attr_mode.attr,
 253         &dev_attr_pscr.attr,
 254         &dev_attr_devid.attr,
 255         NULL,
 256 };
 257
 258 ssize_t trigger_cntr_show(struct device *dev,
 259                           struct device_attribute *attr, char *buf)
 260 {
 261         struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent);
 262         unsigned long val = drvdata->trigger_cntr;
 263
 264         return sprintf(buf, "%#lx\n", val);
 265 }
 266
 267 static ssize_t trigger_cntr_store(struct device *dev,
 268                              struct device_attribute *attr,
 269                              const char *buf, size_t size)
 270 {
 271         int ret;
 272         unsigned long val;
 273         struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent);
 274
 275         ret = kstrtoul(buf, 16, &val);
 276         if (ret)
 277                 return ret;
 278
 279         drvdata->trigger_cntr = val;
 280         return size;
 281 }
 282 static DEVICE_ATTR_RW(trigger_cntr);
 283
 284 static struct attribute *coresight_tmc_attrs[] = {
 285         &dev_attr_trigger_cntr.attr,
 286         NULL,
 287 };
 288
 289 static const struct attribute_group coresight_tmc_group = {
 290         .attrs = coresight_tmc_attrs,
 291 };
 292
 293 static const struct attribute_group coresight_tmc_mgmt_group = {
 294         .attrs = coresight_tmc_mgmt_attrs,
 295         .name = "mgmt",
 296 };
 297
 298 const struct attribute_group *coresight_tmc_groups[] = {
 299         &coresight_tmc_group,
 300         &coresight_tmc_mgmt_group,
 301         NULL,
 302 };
 303
 304 static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 305 {
 306         int ret = 0;
 307         u32 devid;
 308         void __iomem *base;
 309         struct device *dev = &adev->dev;
 310         struct coresight_platform_data *pdata = NULL;
 311         struct tmc_drvdata *drvdata;
 312         struct resource *res = &adev->res;
 313         struct coresight_desc *desc;
 314         struct device_node *np = adev->dev.of_node;
 315
 316         if (np) {
 317                 pdata = of_get_coresight_platform_data(dev, np);
 318                 if (IS_ERR(pdata))
 319                         return PTR_ERR(pdata);
 320                 adev->dev.platform_data = pdata;
 321         }
 322
 323         drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 324         if (!drvdata)
 325                 return -ENOMEM;
 326
 327         drvdata->dev = &adev->dev;
 328         dev_set_drvdata(dev, drvdata);
 329
 330         /* Validity for the resource is already checked by the AMBA core */
 331         base = devm_ioremap_resource(dev, res);
 332         if (IS_ERR(base))
 333                 return PTR_ERR(base);
 334
 335         drvdata->base = base;
 336
 337         spin_lock_init(&drvdata->spinlock);
 338
 339         devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
 340         drvdata->config_type = BMVAL(devid, 6, 7);
 341
 342         if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
 343                 if (np)
 344                         ret = of_property_read_u32(np,
 345                                                    "arm,buffer-size",
 346                                                    &drvdata->size);
 347                 if (ret)
 348                         drvdata->size = SZ_1M;
 349         } else {
 350                 drvdata->size = readl_relaxed(drvdata->base + TMC_RSZ) * 4;
 351         }
 352
 353         pm_runtime_put(&adev->dev);
 354
 355         if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
 356                 drvdata->vaddr = dma_alloc_coherent(dev, drvdata->size,
 357                                                 &drvdata->paddr, GFP_KERNEL);
 358                 if (!drvdata->vaddr)
 359                         return -ENOMEM;
 360
 361                 memset(drvdata->vaddr, 0, drvdata->size);
 362                 drvdata->buf = drvdata->vaddr;
 363         } else {
 364                 drvdata->buf = devm_kzalloc(dev, drvdata->size, GFP_KERNEL);
 365                 if (!drvdata->buf)
 366                         return -ENOMEM;
 367         }
 368
 369         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 370         if (!desc) {
 371                 ret = -ENOMEM;
 372                 goto err_devm_kzalloc;
 373         }
 374
 375         desc->pdata = pdata;
 376         desc->dev = dev;
 377         desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
 378         desc->groups = coresight_tmc_groups;
 379
 380         if (drvdata->config_type == TMC_CONFIG_TYPE_ETB) {
 381                 desc->type = CORESIGHT_DEV_TYPE_SINK;
 382                 desc->ops = &tmc_etb_cs_ops;
 383         } else if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
 384                 desc->type = CORESIGHT_DEV_TYPE_SINK;
 385                 desc->ops = &tmc_etr_cs_ops;
 386         } else {
 387                 desc->type = CORESIGHT_DEV_TYPE_LINKSINK;
 388                 desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_FIFO;
 389                 desc->ops = &tmc_etf_cs_ops;
 390         }
 391
 392         drvdata->csdev = coresight_register(desc);
 393         if (IS_ERR(drvdata->csdev)) {
 394                 ret = PTR_ERR(drvdata->csdev);
 395                 goto err_devm_kzalloc;
 396         }
 397
 398         drvdata->miscdev.name = pdata->name;
 399         drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
 400         drvdata->miscdev.fops = &tmc_fops;
 401         ret = misc_register(&drvdata->miscdev);
 402         if (ret)
 403                 goto err_misc_register;
 404
 405         return 0;
 406
 407 err_misc_register:
 408         coresight_unregister(drvdata->csdev);
 409 err_devm_kzalloc:
 410         if (drvdata->config_type == TMC_CONFIG_TYPE_ETR)
 411                 dma_free_coherent(dev, drvdata->size,
 412                                 drvdata->vaddr, drvdata->paddr);
 413         return ret;
 414 }
 415
 416 static struct amba_id tmc_ids[] = {
 417         {
 418                 .id     = 0x0003b961,
 419                 .mask   = 0x0003ffff,
 420         },
 421         { 0, 0},
 422 };
 423
 424 static struct amba_driver tmc_driver = {
 425         .drv = {
 426                 .name   = "coresight-tmc",
 427                 .owner  = THIS_MODULE,
 428                 .suppress_bind_attrs = true,
 429         },
 430         .probe          = tmc_probe,
 431         .id_table       = tmc_ids,
 432 };
 433 builtin_amba_driver(tmc_driver);