[PATCH 0/6] dmaengine/dra7x: DMA router (crossbar support)

[PATCH 0/6] dmaengine/dra7x: DMA router (crossbar support)

[Peter Ujfalusi]

Hi,

The series adds support for DMA router type of devices. They are used in SoCs
which has more peripherals with DMA request lines than the DMA controller can
handle.
The router itself is not part of the DMA controller and it's operation should be
transparent (as it is in the HW) for the SW stack.

This series takes into accound the comments Sricharan received for his version
of the crossbar driver:
https://lkml.org/lkml/2014/3/7/199

This implementation is not tied to any DMA driver so it is possible to use the
framework by other vendors, also ACPI version of binding can be easy enough to
be added.

The omap-dma part of changes are based on the dma property name change series:
https://lkml.org/lkml/2015/2/20/182

but the code has fallback so it is working w/o the changes in that series.

Regards,
Peter
---
Peter Ujfalusi (6):
  dmaengine: of_dma: Support for DMA routers
  dmaengine: Add driver for TI DMA crossbar on DRA7x
  dmaengine: omap-dma: Use defines for dma channels and request count
  dmaengine: omap-dma: Take DMA request number from DT if it is
    available
  dmaengine: omap-dma: Remove mapping between virtual channels and
    requests
  ARM: DTS: dra7x: Integrate sDMA crossbar

 Documentation/devicetree/bindings/dma/dma.txt |  27 ++++
 arch/arm/boot/dts/dra7.dtsi                   |  57 ++++----
 drivers/dma/Kconfig                           |   4 +
 drivers/dma/Makefile                          |   1 +
 drivers/dma/dmaengine.c                       |   7 +
 drivers/dma/of-dma.c                          |  92 +++++++++++++
 drivers/dma/omap-dma.c                        |  24 +++-
 drivers/dma/ti-dma-crossbar.c                 | 191 ++++++++++++++++++++++++++
 include/linux/dmaengine.h                     |  17 +++
 include/linux/of_dma.h                        |  21 +++
 10 files changed, 413 insertions(+), 28 deletions(-)
 create mode 100644 drivers/dma/ti-dma-crossbar.c

-- 
2.3.0

[PATCH 1/6] dmaengine: of_dma: Support for DMA routers

[Peter Ujfalusi]

DMA routers are transparent devices used to mux DMA requests from
peripherals to DMA controllers. They are used when the SoC integrates more
devices with DMA requests then their controller can handle.
DRA7x is one example of such SoC, where the sDMA can hanlde 128 DMA request
lines, but in SoC level it has 205 DMA requests.

The of_dma_router will be registered as of_dma_controller with special
xlate function and additional parameters and the code will translate and
requests a DMA channel from the real DMA controller.
This way the router can be transparent for the system while remaining generic
enough to be used in different environments.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 Documentation/devicetree/bindings/dma/dma.txt | 27 ++++++++
 drivers/dma/dmaengine.c                       |  7 ++
 drivers/dma/of-dma.c                          | 92 +++++++++++++++++++++++++++
 include/linux/dmaengine.h                     | 17 +++++
 include/linux/of_dma.h                        | 21 ++++++
 5 files changed, 164 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt
index 82104271e754..75fcfc733858 100644
--- a/Documentation/devicetree/bindings/dma/dma.txt
+++ b/Documentation/devicetree/bindings/dma/dma.txt
@@ -31,6 +31,33 @@ Example:
 		dma-requests = <127>;
 	};
 
+* DMA router
+
+DMA routers are transparent IP blocks used to route DMA request lines from
+devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals
+integrated with DMA requests than what the DMA controller can handle directly.
+
+Required property:
+- dma-device:		phandle of the DMA controller. The router is modifying
+			the DMA requests for this controller.
+- #dma-cells: 		Must be set to be the same as the dma-device's
+			#dma-cells
+
+Optional properties:
+- dma-requests: 	Number of incoming request lines the router can handle.
+- dma-device
+	- dma-requests:	The router driver might need to look for this in order
+			to configure the routing.
+
+Example:
+	sdma_xbar: dma-router@4a002b78 {
+		compatible = "ti,dra7-dma-crossbar";
+		reg = <0x4a002b78 0xfc>;
+		#dma-cells = <1>;
+		dma-requests = <205>;
+		ti,dma-safe-map = <0>;
+		dma-device = <&sdma>;
+	};
 
