Re: [Patch v4 06/10] dmaengine: Add dma router for pl08x in LPC32XX SoC

Hi Piotr,

Any reason why dmaengine parts cant be sent separately, why are they clubbed together, I dont see any obvious dependencies...

On 20-06-24, 19:56, Piotr Wojtaszczyk wrote:

LPC32XX connects few of its peripherals to pl08x DMA thru a multiplexer, this driver allows to route a signal request line thru the multiplexer for given peripheral.

What is the difference b/w this and lpc18xx driver, why not reuse that one?

Signed-off-by: Piotr Wojtaszczyk piotr.wojtaszczyk@timesys.com

Changes for v4:

• This patch is new in v4

MAINTAINERS | 1 + drivers/dma/Kconfig | 9 ++ drivers/dma/Makefile | 1 + drivers/dma/lpc32xx-dmamux.c | 195 +++++++++++++++++++++++++++++++++++ 4 files changed, 206 insertions(+) create mode 100644 drivers/dma/lpc32xx-dmamux.c

diff --git a/MAINTAINERS b/MAINTAINERS index fadf1baafd89..5ffe988ee282 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2403,6 +2403,7 @@ R: Vladimir Zapolskiy vz@mleia.com L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) S: Maintained F: Documentation/devicetree/bindings/dma/nxp,lpc3220-dmamux.yaml +F: drivers/dma/lpc32xx-dmamux.c N: lpc32xx

ARM/Marvell Dove/MV78xx0/Orion SOC support diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 002a5ec80620..aeace3d7e066 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -378,6 +378,15 @@ config LPC18XX_DMAMUX Enable support for DMA on NXP LPC18xx/43xx platforms with PL080 and multiplexed DMA request lines.

+config LPC32XX_DMAMUX

• bool "NXP LPC32xx DMA MUX for PL080"
• depends on ARCH_LPC32XX || COMPILE_TEST
• depends on OF && AMBA_PL08X
• select MFD_SYSCON
• help

•  Support for PL080 multiplexed DMA request lines on
  

•  LPC32XX platrofm.
  

config LS2X_APB_DMA tristate "Loongson LS2X APB DMA support" depends on LOONGARCH || COMPILE_TEST diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 802ca916f05f..6f1350b62e7f 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -50,6 +50,7 @@ obj-$(CONFIG_INTEL_IOATDMA) += ioat/ obj-y += idxd/ obj-$(CONFIG_K3_DMA) += k3dma.o obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o +obj-$(CONFIG_LPC32XX_DMAMUX) += lpc32xx-dmamux.o obj-$(CONFIG_LS2X_APB_DMA) += ls2x-apb-dma.o obj-$(CONFIG_MILBEAUT_HDMAC) += milbeaut-hdmac.o obj-$(CONFIG_MILBEAUT_XDMAC) += milbeaut-xdmac.o diff --git a/drivers/dma/lpc32xx-dmamux.c b/drivers/dma/lpc32xx-dmamux.c new file mode 100644 index 000000000000..4e6ce6026164 --- /dev/null +++ b/drivers/dma/lpc32xx-dmamux.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Copyright 2024 Timesys Corporation piotr.wojtaszczyk@timesys.com +// +// Based on TI DMA Crossbar driver by: +// Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com +// Author: Peter Ujfalusi peter.ujfalusi@ti.com

+#include <linux/err.h> +#include <linux/init.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/spinlock.h>

+#define LPC32XX_SSP_CLK_CTRL 0x78 +#define LPC32XX_I2S_CLK_CTRL 0x7c

+struct lpc32xx_dmamux {

• int signal;
• char *name_sel0;
• char *name_sel1;
• int muxval;
• int muxreg;
• int bit;
• bool busy;

+};

+/* From LPC32x0 User manual "3.2.1 DMA request signals" */ +static struct lpc32xx_dmamux lpc32xx_muxes[] = {

• {

• .signal = 3,
  

• .name_sel0 = "spi2-rx-tx",
  

• .name_sel1 = "ssp1-rx",
  

• .muxreg = LPC32XX_SSP_CLK_CTRL,
  

• .bit = 5,
  

• },
• {

• .signal = 10,
  

• .name_sel0 = "uart7-rx",
  

• .name_sel1 = "i2s1-dma1",
  

• .muxreg = LPC32XX_I2S_CLK_CTRL,
  

• .bit = 4,
  

• },
• {

• .signal = 11,
  

• .name_sel0 = "spi1-rx-tx",
  

• .name_sel1 = "ssp1-tx",
  

• .muxreg = LPC32XX_SSP_CLK_CTRL,
  

• .bit = 4,
  

• },
• {

• .signal = 14,
  

• .name_sel0 = "none",
  

• .name_sel1 = "ssp0-rx",
  

• .muxreg = LPC32XX_SSP_CLK_CTRL,
  

• .bit = 3,
  

• },
• {

• .signal = 15,
  

• .name_sel0 = "none",
  

• .name_sel1 = "ssp0-tx",
  

• .muxreg = LPC32XX_SSP_CLK_CTRL,
  

• .bit = 2,
  

• },

+};

