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");