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                 return -EINVAL;
 153         }
 154
 155         if (of_property_read_u32(dma_node, "dma-requests",
 156                                  &xbar->dma_requests)) {
 157                 dev_info(&pdev->dev,
 158                          "Missing XBAR output information, using %u.\n",
 159                          TI_AM335X_XBAR_LINES);
 160                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 161         }
 162         of_node_put(dma_node);
 163
 164         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 165                 dev_info(&pdev->dev,
 166                          "Missing XBAR input information, using %u.\n",
 167                          TI_AM335X_XBAR_LINES);
 168                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 169         }
 170
 171         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 172         iomem = devm_ioremap_resource(&pdev->dev, res);
 173         if (IS_ERR(iomem))
 174                 return PTR_ERR(iomem);
 175
 176         xbar->iomem = iomem;
 177
 178         xbar->dmarouter.dev = &pdev->dev;
 179         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 180
 181         platform_set_drvdata(pdev, xbar);
 182
 183         /* Reset the crossbar */
 184         for (i = 0; i < xbar->dma_requests; i++)
 185                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 186
 187         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 188                                      &xbar->dmarouter);
 189
 190         return ret;
 191 }
 192
 193 /* Crossbar on DRA7xx family */
 194 #define TI_DRA7_XBAR_OUTPUTS    127
 195 #define TI_DRA7_XBAR_INPUTS     256
 196
 197 struct ti_dra7_xbar_data {
 198         void __iomem *iomem;
 199
 200         struct dma_router dmarouter;
 201         struct mutex mutex;
 202         unsigned long *dma_inuse;
 203
 204         u16 safe_val; /* Value to rest the crossbar lines */
 205         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 206         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 207         u32 dma_offset;
 208 };
 209
 210 struct ti_dra7_xbar_map {
 211         u16 xbar_in;
 212         int xbar_out;
 213 };
 214
 215 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 216 {
 217         writew_relaxed(val, iomem + (xbar * 2));
 218 }
 219
 220 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 221 {
 222         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 223         struct ti_dra7_xbar_map *map = route_data;
 224
 225         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 226                 map->xbar_in, map->xbar_out);
 227
 228         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 229         mutex_lock(&xbar->mutex);
 230         clear_bit(map->xbar_out, xbar->dma_inuse);
 231         mutex_unlock(&xbar->mutex);
 232         kfree(map);
 233 }
 234
 235 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 236                                          struct of_dma *ofdma)
 237 {
 238         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 239         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 240         struct ti_dra7_xbar_map *map;
 241
 242         if (dma_spec->args[0] >= xbar->xbar_requests) {
 243                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 244                         dma_spec->args[0]);
 245                 return ERR_PTR(-EINVAL);
 246         }
 247
 248         /* The of_node_put() will be done in the core for the node */
 249         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 250         if (!dma_spec->np) {
 251                 dev_err(&pdev->dev, "Can't get DMA master\n");
 252                 return ERR_PTR(-EINVAL);
 253         }
 254
 255         map = kzalloc(sizeof(*map), GFP_KERNEL);
 256         if (!map) {
 257                 of_node_put(dma_spec->np);
 258                 return ERR_PTR(-ENOMEM);
 259         }
 260
 261         mutex_lock(&xbar->mutex);
 262         map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 263                                             xbar->dma_requests);
 264         mutex_unlock(&xbar->mutex);
 265         if (map->xbar_out == xbar->dma_requests) {
 266                 dev_err(&pdev->dev, "Run out of free DMA requests\n");
 267                 kfree(map);
 268                 return ERR_PTR(-ENOMEM);
 269         }
 270         set_bit(map->xbar_out, xbar->dma_inuse);
 271
 272         map->xbar_in = (u16)dma_spec->args[0];
 273
 274         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 275
 276         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 277                 map->xbar_in, map->xbar_out);
 278
 279         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 280
 281         return map;
 282 }
 283
 284 #define TI_XBAR_EDMA_OFFSET     0
 285 #define TI_XBAR_SDMA_OFFSET     1
 286 static const u32 ti_dma_offset[] = {
 287         [TI_XBAR_EDMA_OFFSET] = 0,
 288         [TI_XBAR_SDMA_OFFSET] = 1,
 289 };
 290
 291 static const struct of_device_id ti_dra7_master_match[] = {
 292         {
 293                 .compatible = "ti,omap4430-sdma",
 294                 .data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
 295         },
 296         {
 297                 .compatible = "ti,edma3",
 298                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 299         },
 300         {
 301                 .compatible = "ti,edma3-tpcc",
 302                 .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 303         },
 304         {},
 305 };
 306
 307 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 308 {
 309         for (; len > 0; len--)
 310                 clear_bit(offset + (len - 1), p);