 * DMA client
 
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index f15712f2fec6..ba60f1f0ddd3 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -271,6 +271,13 @@ static void dma_chan_put(struct dma_chan *chan)
 	/* This channel is not in use anymore, free it */
 	if (!chan->client_count && chan->device->device_free_chan_resources)
 		chan->device->device_free_chan_resources(chan);
+
+	/* If the channel is used via a DMA request router, free the mapping */
+	if (chan->router && chan->router->route_free) {
+		chan->router->route_free(chan->router->dev, chan->route_data);
+		chan->router = NULL;
+		chan->route_data = NULL;
+	}
 }
 
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index ca31f1b45366..c86f8823da0d 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -45,6 +45,53 @@ static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec)
 }
 
 /**
+ * of_dma_router_xlate - translation function for router devices
+ * @dma_spec:	pointer to DMA specifier as found in the device tree
+ * @of_dma:	pointer to DMA controller data (router information)
+ *
+ * The function creates new dma_spec to be passed to the router driver's
+ * of_dma_route_allocate() function to prepare a dma_spec which will be used
+ * to request channel from the real DMA controller.
+ */
+static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
+					    struct of_dma *ofdma)
+{
+	struct dma_chan		*chan;
+	struct of_dma		*ofdma_target;
+	struct device_node	*dma_target;
+	struct of_phandle_args	dma_spec_target;
+	void			*route_data;
+
+	dma_target = of_parse_phandle(dma_spec->np, "dma-device", 0);
+	if (!dma_target) {
+		pr_err("%s: Can't get target DMA\n", __func__);
+		return NULL;
+	}
+
+	/* translate the request for the real DMA controller */
+	memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target));
+	dma_spec_target.np = dma_target;
+	route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma);
+
+	ofdma_target = of_dma_find_controller(&dma_spec_target);
+	if (!ofdma_target) {
+		pr_err("%s: Can't get target ofDMA\n", __func__);
+		return NULL;
+	}
+
+	chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);
+	if (chan) {
+		chan->router = ofdma->dma_router;
+		chan->route_data = route_data;
+	} else {
+		ofdma->dma_router->route_free(ofdma->dma_router->dev, route_data);
+	}
+
+	of_node_put(dma_target);
+	return chan;
+}
+
+/**
  * of_dma_controller_register - Register a DMA controller to DT DMA helpers
  * @np:			device node of DMA controller
  * @of_dma_xlate:	translation function which converts a phandle
@@ -110,6 +157,51 @@ void of_dma_controller_free(struct device_node *np)
 EXPORT_SYMBOL_GPL(of_dma_controller_free);
 
 /**
+ * of_dma_router_register - Register a DMA router to DT DMA helpers as a
+ *			    controller
+ * @np:				device node of DMA router
+ * @of_dma_route_allocate:	setup function for the router which need to
+ *				modify the dma_spec for the DMA controller to
+ *				use and to set up the requested route.
+ * @dma_router:			pointer to dma_router structure to be used when
+ *				the route need to be free up.
+ *
+ * Returns 0 on success or appropriate errno value on error.
+ *
+ * Allocated memory should be freed with appropriate of_dma_controller_free()
+ * call.
+ */
+int of_dma_router_register(struct device_node *np,
+			   void *(*of_dma_route_allocate)
+			   (struct of_phandle_args *, struct of_dma *),
+			   struct dma_router *dma_router)
+{
+	struct of_dma	*ofdma;
+
+	if (!np || !of_dma_route_allocate || !dma_router) {
+		pr_err("%s: not enough information provided\n", __func__);
+		return -EINVAL;
+	}
+
+	ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL);
+	if (!ofdma)
+		return -ENOMEM;
+
+	ofdma->of_node = np;
+	ofdma->of_dma_xlate = of_dma_router_xlate;
+	ofdma->of_dma_route_allocate = of_dma_route_allocate;
+	ofdma->dma_router = dma_router;
+
+	/* Now queue of_dma controller structure in list */
+	mutex_lock(&of_dma_lock);
+	list_add_tail(&ofdma->of_dma_controllers, &of_dma_list);
+	mutex_unlock(&of_dma_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_dma_router_register);
+
+/**
  * of_dma_match_channel - Check if a DMA specifier matches name
  * @np:		device node to look for DMA channels
  * @name:	channel name to be matched
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index b6997a0cb528..f10f9b81fead 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -226,6 +226,16 @@ struct dma_chan_percpu {
 };
 
