tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
18struct rzn1_dmamux_data {
19 struct dma_router dmarouter;
20 DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
21};
22
23struct rzn1_dmamux_map {
24 unsigned int req_idx;
25};
26
27static 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
39static 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
97clear_bitmap:
98 clear_bit(map->req_idx, dmamux->used_chans);
99free_map:
100 kfree(map);
101
102 return ERR_PTR(ret);
103}
104
105#ifdef CONFIG_OF
106static const struct of_device_id rzn1_dmac_match[] = {
107 { .compatible = "renesas,rzn1-dma" },
108 {}
109};
110#endif
111
112static 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
141static const struct of_device_id rzn1_dmamux_match[] = {
142 { .compatible = "renesas,rzn1-dmamux" },
143 {}
144};
145MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
146
147static 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};
154module_platform_driver(rzn1_dmamux_driver);
155
156MODULE_LICENSE("GPL");
157MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
158MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");