Hi Miquel,
Thank you for the patch.
On Fri, Feb 25, 2022 at 12:09 PM Miquel Raynal
<miquel.raynal@xxxxxxxxxxx> wrote:
>
> The Renesas RZN1 DMA IP is a based on a DW core, with eg. an additional
> dmamux register located in the system control area which can take up to
> 32 requests (16 per DMA controller). Each DMA channel can be wired to
> two different peripherals.
>
> We need two additional information from the 'dmas' property: the channel
> (bit in the dmamux register) that must be accessed and the value of the
> mux for this channel.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
> drivers/dma/dw/Kconfig | 8 ++
> drivers/dma/dw/Makefile | 2 +
> drivers/dma/dw/rzn1-dmamux.c | 152 +++++++++++++++++++++++++++++++++++
> 3 files changed, 162 insertions(+)
> create mode 100644 drivers/dma/dw/rzn1-dmamux.c
>
> diff --git a/drivers/dma/dw/Kconfig b/drivers/dma/dw/Kconfig
> index db25f9b7778c..dd53d4a9fa92 100644
> --- a/drivers/dma/dw/Kconfig
> +++ b/drivers/dma/dw/Kconfig
> @@ -16,6 +16,14 @@ 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
Maybe dependencies for ARCH_RZN1and COMPILE_TEST too?
> + 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
> diff --git a/drivers/dma/dw/Makefile b/drivers/dma/dw/Makefile
> index a6f358ad8591..8025f75e589c 100644
> --- a/drivers/dma/dw/Makefile
> +++ b/drivers/dma/dw/Makefile
> @@ -7,5 +7,7 @@ obj-$(CONFIG_DW_DMAC) += dw_dmac.o
> dw_dmac-y := platform.o
> dw_dmac-$(CONFIG_OF) += of.o
>
> +obj-$(CONFIG_RZN1_DMAMUX) += rzn1-dmamux.o
> +
> obj-$(CONFIG_DW_DMAC_PCI) += dw_dmac_pci.o
> dw_dmac_pci-y := pci.o
> diff --git a/drivers/dma/dw/rzn1-dmamux.c b/drivers/dma/dw/rzn1-dmamux.c
> new file mode 100644
> index 000000000000..bc4e2e7c3d18
> --- /dev/null
> +++ b/drivers/dma/dw/rzn1-dmamux.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2022 Schneider-Electric
> + * Author: Miquel Raynal <miquel.raynal@xxxxxxxxxxx
> + * Based on TI crossbar driver written by Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> + */
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/list.h>
> +#include <linux/io.h>
> +#include <linux/of_address.h>
can you please check if the above four includes are really required.
> +#include <linux/of_device.h>
> +#include <linux/of_dma.h>
> +#include <linux/soc/renesas/r9a06g032-sysctrl.h>
> +
headers need to be sorted.
> +#define RZN1_DMAMUX_LINES 64
> +#define RZN1_DMAMUX_SPLIT 16
> +
> +struct rzn1_dmamux_data {
> + struct dma_router dmarouter;
> + u32 used_chans;
> + struct mutex lock;
> +};
> +
> +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);
> +
> + mutex_lock(&dmamux->lock);
> + dmamux->used_chans &= ~BIT(map->req_idx);
> + mutex_unlock(&dmamux->lock);
> +
> + 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;
> +
> + map = kzalloc(sizeof(*map), GFP_KERNEL);
> + if (!map)
> + return ERR_PTR(-ENOMEM);
> +
map needs to be freed in the error path.
> + if (dma_spec->args_count != 6)
> + return ERR_PTR(-EINVAL);
> +
> + 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_SPLIT) {
> + dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + if (map->req_idx >= RZN1_DMAMUX_LINES ||
> + (map->req_idx % RZN1_DMAMUX_SPLIT) != chan) {
> + dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + dmac_idx = map->req_idx < RZN1_DMAMUX_SPLIT ? 0 : 1;
> + 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");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
> + map->req_idx, dmac_idx, chan);
> +
> + mask = BIT(map->req_idx);
> + mutex_lock(&dmamux->lock);
> + dmamux->used_chans |= mask;
> + ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
> + mutex_unlock(&dmamux->lock);
> + if (ret) {
> + rzn1_dmamux_free(&pdev->dev, map);
> + return ERR_PTR(ret);
> + }
> +
> + return map;
> +}
> +
> +static const struct of_device_id rzn1_dmac_match[] __maybe_unused = {
any reason for using __maybe_unused?
> + { .compatible = "renesas,rzn1-dma" },
> + {},
"," not required.
> +};
> +
> +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;
> +
> + mutex_init(&dmamux->lock);
> +
> + 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" },
> + {},
"," not required.
> +};
> +
> +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@xxxxxxxxxxx");
> +MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");
> --
> 2.27.0
>
Cheers,
Prabhakar
