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         u16 mux_val;
  53 };
  54
  55 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u16 val)
  56 {
  57         writeb_relaxed(val & 0x1f, iomem + event);
  58 }
  59
  60 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
  61 {
  62         struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
  63         struct ti_am335x_xbar_map *map = route_data;
  64
  65         dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
  66                 map->mux_val, map->dma_line);
  67
  68         ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
  69         kfree(map);
  70 }
  71
  72 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
  73                                            struct of_dma *ofdma)
  74 {
  75         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  76         struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
  77         struct ti_am335x_xbar_map *map;
  78
  79         if (dma_spec->args_count != 3)
  80                 return ERR_PTR(-EINVAL);
  81
  82         if (dma_spec->args[2] >= xbar->xbar_events) {
  83                 dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
  84                         dma_spec->args[2]);
  85                 return ERR_PTR(-EINVAL);
  86         }
  87
  88         if (dma_spec->args[0] >= xbar->dma_requests) {
  89                 dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
  90                         dma_spec->args[0]);
  91                 return ERR_PTR(-EINVAL);
  92         }
  93
  94         /* The of_node_put() will be done in the core for the node */
  95         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
  96         if (!dma_spec->np) {
  97                 dev_err(&pdev->dev, "Can't get DMA master\n");
  98                 return ERR_PTR(-EINVAL);
  99         }
 100
 101         map = kzalloc(sizeof(*map), GFP_KERNEL);
 102         if (!map) {
 103                 of_node_put(dma_spec->np);
 104                 return ERR_PTR(-ENOMEM);
 105         }
 106
 107         map->dma_line = (u16)dma_spec->args[0];
 108         map->mux_val = (u16)dma_spec->args[2];
 109
 110         dma_spec->args[2] = 0;
 111         dma_spec->args_count = 2;
 112
 113         dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 114                 map->mux_val, map->dma_line);
 115
 116         ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
 117
 118         return map;
 119 }
 120
 121 static const struct of_device_id ti_am335x_master_match[] = {
 122         { .compatible = "ti,edma3-tpcc", },
 123         {},
 124 };
 125
 126 static int ti_am335x_xbar_probe(struct platform_device *pdev)
 127 {
 128         struct device_node *node = pdev->dev.of_node;
 129         const struct of_device_id *match;
 130         struct device_node *dma_node;
 131         struct ti_am335x_xbar_data *xbar;
 132         struct resource *res;
 133         void __iomem *iomem;
 134         int i, ret;
 135
 136         if (!node)
 137                 return -ENODEV;
 138
 139         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 140         if (!xbar)
 141                 return -ENOMEM;
 142
 143         dma_node = of_parse_phandle(node, "dma-masters", 0);
 144         if (!dma_node) {
 145                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 146                 return -ENODEV;
 147         }
 148
 149         match = of_match_node(ti_am335x_master_match, dma_node);
 150         if (!match) {
 151                 dev_err(&pdev->dev, "DMA master is not supported\n");
 152                 of_node_put(dma_node);
 153                 return -EINVAL;
 154         }
 155
 156         if (of_property_read_u32(dma_node, "dma-requests",
 157                                  &xbar->dma_requests)) {
 158                 dev_info(&pdev->dev,
 159                          "Missing XBAR output information, using %u.\n",
 160                          TI_AM335X_XBAR_LINES);
 161                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 162         }
 163         of_node_put(dma_node);
 164
 165         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 166                 dev_info(&pdev->dev,
 167                          "Missing XBAR input information, using %u.\n",
 168                          TI_AM335X_XBAR_LINES);
 169                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 170         }
 171
 172         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 173         iomem = devm_ioremap_resource(&pdev->dev, res);
 174         if (IS_ERR(iomem))
 175                 return PTR_ERR(iomem);
 176
 177         xbar->iomem = iomem;
 178
 179         xbar->dmarouter.dev = &pdev->dev;
 180         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 181
 182         platform_set_drvdata(pdev, xbar);
 183
 184         /* Reset the crossbar */
 185         for (i = 0; i < xbar->dma_requests; i++)
 186                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 187
