[PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[Peter Ujfalusi]

Vinod: is it OK if I send the Documnetation/dmanegine/ update a bit later when
I have finished it?

Changes since v4:
- Comments from Maxime Ripard addressed:
 - long line fixed in of-dma.c
 - node leaks has been fixed in ti-dma-crossbar
 - Using devm_ioremap_resource() in ti-dma-crossbar
 - u16 casting has been addressed
- Router drivers are expected to return with ERR_PTR in case their
  of_dma_route_allocate() callback fails.

Changes since v3:
- Comments from Russell:
 - Warnings removed in case of non DT boot when taking the DMA request number
 - Reduced the number of channels presented to DMAengine
 - removed the dma_sig parameter from omap_dma_chan_init()
- Comments from Arnd:
 - dma-device property renamed to dma-masters
 - Allow list of phandes in dma-masters

Changes since v2:
- not using regmap for the TI crossbar driver.

Changes since v1:
- Comments from Russell King and  Paul Bolle addressed:
 - Use the added defined in the omap-dma changes
 - MODULE_* removed from the ti-dma-crossbar driver.
- DMA router documentation: do not limit the #dma-cells to be the same as the
  dma controller's #dma-cells. It might be possible to have a router which needs
  more information than the DMA controller (direct request pairing for example)
- Use defines in the ti-dma-crossbar driver
- Binding document for the ti-dma-crossbar driver

Intro mail from v1:

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.

Regards,
Peter
---
Peter Ujfalusi (8):
  dmaengine: of_dma: Support for DMA routers
  Documentation: devicetree: dma: Binding documentation for TI DMA
    crossbar
  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
  dmaengine: omap-dma: Reduce the number of virtual channels
  ARM: DTS: dra7x: Integrate sDMA crossbar

 Documentation/devicetree/bindings/dma/dma.txt      |  28 +++
 .../devicetree/bindings/dma/ti-dma-crossbar.txt    |  52 ++++++
 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                               |  89 ++++++++++
 drivers/dma/omap-dma.c                             |  29 +++-
 drivers/dma/ti-dma-crossbar.c                      | 188 +++++++++++++++++++++
 include/linux/dmaengine.h                          |  17 ++
 include/linux/of_dma.h                             |  21 +++
 11 files changed, 463 insertions(+), 30 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
 create mode 100644 drivers/dma/ti-dma-crossbar.c

-- 
2.3.5

[PATCH v5 1/8] 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. The driver for the router is
responsible to craft the dma_spec (in the of_dma_route_allocate callback)
which can be used to 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 | 28 +++++++++
 drivers/dma/dmaengine.c                       |  7 +++
 drivers/dma/of-dma.c                          | 89 +++++++++++++++++++++++++++
 include/linux/dmaengine.h                     | 17 +++++
 include/linux/of_dma.h                        | 21 +++++++
 5 files changed, 162 insertions(+)

diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt
index 82104271e754..6312fb00ce8d 100644
--- a/Documentation/devicetree/bindings/dma/dma.txt
+++ b/Documentation/devicetree/bindings/dma/dma.txt
@@ -31,6 +31,34 @@ 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-masters:		phandle of the DMA controller or list of phandles for
+			the DMA controllers the router can direct the signal to.
+- #dma-cells: 		Must be at least 1. Used to provide DMA router specific
+			information. See DMA client binding below for more
+			details.
+
+Optional properties:
+- dma-requests: 	Number of incoming request lines the router can handle.
+- In the node pointed by the dma-masters:
+	- 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-masters = <&sdma>;
+	};
 
 * DMA client
 
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 24967c89f5d4..c7aa232b4a59 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -267,6 +267,13 @@ 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 cbd4a8aff120..1e1f2986eba8 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -45,6 +45,50 @@ 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 of_phandle_args	dma_spec_target;
+	void			*route_data;
+
+	/* translate the request for the real DMA controller */
+	memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target));
+	route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma);
+	if (IS_ERR(route_data))
+		return NULL;
+
+	ofdma_target = of_dma_find_controller(&dma_spec_target);
+	if (!ofdma_target)
+		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);
+	}
+
+	/*
+	 * Need to put the node back since the ofdma->of_dma_route_allocate
+	 * has taken it for generating the new, translated dma_spec
+	 */
+	of_node_put(dma_spec_target.np);
+	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 +154,51 @@ 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 ad419757241f..abf63ceabef9 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -222,6 +222,16 @@ 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
@@ -232,6 +242,8 @@ 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 {
@@ -247,6 +259,11 @@ 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..98ba7525929e 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)
 {
-- 
2.3.5