 /**
+ * struct dma_router - DMA router structure
+ * @dev: pointer to the DMA router device
+ * @route_free: function to be called when the route can be disconnected
+ */
+struct dma_router {
+	struct device *dev;
+	void (*route_free)(struct device *dev, void *route_data);
+};
+
+/**
  * struct dma_chan - devices supply DMA channels, clients use them
  * @device: ptr to the dma device who supplies this channel, always !%NULL
  * @cookie: last cookie value returned to client
@@ -236,6 +246,8 @@ struct dma_chan_percpu {
  * @local: per-cpu pointer to a struct dma_chan_percpu
  * @client_count: how many clients are using this channel
  * @table_count: number of appearances in the mem-to-mem allocation table
+ * @router: pointer to the DMA router structure
+ * @route_data: channel specific data for the router
  * @private: private data for certain client-channel associations
  */
 struct dma_chan {
@@ -251,6 +263,11 @@ struct dma_chan {
 	struct dma_chan_percpu __percpu *local;
 	int client_count;
 	int table_count;
+
+	/* DMA router */
+	struct dma_router *router;
+	void *route_data;
+
 	void *private;
 };
 
diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h
index 56bc026c143f..734e449f87c1 100644
--- a/include/linux/of_dma.h
+++ b/include/linux/of_dma.h
@@ -23,6 +23,9 @@ struct of_dma {
 	struct device_node	*of_node;
 	struct dma_chan		*(*of_dma_xlate)
 				(struct of_phandle_args *, struct of_dma *);
+	void			*(*of_dma_route_allocate)
+				(struct of_phandle_args *, struct of_dma *);
+	struct dma_router	*dma_router;
 	void			*of_dma_data;
 };
 
@@ -37,12 +40,20 @@ extern int of_dma_controller_register(struct device_node *np,
 		(struct of_phandle_args *, struct of_dma *),
 		void *data);
 extern void of_dma_controller_free(struct device_node *np);
+
+extern int of_dma_router_register(struct device_node *np,
+		void *(*of_dma_route_allocate)
+		(struct of_phandle_args *, struct of_dma *),
+		 struct dma_router *dma_router);
+#define of_dma_router_free of_dma_controller_free
+
 extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 						     const char *name);
 extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 		struct of_dma *ofdma);
 extern struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
 		struct of_dma *ofdma);
+
 #else
 static inline int of_dma_controller_register(struct device_node *np,
 		struct dma_chan *(*of_dma_xlate)
@@ -56,6 +67,16 @@ static inline void of_dma_controller_free(struct device_node *np)
 {
 }
 
+static inline int of_dma_router_register(struct device_node *np,
+		void *(*of_dma_route_allocate)
+		(struct of_phandle_args *, struct of_dma *),
+		 struct dma_router *dma_router)
+{
+	return -ENODEV;
+}
+
+#define of_dma_router_free of_dma_controller_free
+
 static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 						     const char *name)
 {
-- 
2.3.0

[PATCH 2/6] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Peter Ujfalusi]

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@ti.com>
---
 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@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>
+#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@ti.com>");
+MODULE_LICENSE("GPL");
-- 
2.3.0

[PATCH 3/6] dmaengine: omap-dma: Use defines for dma channels and request count

[Peter Ujfalusi]

Instead of magic numbers in the code, use define for number of logical DMA
channels and DMA requests.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/dma/omap-dma.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 7dd6dd121681..56c33e93dd24 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -22,6 +22,9 @@
 
 #include "virt-dma.h"
 