 188         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 189                                      &xbar->dmarouter);
 190
 191         return ret;
 192 }
 193
 194 /* Crossbar on DRA7xx family */
 195 #define TI_DRA7_XBAR_OUTPUTS    127
 196 #define TI_DRA7_XBAR_INPUTS     256
 197
 198 struct ti_dra7_xbar_data {
 199         void __iomem *iomem;
 200
 201         struct dma_router dmarouter;
 202         struct mutex mutex;
 203         unsigned long *dma_inuse;
 204
 205         u16 safe_val; /* Value to rest the crossbar lines */
 206         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 207         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 208         u32 dma_offset;
 209 };
 210
 211 struct ti_dra7_xbar_map {
 212         u16 xbar_in;
 213         int xbar_out;
 214 };
 215
 216 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 217 {
 218         writew_relaxed(val, iomem + (xbar * 2));
 219 }
 220
 221 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 222 {
 223         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 224         struct ti_dra7_xbar_map *map = route_data;
 225
 226         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 227                 map->xbar_in, map->xbar_out);
 228
 229         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 230         mutex_lock(&xbar->mutex);
 231         clear_bit(map->xbar_out, xbar->dma_inuse);
 232         mutex_unlock(&xbar->mutex);
 233         kfree(map);
 234 }
 235
 236 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 237                                          struct of_dma *ofdma)
 238 {
 239         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 240         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 241         struct ti_dra7_xbar_map *map;
 242
 243         if (dma_spec->args[0] >= xbar->xbar_requests) {
 244                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 245                         dma_spec->args[0]);
 246                 return ERR_PTR(-EINVAL);
 247         }
 248
 249         /* The of_node_put() will be done in the core for the node */
 250         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 251         if (!dma_spec->np) {
 252                 dev_err(&pdev->dev, "Can't get DMA master\n");
 253                 return ERR_PTR(-EINVAL);
 254         }
 255
 256         map = kzalloc(sizeof(*map), GFP_KERNEL);
 257         if (!map) {
 258                 of_node_put(dma_spec->np);
 259                 return ERR_PTR(-ENOMEM);
 260         }
 261
 262         mutex_lock(&xbar->mutex);
 263         map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 264                                             xbar->dma_requests);
 265         mutex_unlock(&xbar->mutex);
 266         if (map->xbar_out == xbar->dma_requests) {
 267                 dev_err(&pdev->dev, "Run out of free DMA requests\n");
 268                 kfree(map);
 269                 return ERR_PTR(-ENOMEM);
 270         }
 271         set_bit(map->xbar_out, xbar->dma_inuse);
 272
 273         map->xbar_in = (u16)dma_spec->args[0];
 274
 275         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 276
 277         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 278                 map->xbar_in, map->xbar_out);
 279
 280         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 281
 282         return map;
 283 }
 284
 285 #define TI_XBAR_EDMA_OFFSET     0
 286 #define TI_XBAR_SDMA_OFFSET     1
 287 static const u32 ti_dma_offset[] = {
 288         [TI_XBAR_EDMA_OFFSET] = 0,
 289         [TI_XBAR_SDMA_OFFSET] = 1,
 290 };
 291
 292 static const struct of_device_id ti_dra7_master_match[] = {
 293         {
 294                 .compatible = "ti,omap4430-sdma",
 295                 .data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
 296         },
 297         {
 298                 .compatible = "ti,edma3",
 299                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 300         },
 301         {
 302                 .compatible = "ti,edma3-tpcc",
 303                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 304         },
 305         {},
 306 };
 307
 308 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 309 {
 310         for (; len > 0; len--)
 311                 clear_bit(offset + (len - 1), p);
 312 }
 313
 314 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 315 {
 316         struct device_node *node = pdev->dev.of_node;
 317         const struct of_device_id *match;
 318         struct device_node *dma_node;
 319         struct ti_dra7_xbar_data *xbar;
 320         struct property *prop;
 321         struct resource *res;
 322         u32 safe_val;
 323         int sz;
 324         void __iomem *iomem;
 325         int i, ret;
 326
 327         if (!node)
 328                 return -ENODEV;
 329
 330         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 331         if (!xbar)
 332                 return -ENOMEM;
 333
