The DRA7x has more peripherals with DMA requests than the sDMA can handle: 205 vs 127. All DMA requests are routed through the DMA crossbar, which can be configured to route selected incoming DMA requests to specific sDMA request. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> --- drivers/dma/Kconfig | 4 + drivers/dma/Makefile | 1 + drivers/dma/ti-dma-crossbar.c | 191 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 196 insertions(+) create mode 100644 drivers/dma/ti-dma-crossbar.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index a874b6ec6650..dfe72a0f46dc 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -245,6 +245,9 @@ config TI_EDMA Enable support for the TI EDMA controller. This DMA engine is found on TI DaVinci and AM33xx parts. +config TI_DMA_CROSSBAR + bool + config ARCH_HAS_ASYNC_TX_FIND_CHANNEL bool @@ -330,6 +333,7 @@ config DMA_OMAP depends on ARCH_OMAP select DMA_ENGINE select DMA_VIRTUAL_CHANNELS + select TI_DMA_CROSSBAR if SOC_DRA7XX config DMA_BCM2835 tristate "BCM2835 DMA engine support" diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index f915f61ec574..bc12f9a4e62b 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o obj-$(CONFIG_DMA_OMAP) += omap-dma.o +obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c new file mode 100644 index 000000000000..bf01434df46a --- /dev/null +++ b/drivers/dma/ti-dma-crossbar.c @@ -0,0 +1,191 @@ +/* + * 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/slab.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/io.h> +#include <linux/regmap.h> +#include <linux/idr.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/module.h> + +static DEFINE_IDR(map_idr); + +struct ti_dma_xbar_data { + struct dma_router dmarouter; + struct regmap *regmap; + + uint safe_val; /* Value to rest the crossbar lines */ + uint xbar_requests; /* number of DMA requests connected to XBAR */ + uint dma_requests; /* number of DMA requests forwarded to DMA */ + + void __iomem *iomem; +}; + +struct ti_dma_xbar_map { + int xbar_in; + int xbar_out; +}; + +static void ti_dma_xbar_free(struct device *dev, void *route_data) +{ + struct ti_dma_xbar_data *xbar = dev_get_drvdata(dev); + struct ti_dma_xbar_map *map = route_data; + + dev_dbg(dev, "Unmapping XBAR%d (was routed to %d)\n", + map->xbar_in, map->xbar_out); + + regmap_write(xbar->regmap, map->xbar_out * 2, 0); + idr_remove(&map_idr, map->xbar_out); + kfree(map); +} + +static void *ti_dma_xbar_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 ti_dma_xbar_data *xbar = platform_get_drvdata(pdev); + struct ti_dma_xbar_map *map; + + if (dma_spec->args[0] >= xbar->xbar_requests) { + dev_err(&pdev->dev, "Invalid XBAR request number: %d\n", + dma_spec->args[0]); + return NULL; + } + + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (!map) + return NULL; + + map->xbar_out = idr_alloc(&map_idr, NULL, 0, xbar->dma_requests, + GFP_KERNEL); + map->xbar_in = dma_spec->args[0]; + + /* The DMA request is 1 based in sDMA */ + dma_spec->args[0] = map->xbar_out + 1; + + dev_dbg(&pdev->dev, "Mapping XBAR%d to DMA%d\n", + map->xbar_in, map->xbar_out); + + regmap_write(xbar->regmap, map->xbar_out * 2, map->xbar_in); + + return map; +} + +static const struct regmap_config ti_dma_xbar_regmap_config = { + .reg_bits = 32, + .reg_stride = 2, + .val_bits = 16, + .max_register = 0xfc, + .cache_type = REGCACHE_FLAT, +}; + +static int ti_dma_xbar_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct device_node *dma_node; + struct ti_dma_xbar_data *xbar; + struct resource *res; + void __iomem *iomem; + int i, ret; + + if (!node) + return -ENODEV; + + dma_node = of_parse_phandle(node, "dma-device", 0); + if (!dma_node) { + dev_err(&pdev->dev, "Can't get target DMA node\n"); + return -ENODEV; + } + + xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL); + if (!xbar) + return -ENOMEM; + + if (of_property_read_u32(dma_node, "dma-requests", + &xbar->dma_requests)) { + dev_warn(&pdev->dev, + "DMA request lines not specified, using 127\n"); + xbar->dma_requests = 127; + } + of_node_put(dma_node); + + if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) { + dev_warn(&pdev->dev, + "XBAR request lines not specified, using 255\n"); + xbar->xbar_requests = 256; + } + + if (of_property_read_u32(node, "ti,dma-safe-map", &xbar->safe_val)) + xbar->safe_val = 0; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res), + dev_name(&pdev->dev))) + return -ENODEV; + + iomem = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!iomem) + return -ENOMEM; + + xbar->regmap = devm_regmap_init_mmio(&pdev->dev, iomem, + &ti_dma_xbar_regmap_config); + if (IS_ERR(xbar->regmap)) { + dev_err(&pdev->dev, "regmap init failed\n"); + return PTR_ERR(xbar->regmap); + } + xbar->iomem = iomem; + + xbar->dmarouter.dev = &pdev->dev; + xbar->dmarouter.route_free = ti_dma_xbar_free; + + platform_set_drvdata(pdev, xbar); + + ret = of_dma_router_register(node, ti_dma_xbar_route_allocate, + &xbar->dmarouter); + if (ret) + return -ENODEV; + + /* Reset the crossbar */ + for (i = 0; i < xbar->dma_requests; i++) + regmap_write(xbar->regmap, i * 2, xbar->safe_val); + + return 0; +} + +static const struct of_device_id ti_dma_xbar_match[] = { + { .compatible = "ti,dra7-dma-crossbar" }, + {}, +}; + +static struct platform_driver ti_dma_xbar_driver = { + .probe = ti_dma_xbar_probe, + .driver = { + .name = "ti-dma-crossbar", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(ti_dma_xbar_match), + }, +}; + +int omap_dmaxbar_init(void) +{ + return platform_driver_register(&ti_dma_xbar_driver); +} +arch_initcall(omap_dmaxbar_init); + +MODULE_DESCRIPTION("TI DMA Crossbar"); +MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@xxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