+#define OMAP_SDMA_REQUESTS	127
+#define OMAP_SDMA_CHANNELS	32
+
 struct omap_dmadev {
 	struct dma_device ddev;
 	spinlock_t lock;
@@ -33,7 +36,7 @@ struct omap_dmadev {
 	bool legacy;
 	spinlock_t irq_lock;
 	uint32_t irq_enable_mask;
-	struct omap_chan *lch_map[32];
+	struct omap_chan *lch_map[OMAP_SDMA_CHANNELS];
 };
 
 struct omap_chan {
@@ -1115,7 +1118,7 @@ static int omap_dma_probe(struct platform_device *pdev)
 
 	tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
 
-	for (i = 0; i < 127; i++) {
+	for (i = 0; i < OMAP_SDMA_REQUESTS; i++) {
 		rc = omap_dma_chan_init(od, i);
 		if (rc) {
 			omap_dma_free(od);
-- 
2.3.0

[PATCH 4/6] dmaengine: omap-dma: Take DMA request number from DT if it is available

[Peter Ujfalusi]

Use the dma-requests property from DT to get the number of DMA requests.
In case of legacy boot or failure to find the property, use the default
127 as number of requests.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/dma/omap-dma.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 56c33e93dd24..7def31c919f4 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -34,6 +34,7 @@ struct omap_dmadev {
 	const struct omap_dma_reg *reg_map;
 	struct omap_system_dma_plat_info *plat;
 	bool legacy;
+	unsigned dma_requests;
 	spinlock_t irq_lock;
 	uint32_t irq_enable_mask;
 	struct omap_chan *lch_map[OMAP_SDMA_CHANNELS];
@@ -1118,7 +1119,15 @@ static int omap_dma_probe(struct platform_device *pdev)
 
 	tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
 
-	for (i = 0; i < OMAP_SDMA_REQUESTS; i++) {
+	if (!pdev->dev.of_node || of_property_read_u32(pdev->dev.of_node,
+						       "dma-requests",
+						       &od->dma_requests)) {
+		dev_info(&pdev->dev,
+			 "DMA request lines not specified, using 127\n");
+		od->dma_requests = 127;
+	}
+
+	for (i = 0; i < od->dma_requests; i++) {
 		rc = omap_dma_chan_init(od, i);
 		if (rc) {
 			omap_dma_free(od);
-- 
2.3.0

[PATCH 5/6] dmaengine: omap-dma: Remove mapping between virtual channels and requests

[Peter Ujfalusi]

Do not direct map the virtual channels to sDMA request number. When the
sDMA is behind of a crossbar this direct mapping can cause situations when
certain channel can not be requested since the crossbar request number
will no longer match with the sDMA request line.
The direct mapping for virtual channels with HW request lines will make it
harder to implement MEM_TO_MEM mode for the driver.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/dma/omap-dma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 7def31c919f4..1d759b81e1be 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -593,6 +593,7 @@ static void omap_dma_free_chan_resources(struct dma_chan *chan)
 	omap_free_dma(c->dma_ch);
 
 	dev_dbg(od->ddev.dev, "freeing channel for %u\n", c->dma_sig);
+	c->dma_sig = 0;
 }
 
 static size_t omap_dma_sg_size(struct omap_sg *sg)
@@ -1049,7 +1050,6 @@ static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
 		return -ENOMEM;
 
 	c->reg_map = od->reg_map;
-	c->dma_sig = dma_sig;
 	c->vc.desc_free = omap_dma_desc_free;
 	vchan_init(&c->vc, &od->ddev);
 	INIT_LIST_HEAD(&c->node);
@@ -1219,10 +1219,14 @@ static struct platform_driver omap_dma_driver = {
 bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
 {
 	if (chan->device->dev->driver == &omap_dma_driver.driver) {
+		struct omap_dmadev *od = to_omap_dma_dev(chan->device);
 		struct omap_chan *c = to_omap_dma_chan(chan);
 		unsigned req = *(unsigned *)param;
 
-		return req == c->dma_sig;
+		if (req <= od->dma_requests) {
+			c->dma_sig = req;
+			return true;
+		}
 	}
 	return false;
 }
-- 
2.3.0

[PATCH 6/6] ARM: DTS: dra7x: Integrate sDMA crossbar

[Peter Ujfalusi]

