Re: [PATCH v6 3/3] dmaengine: add driver for Sophgo CV18XX/SG200X dmamux

From: Inochi Amaoto
Date: Sun Apr 07 2024 - 07:57:24 EST

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In reply to: Vinod Koul: "Re: [PATCH v6 3/3] dmaengine: add driver for Sophgo CV18XX/SG200X dmamux"
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On Sun, Apr 07, 2024 at 04:59:39PM +0530, Vinod Koul wrote:
> On 29-03-24, 10:04, 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@xxxxxxxxxxx>
> > ---
> > drivers/dma/Kconfig | 9 ++
> > drivers/dma/Makefile | 1 +
> > drivers/dma/cv1800-dmamux.c | 267 ++++++++++++++++++++++++++++++++++++
> > 3 files changed, 277 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..709414898b67
> > --- /dev/null
> > +++ b/drivers/dma/cv1800-dmamux.c
> > @@ -0,0 +1,267 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2023 Inochi Amaoto <inochiama@xxxxxxxxxxx>
>
> 2024
>
> > + */
> > +
> > +#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/llist.h>
> > +#include <linux/regmap.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/mfd/syscon.h>
> > +
> > +#include <soc/sophgo/cv1800-sysctl.h>
> > +
> > +#define DMAMUX_NCELLS 2
> > +#define MAX_DMA_MAPPING_ID 42
> > +#define MAX_DMA_CPU_ID 2
> > +#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_REGPOS(chid) \
> > + ((chid) / DMAMUX_NR_CH_PER_REGISTER)
> > +#define DMAMUX_CH_REGOFF(chid) \
> > + ((chid) % DMAMUX_NR_CH_PER_REGISTER)
> > +#define DMAMUX_CH_REG(chid) \
> > + ((DMAMUX_CH_REGPOS(chid) * sizeof(u32)) + \
> > + CV1800_SDMA_DMA_CHANNEL_REMAP0)
> > +#define DMAMUX_CH_SET(chid, val) \
> > + (((val) << (DMAMUX_CH_REGOFF(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, 0) | \
> > + DMAMUX_INT_BIT(chid, 1) | \
> > + DMAMUX_INT_BIT(chid, 2))
> > +#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;
> > + struct llist_head free_maps;
> > + struct llist_head reserve_maps;
> > + DECLARE_BITMAP(mapped_peripherals, MAX_DMA_MAPPING_ID);
> > +};
> > +
> > +struct cv1800_dmamux_map {
> > + struct llist_node node;
> > + 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;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&dmamux->lock, flags);
> > +
> > + regmap_update_bits(dmamux->regmap,
> > + DMAMUX_CH_REG(map->channel),
> > + DMAMUX_CH_MASK(map->channel),
> > + 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));
> > +
> > + spin_unlock_irqrestore(&dmamux->lock, flags);
> > +
> > + dev_info(dev, "free channel %u for req %u (cpu %u)\n",
> > + map->channel, map->peripheral, map->cpu);
>
> debug at most please
>
> > +}
> > +
> > +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;
> > + struct llist_node *node;
> > + unsigned long flags;
> > + unsigned int chid, devid, cpuid;
> > + int ret;
> > +
> > + if (dma_spec->args_count != DMAMUX_NCELLS) {
> > + dev_err(&pdev->dev, "invalid number of dma mux args\n");
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + devid = dma_spec->args[0];
> > + cpuid = dma_spec->args[1];
> > + dma_spec->args_count = 1;
> > +
> > + 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);
> > + }
> > +
> > + spin_lock_irqsave(&dmamux->lock, flags);
> > +
> > + if (test_bit(devid, dmamux->mapped_peripherals)) {
> > + llist_for_each_entry(map, dmamux->reserve_maps.first, node) {
> > + if (map->peripheral == devid && map->cpu == cpuid)
> > + goto found;
> > + }
> > +
> > + ret = -EINVAL;
> > + goto failed;
> > + } else {
> > + node = llist_del_first(&dmamux->free_maps);
> > + if (!node) {
> > + ret = -ENODEV;
> > + goto failed;
> > + }
> > +
> > + map = llist_entry(node, struct cv1800_dmamux_map, node);
> > + llist_add(&map->node, &dmamux->reserve_maps);
> > + set_bit(devid, dmamux->mapped_peripherals);
> > + }
> > +
> > +found:
> > + chid = map->channel;
> > + map->peripheral = devid;
> > + map->cpu = cpuid;
> > +
> > + regmap_set_bits(dmamux->regmap,
> > + DMAMUX_CH_REG(chid),
> > + DMAMUX_CH_SET(chid, 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);
> > +
> > + dma_spec->args[0] = chid;
> > +
> > + dev_info(&pdev->dev, "register channel %u for req %u (cpu %u)\n",
> > + chid, devid, cpuid);
>
> Here as well
>
> > +
> > + return map;
> > +
> > +failed:
> > + spin_unlock_irqrestore(&dmamux->lock, flags);
> > + of_node_put(dma_spec->np);
> > + dev_err(&pdev->dev, "errno %d\n", ret);
> > + return ERR_PTR(ret);
> > +
> > +}
> > +
> > +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 cv1800_dmamux_map *tmp;
> > + struct device *parent = dev->parent;
> > + struct device_node *dma_master;
> > + struct regmap *regmap = NULL;
> > + unsigned int i;
> > +
> > + if (!parent)
> > + return -ENODEV;
> > +
> > + regmap = device_node_to_regmap(parent->of_node);
> > + if (IS_ERR(regmap))
> > + return PTR_ERR(regmap);
> > +
> > + dma_master = of_parse_phandle(mux_node, "dma-masters", 0);
> > + if (!dma_master) {
> > + dev_err(dev, "invalid dma-requests property\n");
> > + return -ENODEV;
> > + }
> > + of_node_put(dma_master);
>
> why do this if you dont need it??
>

This is a pre check. It will issue an error if no valid dma-master.
The dma-master is used in the route callback. Is it better to just
leave this check in the callback?

> > +
> > + data = devm_kmalloc(dev, sizeof(*data), GFP_KERNEL);
> > + if (!data)
> > + return -ENOMEM;
> > +
> > + spin_lock_init(&data->lock);
> > + init_llist_head(&data->free_maps);
> > +
> > + for (i = 0; i <= MAX_DMA_CH_ID; i++) {
> > + tmp = devm_kmalloc(dev, sizeof(*tmp), GFP_KERNEL);
> > + if (!tmp) {
> > + /* It is OK for not allocating all channel */
> > + dev_warn(dev, "can not allocate channel %u\n", i);
> > + continue;
> > + }
> > +
> > + init_llist_node(&tmp->node);
> > + tmp->channel = i;
> > + llist_add(&tmp->node, &data->free_maps);
> > + }
> > +
> > + /* if no channel is allocated, the probe must fail */
> > + if (llist_empty(&data->free_maps))
> > + return -ENOMEM;
> > +
> > + data->regmap = regmap;
> > + 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 void cv1800_dmamux_remove(struct platform_device *pdev)
> > +{
> > + of_dma_controller_free(pdev->dev.of_node);
> > +}
> > +
> > +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 = "cv1800-dmamux",
> > + .of_match_table = cv1800_dmamux_ids,
> > + },
> > + .probe = cv1800_dmamux_probe,
> > + .remove_new = cv1800_dmamux_remove,
> > +};
> > +module_platform_driver(cv1800_dmamux_driver);
> > +
> > +MODULE_AUTHOR("Inochi Amaoto <inochiama@xxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("Sophgo CV1800/SG2000 Series Soc DMAMUX driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.44.0
>
> --
> ~Vinod

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