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 ret = -EINVAL;
53 goto put_device;
54 }
55
56 map = kzalloc(sizeof(*map), GFP_KERNEL);
57 if (!map) {
58 ret = -ENOMEM;
59 goto put_device;
60 }
61
62 chan = dma_spec->args[0];
63 map->req_idx = dma_spec->args[4];
64 val = dma_spec->args[5];
65 dma_spec->args_count -= 2;
66
67 if (chan >= RZN1_DMAMUX_LINES_PER_CTLR) {
68 dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
69 ret = -EINVAL;
70 goto free_map;
71 }
72
73 if (map->req_idx >= RZN1_DMAMUX_MAX_LINES ||
74 (map->req_idx % RZN1_DMAMUX_LINES_PER_CTLR) != chan) {
75 dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
76 ret = -EINVAL;
77 goto free_map;
78 }
79
80 dmac_idx = map->req_idx >= RZN1_DMAMUX_LINES_PER_CTLR ? 1 : 0;
81 dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
82 if (!dma_spec->np) {
83 dev_err(&pdev->dev, "Can't get DMA master\n");
84 ret = -EINVAL;
85 goto free_map;
86 }
87
88 dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
89 map->req_idx, dmac_idx, chan);
90
91 if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
92 ret = -EBUSY;
93 goto free_map;
94 }
95
96 mask = BIT(map->req_idx);
97 ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
98 if (ret)
99 goto clear_bitmap;
100
101 put_device(&pdev->dev);
102 return map;
103
104 clear_bitmap:
105 clear_bit(map->req_idx, dmamux->used_chans);
106 free_map:
107 kfree(map);
108 put_device:
109 put_device(&pdev->dev);
110
111 return ERR_PTR(ret);
112 }
113
114 #ifdef CONFIG_OF
115 static const struct of_device_id rzn1_dmac_match[] = {
116 { .compatible = "renesas,rzn1-dma" },
117 {}
118 };
119 #endif
120
rzn1_dmamux_probe(struct platform_device * pdev)121 static int rzn1_dmamux_probe(struct platform_device *pdev)
122 {
123 struct device_node *mux_node = pdev->dev.of_node;
124 const struct of_device_id *match;
125 struct device_node *dmac_node;
126 struct rzn1_dmamux_data *dmamux;
127
128 dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
129 if (!dmamux)
130 return -ENOMEM;
131
132 dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
133 if (!dmac_node)
134 return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
135
136 match = of_match_node(rzn1_dmac_match, dmac_node);
137 of_node_put(dmac_node);
138 if (!match)
139 return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
140
141 dmamux->dmarouter.dev = &pdev->dev;
142 dmamux->dmarouter.route_free = rzn1_dmamux_free;
143
144 platform_set_drvdata(pdev, dmamux);
145
146 return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
147 &dmamux->dmarouter);
148 }
149
150 static const struct of_device_id rzn1_dmamux_match[] = {
151 { .compatible = "renesas,rzn1-dmamux" },
152 {}
153 };
154 MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
155
156 static struct platform_driver rzn1_dmamux_driver = {
157 .driver = {
158 .name = "renesas,rzn1-dmamux",
159 .of_match_table = rzn1_dmamux_match,
160 },
161 .probe = rzn1_dmamux_probe,
162 };
163 module_platform_driver(rzn1_dmamux_driver);
164
165 MODULE_LICENSE("GPL");
166 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
167 MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");
168