DMA: shdma: add DT support

* SHDMA Device Tree bindings

Sh-/r-mobile and r-car systems often have multiple identical DMA controller

instances, capable of serving any of a common set of DMA slave devices, using

the same configuration. To describe this topology we require all compatible

SHDMA DT nodes to be placed under a DMA multiplexer node. All such compatible

DMAC instances have the same number of channels and use the same DMA

descriptors. Therefore respective DMA DT bindings can also all be placed in the

multiplexer node. Even if there is only one such DMAC instance on a system, it

still has to be placed under such a multiplexer node.

* DMA multiplexer

Required properties:

- compatible:	should be "renesas,shdma-mux"

- #dma-cells:	should be <1>, see "dmas" property below

Optional properties (currently unused):

- dma-channels:	number of DMA channels

- dma-requests:	number of DMA request signals

* DMA controller

Required properties:

- compatible:	should be "renesas,shdma"

Example:

	dmac: dma-mux0 {

		compatible = "renesas,shdma-mux";

		#dma-cells = <1>;

		dma-channels = <6>;

		dma-requests = <256>;

		reg = <0 0>;	/* Needed for AUXDATA */

		#address-cells = <1>;

		#size-cells = <1>;

		ranges;

		dma0: shdma@fe008020 {

			compatible = "renesas,shdma";

			reg = <0xfe008020 0x270>,

				<0xfe009000 0xc>;

			interrupt-parent = <&gic>;

			interrupts = <0 34 4

					0 28 4

					0 29 4

					0 30 4

					0 31 4

					0 32 4

					0 33 4>;

			interrupt-names = "error",

					"ch0", "ch1", "ch2", "ch3",

					"ch4", "ch5";

		};

		dma1: shdma@fe018020 {

			...

		};

		dma2: shdma@fe028020 {

			...

		};

	};

* DMA client

Required properties:

- dmas:		a list of <[DMA multiplexer phandle] [MID/RID value]> pairs,

		where MID/RID values are fixed handles, specified in the SoC

		manual

- dma-names:	a list of DMA channel names, one per "dmas" entry

Example:

	dmas = <&dmac 0xd1

		&dmac 0xd2>;

	dma-names = "tx", "rx";

obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o

obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o shdma-of.o

obj-$(CONFIG_SH_DMAE) += shdma.o

obj-$(CONFIG_SUDMAC) += sudmac.o

{

	struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);

	const struct shdma_ops *ops = sdev->ops;

	int ret;

	int ret, match;

	if (schan->dev->of_node) {

		match = schan->hw_req;

		ret = ops->set_slave(schan, match, true);

		if (ret < 0)

			return ret;

		slave_id = schan->slave_id;

	} else {

		match = slave_id;

	}

	if (slave_id < 0 || slave_id >= slave_num)

		return -EINVAL;

	if (test_and_set_bit(slave_id, shdma_slave_used))

		return -EBUSY;

	ret = ops->set_slave(schan, slave_id, false);

	ret = ops->set_slave(schan, match, false);

	if (ret < 0) {

		clear_bit(slave_id, shdma_slave_used);

		return ret;

 * services would have to provide their own filters, which first would check

 * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do

 * this, and only then, in case of a match, call this common filter.

 * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate().

 * In that case the MID-RID value is used for slave channel filtering and is

 * passed to this function in the "arg" parameter.

 */

bool shdma_chan_filter(struct dma_chan *chan, void *arg)

{

	struct shdma_chan *schan = to_shdma_chan(chan);

	struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);

	const struct shdma_ops *ops = sdev->ops;

	int slave_id = (int)arg;

	int match = (int)arg;

	int ret;

	if (slave_id < 0)

	if (match < 0)

		/* No slave requested - arbitrary channel */

		return true;

	if (slave_id >= slave_num)

	if (!schan->dev->of_node && match >= slave_num)

		return false;

	ret = ops->set_slave(schan, slave_id, true);

	ret = ops->set_slave(schan, match, true);

	if (ret < 0)

		return false;

/*

 * SHDMA Device Tree glue

 *

 * Copyright (C) 2013 Renesas Electronics Inc.

 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

 *

 * This is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License as

 * published by the Free Software Foundation.

 */

#include <linux/dmaengine.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_dma.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/shdma-base.h>

#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)

static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,

				       struct of_dma *ofdma)

{

	u32 id = dma_spec->args[0];

	dma_cap_mask_t mask;

	struct dma_chan *chan;

	if (dma_spec->args_count != 1)

		return NULL;

	dma_cap_zero(mask);

	/* Only slave DMA channels can be allocated via DT */

	dma_cap_set(DMA_SLAVE, mask);

	chan = dma_request_channel(mask, shdma_chan_filter, (void *)id);

	if (chan)

		to_shdma_chan(chan)->hw_req = id;

	return chan;

}

static int shdma_of_probe(struct platform_device *pdev)

{

	const struct of_dev_auxdata *lookup = pdev->dev.platform_data;

	int ret;

	if (!lookup)

		return -EINVAL;

	ret = of_dma_controller_register(pdev->dev.of_node,

					 shdma_of_xlate, pdev);

	if (ret < 0)

		return ret;

	ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);

	if (ret < 0)

		of_dma_controller_free(pdev->dev.of_node);

	return ret;

}

static const struct of_device_id shdma_of_match[] = {

	{ .compatible = "renesas,shdma-mux", },

	{ }

};

MODULE_DEVICE_TABLE(of, sh_dmae_of_match);

static struct platform_driver shdma_of = {

	.driver		= {

		.owner	= THIS_MODULE,

		.name	= "shdma-of",

		.of_match_table = shdma_of_match,

	},

	.probe		= shdma_of_probe,

};

module_platform_driver(shdma_of);

MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("SH-DMA driver DT glue");

MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");

	}

}

/*

 * Find a slave channel configuration from the contoller list by either a slave

 * ID in the non-DT case, or by a MID/RID value in the DT case

 */

static const struct sh_dmae_slave_config *dmae_find_slave(

	struct sh_dmae_chan *sh_chan, int slave_id)

	struct sh_dmae_chan *sh_chan, int match)

{

	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);

	struct sh_dmae_pdata *pdata = shdev->pdata;

	const struct sh_dmae_slave_config *cfg;

	int i;

	if (slave_id >= SH_DMA_SLAVE_NUMBER)

	if (!sh_chan->shdma_chan.dev->of_node) {

		if (match >= SH_DMA_SLAVE_NUMBER)

			return NULL;

		for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)

		if (cfg->slave_id == slave_id)

			if (cfg->slave_id == match)

				return cfg;

	} else {

		for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)

			if (cfg->mid_rid == match) {

				sh_chan->shdma_chan.slave_id = cfg->slave_id;

				return cfg;

			}

	}

	return NULL;

}

	return 0;

}

static const struct of_device_id sh_dmae_of_match[] = {

	{ .compatible = "renesas,shdma", },

	{ }

};

MODULE_DEVICE_TABLE(of, sh_dmae_of_match);

static struct platform_driver sh_dmae_driver = {

	.driver 	= {

		.owner	= THIS_MODULE,

		.pm	= &sh_dmae_pm,

		.name	= SH_DMAE_DRV_NAME,

		.of_match_table = sh_dmae_of_match,

	},

	.remove		= sh_dmae_remove,

	.shutdown	= sh_dmae_shutdown,