@@ -16,6 +16,15 @@ config DW_DMAC
Support the Synopsys DesignWare AHB DMA controller. This
can be integrated in chips such as the Intel Cherrytrail.
+config RZN1_DMAMUX
+ tristate "Renesas RZ/N1 DMAMUX driver"
+ depends on DW_DMAC
+ depends on ARCH_RZN1 || COMPILE_TEST
+ help
+ Support the Renesas RZ/N1 DMAMUX which is located in front of
+ the Synopsys DesignWare AHB DMA controller located on Renesas
+ SoCs.
+
config DW_DMAC_PCI
tristate "Synopsys DesignWare AHB DMA PCI driver"
depends on PCI
@@ -9,3 +9,5 @@ dw_dmac-$(CONFIG_OF) += of.o
obj-$(CONFIG_DW_DMAC_PCI) += dw_dmac_pci.o
dw_dmac_pci-y := pci.o
+
+obj-$(CONFIG_RZN1_DMAMUX) += rzn1-dmamux.o
new file mode 100644
@@ -0,0 +1,155 @@
+// 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);
+}
+
+static const struct of_device_id rzn1_dmac_match[] = {
+ { .compatible = "renesas,rzn1-dma" },
+ {}
+};
+
+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" },
+ {}
+};
+
+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");