diff options
Diffstat (limited to 'drivers/dma/dw/rzn1-dmamux.c')
| -rw-r--r-- | drivers/dma/dw/rzn1-dmamux.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/dma/dw/rzn1-dmamux.c b/drivers/dma/dw/rzn1-dmamux.c new file mode 100644 index 000000000000..f9912c3dd4d7 --- /dev/null +++ b/drivers/dma/dw/rzn1-dmamux.c @@ -0,0 +1,158 @@ +// 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"); |