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
  22 static const struct of_device_id ti_dma_xbar_match[] = {
  23         {
  24                 .compatible = "ti,dra7-dma-crossbar",
  25                 .data = (void *)TI_XBAR_DRA7,
  26         },
  27         {
  28                 .compatible = "ti,am335x-edma-crossbar",
  29                 .data = (void *)TI_XBAR_AM335X,
  30         },
  31         {},
  32 };
  33
  34 /* Crossbar on AM335x/AM437x family */
  35 #define TI_AM335X_XBAR_LINES    64
  36
  37 struct ti_am335x_xbar_data {
  38         void __iomem *iomem;
  39
  40         struct dma_router dmarouter;
  41
  42         u32 xbar_events; /* maximum number of events to select in xbar */
  43         u32 dma_requests; /* number of DMA requests on eDMA */
  44 };
  45
  46 struct ti_am335x_xbar_map {
  47         u16 dma_line;
  48         u16 mux_val;
  49 };
  50
  51 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u16 val)
  52 {
  53         writeb_relaxed(val & 0x1f, iomem + event);
  54 }
  55
  56 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
  57 {
  58         struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
  59         struct ti_am335x_xbar_map *map = route_data;
  60
  61         dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
  62                 map->mux_val, map->dma_line);
  63
  64         ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
  65         kfree(map);
  66 }
  67
  68 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
  69                                            struct of_dma *ofdma)
  70 {
  71         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  72         struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
  73         struct ti_am335x_xbar_map *map;
  74
  75         if (dma_spec->args_count != 3)
  76                 return ERR_PTR(-EINVAL);
  77
  78         if (dma_spec->args[2] >= xbar->xbar_events) {
  79                 dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
  80                         dma_spec->args[2]);
  81                 return ERR_PTR(-EINVAL);
  82         }
  83
  84         if (dma_spec->args[0] >= xbar->dma_requests) {
  85                 dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
  86                         dma_spec->args[0]);
  87                 return ERR_PTR(-EINVAL);
  88         }
  89
  90         /* The of_node_put() will be done in the core for the node */
  91         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
  92         if (!dma_spec->np) {
  93                 dev_err(&pdev->dev, "Can't get DMA master\n");
  94                 return ERR_PTR(-EINVAL);
  95         }
  96
  97         map = kzalloc(sizeof(*map), GFP_KERNEL);
  98         if (!map) {
  99                 of_node_put(dma_spec->np);
 100                 return ERR_PTR(-ENOMEM);
 101         }
 102
 103         map->dma_line = (u16)dma_spec->args[0];
 104         map->mux_val = (u16)dma_spec->args[2];
 105
 106         dma_spec->args[2] = 0;
 107         dma_spec->args_count = 2;
 108
 109         dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 110                 map->mux_val, map->dma_line);
 111
 112         ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
 113
 114         return map;
 115 }
 116
 117 static const struct of_device_id ti_am335x_master_match[] = {
 118         { .compatible = "ti,edma3-tpcc", },
 119         {},
 120 };
 121
 122 static int ti_am335x_xbar_probe(struct platform_device *pdev)
 123 {
 124         struct device_node *node = pdev->dev.of_node;
 125         const struct of_device_id *match;
 126         struct device_node *dma_node;
 127         struct ti_am335x_xbar_data *xbar;
 128         struct resource *res;
 129         void __iomem *iomem;
 130         int i, ret;
 131
 132         if (!node)
 133                 return -ENODEV;
 134
 135         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 136         if (!xbar)
 137                 return -ENOMEM;
 138
 139         dma_node = of_parse_phandle(node, "dma-masters", 0);
 140         if (!dma_node) {
 141                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 142                 return -ENODEV;
 143         }
 144
 145         match = of_match_node(ti_am335x_master_match, dma_node);
 146         if (!match) {
 147                 dev_err(&pdev->dev, "DMA master is not supported\n");
 148                 return -EINVAL;
 149         }
 150
 151         if (of_property_read_u32(dma_node, "dma-requests",
 152                                  &xbar->dma_requests)) {
 153                 dev_info(&pdev->dev,
 154                          "Missing XBAR output information, using %u.\n",
 155                          TI_AM335X_XBAR_LINES);
 156                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 157         }
 158         of_node_put(dma_node);
 159
 160         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 161                 dev_info(&pdev->dev,
 162                          "Missing XBAR input information, using %u.\n",
 163                          TI_AM335X_XBAR_LINES);
 164                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 165         }
 166