The sDMA requests are routed through the DMA crossbar and without the
crossbar only peripherals using DMA request 0-127 can be used.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 arch/arm/boot/dts/dra7.dtsi | 57 ++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
index aefa4192533a..bbda4261caf4 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -253,6 +253,15 @@
 			dma-requests = <127>;
 		};
 
+		sdma_xbar: dma-router@4a002b78 {
+			compatible = "ti,dra7-dma-crossbar";
+			reg = <0x4a002b78 0xfc>;
+			#dma-cells = <1>;
+			dma-requests = <205>;
+			ti,dma-safe-map = <0>;
+			dma-device = <&sdma>;
+		};
+
 		gpio1: gpio@4ae10000 {
 			compatible = "ti,omap4-gpio";
 			reg = <0x4ae10000 0x200>;
@@ -348,7 +357,7 @@
 			ti,hwmods = "uart1";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 49>, <&sdma 50>;
+			dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;
 			dma-names = "tx", "rx";
 		};
 
@@ -359,7 +368,7 @@
 			ti,hwmods = "uart2";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 51>, <&sdma 52>;
+			dmas = <&sdma_xbar 51>, <&sdma_xbar 52>;
 			dma-names = "tx", "rx";
 		};
 
@@ -370,7 +379,7 @@
 			ti,hwmods = "uart3";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 53>, <&sdma 54>;
+			dmas = <&sdma_xbar 53>, <&sdma_xbar 54>;
 			dma-names = "tx", "rx";
 		};
 
@@ -381,7 +390,7 @@
 			ti,hwmods = "uart4";
 			clock-frequency = <48000000>;
                         status = "disabled";
-			dmas = <&sdma 55>, <&sdma 56>;
+			dmas = <&sdma_xbar 55>, <&sdma_xbar 56>;
 			dma-names = "tx", "rx";
 		};
 
@@ -392,7 +401,7 @@
 			ti,hwmods = "uart5";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 63>, <&sdma 64>;
+			dmas = <&sdma_xbar 63>, <&sdma_xbar 64>;
 			dma-names = "tx", "rx";
 		};
 
@@ -403,7 +412,7 @@
 			ti,hwmods = "uart6";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 79>, <&sdma 80>;
+			dmas = <&sdma_xbar 79>, <&sdma_xbar 80>;
 			dma-names = "tx", "rx";
 		};
 
