drivers/dma/ti-dma-crossbar.c

   1 /*
   2  *  Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
   3  *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
   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 as
   7  * published by the Free Software Foundation.
   8  *
   9  */
  10 #include <linux/slab.h>
  11 #include <linux/err.h>
  12 #include <linux/init.h>
  13 #include <linux/list.h>
  14 #include <linux/io.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of_device.h>
  17 #include <linux/of_dma.h>
  18
  19 #define TI_XBAR_DRA7            0
  20 #define TI_XBAR_AM335X          1
  21 static const u32 ti_xbar_type[] = {
  22         [TI_XBAR_DRA7] = TI_XBAR_DRA7,
  23         [TI_XBAR_AM335X] = TI_XBAR_AM335X,
  24 };
  25
  26 static const struct of_device_id ti_dma_xbar_match[] = {
  27         {
  28                 .compatible = "ti,dra7-dma-crossbar",
  29                 .data = &ti_xbar_type[TI_XBAR_DRA7],
  30         },
  31         {
  32                 .compatible = "ti,am335x-edma-crossbar",
  33                 .data = &ti_xbar_type[TI_XBAR_AM335X],
  34         },
  35         {},
  36 };
  37
  38 /* Crossbar on AM335x/AM437x family */
  39 #define TI_AM335X_XBAR_LINES    64
  40
  41 struct ti_am335x_xbar_data {
  42         void __iomem *iomem;
  43
  44         struct dma_router dmarouter;
  45
  46         u32 xbar_events; /* maximum number of events to select in xbar */
  47         u32 dma_requests; /* number of DMA requests on eDMA */
  48 };
  49
  50 struct ti_am335x_xbar_map {
  51         u16 dma_line;
  52         u8 mux_val;
  53 };
  54
  55 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
  56 {
  57         /*
  58          * TPCC_EVT_MUX_60_63 register layout is different than the
  59          * rest, in the sense, that event 63 is mapped to lowest byte
  60          * and event 60 is mapped to highest, handle it separately.
  61          */
  62         if (event >= 60 && event <= 63)
  63                 writeb_relaxed(val, iomem + (63 - event % 4));
  64         else
  65                 writeb_relaxed(val, iomem + event);
  66 }
  67
  68 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
  69 {
  70         struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
  71         struct ti_am335x_xbar_map *map = route_data;
  72
  73         dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
  74                 map->mux_val, map->dma_line);
  75
  76         ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
  77         kfree(map);
  78 }
  79
  80 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
  81                                            struct of_dma *ofdma)
  82 {
  83         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  84         struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
  85         struct ti_am335x_xbar_map *map;
  86
  87         if (dma_spec->args_count != 3)
  88                 return ERR_PTR(-EINVAL);
  89
  90         if (dma_spec->args[2] >= xbar->xbar_events) {
  91                 dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
  92                         dma_spec->args[2]);
  93                 return ERR_PTR(-EINVAL);
  94         }
  95
  96         if (dma_spec->args[0] >= xbar->dma_requests) {
  97                 dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
  98                         dma_spec->args[0]);
  99                 return ERR_PTR(-EINVAL);
 100         }
 101
 102         /* The of_node_put() will be done in the core for the node */
 103         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 104         if (!dma_spec->np) {
 105                 dev_err(&pdev->dev, "Can't get DMA master\n");
 106                 return ERR_PTR(-EINVAL);
 107         }
 108
 109         map = kzalloc(sizeof(*map), GFP_KERNEL);
 110         if (!map) {
 111                 of_node_put(dma_spec->np);
 112                 return ERR_PTR(-ENOMEM);
 113         }
 114
 115         map->dma_line = (u16)dma_spec->args[0];
 116         map->mux_val = (u8)dma_spec->args[2];
 117
 118         dma_spec->args[2] = 0;
 119         dma_spec->args_count = 2;
 120
 121         dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 122                 map->mux_val, map->dma_line);
 123
 124         ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
 125
 126         return map;
 127 }
 128
 129 static const struct of_device_id ti_am335x_master_match[] = {
 130         { .compatible = "ti,edma3-tpcc", },
 131         {},
 132 };
 133
 134 static int ti_am335x_xbar_probe(struct platform_device *pdev)
 135 {
 136         struct device_node *node = pdev->dev.of_node;
 137         const struct of_device_id *match;
 138         struct device_node *dma_node;
 139         struct ti_am335x_xbar_data *xbar;
 140         struct resource *res;
 141         void __iomem *iomem;
 142         int i, ret;
 143
 144         if (!node)
 145                 return -ENODEV;
 146
 147         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 148         if (!xbar)
 149                 return -ENOMEM;
 150
 151         dma_node = of_parse_phandle(node, "dma-masters", 0);
 152         if (!dma_node) {
 153                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 154                 return -ENODEV;
 155         }
 156
 157         match = of_match_node(ti_am335x_master_match, dma_node);
 158         if (!match) {
 159                 dev_err(&pdev->dev, "DMA master is not supported\n");
 160                 of_node_put(dma_node);
 161                 return -EINVAL;
 162         }
 163
 164         if (of_property_read_u32(dma_node, "dma-requests",
 165                                  &xbar->dma_requests)) {
 166                 dev_info(&pdev->dev,
 167                          "Missing XBAR output information, using %u.\n",
