Message-ID:
 <IA1PR20MB49530BA6C3CBC3C59C1187FEBB2C2@IA1PR20MB4953.namprd20.prod.outlook.com>
Date: Tue, 19 Mar 2024 12:08:03 +0800
From: Inochi Amaoto <inochiama@...look.com>
To: Samuel Holland <samuel.holland@...ive.com>, 
	Inochi Amaoto <inochiama@...look.com>
Cc: Jisheng Zhang <jszhang@...nel.org>, Liu Gui <kenneth.liu@...hgo.com>, 
	Jingbao Qiu <qiujingbao.dlmu@...il.com>, dlan@...too.org, dmaengine@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org, 
	Vinod Koul <vkoul@...nel.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	Chen Wang <unicorn_wang@...look.com>, Paul Walmsley <paul.walmsley@...ive.com>, 
	Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>
Subject: Re: [PATCH v4 4/4] dmaengine: add driver for Sophgo CV18XX/SG200X
 dmamux

On Mon, Mar 18, 2024 at 10:36:01PM -0500, Samuel Holland wrote:
> On 2024-03-18 1:38 AM, Inochi Amaoto wrote:
> > Sophgo CV18XX/SG200X use DW AXI CORE with a multiplexer for remapping
> > its request lines. The multiplexer supports at most 8 request lines.
> > 
> > Add driver for Sophgo CV18XX/SG200X DMA multiplexer.
> > 
> > Signed-off-by: Inochi Amaoto <inochiama@...look.com>
> > ---
> >  drivers/dma/Kconfig         |   9 ++
> >  drivers/dma/Makefile        |   1 +
> >  drivers/dma/cv1800-dmamux.c | 232 ++++++++++++++++++++++++++++++++++++
> >  3 files changed, 242 insertions(+)
> >  create mode 100644 drivers/dma/cv1800-dmamux.c
> > 
> > diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> > index 002a5ec80620..cb31520b9f86 100644
> > --- a/drivers/dma/Kconfig
> > +++ b/drivers/dma/Kconfig
> > @@ -546,6 +546,15 @@ config PLX_DMA
> >  	  These are exposed via extra functions on the switch's
> >  	  upstream port. Each function exposes one DMA channel.
> > 
> > +config SOPHGO_CV1800_DMAMUX
> > +	tristate "Sophgo CV1800/SG2000 series SoC DMA multiplexer support"
> > +	depends on MFD_SYSCON
> > +	depends on ARCH_SOPHGO
> > +	help
> > +	  Support for the DMA multiplexer on Sophgo CV1800/SG2000
> > +	  series SoCs.
> > +	  Say Y here if your board have this soc.
> > +
> >  config STE_DMA40
> >  	bool "ST-Ericsson DMA40 support"
> >  	depends on ARCH_U8500
> > diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> > index dfd40d14e408..7465f249ee47 100644
> > --- a/drivers/dma/Makefile
> > +++ b/drivers/dma/Makefile
> > @@ -67,6 +67,7 @@ obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/
> >  obj-$(CONFIG_PXA_DMA) += pxa_dma.o
> >  obj-$(CONFIG_RENESAS_DMA) += sh/
> >  obj-$(CONFIG_SF_PDMA) += sf-pdma/
> > +obj-$(CONFIG_SOPHGO_CV1800_DMAMUX) += cv1800-dmamux.o
> >  obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
> >  obj-$(CONFIG_STM32_DMA) += stm32-dma.o
> >  obj-$(CONFIG_STM32_DMAMUX) += stm32-dmamux.o
> > diff --git a/drivers/dma/cv1800-dmamux.c b/drivers/dma/cv1800-dmamux.c
> > new file mode 100644
> > index 000000000000..b41c39f2e338
> > --- /dev/null
> > +++ b/drivers/dma/cv1800-dmamux.c
> > @@ -0,0 +1,232 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2023 Inochi Amaoto <inochiama@...look.com>
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/module.h>
> > +#include <linux/of_dma.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/mfd/syscon.h>
> > +
> > +#include <soc/sophgo/cv1800-sysctl.h>
> > +#include <dt-bindings/dma/cv1800-dma.h>
> > +
> > +#define DMAMUX_NCELLS			3
> > +#define MAX_DMA_MAPPING_ID		DMA_SPI_NOR1
> > +#define MAX_DMA_CPU_ID			DMA_CPU_C906_1
> > +#define MAX_DMA_CH_ID			7
> > +
> > +#define DMAMUX_INTMUX_REGISTER_LEN	4
> > +#define DMAMUX_NR_CH_PER_REGISTER	4
