dma/dw/rzn1-dmamux.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2022 Schneider-Electric
0004  * Author: Miquel Raynal <miquel.raynal@bootlin.com
0005  * Based on TI crossbar driver written by Peter Ujfalusi <peter.ujfalusi@ti.com>
0006  */
0007 #include <linux/bitops.h>
0008 #include <linux/of_device.h>
0009 #include <linux/of_dma.h>
0010 #include <linux/slab.h>
0011 #include <linux/soc/renesas/r9a06g032-sysctrl.h>
0012 #include <linux/types.h>
0013
0014 #define RNZ1_DMAMUX_NCELLS 6
0015 #define RZN1_DMAMUX_MAX_LINES 64
0016 #define RZN1_DMAMUX_LINES_PER_CTLR 16
0017
0018 struct rzn1_dmamux_data {
0019     struct dma_router dmarouter;
0020     DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
0021 };
0022
0023 struct rzn1_dmamux_map {
0024     unsigned int req_idx;
0025 };
0026
0027 static void rzn1_dmamux_free(struct device *dev, void *route_data)
0028 {
0029     struct rzn1_dmamux_data *dmamux = dev_get_drvdata(dev);
0030     struct rzn1_dmamux_map *map = route_data;
0031
0032     dev_dbg(dev, "Unmapping DMAMUX request %u\n", map->req_idx);
0033
0034     clear_bit(map->req_idx, dmamux->used_chans);
0035
0036     kfree(map);
0037 }
0038
0039 static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
0040                     struct of_dma *ofdma)
0041 {
0042     struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
0043     struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
0044     struct rzn1_dmamux_map *map;
0045     unsigned int dmac_idx, chan, val;
0046     u32 mask;
0047     int ret;
0048
0049     if (dma_spec->args_count != RNZ1_DMAMUX_NCELLS)
0050         return ERR_PTR(-EINVAL);
0051
0052     map = kzalloc(sizeof(*map), GFP_KERNEL);
0053     if (!map)
0054         return ERR_PTR(-ENOMEM);
0055
0056     chan = dma_spec->args[0];
0057     map->req_idx = dma_spec->args[4];
0058     val = dma_spec->args[5];
0059     dma_spec->args_count -= 2;
0060
0061     if (chan >= RZN1_DMAMUX_LINES_PER_CTLR) {
0062         dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
0063         ret = -EINVAL;
0064         goto free_map;
0065     }
0066
0067     if (map->req_idx >= RZN1_DMAMUX_MAX_LINES ||
0068         (map->req_idx % RZN1_DMAMUX_LINES_PER_CTLR) != chan) {
0069         dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
0070         ret = -EINVAL;
0071         goto free_map;
0072     }
0073
0074     dmac_idx = map->req_idx >= RZN1_DMAMUX_LINES_PER_CTLR ? 1 : 0;
0075     dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
0076     if (!dma_spec->np) {
0077         dev_err(&pdev->dev, "Can't get DMA master\n");
0078         ret = -EINVAL;
0079         goto free_map;
0080     }
0081
0082     dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
0083         map->req_idx, dmac_idx, chan);
0084
0085     if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
0086         ret = -EBUSY;
0087         goto free_map;
0088     }
0089
0090     mask = BIT(map->req_idx);
0091     ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
0092     if (ret)
0093         goto clear_bitmap;
0094
0095     return map;
0096
0097 clear_bitmap:
0098     clear_bit(map->req_idx, dmamux->used_chans);
0099 free_map:
0100     kfree(map);
0101
0102     return ERR_PTR(ret);
0103 }
0104
0105 #ifdef CONFIG_OF
0106 static const struct of_device_id rzn1_dmac_match[] = {
0107     { .compatible = "renesas,rzn1-dma" },
0108     {}
0109 };
0110 #endif
0111
0112 static int rzn1_dmamux_probe(struct platform_device *pdev)
0113 {
0114     struct device_node *mux_node = pdev->dev.of_node;
0115     const struct of_device_id *match;
0116     struct device_node *dmac_node;
0117     struct rzn1_dmamux_data *dmamux;
0118
0119     dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
0120     if (!dmamux)
0121         return -ENOMEM;
0122
0123     dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
0124     if (!dmac_node)
0125         return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
0126
0127     match = of_match_node(rzn1_dmac_match, dmac_node);
0128     of_node_put(dmac_node);
0129     if (!match)
0130         return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
0131
0132     dmamux->dmarouter.dev = &pdev->dev;
0133     dmamux->dmarouter.route_free = rzn1_dmamux_free;
0134
0135     platform_set_drvdata(pdev, dmamux);
0136
0137     return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
0138                       &dmamux->dmarouter);
0139 }
0140
0141 static const struct of_device_id rzn1_dmamux_match[] = {
0142     { .compatible = "renesas,rzn1-dmamux" },
0143     {}
0144 };
0145 MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
0146
0147 static struct platform_driver rzn1_dmamux_driver = {
0148     .driver = {
0149         .name = "renesas,rzn1-dmamux",
0150         .of_match_table = rzn1_dmamux_match,
0151     },
0152     .probe  = rzn1_dmamux_probe,
0153 };
0154 module_platform_driver(rzn1_dmamux_driver);
0155
0156 MODULE_LICENSE("GPL");
0157 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
0158 MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");