[PATCH v5 2/8] Documentation: devicetree: dma: Binding documentation for TI DMA crossbar

[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 request
line of the DMA controller.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 .../devicetree/bindings/dma/ti-dma-crossbar.txt    | 52 ++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt

diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
new file mode 100644
index 000000000000..63a48928f3a8
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
@@ -0,0 +1,52 @@
+Texas Instruments DMA Crossbar (DMA request router)
+
+Required properties:
+- compatible:	"ti,dra7-dma-crossbar" for DRA7xx DMA crossbar
+- reg:		Memory map for accessing module
+- #dma-cells:	Should be set to <1>.
+		Clients should use the crossbar request number (input)
+- dma-requests:	Number of DMA requests the crossbar can receive
+- dma-masters:	phandle pointing to the DMA controller
+
+The DMA controller node need to have the following poroperties:
+- dma-requests:	Number of DMA requests the controller can handle
+
+Optional properties:
+- ti,dma-safe-map: Safe routing value for unused request lines
+
+Example:
+
+/* DMA controller */
+sdma: dma-controller@4a056000 {
+	compatible = "ti,omap4430-sdma";
+	reg = <0x4a056000 0x1000>;
+	interrupts =	<GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>,
+			<GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>,
+			<GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>,
+			<GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;
+	#dma-cells = <1>;
+	dma-channels = <32>;
+	dma-requests = <127>;
+};
+
+/* DMA crossbar */
+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-masters = <&sdma>;
+};
+
+/* DMA client */
+uart1: serial@4806a000 {
+	compatible = "ti,omap4-uart";
+	reg = <0x4806a000 0x100>;
+	interrupts-extended = <&gic GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>;
+	ti,hwmods = "uart1";
+	clock-frequency = <48000000>;
+	status = "disabled";
+	dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;
+	dma-names = "tx", "rx";
+};
-- 
2.3.5

[PATCH v5 3/8] 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 | 188 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+)
 create mode 100644 drivers/dma/ti-dma-crossbar.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 91eced044321..33a7401597be 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -234,6 +234,9 @@ 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
 