@@ -819,7 +828,7 @@
 			ti,hwmods = "mmc1";
 			ti,dual-volt;
 			ti,needs-special-reset;
-			dmas = <&sdma 61>, <&sdma 62>;
+			dmas = <&sdma_xbar 61>, <&sdma_xbar 62>;
 			dma-names = "tx", "rx";
 			status = "disabled";
 			pbias-supply = <&pbias_mmc_reg>;
@@ -831,7 +840,7 @@
 			interrupts = <GIC_SPI 81 IRQ_TYPE_LEVEL_HIGH>;
 			ti,hwmods = "mmc2";
 			ti,needs-special-reset;
-			dmas = <&sdma 47>, <&sdma 48>;
+			dmas = <&sdma_xbar 47>, <&sdma_xbar 48>;
 			dma-names = "tx", "rx";
 			status = "disabled";
 		};
@@ -842,7 +851,7 @@
 			interrupts = <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
 			ti,hwmods = "mmc3";
 			ti,needs-special-reset;
-			dmas = <&sdma 77>, <&sdma 78>;
+			dmas = <&sdma_xbar 77>, <&sdma_xbar 78>;
 			dma-names = "tx", "rx";
 			status = "disabled";
 		};
@@ -853,7 +862,7 @@
 			interrupts = <GIC_SPI 91 IRQ_TYPE_LEVEL_HIGH>;
 			ti,hwmods = "mmc4";
 			ti,needs-special-reset;
-			dmas = <&sdma 57>, <&sdma 58>;
+			dmas = <&sdma_xbar 57>, <&sdma_xbar 58>;
 			dma-names = "tx", "rx";
 			status = "disabled";
 		};
@@ -998,14 +1007,14 @@
 			#size-cells = <0>;
 			ti,hwmods = "mcspi1";
 			ti,spi-num-cs = <4>;
-			dmas = <&sdma 35>,
-			       <&sdma 36>,
-			       <&sdma 37>,
-			       <&sdma 38>,
-			       <&sdma 39>,
-			       <&sdma 40>,
-			       <&sdma 41>,
-			       <&sdma 42>;
+			dmas = <&sdma_xbar 35>,
+			       <&sdma_xbar 36>,
+			       <&sdma_xbar 37>,
+			       <&sdma_xbar 38>,
+			       <&sdma_xbar 39>,
+			       <&sdma_xbar 40>,
+			       <&sdma_xbar 41>,
+			       <&sdma_xbar 42>;
 			dma-names = "tx0", "rx0", "tx1", "rx1",
 				    "tx2", "rx2", "tx3", "rx3";
 			status = "disabled";
@@ -1019,10 +1028,10 @@
 			#size-cells = <0>;
 			ti,hwmods = "mcspi2";
 			ti,spi-num-cs = <2>;
-			dmas = <&sdma 43>,
-			       <&sdma 44>,
-			       <&sdma 45>,
-			       <&sdma 46>;
+			dmas = <&sdma_xbar 43>,
+			       <&sdma_xbar 44>,
+			       <&sdma_xbar 45>,
+			       <&sdma_xbar 46>;
 			dma-names = "tx0", "rx0", "tx1", "rx1";
 			status = "disabled";
 		};
@@ -1035,7 +1044,7 @@
 			#size-cells = <0>;
 			ti,hwmods = "mcspi3";
 			ti,spi-num-cs = <2>;
-			dmas = <&sdma 15>, <&sdma 16>;
+			dmas = <&sdma_xbar 15>, <&sdma_xbar 16>;
 			dma-names = "tx0", "rx0";
 			status = "disabled";
 		};
@@ -1048,7 +1057,7 @@
 			#size-cells = <0>;
 			ti,hwmods = "mcspi4";
 			ti,spi-num-cs = <1>;
-			dmas = <&sdma 70>, <&sdma 71>;
+			dmas = <&sdma_xbar 70>, <&sdma_xbar 71>;
 			dma-names = "tx0", "rx0";
 			status = "disabled";
 		};
-- 
2.3.0

Re: [PATCH 4/6] dmaengine: omap-dma: Take DMA request number from DT if it is available

[Russell King - ARM Linux]

On Tue, Feb 24, 2015 at 04:21:21PM +0200, Peter Ujfalusi wrote:
> Use the dma-requests property from DT to get the number of DMA requests.
> In case of legacy boot or failure to find the property, use the default
> 127 as number of requests.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---
>  drivers/dma/omap-dma.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
> index 56c33e93dd24..7def31c919f4 100644
> --- a/drivers/dma/omap-dma.c
> +++ b/drivers/dma/omap-dma.c
> @@ -34,6 +34,7 @@ struct omap_dmadev {
>  	const struct omap_dma_reg *reg_map;
>  	struct omap_system_dma_plat_info *plat;
>  	bool legacy;
> +	unsigned dma_requests;
>  	spinlock_t irq_lock;
>  	uint32_t irq_enable_mask;
>  	struct omap_chan *lch_map[OMAP_SDMA_CHANNELS];
> @@ -1118,7 +1119,15 @@ static int omap_dma_probe(struct platform_device *pdev)
>  
>  	tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
>  
> -	for (i = 0; i < OMAP_SDMA_REQUESTS; i++) {
> +	if (!pdev->dev.of_node || of_property_read_u32(pdev->dev.of_node,
> +						       "dma-requests",
> +						       &od->dma_requests)) {
> +		dev_info(&pdev->dev,
> +			 "DMA request lines not specified, using 127\n");
> +		od->dma_requests = 127;

What happened to OMAP_SDMA_REQUESTS?

If you're not going to use OMAP_SDMA_REQUESTS, then don't add it.  If
you are going to use it, please also change the dev_info() line to use
that macro too.

Thanks.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH 5/6] dmaengine: omap-dma: Remove mapping between virtual channels and requests

[Russell King - ARM Linux]

On Tue, Feb 24, 2015 at 04:21:22PM +0200, Peter Ujfalusi wrote:
> Do not direct map the virtual channels to sDMA request number. When the
> sDMA is behind of a crossbar this direct mapping can cause situations when
> certain channel can not be requested since the crossbar request number
> will no longer match with the sDMA request line.
> The direct mapping for virtual channels with HW request lines will make it
> harder to implement MEM_TO_MEM mode for the driver.

