ti/dma-crossbar.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
   4  *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   5  */
   6 #include <linux/platform_device.h>
   7 #include <linux/slab.h>
   8 #include <linux/err.h>
   9 #include <linux/init.h>
  10 #include <linux/list.h>
  11 #include <linux/io.h>
  12 #include <linux/of.h>
  13 #include <linux/of_dma.h>
  14 #include <linux/of_platform.h>
  15
  16 #define TI_XBAR_DRA7            0
  17 #define TI_XBAR_AM335X          1
  18 static const u32 ti_xbar_type[] = {
  19         [TI_XBAR_DRA7] = TI_XBAR_DRA7,
  20         [TI_XBAR_AM335X] = TI_XBAR_AM335X,
  21 };
  22
  23 static const struct of_device_id ti_dma_xbar_match[] = {
  24         {
  25                 .compatible = "ti,dra7-dma-crossbar",
  26                 .data = &ti_xbar_type[TI_XBAR_DRA7],
  27         },
  28         {
  29                 .compatible = "ti,am335x-edma-crossbar",
  30                 .data = &ti_xbar_type[TI_XBAR_AM335X],
  31         },
  32         {},
  33 };
  34
  35 /* Crossbar on AM335x/AM437x family */
  36 #define TI_AM335X_XBAR_LINES    64
  37
  38 struct ti_am335x_xbar_data {
  39         void __iomem *iomem;
  40
  41         struct dma_router dmarouter;
  42
  43         u32 xbar_events; /* maximum number of events to select in xbar */
  44         u32 dma_requests; /* number of DMA requests on eDMA */
  45 };
  46
  47 struct ti_am335x_xbar_map {
  48         u16 dma_line;
  49         u8 mux_val;
  50 };
  51
  52 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
  53 {
  54         /*
  55          * TPCC_EVT_MUX_60_63 register layout is different than the
  56          * rest, in the sense, that event 63 is mapped to lowest byte
  57          * and event 60 is mapped to highest, handle it separately.
  58          */
  59         if (event >= 60 && event <= 63)
  60                 writeb_relaxed(val, iomem + (63 - event % 4));
  61         else
  62                 writeb_relaxed(val, iomem + event);
  63 }
  64
  65 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
  66 {
  67         struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
  68         struct ti_am335x_xbar_map *map = route_data;
  69
  70         dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
  71                 map->mux_val, map->dma_line);
  72
  73         ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
  74         kfree(map);
  75 }
  76
  77 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
  78                                            struct of_dma *ofdma)
  79 {
  80         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  81         struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
  82         struct ti_am335x_xbar_map *map;
  83
  84         if (dma_spec->args_count != 3)
  85                 return ERR_PTR(-EINVAL);
  86
  87         if (dma_spec->args[2] >= xbar->xbar_events) {
  88                 dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
  89                         dma_spec->args[2]);
  90                 return ERR_PTR(-EINVAL);
  91         }
  92
  93         if (dma_spec->args[0] >= xbar->dma_requests) {
  94                 dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
  95                         dma_spec->args[0]);
  96                 return ERR_PTR(-EINVAL);
  97         }
  98
  99         /* The of_node_put() will be done in the core for the node */
 100         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 101         if (!dma_spec->np) {
 102                 dev_err(&pdev->dev, "Can't get DMA master\n");
 103                 return ERR_PTR(-EINVAL);
 104         }
 105
 106         map = kzalloc(sizeof(*map), GFP_KERNEL);
 107         if (!map) {
 108                 of_node_put(dma_spec->np);
 109                 return ERR_PTR(-ENOMEM);
 110         }
 111
 112         map->dma_line = (u16)dma_spec->args[0];
 113         map->mux_val = (u8)dma_spec->args[2];
 114
 115         dma_spec->args[2] = 0;
 116         dma_spec->args_count = 2;
 117
 118         dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 119                 map->mux_val, map->dma_line);
 120
 121         ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
 122
 123         return map;
 124 }
 125
 126 static const struct of_device_id ti_am335x_master_match[] __maybe_unused = {
 127         { .compatible = "ti,edma3-tpcc", },
 128         {},
 129 };
 130
 131 static int ti_am335x_xbar_probe(struct platform_device *pdev)
 132 {
 133         struct device_node *node = pdev->dev.of_node;
 134         const struct of_device_id *match;
 135         struct device_node *dma_node;
 136         struct ti_am335x_xbar_data *xbar;
 137         void __iomem *iomem;
 138         int i, ret;
 139
 140         if (!node)
 141                 return -ENODEV;
 142
 143         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 144         if (!xbar)
 145                 return -ENOMEM;
 146
 147         dma_node = of_parse_phandle(node, "dma-masters", 0);
 148         if (!dma_node) {
 149                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 150                 return -ENODEV;
 151         }
 152
 153         match = of_match_node(ti_am335x_master_match, dma_node);
 154         if (!match) {
 155                 dev_err(&pdev->dev, "DMA master is not supported\n");
 156                 of_node_put(dma_node);
 157                 return -EINVAL;
 158         }
 159
 160         if (of_property_read_u32(dma_node, "dma-requests",
 161                                  &xbar->dma_requests)) {
 162                 dev_info(&pdev->dev,
 163                          "Missing XBAR output information, using %u.\n",