@@ -319,6 +322,7 @@ 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 7e8301cb489d..19ac70b8af0a 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..24f5ca2356bf
--- /dev/null
+++ b/drivers/dma/ti-dma-crossbar.c
@@ -0,0 +1,188 @@
+/*
+ *  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/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
+
+static DEFINE_IDR(map_idr);
+
+struct ti_dma_xbar_data {
+	void __iomem *iomem;
+
+	struct dma_router dmarouter;
+
+	u16 safe_val; /* Value to rest the crossbar lines */
+	u32 xbar_requests; /* number of DMA requests connected to XBAR */
+	u32 dma_requests; /* number of DMA requests forwarded to DMA */
+};
+
+struct ti_dma_xbar_map {
+	u16 xbar_in;
+	int xbar_out;
+};
+
+static inline void ti_dma_xbar_write(void __iomem *iomem, int xbar, u16 val)
+{
+	writew_relaxed(val, iomem + (xbar * 2));
+}
+
+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%u (was routed to %d)\n",
+		map->xbar_in, map->xbar_out);
+
+	ti_dma_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
+	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 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);
+	}
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (!map) {
+		of_node_put(dma_spec->np);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	map->xbar_out = idr_alloc(&map_idr, NULL, 0, xbar->dma_requests,
+				  GFP_KERNEL);
+	map->xbar_in = (u16)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%u to DMA%d\n",
+		map->xbar_in, map->xbar_out);
+
+	ti_dma_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);
+
+	return map;
+}
+
+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;
+	u32 safe_val;
+	void __iomem *iomem;
+	int i, ret;
+
+	if (!node)
+		return -ENODEV;
+
+	xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
+	if (!xbar)
+		return -ENOMEM;
+
+	dma_node = of_parse_phandle(node, "dma-masters", 0);
+	if (!dma_node) {
+		dev_err(&pdev->dev, "Can't get DMA master node\n");
+		return -ENODEV;
+	}
+
+	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);
+
+	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
+		dev_info(&pdev->dev,
+			 "Missing XBAR input information, using %u.\n",
+			 TI_XBAR_INPUTS);
+		xbar->xbar_requests = TI_XBAR_INPUTS;
+	}
+
+	if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
+		xbar->safe_val = (u16)safe_val;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	iomem = devm_ioremap_resource(&pdev->dev, res);
+	if (!iomem)
+		return -ENOMEM;
+
+	xbar->iomem = iomem;
+
+	xbar->dmarouter.dev = &pdev->dev;
+	xbar->dmarouter.route_free = ti_dma_xbar_free;
+
+	platform_set_drvdata(pdev, xbar);
+
+	/* Reset the crossbar */
+	for (i = 0; i < xbar->dma_requests; i++)
+		ti_dma_xbar_write(xbar->iomem, i, xbar->safe_val);
+
+	ret = of_dma_router_register(node, ti_dma_xbar_route_allocate,
+				     &xbar->dmarouter);
+	if (ret) {
+		/* Restore the defaults for the crossbar */
+		for (i = 0; i < xbar->dma_requests; i++)
+			ti_dma_xbar_write(xbar->iomem, i, i);
+	}
+
+	return ret;
+}
+
+static const struct of_device_id ti_dma_xbar_match[] = {
+	{ .compatible = "ti,dra7-dma-crossbar" },
+	{},
+};
+
+static struct platform_driver ti_dma_xbar_driver = {
+	.driver = {
+		.name = "ti-dma-crossbar",
+		.of_match_table = of_match_ptr(ti_dma_xbar_match),
+	},
+	.probe	= ti_dma_xbar_probe,
+};
+
+int omap_dmaxbar_init(void)
+{
+	return platform_driver_register(&ti_dma_xbar_driver);
+}
+arch_initcall(omap_dmaxbar_init);
-- 
2.3.5

[PATCH v5 4/8] 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 167dbaf65742..4065963fbffb 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 {
@@ -1116,7 +1119,7 @@ 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);
-- 
2.3.5

[PATCH v5 5/8] 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 | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 4065963fbffb..211c9c1edf08 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];
@@ -1119,7 +1120,16 @@ 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++) {
+	od->dma_requests = OMAP_SDMA_REQUESTS;
+	if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
+						      "dma-requests",
+						      &od->dma_requests)) {
+		dev_info(&pdev->dev,
+			 "Missing dma-requests property, using %u.\n",
+			 OMAP_SDMA_REQUESTS);
+	}
+
+	for (i = 0; i < od->dma_requests; i++) {
 		rc = omap_dma_chan_init(od, i);
 		if (rc) {
 			omap_dma_free(od);
-- 
2.3.5

[PATCH v5 6/8] 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 | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 211c9c1edf08..b19b9ee8f1d1 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)
@@ -1041,7 +1042,7 @@ static int omap_dma_resume(struct dma_chan *chan)
 	return 0;
 }
 
-static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
+static int omap_dma_chan_init(struct omap_dmadev *od)
 {
 	struct omap_chan *c;
 
@@ -1050,7 +1051,6 @@ 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);
@@ -1130,7 +1130,7 @@ static int omap_dma_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < od->dma_requests; i++) {
-		rc = omap_dma_chan_init(od, i);
+		rc = omap_dma_chan_init(od);
 		if (rc) {
 			omap_dma_free(od);
 			return rc;
@@ -1221,10 +1221,14 @@ 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;
 }
-- 
2.3.5

[PATCH v5 7/8] dmaengine: omap-dma: Reduce the number of virtual channels

[Peter Ujfalusi]

Since the mapping between the hardware request lines and channels has been
removed it no longer make sense to have too many channels.
Set the number of channels to match with the number of logical channels
supported by sDMA.

