linuxdebug/drivers/dma/dw/rzn1-dmamux.c

159 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2022 Schneider-Electric
* Author: Miquel Raynal <miquel.raynal@bootlin.com
* Based on TI crossbar driver written by Peter Ujfalusi <peter.ujfalusi@ti.com>
*/
#include <linux/bitops.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/slab.h>
#include <linux/soc/renesas/r9a06g032-sysctrl.h>
#include <linux/types.h>
#define RNZ1_DMAMUX_NCELLS 6
#define RZN1_DMAMUX_MAX_LINES 64
#define RZN1_DMAMUX_LINES_PER_CTLR 16
struct rzn1_dmamux_data {
struct dma_router dmarouter;
DECLARE_BITMAP(used_chans, 2 * RZN1_DMAMUX_LINES_PER_CTLR);
};
struct rzn1_dmamux_map {
unsigned int req_idx;
};
static void rzn1_dmamux_free(struct device *dev, void *route_data)
{
struct rzn1_dmamux_data *dmamux = dev_get_drvdata(dev);
struct rzn1_dmamux_map *map = route_data;
dev_dbg(dev, "Unmapping DMAMUX request %u\n", map->req_idx);
clear_bit(map->req_idx, dmamux->used_chans);
kfree(map);
}
static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
struct rzn1_dmamux_map *map;
unsigned int dmac_idx, chan, val;
u32 mask;
int ret;
if (dma_spec->args_count != RNZ1_DMAMUX_NCELLS)
return ERR_PTR(-EINVAL);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (!map)
return ERR_PTR(-ENOMEM);
chan = dma_spec->args[0];
map->req_idx = dma_spec->args[4];
val = dma_spec->args[5];
dma_spec->args_count -= 2;
if (chan >= RZN1_DMAMUX_LINES_PER_CTLR) {
dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
ret = -EINVAL;
goto free_map;
}
if (map->req_idx >= RZN1_DMAMUX_MAX_LINES ||
(map->req_idx % RZN1_DMAMUX_LINES_PER_CTLR) != chan) {
dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
ret = -EINVAL;
goto free_map;
}
dmac_idx = map->req_idx >= RZN1_DMAMUX_LINES_PER_CTLR ? 1 : 0;
dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
if (!dma_spec->np) {
dev_err(&pdev->dev, "Can't get DMA master\n");
ret = -EINVAL;
goto free_map;
}
dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
map->req_idx, dmac_idx, chan);
if (test_and_set_bit(map->req_idx, dmamux->used_chans)) {
ret = -EBUSY;
goto free_map;
}
mask = BIT(map->req_idx);
ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
if (ret)
goto clear_bitmap;
return map;
clear_bitmap:
clear_bit(map->req_idx, dmamux->used_chans);
free_map:
kfree(map);
return ERR_PTR(ret);
}
#ifdef CONFIG_OF
static const struct of_device_id rzn1_dmac_match[] = {
{ .compatible = "renesas,rzn1-dma" },
{}
};
#endif
static int rzn1_dmamux_probe(struct platform_device *pdev)
{
struct device_node *mux_node = pdev->dev.of_node;
const struct of_device_id *match;
struct device_node *dmac_node;
struct rzn1_dmamux_data *dmamux;
dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
if (!dmamux)
return -ENOMEM;
dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
if (!dmac_node)
return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
match = of_match_node(rzn1_dmac_match, dmac_node);
of_node_put(dmac_node);
if (!match)
return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
dmamux->dmarouter.dev = &pdev->dev;
dmamux->dmarouter.route_free = rzn1_dmamux_free;
platform_set_drvdata(pdev, dmamux);
return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
&dmamux->dmarouter);
}
static const struct of_device_id rzn1_dmamux_match[] = {
{ .compatible = "renesas,rzn1-dmamux" },
{}
};
MODULE_DEVICE_TABLE(of, rzn1_dmamux_match);
static struct platform_driver rzn1_dmamux_driver = {
.driver = {
.name = "renesas,rzn1-dmamux",
.of_match_table = rzn1_dmamux_match,
},
.probe = rzn1_dmamux_probe,
};
module_platform_driver(rzn1_dmamux_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");