xref: /openbmc/linux/drivers/dma/dw/rzn1-dmamux.c (revision 897500c7)
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 
rzn1_dmamux_free(struct device * dev,void * route_data)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 
rzn1_dmamux_route_allocate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)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 
rzn1_dmamux_probe(struct platform_device * pdev)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