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
20struct rzn1_dmamux_data {
21	struct dma_router dmarouter;
22	DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
23};
24
25struct rzn1_dmamux_map {
26	unsigned int req_idx;
27};
28
29static 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
41static 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
99clear_bitmap:
100	clear_bit(map->req_idx, dmamux->used_chans);
101free_map:
102	kfree(map);
103
104	return ERR_PTR(ret);
105}
106
107#ifdef CONFIG_OF
108static const struct of_device_id rzn1_dmac_match[] = {
109	{ .compatible = "renesas,rzn1-dma" },
110	{}
111};
112#endif
113
114static 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
143static const struct of_device_id rzn1_dmamux_match[] = {
144	{ .compatible = "renesas,rzn1-dmamux" },
145	{}
146};
147MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
148
149static 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};
156module_platform_driver(rzn1_dmamux_driver);
157
158MODULE_LICENSE("GPL");
159MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
160MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");
161