 311 }
 312
 313 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 314 {
 315         struct device_node *node = pdev->dev.of_node;
 316         const struct of_device_id *match;
 317         struct device_node *dma_node;
 318         struct ti_dra7_xbar_data *xbar;
 319         struct property *prop;
 320         struct resource *res;
 321         u32 safe_val;
 322         int sz;
 323         void __iomem *iomem;
 324         int i, ret;
 325
 326         if (!node)
 327                 return -ENODEV;
 328
 329         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 330         if (!xbar)
 331                 return -ENOMEM;
 332
 333         dma_node = of_parse_phandle(node, "dma-masters", 0);
 334         if (!dma_node) {
 335                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 336                 return -ENODEV;
 337         }
 338
 339         match = of_match_node(ti_dra7_master_match, dma_node);
 340         if (!match) {
 341                 dev_err(&pdev->dev, "DMA master is not supported\n");
 342                 return -EINVAL;
 343         }
 344
 345         if (of_property_read_u32(dma_node, "dma-requests",
 346                                  &xbar->dma_requests)) {
 347                 dev_info(&pdev->dev,
 348                          "Missing XBAR output information, using %u.\n",
 349                          TI_DRA7_XBAR_OUTPUTS);
 350                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 351         }
 352         of_node_put(dma_node);
 353
 354         xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 355                                        BITS_TO_LONGS(xbar->dma_requests),
 356                                        sizeof(unsigned long), GFP_KERNEL);
 357         if (!xbar->dma_inuse)
 358                 return -ENOMEM;
 359
 360         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 361                 dev_info(&pdev->dev,
 362                          "Missing XBAR input information, using %u.\n",
 363                          TI_DRA7_XBAR_INPUTS);
 364                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 365         }
 366
 367         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 368                 xbar->safe_val = (u16)safe_val;
 369
 370
 371         prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 372         if (prop) {
 373                 const char pname[] = "ti,reserved-dma-request-ranges";
 374                 u32 (*rsv_events)[2];
 375                 size_t nelm = sz / sizeof(*rsv_events);
 376                 int i;
 377
 378                 if (!nelm)
 379                         return -EINVAL;
 380
 381                 rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 382                 if (!rsv_events)
 383                         return -ENOMEM;
 384
 385                 ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 386                                                  nelm * 2);
 387                 if (ret)
 388                         return ret;
 389
 390                 for (i = 0; i < nelm; i++) {
 391                         ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 392                                              xbar->dma_inuse);
 393                 }
 394                 kfree(rsv_events);
 395         }
 396
 397         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 398         iomem = devm_ioremap_resource(&pdev->dev, res);
 399         if (IS_ERR(iomem))
 400                 return PTR_ERR(iomem);
 401
 402         xbar->iomem = iomem;
 403
 404         xbar->dmarouter.dev = &pdev->dev;
 405         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 406         xbar->dma_offset = *(u32 *)match->data;
 407
 408         mutex_init(&xbar->mutex);
 409         platform_set_drvdata(pdev, xbar);
 410
 411         /* Reset the crossbar */
 412         for (i = 0; i < xbar->dma_requests; i++) {
 413                 if (!test_bit(i, xbar->dma_inuse))
 414                         ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 415         }
 416
 417         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 418                                      &xbar->dmarouter);
 419         if (ret) {
 420                 /* Restore the defaults for the crossbar */
 421                 for (i = 0; i < xbar->dma_requests; i++) {
 422                         if (!test_bit(i, xbar->dma_inuse))
 423                                 ti_dra7_xbar_write(xbar->iomem, i, i);
 424                 }
 425         }
 426
 427         return ret;
 428 }
 429
 430 static int ti_dma_xbar_probe(struct platform_device *pdev)
 431 {
 432         const struct of_device_id *match;
 433         int ret;
 434
 435         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 436         if (unlikely(!match))
 437                 return -EINVAL;
 438
 439         switch (*(u32 *)match->data) {
 440         case TI_XBAR_DRA7:
 441                 ret = ti_dra7_xbar_probe(pdev);
 442                 break;
 443         case TI_XBAR_AM335X:
 444                 ret = ti_am335x_xbar_probe(pdev);
 445                 break;
 446         default:
 447                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 448                 ret = -ENODEV;
 449                 break;
 450         }
 451
 452         return ret;
 453 }
 454
 455 static struct platform_driver ti_dma_xbar_driver = {
 456         .driver = {
 457                 .name = "ti-dma-crossbar",
 458                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 459         },
 460         .probe  = ti_dma_xbar_probe,
 461 };
 462
 463 static int omap_dmaxbar_init(void)
 464 {
 465         return platform_driver_register(&ti_dma_xbar_driver);
 466 }
 467 arch_initcall(omap_dmaxbar_init);