 334         dma_node = of_parse_phandle(node, "dma-masters", 0);
 335         if (!dma_node) {
 336                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 337                 return -ENODEV;
 338         }
 339
 340         match = of_match_node(ti_dra7_master_match, dma_node);
 341         if (!match) {
 342                 dev_err(&pdev->dev, "DMA master is not supported\n");
 343                 of_node_put(dma_node);
 344                 return -EINVAL;
 345         }
 346
 347         if (of_property_read_u32(dma_node, "dma-requests",
 348                                  &xbar->dma_requests)) {
 349                 dev_info(&pdev->dev,
 350                          "Missing XBAR output information, using %u.\n",
 351                          TI_DRA7_XBAR_OUTPUTS);
 352                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 353         }
 354         of_node_put(dma_node);
 355
 356         xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 357                                        BITS_TO_LONGS(xbar->dma_requests),
 358                                        sizeof(unsigned long), GFP_KERNEL);
 359         if (!xbar->dma_inuse)
 360                 return -ENOMEM;
 361
 362         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 363                 dev_info(&pdev->dev,
 364                          "Missing XBAR input information, using %u.\n",
 365                          TI_DRA7_XBAR_INPUTS);
 366                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 367         }
 368
 369         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 370                 xbar->safe_val = (u16)safe_val;
 371
 372
 373         prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 374         if (prop) {
 375                 const char pname[] = "ti,reserved-dma-request-ranges";
 376                 u32 (*rsv_events)[2];
 377                 size_t nelm = sz / sizeof(*rsv_events);
 378                 int i;
 379
 380                 if (!nelm)
 381                         return -EINVAL;
 382
 383                 rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 384                 if (!rsv_events)
 385                         return -ENOMEM;
 386
 387                 ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 388                                                  nelm * 2);
 389                 if (ret)
 390                         return ret;
 391
 392                 for (i = 0; i < nelm; i++) {
 393                         ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 394                                              xbar->dma_inuse);
 395                 }
 396                 kfree(rsv_events);
 397         }
 398
 399         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 400         iomem = devm_ioremap_resource(&pdev->dev, res);
 401         if (IS_ERR(iomem))
 402                 return PTR_ERR(iomem);
 403
 404         xbar->iomem = iomem;
 405
 406         xbar->dmarouter.dev = &pdev->dev;
 407         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 408         xbar->dma_offset = *(u32 *)match->data;
 409
 410         mutex_init(&xbar->mutex);
 411         platform_set_drvdata(pdev, xbar);
 412
 413         /* Reset the crossbar */
 414         for (i = 0; i < xbar->dma_requests; i++) {
 415                 if (!test_bit(i, xbar->dma_inuse))
 416                         ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 417         }
 418
 419         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 420                                      &xbar->dmarouter);
 421         if (ret) {
 422                 /* Restore the defaults for 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, i);
 426                 }
 427         }
 428
 429         return ret;
 430 }
 431
 432 static int ti_dma_xbar_probe(struct platform_device *pdev)
 433 {
 434         const struct of_device_id *match;
 435         int ret;
 436
 437         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 438         if (unlikely(!match))
 439                 return -EINVAL;
 440
 441         switch (*(u32 *)match->data) {
 442         case TI_XBAR_DRA7:
 443                 ret = ti_dra7_xbar_probe(pdev);
 444                 break;
 445         case TI_XBAR_AM335X:
 446                 ret = ti_am335x_xbar_probe(pdev);
 447                 break;
 448         default:
 449                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 450                 ret = -ENODEV;
 451                 break;
 452         }
 453
 454         return ret;
 455 }
 456
 457 static struct platform_driver ti_dma_xbar_driver = {
 458         .driver = {
 459                 .name = "ti-dma-crossbar",
 460                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 461         },
 462         .probe  = ti_dma_xbar_probe,
 463 };
 464
 465 static int omap_dmaxbar_init(void)
 466 {
 467         return platform_driver_register(&ti_dma_xbar_driver);
 468 }
 469 arch_initcall(omap_dmaxbar_init);