 167         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 168         iomem = devm_ioremap_resource(&pdev->dev, res);
 169         if (IS_ERR(iomem))
 170                 return PTR_ERR(iomem);
 171
 172         xbar->iomem = iomem;
 173
 174         xbar->dmarouter.dev = &pdev->dev;
 175         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 176
 177         platform_set_drvdata(pdev, xbar);
 178
 179         /* Reset the crossbar */
 180         for (i = 0; i < xbar->dma_requests; i++)
 181                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 182
 183         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 184                                      &xbar->dmarouter);
 185
 186         return ret;
 187 }
 188
 189 /* Crossbar on DRA7xx family */
 190 #define TI_DRA7_XBAR_OUTPUTS    127
 191 #define TI_DRA7_XBAR_INPUTS     256
 192
 193 #define TI_XBAR_EDMA_OFFSET     0
 194 #define TI_XBAR_SDMA_OFFSET     1
 195
 196 struct ti_dra7_xbar_data {
 197         void __iomem *iomem;
 198
 199         struct dma_router dmarouter;
 200         struct mutex mutex;
 201         unsigned long *dma_inuse;
 202
 203         u16 safe_val; /* Value to rest the crossbar lines */
 204         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 205         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 206         u32 dma_offset;
 207 };
 208
 209 struct ti_dra7_xbar_map {
 210         u16 xbar_in;
 211         int xbar_out;
 212 };
 213
 214 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 215 {
 216         writew_relaxed(val, iomem + (xbar * 2));
 217 }
 218
 219 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 220 {
 221         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 222         struct ti_dra7_xbar_map *map = route_data;
 223
 224         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 225                 map->xbar_in, map->xbar_out);
 226
 227         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 228         mutex_lock(&xbar->mutex);
 229         clear_bit(map->xbar_out, xbar->dma_inuse);
 230         mutex_unlock(&xbar->mutex);
 231         kfree(map);
 232 }
 233
 234 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 235                                          struct of_dma *ofdma)
 236 {
 237         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 238         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 239         struct ti_dra7_xbar_map *map;
 240
 241         if (dma_spec->args[0] >= xbar->xbar_requests) {
 242                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 243                         dma_spec->args[0]);
 244                 return ERR_PTR(-EINVAL);
 245         }
 246
 247         /* The of_node_put() will be done in the core for the node */
 248         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 249         if (!dma_spec->np) {
 250                 dev_err(&pdev->dev, "Can't get DMA master\n");
 251                 return ERR_PTR(-EINVAL);
 252         }
 253
 254         map = kzalloc(sizeof(*map), GFP_KERNEL);
 255         if (!map) {
 256                 of_node_put(dma_spec->np);
 257                 return ERR_PTR(-ENOMEM);
 258         }
 259
 260         mutex_lock(&xbar->mutex);
 261         map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 262                                             xbar->dma_requests);
 263         mutex_unlock(&xbar->mutex);
 264         if (map->xbar_out == xbar->dma_requests) {
 265                 dev_err(&pdev->dev, "Run out of free DMA requests\n");
 266                 kfree(map);
 267                 return ERR_PTR(-ENOMEM);
 268         }
 269         set_bit(map->xbar_out, xbar->dma_inuse);
 270
 271         map->xbar_in = (u16)dma_spec->args[0];
 272
 273         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 274
 275         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 276                 map->xbar_in, map->xbar_out);
 277
 278         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 279
 280         return map;
 281 }
 282
 283 static const struct of_device_id ti_dra7_master_match[] = {
 284         {
 285                 .compatible = "ti,omap4430-sdma",
 286                 .data = (void *)TI_XBAR_SDMA_OFFSET,
 287         },
 288         {
 289                 .compatible = "ti,edma3",
 290                 .data = (void *)TI_XBAR_EDMA_OFFSET,
 291         },
 292         {
 293                 .compatible = "ti,edma3-tpcc",
 294                 .data = (void *)TI_XBAR_EDMA_OFFSET,
 295         },
 296         {},
 297 };
 298
 299 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 300 {
 301         for (; len > 0; len--)
 302                 clear_bit(offset + (len - 1), p);
 303 }
 304
 305 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 306 {
 307         struct device_node *node = pdev->dev.of_node;
 308         const struct of_device_id *match;
 309         struct device_node *dma_node;
 310         struct ti_dra7_xbar_data *xbar;
 311         struct property *prop;
 312         struct resource *res;
 313         u32 safe_val;
 314         size_t sz;
 315         void __iomem *iomem;
 316         int i, ret;
 317
 318         if (!node)
 319                 return -ENODEV;
 320