+struct lpc32xx_dmamux_data {

• struct dma_router dmarouter;
• struct regmap *reg;
• spinlock_t lock; /* protects busy status flag */

+};

+static void lpc32xx_dmamux_release(struct device *dev, void *route_data) +{

• struct lpc32xx_dmamux_data *dmamux = dev_get_drvdata(dev);
• struct lpc32xx_dmamux *mux = route_data;
• unsigned long flags;
• dev_dbg(dev, "releasing dma request signal %d routed to %s\n",

• mux->signal, mux->muxval ? mux->name_sel1 : mux->name_sel1);
  

• guard(spinlock)(&dmamux->lock);
• mux->busy = false;

+}

+static void *lpc32xx_dmamux_reserve(struct of_phandle_args *dma_spec,

• 		    struct of_dma *ofdma)
  

+{

• struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
• struct device *dev = &pdev->dev;
• struct lpc32xx_dmamux_data *dmamux = platform_get_drvdata(pdev);
• unsigned long flags;
• struct lpc32xx_dmamux *mux = NULL;
• int i;
• if (dma_spec->args_count != 3) {

• dev_err(&pdev->dev, "invalid number of dma mux args\n");
  

• return ERR_PTR(-EINVAL);
  

• }
• for (i = 0; i < ARRAY_SIZE(lpc32xx_muxes); i++) {

• if (lpc32xx_muxes[i].signal == dma_spec->args[0])
  

• 	mux = &lpc32xx_muxes[i];
  

• }
• if (!mux) {

• dev_err(&pdev->dev, "invalid mux request number: %d\n",
  

• 	dma_spec->args[0]);
  

• return ERR_PTR(-EINVAL);
  

• }
• if (dma_spec->args[2] > 1) {

• dev_err(&pdev->dev, "invalid dma mux value: %d\n",
  

• 	dma_spec->args[1]);
  

• return ERR_PTR(-EINVAL);
  

• }
• /* The of_node_put() will be done in the core for the node */
• 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 (mux->busy) {

• spin_unlock_irqrestore(&dmamux->lock, flags);
  

• dev_err(dev, "dma request signal %d busy, routed to %s\n",
  

• 	mux->signal, mux->muxval ? mux->name_sel1 : mux->name_sel1);
  

• of_node_put(dma_spec->np);
  

• return ERR_PTR(-EBUSY);
  

• }
• mux->busy = true;
• mux->muxval = dma_spec->args[2] ? BIT(mux->bit) : 0;
• regmap_update_bits(dmamux->reg, mux->muxreg, BIT(mux->bit), mux->muxval);
• spin_unlock_irqrestore(&dmamux->lock, flags);
• dma_spec->args[2] = 0;
• dma_spec->args_count = 2;
• dev_dbg(dev, "dma request signal %d routed to %s\n",

• mux->signal, mux->muxval ? mux->name_sel1 : mux->name_sel1);
  

• return mux;

+}

+static int lpc32xx_dmamux_probe(struct platform_device *pdev) +{

• struct device_node *np = pdev->dev.of_node;
• struct lpc32xx_dmamux_data *dmamux;
• int ret;
• dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
• if (!dmamux)

• return -ENOMEM;
  

• dmamux->reg = syscon_node_to_regmap(np->parent);
• if (IS_ERR(dmamux->reg)) {

• dev_err(&pdev->dev, "syscon lookup failed\n");
  

• return PTR_ERR(dmamux->reg);
  

• }
• spin_lock_init(&dmamux->lock);
• platform_set_drvdata(pdev, dmamux);
• dmamux->dmarouter.dev = &pdev->dev;
• dmamux->dmarouter.route_free = lpc32xx_dmamux_release;
• return of_dma_router_register(np, lpc32xx_dmamux_reserve,

• 		      &dmamux->dmarouter);
  

+}

+static const struct of_device_id lpc32xx_dmamux_match[] = {

• { .compatible = "nxp,lpc3220-dmamux" },
• {},

+};

+static struct platform_driver lpc32xx_dmamux_driver = {

• .probe = lpc32xx_dmamux_probe,
• .driver = {

• .name = "lpc32xx-dmamux",
  

• .of_match_table = lpc32xx_dmamux_match,
  

• },

+};

+static int __init lpc32xx_dmamux_init(void) +{

• return platform_driver_register(&lpc32xx_dmamux_driver);

+}

+arch_initcall(lpc32xx_dmamux_init);

2.25.1