Commit 134d9c52 authored by Miquel Raynal's avatar Miquel Raynal Committed by Vinod Koul
Browse files

dmaengine: dw: dmamux: Introduce RZN1 DMA router support 



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: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220427095653.91804-6-miquel.raynal@bootlin.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 885525c1

drivers/dma/dw/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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

drivers/dma/dw/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -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

drivers/dma/dw/rzn1-dmamux.c

0 → 100644
+155 −0
Original line number Diff line number Diff line 
// 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");