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

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index b19b9ee8f1d1..7f154c138200 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -1129,7 +1129,7 @@ static int omap_dma_probe(struct platform_device *pdev)
 			 OMAP_SDMA_REQUESTS);
 	}
 
-	for (i = 0; i < od->dma_requests; i++) {
+	for (i = 0; i < OMAP_SDMA_CHANNELS; i++) {
 		rc = omap_dma_chan_init(od);
 		if (rc) {
 			omap_dma_free(od);
-- 
2.3.5

[PATCH v5 8/8] 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 5332b57b4950..a2f4aa01984f 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -303,6 +303,15 @@
 			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-masters = <&sdma>;
+		};
+
 		gpio1: gpio@4ae10000 {
 			compatible = "ti,omap4-gpio";
 			reg = <0x4ae10000 0x200>;
@@ -398,7 +407,7 @@
 			ti,hwmods = "uart1";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 49>, <&sdma 50>;
+			dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;
 			dma-names = "tx", "rx";
 		};
 
@@ -409,7 +418,7 @@
 			ti,hwmods = "uart2";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 51>, <&sdma 52>;
+			dmas = <&sdma_xbar 51>, <&sdma_xbar 52>;
 			dma-names = "tx", "rx";
 		};
 
@@ -420,7 +429,7 @@
 			ti,hwmods = "uart3";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 53>, <&sdma 54>;
+			dmas = <&sdma_xbar 53>, <&sdma_xbar 54>;
 			dma-names = "tx", "rx";
 		};
 
@@ -431,7 +440,7 @@
 			ti,hwmods = "uart4";
 			clock-frequency = <48000000>;
                         status = "disabled";
-			dmas = <&sdma 55>, <&sdma 56>;
+			dmas = <&sdma_xbar 55>, <&sdma_xbar 56>;
 			dma-names = "tx", "rx";
 		};
 
@@ -442,7 +451,7 @@
 			ti,hwmods = "uart5";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 63>, <&sdma 64>;
+			dmas = <&sdma_xbar 63>, <&sdma_xbar 64>;
 			dma-names = "tx", "rx";
 		};
 
@@ -453,7 +462,7 @@
 			ti,hwmods = "uart6";
 			clock-frequency = <48000000>;
 			status = "disabled";
-			dmas = <&sdma 79>, <&sdma 80>;
+			dmas = <&sdma_xbar 79>, <&sdma_xbar 80>;
 			dma-names = "tx", "rx";
 		};
 
@@ -862,7 +871,7 @@
 			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>;
@@ -874,7 +883,7 @@
 			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";
 		};
@@ -885,7 +894,7 @@
 			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";
 		};
@@ -896,7 +905,7 @@
 			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";
 		};
@@ -1041,14 +1050,14 @@
 			#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";
@@ -1062,10 +1071,10 @@
 			#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";
 		};
@@ -1078,7 +1087,7 @@
 			#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";
 		};
@@ -1091,7 +1100,7 @@
 			#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";
 		};
-- 
2.3.5

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Tony Lindgren]

* Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
> The sDMA requests are routed through the DMA crossbar and without the
> crossbar only peripherals using DMA request 0-127 can be used.

I assume this can be merged separately from the driver
changes?

Otherwise we'll have the same kind of "flag day" mess with
the IRQ crossbar..