 164                          TI_AM335X_XBAR_LINES);
 165                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 166         }
 167         of_node_put(dma_node);
 168
 169         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 170                 dev_info(&pdev->dev,
 171                          "Missing XBAR input information, using %u.\n",
 172                          TI_AM335X_XBAR_LINES);
 173                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 174         }
 175
 176         iomem = devm_platform_ioremap_resource(pdev, 0);
 177         if (IS_ERR(iomem))
 178                 return PTR_ERR(iomem);
 179
 180         xbar->iomem = iomem;
 181
 182         xbar->dmarouter.dev = &pdev->dev;
 183         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 184
 185         platform_set_drvdata(pdev, xbar);
 186
 187         /* Reset the crossbar */
 188         for (i = 0; i < xbar->dma_requests; i++)
 189                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 190
 191         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 192                                      &xbar->dmarouter);
 193
 194         return ret;
 195 }
 196
 197 /* Crossbar on DRA7xx family */
 198 #define TI_DRA7_XBAR_OUTPUTS    127
 199 #define TI_DRA7_XBAR_INPUTS     256
 200
 201 struct ti_dra7_xbar_data {
 202         void __iomem *iomem;
 203
 204         struct dma_router dmarouter;
 205         struct mutex mutex;
 206         unsigned long *dma_inuse;
 207
 208         u16 safe_val; /* Value to rest the crossbar lines */
 209         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 210         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 211         u32 dma_offset;
 212 };
 213
 214 struct ti_dra7_xbar_map {
 215         u16 xbar_in;
 216         int xbar_out;
 217 };
 218
 219 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 220 {
 221         writew_relaxed(val, iomem + (xbar * 2));
 222 }
 223
 224 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 225 {
 226         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 227         struct ti_dra7_xbar_map *map = route_data;
 228
 229         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 230                 map->xbar_in, map->xbar_out);
 231
 232         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 233         mutex_lock(&xbar->mutex);
 234         clear_bit(map->xbar_out, xbar->dma_inuse);
 235         mutex_unlock(&xbar->mutex);
 236         kfree(map);
 237 }
 238
 239 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 240                                          struct of_dma *ofdma)
 241 {
 242         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 243         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 244         struct ti_dra7_xbar_map *map;
 245
 246         if (dma_spec->args[0] >= xbar->xbar_requests) {
 247                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 248                         dma_spec->args[0]);
 249                 put_device(&pdev->dev);
 250                 return ERR_PTR(-EINVAL);
 251         }
 252
 253         /* The of_node_put() will be done in the core for the node */
 254         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 255         if (!dma_spec->np) {
 256                 dev_err(&pdev->dev, "Can't get DMA master\n");
 257                 put_device(&pdev->dev);
 258                 return ERR_PTR(-EINVAL);
 259         }
 260
 261         map = kzalloc(sizeof(*map), GFP_KERNEL);
 262         if (!map) {
 263                 of_node_put(dma_spec->np);
 264                 put_device(&pdev->dev);
 265                 return ERR_PTR(-ENOMEM);
 266         }
 267
 268         mutex_lock(&xbar->mutex);
 269         map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 270                                             xbar->dma_requests);
 271         if (map->xbar_out == xbar->dma_requests) {
 272                 mutex_unlock(&xbar->mutex);
 273                 dev_err(&pdev->dev, "Run out of free DMA requests\n");
 274                 kfree(map);
 275                 of_node_put(dma_spec->np);
 276                 put_device(&pdev->dev);
 277                 return ERR_PTR(-ENOMEM);
 278         }
 279         set_bit(map->xbar_out, xbar->dma_inuse);
 280         mutex_unlock(&xbar->mutex);
 281
 282         map->xbar_in = (u16)dma_spec->args[0];
 283
 284         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 285
 286         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 287                 map->xbar_in, map->xbar_out);
 288
 289         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 290
 291         return map;
 292 }
 293
 294 #define TI_XBAR_EDMA_OFFSET     0
 295 #define TI_XBAR_SDMA_OFFSET     1
 296 static const u32 ti_dma_offset[] = {
 297         [TI_XBAR_EDMA_OFFSET] = 0,
 298         [TI_XBAR_SDMA_OFFSET] = 1,
 299 };
 300
 301 static const struct of_device_id ti_dra7_master_match[] __maybe_unused = {
 302         {
 303                 .compatible = "ti,omap4430-sdma",
 304                 .data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
 305         },
 306         {
 307                 .compatible = "ti,edma3",
 308                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 309         },
 310         {
 311                 .compatible = "ti,edma3-tpcc",
 312                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 313         },
 314         {},
 315 };
 316
 317 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 318 {
 319         for (; len > 0; len--)
 320                 set_bit(offset + (len - 1), p);
 321 }
 322
 323 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 324 {
