kernel/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         u16 mux_val;
  50 };
  51
  52 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u16 val)
  53 {
  54         writeb_relaxed(val & 0x1f, iomem + event);
  55 }
  56
  57 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
  58 {
  59         struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
  60         struct ti_am335x_xbar_map *map = route_data;
  61
  62         dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
  63                 map->mux_val, map->dma_line);
  64
  65         ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
  66         kfree(map);
  67 }
  68
  69 static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
  70                                            struct of_dma *ofdma)
  71 {
  72         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  73         struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
  74         struct ti_am335x_xbar_map *map;
  75
  76         if (dma_spec->args_count != 3)
  77                 return ERR_PTR(-EINVAL);
  78
  79         if (dma_spec->args[2] >= xbar->xbar_events) {
  80                 dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
  81                         dma_spec->args[2]);
  82                 return ERR_PTR(-EINVAL);
  83         }
  84
  85         if (dma_spec->args[0] >= xbar->dma_requests) {
  86                 dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
  87                         dma_spec->args[0]);
  88                 return ERR_PTR(-EINVAL);
  89         }
  90
  91         /* The of_node_put() will be done in the core for the node */
  92         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
  93         if (!dma_spec->np) {
  94                 dev_err(&pdev->dev, "Can't get DMA master\n");
  95                 return ERR_PTR(-EINVAL);
  96         }
  97
  98         map = kzalloc(sizeof(*map), GFP_KERNEL);
  99         if (!map) {
 100                 of_node_put(dma_spec->np);
 101                 return ERR_PTR(-ENOMEM);
 102         }
 103
 104         map->dma_line = (u16)dma_spec->args[0];
 105         map->mux_val = (u16)dma_spec->args[2];
 106
 107         dma_spec->args[2] = 0;
 108         dma_spec->args_count = 2;
 109
 110         dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 111                 map->mux_val, map->dma_line);
 112
 113         ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);
 114
 115         return map;
 116 }
 117
 118 static const struct of_device_id ti_am335x_master_match[] = {
 119         { .compatible = "ti,edma3-tpcc", },
 120         {},
 121 };
 122
 123 static int ti_am335x_xbar_probe(struct platform_device *pdev)
 124 {
 125         struct device_node *node = pdev->dev.of_node;
 126         const struct of_device_id *match;
 127         struct device_node *dma_node;
 128         struct ti_am335x_xbar_data *xbar;
 129         struct resource *res;
 130         void __iomem *iomem;
 131         int i, ret;
 132
 133         if (!node)
 134                 return -ENODEV;
 135
 136         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 137         if (!xbar)
 138                 return -ENOMEM;
 139
 140         dma_node = of_parse_phandle(node, "dma-masters", 0);
 141         if (!dma_node) {
 142                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 143                 return -ENODEV;
 144         }
 145
 146         match = of_match_node(ti_am335x_master_match, dma_node);
 147         if (!match) {
 148                 dev_err(&pdev->dev, "DMA master is not supported\n");
 149                 return -EINVAL;
 150         }
 151
 152         if (of_property_read_u32(dma_node, "dma-requests",
 153                                  &xbar->dma_requests)) {
 154                 dev_info(&pdev->dev,
 155                          "Missing XBAR output information, using %u.\n",
 156                          TI_AM335X_XBAR_LINES);
 157                 xbar->dma_requests = TI_AM335X_XBAR_LINES;
 158         }
 159         of_node_put(dma_node);
 160
 161         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 162                 dev_info(&pdev->dev,
 163                          "Missing XBAR input information, using %u.\n",
 164                          TI_AM335X_XBAR_LINES);
 165                 xbar->xbar_events = TI_AM335X_XBAR_LINES;
 166         }
 167
 168         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 169         iomem = devm_ioremap_resource(&pdev->dev, res);
 170         if (IS_ERR(iomem))
 171                 return PTR_ERR(iomem);
 172
 173         xbar->iomem = iomem;
 174
 175         xbar->dmarouter.dev = &pdev->dev;
 176         xbar->dmarouter.route_free = ti_am335x_xbar_free;
 177
 178         platform_set_drvdata(pdev, xbar);
 179
 180         /* Reset the crossbar */
 181         for (i = 0; i < xbar->dma_requests; i++)
 182                 ti_am335x_xbar_write(xbar->iomem, i, 0);
 183
 184         ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 185                                      &xbar->dmarouter);
 186
 187         return ret;
 188 }
 189
 190 /* Crossbar on DRA7xx family */
 191 #define TI_DRA7_XBAR_OUTPUTS    127
 192 #define TI_DRA7_XBAR_INPUTS     256
 193
 194 #define TI_XBAR_EDMA_OFFSET     0
 195 #define TI_XBAR_SDMA_OFFSET     1
 196
 197 struct ti_dra7_xbar_data {
 198         void __iomem *iomem;
 199
 200         struct dma_router dmarouter;
 201         struct idr map_idr;
 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         idr_remove(&xbar->map_idr, map->xbar_out);
 229         kfree(map);
 230 }
 231
 232 static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
 233                                          struct of_dma *ofdma)
 234 {
 235         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