Regards,

Tony
 
> 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 5332b57b4950..a2f4aa01984f 100644
> --- a/arch/arm/boot/dts/dra7.dtsi
> +++ b/arch/arm/boot/dts/dra7.dtsi
> @@ -303,6 +303,15 @@
>  			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-masters = <&sdma>;
> +		};
> +
>  		gpio1: gpio@4ae10000 {
>  			compatible = "ti,omap4-gpio";
>  			reg = <0x4ae10000 0x200>;
> @@ -398,7 +407,7 @@
>  			ti,hwmods = "uart1";
>  			clock-frequency = <48000000>;
>  			status = "disabled";
> -			dmas = <&sdma 49>, <&sdma 50>;
> +			dmas = <&sdma_xbar 49>, <&sdma_xbar 50>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -409,7 +418,7 @@
>  			ti,hwmods = "uart2";
>  			clock-frequency = <48000000>;
>  			status = "disabled";
> -			dmas = <&sdma 51>, <&sdma 52>;
> +			dmas = <&sdma_xbar 51>, <&sdma_xbar 52>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -420,7 +429,7 @@
>  			ti,hwmods = "uart3";
>  			clock-frequency = <48000000>;
>  			status = "disabled";
> -			dmas = <&sdma 53>, <&sdma 54>;
> +			dmas = <&sdma_xbar 53>, <&sdma_xbar 54>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -431,7 +440,7 @@
>  			ti,hwmods = "uart4";
>  			clock-frequency = <48000000>;
>                          status = "disabled";
> -			dmas = <&sdma 55>, <&sdma 56>;
> +			dmas = <&sdma_xbar 55>, <&sdma_xbar 56>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -442,7 +451,7 @@
>  			ti,hwmods = "uart5";
>  			clock-frequency = <48000000>;
>  			status = "disabled";
> -			dmas = <&sdma 63>, <&sdma 64>;
> +			dmas = <&sdma_xbar 63>, <&sdma_xbar 64>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -453,7 +462,7 @@
>  			ti,hwmods = "uart6";
>  			clock-frequency = <48000000>;
>  			status = "disabled";
> -			dmas = <&sdma 79>, <&sdma 80>;
> +			dmas = <&sdma_xbar 79>, <&sdma_xbar 80>;
>  			dma-names = "tx", "rx";
>  		};
>  
> @@ -862,7 +871,7 @@
>  			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>;
> @@ -874,7 +883,7 @@
>  			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";
>  		};
> @@ -885,7 +894,7 @@
>  			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";
>  		};
> @@ -896,7 +905,7 @@
>  			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";
>  		};
> @@ -1041,14 +1050,14 @@
>  			#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";
> @@ -1062,10 +1071,10 @@
>  			#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";
>  		};
> @@ -1078,7 +1087,7 @@
>  			#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";
>  		};
> @@ -1091,7 +1100,7 @@
>  			#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";
>  		};
> -- 
> 2.3.5
> 

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Peter Ujfalusi]

On 04/09/2015 06:18 PM, Tony Lindgren wrote:
> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
>> The sDMA requests are routed through the DMA crossbar and without the
>> crossbar only peripherals using DMA request 0-127 can be used.
> 
> I assume this can be merged separately from the driver
> changes?

Unfortunately not. We need to have the drivers in place for the DTS changes to
work.

> 
> Otherwise we'll have the same kind of "flag day" mess with
> the IRQ crossbar..
> 
> Regards,
> 
> Tony
>  

-- 
Péter

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Tony Lindgren]

* Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 11:55]:
> On 04/09/2015 06:18 PM, Tony Lindgren wrote:
> > * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
> >> The sDMA requests are routed through the DMA crossbar and without the
> >> crossbar only peripherals using DMA request 0-127 can be used.
> > 
> > I assume this can be merged separately from the driver
> > changes?
> 
> Unfortunately not. We need to have the drivers in place for the DTS changes to
> work.

Right but just merging the driver changes presumably won't
break things?

Regards,

Tony

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Peter Ujfalusi]

On 04/09/2015 10:01 PM, Tony Lindgren wrote:
> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 11:55]:
>> On 04/09/2015 06:18 PM, Tony Lindgren wrote:
>>> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
>>>> The sDMA requests are routed through the DMA crossbar and without the
>>>> crossbar only peripherals using DMA request 0-127 can be used.
>>>
>>> I assume this can be merged separately from the driver
>>> changes?
>>
>> Unfortunately not. We need to have the drivers in place for the DTS changes to
>> work.
> 
> Right but just merging the driver changes presumably won't
> break things?

No, they will not break anything. We just do not have control over the DMA
crossbar (in a same way as we don't have control right now).

-- 
Péter

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Tony Lindgren]

* Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 12:07]:
> On 04/09/2015 10:01 PM, Tony Lindgren wrote:
> > * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 11:55]:
> >> On 04/09/2015 06:18 PM, Tony Lindgren wrote:
> >>> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
> >>>> The sDMA requests are routed through the DMA crossbar and without the
> >>>> crossbar only peripherals using DMA request 0-127 can be used.
> >>>
> >>> I assume this can be merged separately from the driver
> >>> changes?
> >>
> >> Unfortunately not. We need to have the drivers in place for the DTS changes to
> >> work.
> > 
> > Right but just merging the driver changes presumably won't
> > break things?
> 
> No, they will not break anything. We just do not have control over the DMA
> crossbar (in a same way as we don't have control right now).

OK good to hear.

