[PATCH v2 3/7] dmaengine: Add driver for TI DMA crossbar on DRA7x
From: Vinod Koul <hidden>
Date: 2015-03-26 11:00:19
Also in:
linux-devicetree, linux-omap, lkml
On Wed, Mar 11, 2015 at 03:23:26PM +0200, Peter Ujfalusi wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- drivers/dma/Kconfig | 4 + drivers/dma/Makefile | 1 + drivers/dma/ti-dma-crossbar.c | 190 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 195 insertions(+) create mode 100644 drivers/dma/ti-dma-crossbar.cdiff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 074ffad334a7..519657a37ca1 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig@@ -247,6 +247,9 @@ 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@@ -332,6 +335,7 @@ 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 bf4485800c60..6ec7af6a416c 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile@@ -39,6 +39,7 @@ 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.odiff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c new file mode 100644 index 000000000000..591307bd4370 --- /dev/null +++ b/drivers/dma/ti-dma-crossbar.c@@ -0,0 +1,190 @@ +/* + * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com + * Author: Peter Ujfalusi <peter.ujfalusi@ti.com> + * + * 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> + +#define TI_XBAR_OUTPUTS 127 +#define TI_XBAR_INPUTS 256
Ideally this should be moved to DT. Will next revision of this chip always support these output and inputs?
+
+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);just out of curiosity how much do you save using regmap :)
+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_info(&pdev->dev,
+ "Missing XBAR output information, using %u.\n",
+ TI_XBAR_OUTPUTS);
+ xbar->dma_requests = TI_XBAR_OUTPUTS;
+ }
+ of_node_put(dma_node);_put here?
+int omap_dmaxbar_init(void)
+{
+ return platform_driver_register(&ti_dma_xbar_driver);
+}
+arch_initcall(omap_dmaxbar_init);why arch_initcall? -- ~Vinod