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.
Signed-off-by: Piotr Wojtaszczyk piotr.wojtaszczyk@timesys.com --- Changes for v5: - Fix struct declaration order - Removed unused variables - Break search loop if expected lpc32xx_muxes[i].signal is found
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 ceec359c68fc..118d48747641 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2404,6 +2404,7 @@ 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
ARM/Marvell Dove/MV78xx0/Orion SOC support M: Andrew Lunn andrew@lunn.ch 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..351d7e23e615 --- /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; +}; + +struct lpc32xx_dmamux_data { + struct dma_router dmarouter; + struct regmap *reg; + spinlock_t lock; /* protects busy status flag */ +}; + +/* 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, + }, +}; + +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; + + 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]; + break; + } + } + 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; + + 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);