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_OUTPUTS 127
  21 #define TI_XBAR_INPUTS  256
  22
  23 #define TI_XBAR_EDMA_OFFSET     0
  24 #define TI_XBAR_SDMA_OFFSET     1
  25
  26 struct ti_dma_xbar_data {
  27         void __iomem *iomem;
  28
  29         struct dma_router dmarouter;
  30         struct idr map_idr;
  31
  32         u16 safe_val; /* Value to rest the crossbar lines */
  33         u32 xbar_requests; /* number of DMA requests connected to XBAR */
  34         u32 dma_requests; /* number of DMA requests forwarded to DMA */
  35         u32 dma_offset;
  36 };
  37
  38 struct ti_dma_xbar_map {
  39         u16 xbar_in;
  40         int xbar_out;
  41 };
  42
  43 static inline void ti_dma_xbar_write(void __iomem *iomem, int xbar, u16 val)
  44 {
  45         writew_relaxed(val, iomem + (xbar * 2));
  46 }
  47
  48 static void ti_dma_xbar_free(struct device *dev, void *route_data)
  49 {
  50         struct ti_dma_xbar_data *xbar = dev_get_drvdata(dev);
  51         struct ti_dma_xbar_map *map = route_data;
  52
  53         dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
  54                 map->xbar_in, map->xbar_out);
  55
  56         ti_dma_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
  57         idr_remove(&xbar->map_idr, map->xbar_out);
  58         kfree(map);
  59 }
  60
  61 static void *ti_dma_xbar_route_allocate(struct of_phandle_args *dma_spec,
  62                                         struct of_dma *ofdma)
  63 {
  64         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  65         struct ti_dma_xbar_data *xbar = platform_get_drvdata(pdev);
  66         struct ti_dma_xbar_map *map;
  67
  68         if (dma_spec->args[0] >= xbar->xbar_requests) {
  69                 dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
  70                         dma_spec->args[0]);
  71                 return ERR_PTR(-EINVAL);
  72         }
  73
  74         /* The of_node_put() will be done in the core for the node */
  75         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
  76         if (!dma_spec->np) {
  77                 dev_err(&pdev->dev, "Can't get DMA master\n");
  78                 return ERR_PTR(-EINVAL);
  79         }
  80
  81         map = kzalloc(sizeof(*map), GFP_KERNEL);
  82         if (!map) {
  83                 of_node_put(dma_spec->np);
  84                 return ERR_PTR(-ENOMEM);
  85         }
  86
  87         map->xbar_out = idr_alloc(&xbar->map_idr, NULL, 0, xbar->dma_requests,
  88                                   GFP_KERNEL);
  89         map->xbar_in = (u16)dma_spec->args[0];
  90
  91         dma_spec->args[0] = map->xbar_out + xbar->dma_offset;
  92
  93         dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
  94                 map->xbar_in, map->xbar_out);
  95
  96         ti_dma_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
  97
  98         return map;
  99 }
 100
 101 static const struct of_device_id ti_dma_master_match[] = {
 102         {
 103                 .compatible = "ti,omap4430-sdma",
 104                 .data = (void *)TI_XBAR_SDMA_OFFSET,
 105         },
 106         {
 107                 .compatible = "ti,edma3",
 108                 .data = (void *)TI_XBAR_EDMA_OFFSET,
 109         },
 110         {},
 111 };
 112
 113 static int ti_dma_xbar_probe(struct platform_device *pdev)
 114 {
 115         struct device_node *node = pdev->dev.of_node;
 116         const struct of_device_id *match;
 117         struct device_node *dma_node;
 118         struct ti_dma_xbar_data *xbar;
 119         struct resource *res;
 120         u32 safe_val;
 121         void __iomem *iomem;
 122         int i, ret;
 123
 124         if (!node)
 125                 return -ENODEV;
 126
 127         xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
 128         if (!xbar)
 129                 return -ENOMEM;
 130
 131         idr_init(&xbar->map_idr);
 132
 133         dma_node = of_parse_phandle(node, "dma-masters", 0);
 134         if (!dma_node) {
 135                 dev_err(&pdev->dev, "Can't get DMA master node\n");
 136                 return -ENODEV;
 137         }
 138
 139         match = of_match_node(ti_dma_master_match, dma_node);
 140         if (!match) {
 141                 dev_err(&pdev->dev, "DMA master is not supported\n");
 142                 return -EINVAL;
 143         }
 144
 145         if (of_property_read_u32(dma_node, "dma-requests",
 146                                  &xbar->dma_requests)) {
 147                 dev_info(&pdev->dev,
 148                          "Missing XBAR output information, using %u.\n",
 149                          TI_XBAR_OUTPUTS);
 150                 xbar->dma_requests = TI_XBAR_OUTPUTS;
 151         }
 152         of_node_put(dma_node);
 153
 154         if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 155                 dev_info(&pdev->dev,
 156                          "Missing XBAR input information, using %u.\n",
 157                          TI_XBAR_INPUTS);
 158                 xbar->xbar_requests = TI_XBAR_INPUTS;
 159         }
 160
 161         if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
 162                 xbar->safe_val = (u16)safe_val;
 163
 164         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 165         iomem = devm_ioremap_resource(&pdev->dev, res);
 166         if (IS_ERR(iomem))
 167                 return PTR_ERR(iomem);
 168
 169         xbar->iomem = iomem;
 170
 171         xbar->dmarouter.dev = &pdev->dev;
 172         xbar->dmarouter.route_free = ti_dma_xbar_free;
 173         xbar->dma_offset = (u32)match->data;
 174
 175         platform_set_drvdata(pdev, xbar);
 176
 177         /* Reset the crossbar */
 178         for (i = 0; i < xbar->dma_requests; i++)
 179                 ti_dma_xbar_write(xbar->iomem, i, xbar->safe_val);
 180
 181         ret = of_dma_router_register(node, ti_dma_xbar_route_allocate,
 182                                      &xbar->dmarouter);
 183         if (ret) {
 184                 /* Restore the defaults for the crossbar */
 185                 for (i = 0; i < xbar->dma_requests; i++)
 186                         ti_dma_xbar_write(xbar->iomem, i, i);
 187         }
 188
 189         return ret;
 190 }
 191
 192 static const struct of_device_id ti_dma_xbar_match[] = {
 193         { .compatible = "ti,dra7-dma-crossbar" },
 194         {},
 195 };
 196
 197 static struct platform_driver ti_dma_xbar_driver = {
 198         .driver = {
 199                 .name = "ti-dma-crossbar",
 200                 .of_match_table = of_match_ptr(ti_dma_xbar_match),
 201         },
 202         .probe  = ti_dma_xbar_probe,
 203 };
 204
 205 int omap_dmaxbar_init(void)
 206 {
 207         return platform_driver_register(&ti_dma_xbar_driver);
 208 }
 209 arch_initcall(omap_dmaxbar_init);