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"); 161