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/idr.h>
  16 #include <linux/of_address.h>
  17 #include <linux/of_device.h>
  18 #include <linux/of_dma.h>
  19
  20 #define TI_XBAR_DRA7            0
  21 #define TI_XBAR_AM335X          1
  22
  23 static const struct of_device_id ti_dma_xbar_match[] = {
  24         {
  25                 .compatible = "ti,dra7-dma-crossbar",
  26                 .data = (void *)TI_XBAR_DRA7,
  27         },
  28         {
  29                 .compatible = "ti,am335x-edma-crossbar",
  30                 .data = (void *)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[] = {
 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         struct resource *res;
 138         void __iomem *iomem;
 139         int i, ret;
 140
 141         if (!node)
 142                 return -ENODEV;
 143
 144         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 145         if (!xbar)
 146                 return -ENOMEM;
 147
 148         dma_node = of_parse_phandle(node, "dma-masters", 0);
 149         if (!dma_node) {
 150                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 151                 return -ENODEV;
 152         }
 153
 154         match = of_match_node(ti_am335x_master_match, dma_node);
 155         if (!match) {
 156                 dev_err(&pdev->dev, "DMA master is not supported\n");
 157                 of_node_put(dma_node);
 158                 return -EINVAL;
 159         }
 160
 161         if (of_property_read_u32(dma_node, "dma-requests",
 162                                  &xbar->dma_requests)) {
 163                 dev_info(&pdev->dev,
 164                          "Missing XBAR output information, using %u.\n",
 165                          TI_AM335X_XBAR_LINES);
 166                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 167         }
 168         of_node_put(dma_node);
 169
 170         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 171                 dev_info(&pdev->dev,
 172                          "Missing XBAR input information, using %u.\n",
 173                          TI_AM335X_XBAR_LINES);
 174                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 175         }
 176
 177         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 178         iomem = devm_ioremap_resource(&pdev->dev, res);
 179         if (IS_ERR(iomem))
 180                 return PTR_ERR(iomem);
 181
 182         xbar->iomem = iomem;
 183
 184         xbar->dmarouter.dev = &pdev->dev;
 185         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 186
 187         platform_set_drvdata(pdev, xbar);
 188
 189         /* Reset the crossbar */
 190         for (i = 0; i < xbar->dma_requests; i++)
 191                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 192
 193         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 194                                      &xbar->dmarouter);
 195
 196         return ret;
 197 }
 198
 199 /* Crossbar on DRA7xx family */
 200 #define TI_DRA7_XBAR_OUTPUTS    127
 201 #define TI_DRA7_XBAR_INPUTS     256
 202
 203 #define TI_XBAR_EDMA_OFFSET     0
 204 #define TI_XBAR_SDMA_OFFSET     1
 205
 206 struct ti_dra7_xbar_data {
 207         void __iomem *iomem;
 208
 209         struct dma_router dmarouter;
 210         struct idr map_idr;
 211
 212         u16 safe_val; /* Value to rest the crossbar lines */
 213         u32 xbar_requests; /* number of DMA requests connected to XBAR */
 214         u32 dma_requests; /* number of DMA requests forwarded to DMA */
 215         u32 dma_offset;
 216 };
 217
 218 struct ti_dra7_xbar_map {
 219         u16 xbar_in;
 220         int xbar_out;
 221 };
 222
 223 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 224 {
 225         writew_relaxed(val, iomem + (xbar * 2));
 226 }
 227
 228 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 229 {
 230         struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 231         struct ti_dra7_xbar_map *map = route_data;
 232
 233         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
 234                 map->xbar_in, map->xbar_out);
 235
 236         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 237         idr_remove(&xbar->map_idr, map->xbar_out);
 238         kfree(map);
 239 }
 240
 241 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 242                                          struct of_dma *ofdma)
 243 {
 244         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 245         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 246         struct ti_dra7_xbar_map *map;
 247
 248         if (dma_spec->args[0] >= xbar->xbar_requests) {
 249                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 250                         dma_spec->args[0]);
 251                 return ERR_PTR(-EINVAL);
 252         }
 253
 254         /* The of_node_put() will be done in the core for the node */
 255         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 256         if (!dma_spec->np) {
 257                 dev_err(&pdev->dev, "Can't get DMA master\n");
 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                 return ERR_PTR(-ENOMEM);