> > +#define DMAMUX_BIT_PER_CH		8
> > +#define DMAMUX_CH_MASk			GENMASK(5, 0)
> > +#define DMAMUX_INT_BIT_PER_CPU		10
> > +#define DMAMUX_CH_UPDATE_BIT		BIT(31)
> > +
> > +#define DMAMUX_CH_SET(chid, val) \
> > +	(((val) << ((chid) * DMAMUX_BIT_PER_CH)) | DMAMUX_CH_UPDATE_BIT)
> > +#define DMAMUX_CH_MASK(chid) \
> > +	DMAMUX_CH_SET(chid, DMAMUX_CH_MASk)
> > +
> > +#define DMAMUX_INT_BIT(chid, cpuid) \
> > +	BIT((cpuid) * DMAMUX_INT_BIT_PER_CPU + (chid))
> > +#define DMAMUX_INTEN_BIT(cpuid) \
> > +	DMAMUX_INT_BIT(8, cpuid)
> > +#define DMAMUX_INT_CH_BIT(chid, cpuid) \
> > +	(DMAMUX_INT_BIT(chid, cpuid) | DMAMUX_INTEN_BIT(cpuid))
> > +#define DMAMUX_INT_MASK(chid) \
> > +	(DMAMUX_INT_BIT(chid, DMA_CPU_A53) | \
> > +	 DMAMUX_INT_BIT(chid, DMA_CPU_C906_0) | \
> > +	 DMAMUX_INT_BIT(chid, DMA_CPU_C906_1))
> > +#define DMAMUX_INT_CH_MASK(chid, cpuid) \
> > +	(DMAMUX_INT_MASK(chid) | DMAMUX_INTEN_BIT(cpuid))
> > +
> > +struct cv1800_dmamux_data {
> > +	struct dma_router	dmarouter;
> > +	struct regmap		*regmap;
> > +	spinlock_t		lock;
> > +	DECLARE_BITMAP(used_chans, MAX_DMA_CH_ID);
> > +	DECLARE_BITMAP(mapped_peripherals, MAX_DMA_MAPPING_ID);
> > +};
> > +
> > +struct cv1800_dmamux_map {
> > +	unsigned int channel;
> > +	unsigned int peripheral;
> > +	unsigned int cpu;
> > +};
> > +
> > +static void cv1800_dmamux_free(struct device *dev, void *route_data)
> > +{
> > +	struct cv1800_dmamux_data *dmamux = dev_get_drvdata(dev);
> > +	struct cv1800_dmamux_map *map = route_data;
> > +	u32 regoff = map->channel % DMAMUX_NR_CH_PER_REGISTER;
> > +	u32 regpos = map->channel / DMAMUX_NR_CH_PER_REGISTER;
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&dmamux->lock, flags);
> > +
> > +	regmap_update_bits(dmamux->regmap,
> > +			   regpos + CV1800_SDMA_DMA_CHANNEL_REMAP0,
> > +			   DMAMUX_CH_MASK(regoff),
> > +			   DMAMUX_CH_UPDATE_BIT);
> > +
> > +	regmap_update_bits(dmamux->regmap, CV1800_SDMA_DMA_INT_MUX,
> > +			   DMAMUX_INT_CH_MASK(map->channel, map->cpu),
> > +			   DMAMUX_INTEN_BIT(map->cpu));
> > +
> > +	clear_bit(map->channel, dmamux->used_chans);
> > +	clear_bit(map->peripheral, dmamux->mapped_peripherals);
> > +
> > +	spin_unlock_irqrestore(&dmamux->lock, flags);
> > +
> > +	kfree(map);
> > +}
> > +
> > +static void *cv1800_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 cv1800_dmamux_data *dmamux = platform_get_drvdata(pdev);
> > +	struct cv1800_dmamux_map *map;
> > +	unsigned long flags;
> > +	unsigned int chid, devid, cpuid;
> > +	u32 regoff, regpos;
> > +
> > +	if (dma_spec->args_count != DMAMUX_NCELLS) {
> > +		dev_err(&pdev->dev, "invalid number of dma mux args\n");
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +
> > +	chid = dma_spec->args[0];
> > +	devid = dma_spec->args[1];
> > +	cpuid = dma_spec->args[2];
> > +	dma_spec->args_count -= 2;
> > +
> > +	if (chid > MAX_DMA_CH_ID) {
> > +		dev_err(&pdev->dev, "invalid channel id: %u\n", chid);
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +
> > +	if (devid > MAX_DMA_MAPPING_ID) {
> > +		dev_err(&pdev->dev, "invalid device id: %u\n", devid);
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +
> > +	if (cpuid > MAX_DMA_CPU_ID) {
> > +		dev_err(&pdev->dev, "invalid cpu id: %u\n", cpuid);
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +
> > +	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
> > +	if (!dma_spec->np) {
> > +		dev_err(&pdev->dev, "can't get dma master\n");
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +
> > +	map = kzalloc(sizeof(*map), GFP_KERNEL);
