dw/rzn1-dmamux.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2022 Schneider-Electric
   4  * Author: Miquel Raynal <miquel.raynal@bootlin.com
   5  * Based on TI crossbar driver written by Peter Ujfalusi <peter.ujfalusi@ti.com>
   6  */
   7 #include <linux/bitops.h>
   8 #include <linux/of.h>
   9 #include <linux/of_dma.h>
  10 #include <linux/of_platform.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13 #include <linux/soc/renesas/r9a06g032-sysctrl.h>
  14 #include <linux/types.h>
  15
  16 #define RNZ1_DMAMUX_NCELLS 6
  17 #define RZN1_DMAMUX_MAX_LINES 64
  18 #define RZN1_DMAMUX_LINES_PER_CTLR 16
  19
  20 struct rzn1_dmamux_data {
  21         struct dma_router dmarouter;
  22         DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
  23 };
  24
  25 struct rzn1_dmamux_map {
  26         unsigned int req_idx;
  27 };
  28
  29 static void rzn1_dmamux_free(struct device *dev, void *route_data)
  30 {
  31         struct rzn1_dmamux_data *dmamux = dev_get_drvdata(dev);
  32         struct rzn1_dmamux_map *map = route_data;
  33
  34         dev_dbg(dev, "Unmapping DMAMUX request %u\n", map->req_idx);
  35
  36         clear_bit(map->req_idx, dmamux->used_chans);
  37
  38         kfree(map);
  39 }
  40
  41 static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
  42                                         struct of_dma *ofdma)
  43 {
  44         struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
  45         struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
  46         struct rzn1_dmamux_map *map;
  47         unsigned int dmac_idx, chan, val;
  48         u32 mask;
  49         int ret;
  50
  51         if (dma_spec->args_count != RNZ1_DMAMUX_NCELLS)
  52                 return ERR_PTR(-EINVAL);
  53
  54         map = kzalloc(sizeof(*map), GFP_KERNEL);
  55         if (!map)
  56                 return ERR_PTR(-ENOMEM);
  57
  58         chan = dma_spec->args[0];
  59         map->req_idx = dma_spec->args[4];
  60         val = dma_spec->args[5];
  61         dma_spec->args_count -= 2;
  62
  63         if (chan >= RZN1_DMAMUX_LINES_PER_CTLR) {
  64                 dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
  65                 ret = -EINVAL;
  66                 goto free_map;
  67         }
  68
  69         if (map->req_idx >= RZN1_DMAMUX_MAX_LINES ||
  70             (map->req_idx % RZN1_DMAMUX_LINES_PER_CTLR) != chan) {
  71                 dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
  72                 ret = -EINVAL;
  73                 goto free_map;
  74         }
  75
  76         dmac_idx = map->req_idx >= RZN1_DMAMUX_LINES_PER_CTLR ? 1 : 0;
  77         dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
  78         if (!dma_spec->np) {
  79                 dev_err(&pdev->dev, "Can't get DMA master\n");
  80                 ret = -EINVAL;
  81                 goto free_map;
  82         }
  83
  84         dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
  85                 map->req_idx, dmac_idx, chan);
  86
  87         if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
  88                 ret = -EBUSY;
  89                 goto free_map;
  90         }
  91
  92         mask = BIT(map->req_idx);
  93         ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
  94         if (ret)
  95                 goto clear_bitmap;
  96
  97         return map;
  98
  99 clear_bitmap:
 100         clear_bit(map->req_idx, dmamux->used_chans);
 101 free_map:
 102         kfree(map);
 103
 104         return ERR_PTR(ret);
 105 }
 106
 107 #ifdef CONFIG_OF
 108 static const struct of_device_id rzn1_dmac_match[] = {
 109         { .compatible = "renesas,rzn1-dma" },
 110         {}
 111 };
 112 #endif
 113
 114 static int rzn1_dmamux_probe(struct platform_device *pdev)
 115 {
 116         struct device_node *mux_node = pdev->dev.of_node;
 117         const struct of_device_id *match;
 118         struct device_node *dmac_node;
 119         struct rzn1_dmamux_data *dmamux;
 120
 121         dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
 122         if (!dmamux)
 123                 return -ENOMEM;
 124
 125         dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
 126         if (!dmac_node)
 127                 return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
 128
 129         match = of_match_node(rzn1_dmac_match, dmac_node);
 130         of_node_put(dmac_node);
 131         if (!match)
 132                 return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
 133
 134         dmamux->dmarouter.dev = &pdev->dev;
 135         dmamux->dmarouter.route_free = rzn1_dmamux_free;
 136
 137         platform_set_drvdata(pdev, dmamux);
 138
 139         return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
 140                                       &dmamux->dmarouter);
 141 }
 142
 143 static const struct of_device_id rzn1_dmamux_match[] = {
 144         { .compatible = "renesas,rzn1-dmamux" },
 145         {}
 146 };
 147 MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
 148
 149 static struct platform_driver rzn1_dmamux_driver = {
 150         .driver = {
 151                 .name = "renesas,rzn1-dmamux",
 152                 .of_match_table = rzn1_dmamux_match,
 153         },
 154         .probe  = rzn1_dmamux_probe,
 155 };
 156 module_platform_driver(rzn1_dmamux_driver);
 157
 158 MODULE_LICENSE("GPL");
 159 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
 160 MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");