Add support for DMA on NXP LPC18xx/43xx platforms which has a multiplexer in front of the PL080 dma request lines. The mux is a single register in the LPC18xx/43xx CREG block and can multiplex up to 4 request lines to each of the 16 lines on the PL080. Signed-off-by: Joachim Eastwood <manabian@xxxxxxxxx> --- drivers/dma/Kconfig | 9 +++ drivers/dma/Makefile | 1 + drivers/dma/lpc18xx-dmamux.c | 183 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 193 insertions(+) create mode 100644 drivers/dma/lpc18xx-dmamux.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 88d474b78076..9d5a77cb9715 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -63,6 +63,15 @@ config AMBA_PL08X Platform has a PL08x DMAC device which can provide DMA engine support +config LPC18XX_DMAMUX + bool "NXP LPC18xx/43xx DMA MUX for PL080" + depends on ARCH_LPC18XX || COMPILE_TEST + depends on OF && AMBA_PL08X + select MFD_SYSCON + help + Enable support for DMA on NXP LPC18xx/43xx platforms + with PL080 and multiplexed DMA request lines. + config INTEL_IOATDMA tristate "Intel I/OAT DMA support" depends on PCI && X86 diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 6a4d6f2827da..800cb2d20be8 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_TI_EDMA) += edma.o obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o +obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o obj-$(CONFIG_PL330_DMA) += pl330.o obj-$(CONFIG_PCH_DMA) += pch_dma.o obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o diff --git a/drivers/dma/lpc18xx-dmamux.c b/drivers/dma/lpc18xx-dmamux.c new file mode 100644 index 000000000000..761f32687055 --- /dev/null +++ b/drivers/dma/lpc18xx-dmamux.c @@ -0,0 +1,183 @@ +/* + * DMA Router driver for LPC18xx/43xx DMA MUX + * + * Copyright (C) 2015 Joachim Eastwood <manabian@xxxxxxxxx> + * + * Based on TI DMA Crossbar driver by: + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com + * Author: Peter Ujfalusi <peter.ujfalusi@xxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/mfd/syscon.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/regmap.h> +#include <linux/spinlock.h> + +/* CREG register offset and macros for mux manipulation */ +#define LPC18XX_CREG_DMAMUX 0x11c +#define LPC18XX_DMAMUX_VAL(v, n) ((v) << (n * 2)) +#define LPC18XX_DMAMUX_MASK(n) (0x3 << (n * 2)) +#define LPC18XX_DMAMUX_MAX_VAL 0x3 + +struct lpc18xx_dmamux { + u32 value; + bool busy; +}; + +struct lpc18xx_dmamux_data { + struct dma_router dmarouter; + struct lpc18xx_dmamux *muxes; + u32 dma_master_requests; + u32 dma_mux_requests; + struct regmap *reg; + spinlock_t lock; +}; + +static void lpc18xx_dmamux_free(struct device *dev, void *route_data) +{ + struct lpc18xx_dmamux_data *dmamux = dev_get_drvdata(dev); + struct lpc18xx_dmamux *mux = route_data; + unsigned long flags; + + spin_lock_irqsave(&dmamux->lock, flags); + mux->busy = false; + spin_unlock_irqrestore(&dmamux->lock, flags); +} + +static void *lpc18xx_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 lpc18xx_dmamux_data *dmamux = platform_get_drvdata(pdev); + unsigned long flags; + unsigned mux; + + if (dma_spec->args_count != 3) { + dev_err(&pdev->dev, "invalid number of dma mux args\n"); + return ERR_PTR(-EINVAL); + } + + mux = dma_spec->args[0]; + if (mux >= dmamux->dma_master_requests) { + dev_err(&pdev->dev, "invalid mux number: %d\n", + dma_spec->args[0]); + return ERR_PTR(-EINVAL); + } + + if (dma_spec->args[1] > LPC18XX_DMAMUX_MAX_VAL) { + 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 (dmamux->muxes[mux].busy) { + spin_unlock_irqrestore(&dmamux->lock, flags); + dev_err(&pdev->dev, "dma request %u busy with %u.%u\n", + mux, mux, dmamux->muxes[mux].value); + of_node_put(dma_spec->np); + return ERR_PTR(-EBUSY); + } + + dmamux->muxes[mux].busy = true; + dmamux->muxes[mux].value = dma_spec->args[1]; + + regmap_update_bits(dmamux->reg, LPC18XX_CREG_DMAMUX, + LPC18XX_DMAMUX_MASK(mux), + LPC18XX_DMAMUX_VAL(dmamux->muxes[mux].value, mux)); + spin_unlock_irqrestore(&dmamux->lock, flags); + + dma_spec->args[1] = dma_spec->args[2]; + dma_spec->args_count = 2; + + dev_dbg(&pdev->dev, "mapping dmamux %u.%u to dma request %u\n", mux, + dmamux->muxes[mux].value, mux); + + return &dmamux->muxes[mux]; +} + +static int lpc18xx_dmamux_probe(struct platform_device *pdev) +{ + struct device_node *dma_np, *np = pdev->dev.of_node; + struct lpc18xx_dmamux_data *dmamux; + int ret; + + dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL); + if (!dmamux) + return -ENOMEM; + + dmamux->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg"); + if (IS_ERR(dmamux->reg)) { + dev_err(&pdev->dev, "syscon lookup failed\n"); + return PTR_ERR(dmamux->reg); + } + + ret = of_property_read_u32(np, "dma-requests", + &dmamux->dma_mux_requests); + if (ret) { + dev_err(&pdev->dev, "missing dma-requests property\n"); + return ret; + } + + dma_np = of_parse_phandle(np, "dma-masters", 0); + if (!dma_np) { + dev_err(&pdev->dev, "can't get dma master\n"); + return -ENODEV; + } + + ret = of_property_read_u32(dma_np, "dma-requests", + &dmamux->dma_master_requests); + of_node_put(dma_np); + if (ret) { + dev_err(&pdev->dev, "missing master dma-requests property\n"); + return ret; + } + + dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dma_master_requests, + sizeof(struct lpc18xx_dmamux), + GFP_KERNEL); + if (!dmamux->muxes) + return -ENOMEM; + + spin_lock_init(&dmamux->lock); + platform_set_drvdata(pdev, dmamux); + dmamux->dmarouter.dev = &pdev->dev; + dmamux->dmarouter.route_free = lpc18xx_dmamux_free; + + return of_dma_router_register(np, lpc18xx_dmamux_reserve, + &dmamux->dmarouter); +} + +static const struct of_device_id lpc18xx_dmamux_match[] = { + { .compatible = "nxp,lpc1850-dmamux" }, + {}, +}; + +static struct platform_driver lpc18xx_dmamux_driver = { + .probe = lpc18xx_dmamux_probe, + .driver = { + .name = "lpc18xx-dmamux", + .of_match_table = lpc18xx_dmamux_match, + }, +}; + +static int __init lpc18xx_dmamux_init(void) +{ + return platform_driver_register(&lpc18xx_dmamux_driver); +} +arch_initcall(lpc18xx_dmamux_init); -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