 321         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 322         if (!xbar)
 323                 return -ENOMEM;
 324
 325         dma_node = of_parse_phandle(node, "dma-masters", 0);
 326         if (!dma_node) {
 327                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 328                 return -ENODEV;
 329         }
 330
 331         match = of_match_node(ti_dra7_master_match, dma_node);
 332         if (!match) {
 333                 dev_err(&pdev->dev, "DMA master is not supported\n");
 334                 return -EINVAL;
 335         }
 336
 337         if (of_property_read_u32(dma_node, "dma-requests",
 338                                  &xbar->dma_requests)) {
 339                 dev_info(&pdev->dev,
 340                          "Missing XBAR output information, using %u.\n",
 341                          TI_DRA7_XBAR_OUTPUTS);
 342                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 343         }
 344         of_node_put(dma_node);
 345
 346         xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 347                                        BITS_TO_LONGS(xbar->dma_requests),
 348                                        sizeof(unsigned long), GFP_KERNEL);
 349         if (!xbar->dma_inuse)
 350                 return -ENOMEM;
 351
 352         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 353                 dev_info(&pdev->dev,
 354                          "Missing XBAR input information, using %u.\n",
 355                          TI_DRA7_XBAR_INPUTS);
 356                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 357         }
 358
 359         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 360                 xbar->safe_val = (u16)safe_val;
 361
 362
 363         prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 364         if (prop) {
 365                 const char pname[] = "ti,reserved-dma-request-ranges";
 366                 u32 (*rsv_events)[2];
 367                 size_t nelm = sz / sizeof(*rsv_events);
 368                 int i;
 369
 370                 if (!nelm)
 371                         return -EINVAL;
 372
 373                 rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 374                 if (!rsv_events)
 375                         return -ENOMEM;
 376
 377                 ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 378                                                  nelm * 2);
 379                 if (ret)
 380                         return ret;
 381
 382                 for (i = 0; i < nelm; i++) {
 383                         ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 384                                              xbar->dma_inuse);
 385                 }
 386                 kfree(rsv_events);
 387         }
 388
 389         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 390         iomem = devm_ioremap_resource(&pdev->dev, res);
 391         if (IS_ERR(iomem))
 392                 return PTR_ERR(iomem);
 393
 394         xbar->iomem = iomem;
 395
 396         xbar->dmarouter.dev = &pdev->dev;
 397         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 398         xbar->dma_offset = (u32)match->data;
 399
 400         mutex_init(&xbar->mutex);
 401         platform_set_drvdata(pdev, xbar);
 402
 403         /* Reset the crossbar */
 404         for (i = 0; i < xbar->dma_requests; i++) {
 405                 if (!test_bit(i, xbar->dma_inuse))
 406                         ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 407         }
 408
 409         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 410                                      &xbar->dmarouter);
 411         if (ret) {
 412                 /* Restore the defaults for the crossbar */
 413                 for (i = 0; i < xbar->dma_requests; i++) {
 414                         if (!test_bit(i, xbar->dma_inuse))
 415                                 ti_dra7_xbar_write(xbar->iomem, i, i);
 416                 }
 417         }
 418
 419         return ret;
 420 }
 421
 422 static int ti_dma_xbar_probe(struct platform_device *pdev)
 423 {
 424         const struct of_device_id *match;
 425         int ret;
 426
 427         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 428         if (unlikely(!match))
 429                 return -EINVAL;
 430
 431         switch ((u32)match->data) {
 432         case TI_XBAR_DRA7:
 433                 ret = ti_dra7_xbar_probe(pdev);
 434                 break;
 435         case TI_XBAR_AM335X:
 436                 ret = ti_am335x_xbar_probe(pdev);
 437                 break;
 438         default:
 439                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 440                 ret = -ENODEV;
 441                 break;
 442         }
 443
 444         return ret;
 445 }
 446
 447 static struct platform_driver ti_dma_xbar_driver = {
 448         .driver = {
 449                 .name = "ti-dma-crossbar",
 450                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 451         },
 452         .probe  = ti_dma_xbar_probe,
 453 };
 454
 455 static int omap_dmaxbar_init(void)
 456 {
 457         return platform_driver_register(&ti_dma_xbar_driver);
 458 }
 459 arch_initcall(omap_dmaxbar_init);