 325         struct device_node *node = pdev->dev.of_node;
 326         const struct of_device_id *match;
 327         struct device_node *dma_node;
 328         struct ti_dra7_xbar_data *xbar;
 329         struct property *prop;
 330         u32 safe_val;
 331         int sz;
 332         void __iomem *iomem;
 333         int i, ret;
 334
 335         if (!node)
 336                 return -ENODEV;
 337
 338         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 339         if (!xbar)
 340                 return -ENOMEM;
 341
 342         dma_node = of_parse_phandle(node, "dma-masters", 0);
 343         if (!dma_node) {
 344                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 345                 return -ENODEV;
 346         }
 347
 348         match = of_match_node(ti_dra7_master_match, dma_node);
 349         if (!match) {
 350                 dev_err(&pdev->dev, "DMA master is not supported\n");
 351                 of_node_put(dma_node);
 352                 return -EINVAL;
 353         }
 354
 355         if (of_property_read_u32(dma_node, "dma-requests",
 356                                  &xbar->dma_requests)) {
 357                 dev_info(&pdev->dev,
 358                          "Missing XBAR output information, using %u.\n",
 359                          TI_DRA7_XBAR_OUTPUTS);
 360                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 361         }
 362         of_node_put(dma_node);
 363
 364         xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 365                                        BITS_TO_LONGS(xbar->dma_requests),
 366                                        sizeof(unsigned long), GFP_KERNEL);
 367         if (!xbar->dma_inuse)
 368                 return -ENOMEM;
 369
 370         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 371                 dev_info(&pdev->dev,
 372                          "Missing XBAR input information, using %u.\n",
 373                          TI_DRA7_XBAR_INPUTS);
 374                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 375         }
 376
 377         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 378                 xbar->safe_val = (u16)safe_val;
 379
 380
 381         prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 382         if (prop) {
 383                 const char pname[] = "ti,reserved-dma-request-ranges";
 384                 u32 (*rsv_events)[2];
 385                 size_t nelm = sz / sizeof(*rsv_events);
 386                 int i;
 387
 388                 if (!nelm)
 389                         return -EINVAL;
 390
 391                 rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 392                 if (!rsv_events)
 393                         return -ENOMEM;
 394
 395                 ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 396                                                  nelm * 2);
 397                 if (ret) {
 398                         kfree(rsv_events);
 399                         return ret;
 400                 }
 401
 402                 for (i = 0; i < nelm; i++) {
 403                         ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 404                                              xbar->dma_inuse);
 405                 }
 406                 kfree(rsv_events);
 407         }
 408
 409         iomem = devm_platform_ioremap_resource(pdev, 0);
 410         if (IS_ERR(iomem))
 411                 return PTR_ERR(iomem);
 412
 413         xbar->iomem = iomem;
 414
 415         xbar->dmarouter.dev = &pdev->dev;
 416         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 417         xbar->dma_offset = *(u32 *)match->data;
 418
 419         mutex_init(&xbar->mutex);
 420         platform_set_drvdata(pdev, xbar);
 421
 422         /* Reset the crossbar */
 423         for (i = 0; i < xbar->dma_requests; i++) {
 424                 if (!test_bit(i, xbar->dma_inuse))
 425                         ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 426         }
 427
 428         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 429                                      &xbar->dmarouter);
 430         if (ret) {
 431                 /* Restore the defaults for the crossbar */
 432                 for (i = 0; i < xbar->dma_requests; i++) {
 433                         if (!test_bit(i, xbar->dma_inuse))
 434                                 ti_dra7_xbar_write(xbar->iomem, i, i);
 435                 }
 436         }
 437
 438         return ret;
 439 }
 440
 441 static int ti_dma_xbar_probe(struct platform_device *pdev)
 442 {
 443         const struct of_device_id *match;
 444         int ret;
 445
 446         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 447         if (unlikely(!match))
 448                 return -EINVAL;
 449
 450         switch (*(u32 *)match->data) {
 451         case TI_XBAR_DRA7:
 452                 ret = ti_dra7_xbar_probe(pdev);
 453                 break;
 454         case TI_XBAR_AM335X:
 455                 ret = ti_am335x_xbar_probe(pdev);
 456                 break;
 457         default:
 458                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 459                 ret = -ENODEV;
 460                 break;
 461         }
 462
 463         return ret;
 464 }
 465
 466 static struct platform_driver ti_dma_xbar_driver = {
 467         .driver = {
 468                 .name = "ti-dma-crossbar",
 469                 .of_match_table = ti_dma_xbar_match,
 470         },
 471         .probe  = ti_dma_xbar_probe,
 472 };
 473
 474 static int omap_dmaxbar_init(void)
 475 {
 476         return platform_driver_register(&ti_dma_xbar_driver);
 477 }
 478 arch_initcall(omap_dmaxbar_init);