I assume when you talk about MEM_TO_MEM, you're referring to a DMA_MEMCPY
driver.

mem2mem should not be handled by the slave driver.  This should be a
separate DMA engine driver structure which does not have DMA_SLAVE set.

See how amba-pl08x handles this.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH 4/6] dmaengine: omap-dma: Take DMA request number from DT if it is available

[Peter Ujfalusi]

On 02/24/2015 04:25 PM, Russell King - ARM Linux wrote:
> On Tue, Feb 24, 2015 at 04:21:21PM +0200, Peter Ujfalusi wrote:
>> Use the dma-requests property from DT to get the number of DMA requests.
>> In case of legacy boot or failure to find the property, use the default
>> 127 as number of requests.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> ---
>>  drivers/dma/omap-dma.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
>> index 56c33e93dd24..7def31c919f4 100644
>> --- a/drivers/dma/omap-dma.c
>> +++ b/drivers/dma/omap-dma.c
>> @@ -34,6 +34,7 @@ struct omap_dmadev {
>>  	const struct omap_dma_reg *reg_map;
>>  	struct omap_system_dma_plat_info *plat;
>>  	bool legacy;
>> +	unsigned dma_requests;
>>  	spinlock_t irq_lock;
>>  	uint32_t irq_enable_mask;
>>  	struct omap_chan *lch_map[OMAP_SDMA_CHANNELS];
>> @@ -1118,7 +1119,15 @@ static int omap_dma_probe(struct platform_device *pdev)
>>  
>>  	tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
>>  
>> -	for (i = 0; i < OMAP_SDMA_REQUESTS; i++) {
>> +	if (!pdev->dev.of_node || of_property_read_u32(pdev->dev.of_node,
>> +						       "dma-requests",
>> +						       &od->dma_requests)) {
>> +		dev_info(&pdev->dev,
>> +			 "DMA request lines not specified, using 127\n");
>> +		od->dma_requests = 127;
> 
> What happened to OMAP_SDMA_REQUESTS?
> 
> If you're not going to use OMAP_SDMA_REQUESTS, then don't add it.  If
> you are going to use it, please also change the dev_info() line to use
> that macro too.

Aargh, yes you are right. Will fix this up in v2.

-- 
Péter

Re: [PATCH 5/6] dmaengine: omap-dma: Remove mapping between virtual channels and requests

[Peter Ujfalusi]

On 02/24/2015 04:28 PM, Russell King - ARM Linux wrote:
> On Tue, Feb 24, 2015 at 04:21:22PM +0200, Peter Ujfalusi wrote:
>> Do not direct map the virtual channels to sDMA request number. When the
>> sDMA is behind of a crossbar this direct mapping can cause situations when
>> certain channel can not be requested since the crossbar request number
>> will no longer match with the sDMA request line.
>> The direct mapping for virtual channels with HW request lines will make it
>> harder to implement MEM_TO_MEM mode for the driver.
> 
> I assume when you talk about MEM_TO_MEM, you're referring to a DMA_MEMCPY
> driver.
> 
> mem2mem should not be handled by the slave driver.  This should be a
> separate DMA engine driver structure which does not have DMA_SLAVE set.
> 
> See how amba-pl08x handles this.

Thanks for the pointer. I'm just planning to add the DMA_MEMCPY support for
omap-dma. With that in place we can convert the remaining legacy API users to
use dmaengine (as I recall all of them are using DMA for memcopy)

-- 
Péter

Re: [PATCH 2/6] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Paul Bolle]

On Tue, 2015-02-24 at 16:21 +0200, Peter Ujfalusi wrote:
> 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@ti.com>
> ---
>  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

A simple observation follows.

> 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
> +

This is a bool symbol...

>  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

... so this file will be either not built or built into the kernel...

>  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@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>
> +#include <linux/module.h>

...  this includes linux/module.h ...

[...]

> +static struct platform_driver ti_dma_xbar_driver = {
> +	.probe	= ti_dma_xbar_probe,
> +	.driver = {
> +		.name = "ti-dma-crossbar",
> +		.owner = THIS_MODULE,

... is that needed to make this work?