 236         struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 237         struct ti_dra7_xbar_map *map;
 238
 239         if (dma_spec->args[0] >= xbar->xbar_requests) {
 240                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
 241                         dma_spec->args[0]);
 242                 return ERR_PTR(-EINVAL);
 243         }
 244
 245         /* The of_node_put() will be done in the core for the node */
 246         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
 247         if (!dma_spec->np) {
 248                 dev_err(&pdev->dev, "Can't get DMA master\n");
 249                 return ERR_PTR(-EINVAL);
 250         }
 251
 252         map = kzalloc(sizeof(*map), GFP_KERNEL);
 253         if (!map) {
 254                 of_node_put(dma_spec->np);
 255                 return ERR_PTR(-ENOMEM);
 256         }
 257
 258         map->xbar_out = idr_alloc(&xbar->map_idr, NULL, 0, xbar->dma_requests,
 259                                   GFP_KERNEL);
 260         map->xbar_in = (u16)dma_spec->args[0];
 261
 262         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
 263
 264         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
 265                 map->xbar_in, map->xbar_out);
 266
 267         ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
 268
 269         return map;
 270 }
 271
 272 static const struct of_device_id ti_dra7_master_match[] = {
 273         {
 274                 .compatible = "ti,omap4430-sdma",
 275                 .data = (void *)TI_XBAR_SDMA_OFFSET,
 276         },
 277         {
 278                 .compatible = "ti,edma3",
 279                 .data = (void *)TI_XBAR_EDMA_OFFSET,
 280         },
 281         {},
 282 };
 283
 284 static int ti_dra7_xbar_probe(struct platform_device *pdev)
 285 {
 286         struct device_node *node = pdev->dev.of_node;
 287         const struct of_device_id *match;
 288         struct device_node *dma_node;
 289         struct ti_dra7_xbar_data *xbar;
 290         struct resource *res;
 291         u32 safe_val;
 292         void __iomem *iomem;
 293         int i, ret;
 294
 295         if (!node)
 296                 return -ENODEV;
 297
 298         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 299         if (!xbar)
 300                 return -ENOMEM;
 301
 302         idr_init(&xbar->map_idr);
 303
 304         dma_node = of_parse_phandle(node, "dma-masters", 0);
 305         if (!dma_node) {
 306                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 307                 return -ENODEV;
 308         }
 309
 310         match = of_match_node(ti_dra7_master_match, dma_node);
 311         if (!match) {
 312                 dev_err(&pdev->dev, "DMA master is not supported\n");
 313                 return -EINVAL;
 314         }
 315
 316         if (of_property_read_u32(dma_node, "dma-requests",
 317                                  &xbar->dma_requests)) {
 318                 dev_info(&pdev->dev,
 319                          "Missing XBAR output information, using %u.\n",
 320                          TI_DRA7_XBAR_OUTPUTS);
 321                 xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 322         }
 323         of_node_put(dma_node);
 324
 325         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 326                 dev_info(&pdev->dev,
 327                          "Missing XBAR input information, using %u.\n",
 328                          TI_DRA7_XBAR_INPUTS);
 329                 xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 330         }
 331
 332         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 333                 xbar->safe_val = (u16)safe_val;
 334
 335         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 336         iomem = devm_ioremap_resource(&pdev->dev, res);
 337         if (IS_ERR(iomem))
 338                 return PTR_ERR(iomem);
 339
 340         xbar->iomem = iomem;
 341
 342         xbar->dmarouter.dev = &pdev->dev;
 343         xbar->dmarouter.route_free = ti_dra7_xbar_free;
 344         xbar->dma_offset = (u32)match->data;
 345
 346         platform_set_drvdata(pdev, xbar);
 347
 348         /* Reset the crossbar */
 349         for (i = 0; i < xbar->dma_requests; i++)
 350                 ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 351
 352         ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 353                                      &xbar->dmarouter);
 354         if (ret) {
 355                 /* Restore the defaults for the crossbar */
 356                 for (i = 0; i < xbar->dma_requests; i++)
 357                         ti_dra7_xbar_write(xbar->iomem, i, i);
 358         }
 359
 360         return ret;
 361 }
 362
 363 static int ti_dma_xbar_probe(struct platform_device *pdev)
 364 {
 365         const struct of_device_id *match;
 366         int ret;
 367
 368         match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 369         if (unlikely(!match))
 370                 return -EINVAL;
 371
 372         switch ((u32)match->data) {
 373         case TI_XBAR_DRA7:
 374                 ret = ti_dra7_xbar_probe(pdev);
 375                 break;
 376         case TI_XBAR_AM335X:
 377                 ret = ti_am335x_xbar_probe(pdev);
 378                 break;
 379         default:
 380                 dev_err(&pdev->dev, "Unsupported crossbar\n");
 381                 ret = -ENODEV;
 382                 break;
 383         }
 384
 385         return ret;
 386 }
 387
 388 static struct platform_driver ti_dma_xbar_driver = {
 389         .driver = {
 390                 .name = "ti-dma-crossbar",
 391                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 392         },
 393         .probe  = ti_dma_xbar_probe,
 394 };
 395
 396 int omap_dmaxbar_init(void)
 397 {
 398         return platform_driver_register(&ti_dma_xbar_driver);
 399 }
 400 arch_initcall(omap_dmaxbar_init);