> > +	if (!map)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	map->channel = chid;
> > +	map->peripheral = devid;
> > +	map->cpu = cpuid;
> > +
> > +	regoff = chid % DMAMUX_NR_CH_PER_REGISTER;
> > +	regpos = chid / DMAMUX_NR_CH_PER_REGISTER;
> > +
> > +	spin_lock_irqsave(&dmamux->lock, flags);
> > +
> > +	if (test_and_set_bit(devid, dmamux->mapped_peripherals)) {
> > +		dev_err(&pdev->dev, "already used device mapping: %u\n", devid);
> > +		goto failed;
> > +	}
> > +
> > +	if (test_and_set_bit(chid, dmamux->used_chans)) {
> > +		clear_bit(devid, dmamux->mapped_peripherals);
> > +		dev_err(&pdev->dev, "already used channel id: %u\n", chid);
> > +		goto failed;
> > +	}
> > +
> > +	regmap_set_bits(dmamux->regmap,
> > +			regpos + CV1800_SDMA_DMA_CHANNEL_REMAP0,
> > +			DMAMUX_CH_SET(regoff, devid));
> > +
> > +	regmap_update_bits(dmamux->regmap, CV1800_SDMA_DMA_INT_MUX,
> > +			   DMAMUX_INT_CH_MASK(chid, cpuid),
> > +			   DMAMUX_INT_CH_BIT(chid, cpuid));
> > +
> > +	spin_unlock_irqrestore(&dmamux->lock, flags);
> > +
> > +	dev_info(&pdev->dev, "register channel %u for req %u (cpu %u)\n",
> > +		 chid, devid, cpuid);
> > +
> > +	return map;
> > +
> > +failed:
> > +	spin_unlock_irqrestore(&dmamux->lock, flags);
> > +	dev_err(&pdev->dev, "already used channel id: %u\n", chid);
> 
> This error is already logged above.
> 
> > +	return ERR_PTR(-EBUSY);
> > +}
> > +
> > +static int cv1800_dmamux_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct device_node *mux_node = dev->of_node;
> > +	struct cv1800_dmamux_data *data;
> > +	struct device *parent = dev->parent;
> > +	struct device_node *dma_master;
> > +	struct regmap *map = NULL;
> > +
> > +	if (!parent)
> > +		return -ENODEV;
> > +
> > +	map = device_node_to_regmap(parent->of_node);
> > +	if (IS_ERR(map))
> > +		return PTR_ERR(map);
> > +
> > +	dma_master = of_parse_phandle(mux_node, "dma-masters", 0);
> > +	if (!dma_master) {
> > +		dev_err(dev, "invalid dma-requests property\n");
> 
> This error message doesn't match the property the code looks at.
> 
> > +		return -ENODEV;
> > +	}
> > +	of_node_put(dma_master);
> > +
> > +	data = devm_kmalloc(dev, sizeof(*data), GFP_KERNEL);
> > +	if (!data)
> > +		return -ENOMEM;
> > +
> > +	spin_lock_init(&data->lock);
> > +	data->regmap = map;
> > +	data->dmarouter.dev = dev;
> > +	data->dmarouter.route_free = cv1800_dmamux_free;
> > +
> > +	platform_set_drvdata(pdev, data);
> > +
> > +	return of_dma_router_register(mux_node,
> > +				      cv1800_dmamux_route_allocate,
> > +				      &data->dmarouter);
> > +}
> > +
> > +static const struct of_device_id cv1800_dmamux_ids[] = {
> > +	{ .compatible = "sophgo,cv1800-dmamux", },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, cv1800_dmamux_ids);
> > +
> > +static struct platform_driver cv1800_dmamux_driver = {
> > +	.driver = {
> > +		.name = "fsl-raideng",
> 
> copy-paste error?

Thanks for point it out.

> 
> > +		.of_match_table = cv1800_dmamux_ids,
> > +	},
> > +	.probe = cv1800_dmamux_probe,
> > +};
> > +module_platform_driver(cv1800_dmamux_driver);
> 
> This driver can be built as an unloadable module, so it needs a .remove_new
> function calling at least of_dma_controller_free().
> 

Thanks.

> Regards,
> Samuel
> 
> > +
> > +MODULE_AUTHOR("Inochi Amaoto <inochiama@...look.com>");
> > +MODULE_DESCRIPTION("Sophgo CV1800/SG2000 Series Soc DMAMUX driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.44.0
> > 
> > 
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
> 

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