Thanks,

Tony

Re: [PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[Peter Ujfalusi]

On 04/09/2015 12:35 PM, Peter Ujfalusi wrote:
> Vinod: is it OK if I send the Documnetation/dmanegine/ update a bit later when
> I have finished it?
> 
> Changes since v4:
> - Comments from Maxime Ripard addressed:
>  - long line fixed in of-dma.c
>  - node leaks has been fixed in ti-dma-crossbar
>  - Using devm_ioremap_resource() in ti-dma-crossbar
>  - u16 casting has been addressed
> - Router drivers are expected to return with ERR_PTR in case their
>   of_dma_route_allocate() callback fails.

Are there more comments I need to address with this series?

Thanks,
Péter

> Changes since v3:
> - Comments from Russell:
>  - Warnings removed in case of non DT boot when taking the DMA request number
>  - Reduced the number of channels presented to DMAengine
>  - removed the dma_sig parameter from omap_dma_chan_init()
> - Comments from Arnd:
>  - dma-device property renamed to dma-masters
>  - Allow list of phandes in dma-masters
> 
> Changes since v2:
> - not using regmap for the TI crossbar driver.
> 
> Changes since v1:
> - Comments from Russell King and  Paul Bolle addressed:
>  - Use the added defined in the omap-dma changes
>  - MODULE_* removed from the ti-dma-crossbar driver.
> - DMA router documentation: do not limit the #dma-cells to be the same as the
>   dma controller's #dma-cells. It might be possible to have a router which needs
>   more information than the DMA controller (direct request pairing for example)
> - Use defines in the ti-dma-crossbar driver
> - Binding document for the ti-dma-crossbar driver
> 
> Intro mail from v1:
> 
> 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.
> 
> Regards,
> Peter
> ---
> Peter Ujfalusi (8):
>   dmaengine: of_dma: Support for DMA routers
>   Documentation: devicetree: dma: Binding documentation for TI DMA
>     crossbar
>   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
>   dmaengine: omap-dma: Reduce the number of virtual channels
>   ARM: DTS: dra7x: Integrate sDMA crossbar
> 
>  Documentation/devicetree/bindings/dma/dma.txt      |  28 +++
>  .../devicetree/bindings/dma/ti-dma-crossbar.txt    |  52 ++++++
>  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                               |  89 ++++++++++
>  drivers/dma/omap-dma.c                             |  29 +++-
>  drivers/dma/ti-dma-crossbar.c                      | 188 +++++++++++++++++++++
>  include/linux/dmaengine.h                          |  17 ++
>  include/linux/of_dma.h                             |  21 +++
>  11 files changed, 463 insertions(+), 30 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
>  create mode 100644 drivers/dma/ti-dma-crossbar.c
> 

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Vinod Koul]

On Thu, Apr 09, 2015 at 12:35:49PM +0300, Peter Ujfalusi wrote:
> +int omap_dmaxbar_init(void)
> +{
> +	return platform_driver_register(&ti_dma_xbar_driver);
> +}
> +arch_initcall(omap_dmaxbar_init);
All looks fine except this bit, I think I did point out this last time as
well, though dont recall your answer. We rather depend on defered probe and
not rely on module ordering.

-- 
~Vinod

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Vinod Koul]

On Thu, Apr 09, 2015 at 12:35:54PM +0300, Peter Ujfalusi wrote:
> The sDMA requests are routed through the DMA crossbar and without the
> crossbar only peripherals using DMA request 0-127 can be used.
> 
Need an ACK from ARM folks before I apply this and the DT ones too please

-- 
~Vinod

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Peter Ujfalusi]

On 05/04/2015 08:38 AM, Vinod Koul wrote:
> On Thu, Apr 09, 2015 at 12:35:49PM +0300, Peter Ujfalusi wrote:
>> +int omap_dmaxbar_init(void)
>> +{
>> +	return platform_driver_register(&ti_dma_xbar_driver);
>> +}
>> +arch_initcall(omap_dmaxbar_init);
> All looks fine except this bit, I think I did point out this last time as
> well, though dont recall your answer. We rather depend on defered probe and
> not rely on module ordering.