 265         }
 266
 267         map->xbar_out = idr_alloc(&xbar->map_idr, NULL, 0, xbar->dma_requests,
 268                                   GFP_KERNEL);
 269         map->xbar_in = (u16)dma_spec->args[0];
 270
 271         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 272
 273         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 274                 map->xbar_in, map->xbar_out);
 275
 276         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 277
 278         return map;
 279 }
 280
 281 static const struct of_device_id ti_dra7_master_match[] = {
 282         {
 283                 .compatible = "ti,omap4430-sdma",
 284                 .data = (void *)TI_XBAR_SDMA_OFFSET,
 285         },
 286         {
 287                 .compatible = "ti,edma3",
 288                 .data = (void *)TI_XBAR_EDMA_OFFSET,
 289         },
 290         {},
 291 };
 292
 293 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 294 {
 295         struct device_node *node = pdev->dev.of_node;
 296         const struct of_device_id *match;
 297         struct device_node *dma_node;
 298         struct ti_dra7_xbar_data *xbar;
 299         struct resource *res;
 300         u32 safe_val;
 301         void __iomem *iomem;
 302         int i, ret;
 303
 304         if (!node)
 305                 return -ENODEV;
 306
 307         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 308         if (!xbar)
 309                 return -ENOMEM;
 310
 311         idr_init(&xbar->map_idr);
 312
 313         dma_node = of_parse_phandle(node, "dma-masters", 0);
 314         if (!dma_node) {
 315                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 316                 return -ENODEV;
 317         }
 318
 319         match = of_match_node(ti_dra7_master_match, dma_node);
 320         if (!match) {
 321                 dev_err(&pdev->dev, "DMA master is not supported\n");
 322                 of_node_put(dma_node);
 323                 return -EINVAL;
 324         }
 325
 326         if (of_property_read_u32(dma_node, "dma-requests",
 327                                  &xbar->dma_requests)) {
 328                 dev_info(&pdev->dev,
 329                          "Missing XBAR output information, using %u.\n",
 330                          TI_DRA7_XBAR_OUTPUTS);
 331                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 332         }
 333         of_node_put(dma_node);
 334
 335         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 336                 dev_info(&pdev->dev,
 337                          "Missing XBAR input information, using %u.\n",
 338                          TI_DRA7_XBAR_INPUTS);
 339                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 340         }
 341
 342         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 343                 xbar->safe_val = (u16)safe_val;
 344
 345         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 346         iomem = devm_ioremap_resource(&pdev->dev, res);
 347         if (IS_ERR(iomem))
 348                 return PTR_ERR(iomem);
 349
 350         xbar->iomem = iomem;
 351
 352         xbar->dmarouter.dev = &pdev->dev;
 353         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 354         xbar->dma_offset = (u32)match->data;
 355
 356         platform_set_drvdata(pdev, xbar);
 357
 358         /* Reset the crossbar */
 359         for (i = 0; i < xbar->dma_requests; i++)
 360                 ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 361
 362         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 363                                      &xbar->dmarouter);
 364         if (ret) {
 365                 /* Restore the defaults for the crossbar */
 366                 for (i = 0; i < xbar->dma_requests; i++)
 367                         ti_dra7_xbar_write(xbar->iomem, i, i);
 368         }
 369
 370         return ret;
 371 }
 372
 373 static int ti_dma_xbar_probe(struct platform_device *pdev)
 374 {
 375         const struct of_device_id *match;
 376         int ret;
 377
 378         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 379         if (unlikely(!match))
 380                 return -EINVAL;
 381
 382         switch ((u32)match->data) {
 383         case TI_XBAR_DRA7:
 384                 ret = ti_dra7_xbar_probe(pdev);
 385                 break;
 386         case TI_XBAR_AM335X:
 387                 ret = ti_am335x_xbar_probe(pdev);
 388                 break;
 389         default:
 390                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 391                 ret = -ENODEV;
 392                 break;
 393         }
 394
 395         return ret;
 396 }
 397
 398 static struct platform_driver ti_dma_xbar_driver = {
 399         .driver = {
 400                 .name = "ti-dma-crossbar",
 401                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 402         },
 403         .probe  = ti_dma_xbar_probe,
 404 };
 405
 406 int omap_dmaxbar_init(void)
 407 {
 408         return platform_driver_register(&ti_dma_xbar_driver);
 409 }
 410 arch_initcall(omap_dmaxbar_init);