 168                          TI_AM335X_XBAR_LINES);
 169                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 170         }
 171         of_node_put(dma_node);
 172
 173         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 174                 dev_info(&pdev->dev,
 175                          "Missing XBAR input information, using %u.\n",
 176                          TI_AM335X_XBAR_LINES);
 177                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 178         }
 179
 180         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 181         iomem = devm_ioremap_resource(&pdev->dev, res);
 182         if (IS_ERR(iomem))
 183                 return PTR_ERR(iomem);
 184
 185         xbar->iomem = iomem;
 186
 187         xbar->dmarouter.dev = &pdev->dev;
 188         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 189
 190         platform_set_drvdata(pdev, xbar);
 191
 192         /* Reset the crossbar */
 193         for (i = 0; i < xbar->dma_requests; i++)
 194                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 195
 196         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 197                                      &xbar->dmarouter);
 198
 199         return ret;
 200 }
 201
 202 /* Crossbar on DRA7xx family */
 203 #define TI_DRA7_XBAR_OUTPUTS    127
 204 #define TI_DRA7_XBAR_INPUTS     256
 205
 206 struct ti_dra7_xbar_data {
 207         void __iomem *iomem;
 208
 209         struct dma_router dmarouter;
 210         struct mutex mutex;
 211         unsigned long *dma_inuse;
 212
 213         u16 safe_val; /* Value to rest the crossbar lines */
 214         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 215         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 216         u32 dma_offset;
 217 };
 218
 219 struct ti_dra7_xbar_map {
 220         u16 xbar_in;
 221         int xbar_out;
 222 };
 223
 224 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 225 {
 226         writew_relaxed(val, iomem + (xbar * 2));
 227 }
 228
 229 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 230 {
 231         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 232         struct ti_dra7_xbar_map *map = route_data;
 233
 234         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 235                 map->xbar_in, map->xbar_out);
 236
 237         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 238         mutex_lock(&xbar->mutex);
 239         clear_bit(map->xbar_out, xbar->dma_inuse);
 240         mutex_unlock(&xbar->mutex);
 241         kfree(map);
 242 }
 243
 244 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 245                                          struct of_dma *ofdma)
 246 {
 247         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 248         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 249         struct ti_dra7_xbar_map *map;
 250
 251         if (dma_spec->args[0] >= xbar->xbar_requests) {
 252                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 253                         dma_spec->args[0]);
 254                 put_device(&pdev->dev);
 255                 return ERR_PTR(-EINVAL);
 256         }
 257
 258         /* The of_node_put() will be done in the core for the node */
 259         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 260         if (!dma_spec->np) {
 261                 dev_err(&pdev->dev, "Can't get DMA master\n");
 262                 put_device(&pdev->dev);
 263                 return ERR_PTR(-EINVAL);
 264         }
 265
 266         map = kzalloc(sizeof(*map), GFP_KERNEL);
 267         if (!map) {
 268                 of_node_put(dma_spec->np);
 269                 put_device(&pdev->dev);
 270                 return ERR_PTR(-ENOMEM);
 271         }
 272
 273         mutex_lock(&xbar->mutex);
 274         map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 275                                             xbar->dma_requests);
 276         if (map->xbar_out == xbar->dma_requests) {
 277                 mutex_unlock(&xbar->mutex);
 278                 dev_err(&pdev->dev, "Run out of free DMA requests\n");
 279                 kfree(map);
 280                 of_node_put(dma_spec->np);
 281                 put_device(&pdev->dev);
 282                 return ERR_PTR(-ENOMEM);
 283         }
 284         set_bit(map->xbar_out, xbar->dma_inuse);
 285         mutex_unlock(&xbar->mutex);
 286
 287         map->xbar_in = (u16)dma_spec->args[0];
 288
 289         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 290
 291         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 292                 map->xbar_in, map->xbar_out);
 293
 294         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 295
 296         return map;
 297 }
 298
 299 #define TI_XBAR_EDMA_OFFSET     0
 300 #define TI_XBAR_SDMA_OFFSET     1
 301 static const u32 ti_dma_offset[] = {
 302         [TI_XBAR_EDMA_OFFSET] = 0,
 303         [TI_XBAR_SDMA_OFFSET] = 1,
 304 };
 305
 306 static const struct of_device_id ti_dra7_master_match[] = {
 307         {
 308                 .compatible = "ti,omap4430-sdma",
 309                 .data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
 310         },
 311         {
 312                 .compatible = "ti,edma3",
 313                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 314         },
 315         {
 316                 .compatible = "ti,edma3-tpcc",
 317                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 318         },
 319         {},
 320 };
 321
 322 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 323 {
 324         for (; len > 0; len--)
 325                 clear_bit(offset + (len - 1), p);
 326 }
 327
 328 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 329 {