> +		.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@ti.com>");
> +MODULE_LICENSE("GPL");

And why are these three macros needed?

By the way: there's a mismatch between the header (which is GPL v2) and
the MODULE_LICENSE() string (which means GPL v2 or later).

Paul Bolle

Re: [PATCH 2/6] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Peter Ujfalusi]

On 02/28/2015 06:00 PM, Paul Bolle wrote:
> On Tue, 2015-02-24 at 16:21 +0200, Peter Ujfalusi wrote:
>> 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@ti.com>
>> ---
>>  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
> 
> A simple observation follows.
> 
>> 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
>> +
> 
> This is a bool symbol...
> 
>>  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-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
> 
> ... so this file will be either not built or built into the kernel...
> 
>>  obj-$(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@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>
>> +#include <linux/module.h>
> 
> ...  this includes linux/module.h ...
> 
> [...]
> 
>> +static struct platform_driver ti_dma_xbar_driver = {
>> +	.probe	= ti_dma_xbar_probe,
>> +	.driver = {
>> +		.name = "ti-dma-crossbar",
>> +		.owner = THIS_MODULE,
> 
> ... is that needed to make this work?
> 
>> +		.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@ti.com>");
>> +MODULE_LICENSE("GPL");
> 
> And why are these three macros needed?
> 
> By the way: there's a mismatch between the header (which is GPL v2) and
> the MODULE_LICENSE() string (which means GPL v2 or later).

True, the linux/module.h and the lines with *MODULE* in it is not needed in
case the driver will be not built as module. I have not really thought about
this to be honest, I have had these macros in most (all?) of the drivers I wrote.
They will be gone in V2 of the series.

Thanks,
Péter

Re: [PATCH 0/6] dmaengine/dra7x: DMA router (crossbar support)

[Peter Ujfalusi]

Hi,

On 02/24/2015 04:21 PM, Peter Ujfalusi wrote:
> Hi,
> 
> The series adds support for DMA router type of devices. They are used in SoCs
> which has more peripherals with DMA request lines than the DMA controller can
> handle.
> The router itself is not part of the DMA controller and it's operation should be
> transparent (as it is in the HW) for the SW stack.
> 
> This series takes into accound the comments Sricharan received for his version
> of the crossbar driver:
> https://lkml.org/lkml/2014/3/7/199
> 
> This implementation is not tied to any DMA driver so it is possible to use the
> framework by other vendors, also ACPI version of binding can be easy enough to
> be added.
> 
> The omap-dma part of changes are based on the dma property name change series:
> https://lkml.org/lkml/2015/2/20/182
> 
> but the code has fallback so it is working w/o the changes in that series.

Gentle ping on this series before I send the V2 with the comments from Russell
and Paul addressed.

Kind Regards,
Péter

> 
> Regards,
> Peter
> ---
> Peter Ujfalusi (6):
>   dmaengine: of_dma: Support for DMA routers
>   dmaengine: Add driver for TI DMA crossbar on DRA7x
>   dmaengine: omap-dma: Use defines for dma channels and request count
>   dmaengine: omap-dma: Take DMA request number from DT if it is
>     available
>   dmaengine: omap-dma: Remove mapping between virtual channels and
>     requests
>   ARM: DTS: dra7x: Integrate sDMA crossbar
> 
>  Documentation/devicetree/bindings/dma/dma.txt |  27 ++++
>  arch/arm/boot/dts/dra7.dtsi                   |  57 ++++----
>  drivers/dma/Kconfig                           |   4 +
>  drivers/dma/Makefile                          |   1 +
>  drivers/dma/dmaengine.c                       |   7 +
>  drivers/dma/of-dma.c                          |  92 +++++++++++++
>  drivers/dma/omap-dma.c                        |  24 +++-
>  drivers/dma/ti-dma-crossbar.c                 | 191 ++++++++++++++++++++++++++
>  include/linux/dmaengine.h                     |  17 +++
>  include/linux/of_dma.h                        |  21 +++
>  10 files changed, 413 insertions(+), 28 deletions(-)
>  create mode 100644 drivers/dma/ti-dma-crossbar.c
>