On 06-04-22, 18:18, Miquel Raynal wrote:
> The Renesas RZN1 DMA IP is 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>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/dma/dw/Kconfig | 9 ++
> drivers/dma/dw/Makefile | 2 +
> drivers/dma/dw/rzn1-dmamux.c | 157 +++++++++++++++++++++++++++++++++++
> 3 files changed, 168 insertions(+)
> create mode 100644 drivers/dma/dw/rzn1-dmamux.c
>
> diff --git a/drivers/dma/dw/Kconfig b/drivers/dma/dw/Kconfig
> index db25f9b7778c..a9828ddd6d06 100644
> --- a/drivers/dma/dw/Kconfig
> +++ b/drivers/dma/dw/Kconfig
> @@ -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
> diff --git a/drivers/dma/dw/Makefile b/drivers/dma/dw/Makefile
> index a6f358ad8591..e1796015f213 100644
> --- a/drivers/dma/dw/Makefile
> +++ b/drivers/dma/dw/Makefile
> @@ -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
> diff --git a/drivers/dma/dw/rzn1-dmamux.c b/drivers/dma/dw/rzn1-dmamux.c
> new file mode 100644
> index 000000000000..5f878a55158f
> --- /dev/null
> +++ b/drivers/dma/dw/rzn1-dmamux.c
> @@ -0,0 +1,157 @@
> +// 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/of_device.h>
> +#include <linux/of_dma.h>
> +#include <linux/slab.h>
> +#include <linux/soc/renesas/r9a06g032-sysctrl.h>
> +
> +#define RZN1_DMAMUX_LINES 64
> +#define RZN1_DMAMUX_MAX_LINES 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);
Why not use idr or bitmap for this. Hint: former does locking as well
> +
> + 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 != 6)
magic
> + 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_MAX_LINES) {
> + dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
> + ret = -EINVAL;
> + goto free_map;
> + }
> +
> + if (map->req_idx >= RZN1_DMAMUX_LINES ||
> + (map->req_idx % RZN1_DMAMUX_MAX_LINES) != 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_MAX_LINES ? 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);
> +
> + mask = BIT(map->req_idx);
> + mutex_lock(&dmamux->lock);
> + dmamux->used_chans |= mask;
> + ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
I guess due to this it would be merged by whosoever merges this api.
Please mention this in cover letter and how you propose this should be
merged
--
~Vinod