 330         struct device_node *node = pdev->dev.of_node;
 331         const struct of_device_id *match;
 332         struct device_node *dma_node;
 333         struct ti_dra7_xbar_data *xbar;
 334         struct property *prop;
 335         struct resource *res;
 336         u32 safe_val;
 337         int sz;
 338         void __iomem *iomem;
 339         int i, ret;
 340
 341         if (!node)
 342                 return -ENODEV;
 343
 344         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 345         if (!xbar)
 346                 return -ENOMEM;
 347
 348         dma_node = of_parse_phandle(node, "dma-masters", 0);
 349         if (!dma_node) {
 350                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 351                 return -ENODEV;
 352         }
 353
 354         match = of_match_node(ti_dra7_master_match, dma_node);
 355         if (!match) {
 356                 dev_err(&pdev->dev, "DMA master is not supported\n");
 357                 of_node_put(dma_node);
 358                 return -EINVAL;
 359         }
 360
 361         if (of_property_read_u32(dma_node, "dma-requests",
 362                                  &xbar->dma_requests)) {
 363                 dev_info(&pdev->dev,
 364                          "Missing XBAR output information, using %u.\n",
 365                          TI_DRA7_XBAR_OUTPUTS);
 366                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 367         }
 368         of_node_put(dma_node);
 369
 370         xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 371                                        BITS_TO_LONGS(xbar->dma_requests),
 372                                        sizeof(unsigned long), GFP_KERNEL);
 373         if (!xbar->dma_inuse)
 374                 return -ENOMEM;
 375
 376         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 377                 dev_info(&pdev->dev,
 378                          "Missing XBAR input information, using %u.\n",
 379                          TI_DRA7_XBAR_INPUTS);
 380                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 381         }
 382
 383         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 384                 xbar->safe_val = (u16)safe_val;
 385
 386
 387         prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 388         if (prop) {
 389                 const char pname[] = "ti,reserved-dma-request-ranges";
 390                 u32 (*rsv_events)[2];
 391                 size_t nelm = sz / sizeof(*rsv_events);
 392                 int i;
 393
 394                 if (!nelm)
 395                         return -EINVAL;
 396
 397                 rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 398                 if (!rsv_events)
 399                         return -ENOMEM;
 400
 401                 ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 402                                                  nelm * 2);
 403                 if (ret) {
 404                         kfree(rsv_events);
 405                         return ret;
 406                 }
 407
 408                 for (i = 0; i < nelm; i++) {
 409                         ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 410                                              xbar->dma_inuse);
 411                 }
 412                 kfree(rsv_events);
 413         }
 414
 415         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 416         iomem = devm_ioremap_resource(&pdev->dev, res);
 417         if (IS_ERR(iomem))
 418                 return PTR_ERR(iomem);
 419
 420         xbar->iomem = iomem;
 421
 422         xbar->dmarouter.dev = &pdev->dev;
 423         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 424         xbar->dma_offset = *(u32 *)match->data;
 425
 426         mutex_init(&xbar->mutex);
 427         platform_set_drvdata(pdev, xbar);
 428
 429         /* Reset the crossbar */
 430         for (i = 0; i < xbar->dma_requests; i++) {
 431                 if (!test_bit(i, xbar->dma_inuse))
 432                         ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 433         }
 434
 435         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 436                                      &xbar->dmarouter);
 437         if (ret) {
 438                 /* Restore the defaults for the crossbar */
 439                 for (i = 0; i < xbar->dma_requests; i++) {
 440                         if (!test_bit(i, xbar->dma_inuse))
 441                                 ti_dra7_xbar_write(xbar->iomem, i, i);
 442                 }
 443         }
 444
 445         return ret;
 446 }
 447
 448 static int ti_dma_xbar_probe(struct platform_device *pdev)
 449 {
 450         const struct of_device_id *match;
 451         int ret;
 452
 453         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 454         if (unlikely(!match))
 455                 return -EINVAL;
 456
 457         switch (*(u32 *)match->data) {
 458         case TI_XBAR_DRA7:
 459                 ret = ti_dra7_xbar_probe(pdev);
 460                 break;
 461         case TI_XBAR_AM335X:
 462                 ret = ti_am335x_xbar_probe(pdev);
 463                 break;
 464         default:
 465                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 466                 ret = -ENODEV;
 467                 break;
 468         }
 469
 470         return ret;
 471 }
 472
 473 static struct platform_driver ti_dma_xbar_driver = {
 474         .driver = {
 475                 .name = "ti-dma-crossbar",
 476                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 477         },
 478         .probe  = ti_dma_xbar_probe,
 479 };
 480
 481 static int omap_dmaxbar_init(void)
 482 {
 483         return platform_driver_register(&ti_dma_xbar_driver);
 484 }
 485 arch_initcall(omap_dmaxbar_init);