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