Can not find my previous response in my mailbox anymore thanks to Thunderbird:
it corrupted all of my local mbox files when I did a backup from the server :(

I don't think the deferred probing is working with dmaengine since we return
NULL in any case when the channel can not be requested for whatever reason.
The request calls are eating up the error code (if any) which is coming when
the channel is requested. With the exception of
dma_request_slave_channel_reason(), which will return the reason for the
failure, but most drivers are not using this.

There is also a fallback in dma_request_slave_channel_compat() if the channel
can not be requested via of/acpi it will try to get the channel via legacy
mode also.

Should all drivers using DMA via dmaengine should return with -EPROBE_DEFER
from their probe if they can not get the DMA channel? Some drivers uses the
existence/non existence of the DMA resource as a means to decide to use DMA or
PIO mode...

If the crossbar is not in the same initcall level we can have bad race
conditions also:
omap-dma can handle up to 127 DMA requests.
omap-dma is loaded but the crossbar driver is not.

A driver requests DMA for crossbar line 135:
We will have failure from of_dma_request_slave_channel() since the CB driver
is not yet loaded (returning with -EPROBE_DEFER), then the legacy call will
try to get the channel from the loaded DMA driver, but that is going to fail
as well (135 is not valid for omap-dma).

Another driver would request DMA for crossbar line 100:
The legacy call will actually find it a valid request and get the channel from
omap-dma driver, but this will not work in reality: the crossbar also need to
be configured to route the signal to the correct line.
This driver would think it has valid DMA, but in fact it has non working DMA.

-- 
Péter

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Vinod Koul]

On Thu, May 07, 2015 at 12:48:34PM +0300, Peter Ujfalusi wrote:
> On 05/04/2015 08:38 AM, Vinod Koul wrote:
> > On Thu, Apr 09, 2015 at 12:35:49PM +0300, Peter Ujfalusi wrote:
> >> +int omap_dmaxbar_init(void)
> >> +{
> >> +	return platform_driver_register(&ti_dma_xbar_driver);
> >> +}
> >> +arch_initcall(omap_dmaxbar_init);
> > All looks fine except this bit, I think I did point out this last time as
> > well, though dont recall your answer. We rather depend on defered probe and
> > not rely on module ordering.
> 
> Can not find my previous response in my mailbox anymore thanks to Thunderbird:
> it corrupted all of my local mbox files when I did a backup from the server :(
> 
> I don't think the deferred probing is working with dmaengine since we return
> NULL in any case when the channel can not be requested for whatever reason.
> The request calls are eating up the error code (if any) which is coming when
> the channel is requested. With the exception of
> dma_request_slave_channel_reason(), which will return the reason for the
> failure, but most drivers are not using this.
Yes that was the reason for this API and I was expecting people ot start
using this and eliminate the init level dependecy

> 
> There is also a fallback in dma_request_slave_channel_compat() if the channel
> can not be requested via of/acpi it will try to get the channel via legacy
> mode also.
> 
> Should all drivers using DMA via dmaengine should return with -EPROBE_DEFER
> from their probe if they can not get the DMA channel? Some drivers uses the
> existence/non existence of the DMA resource as a means to decide to use DMA or
> PIO mode...
Yes we should do that.

> 
> If the crossbar is not in the same initcall level we can have bad race
> conditions also:
> omap-dma can handle up to 127 DMA requests.
> omap-dma is loaded but the crossbar driver is not.
> 
> A driver requests DMA for crossbar line 135:
> We will have failure from of_dma_request_slave_channel() since the CB driver
> is not yet loaded (returning with -EPROBE_DEFER), then the legacy call will
> try to get the channel from the loaded DMA driver, but that is going to fail
> as well (135 is not valid for omap-dma).
> 
> Another driver would request DMA for crossbar line 100:
> The legacy call will actually find it a valid request and get the channel from
> omap-dma driver, but this will not work in reality: the crossbar also need to
> be configured to route the signal to the correct line.
> This driver would think it has valid DMA, but in fact it has non working DMA.
I think you cna start doing the conversion of omap driver thuis you dont
have dependency on others.

Now as far as this series is concerned, rest of it looks good so I am
willing to merge to if you plan to work on defered probe :) I think its a
fair bargain!

-- 
~Vinod

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Peter Ujfalusi]

On 05/08/2015 06:41 AM, Vinod Koul wrote:
> Now as far as this series is concerned, rest of it looks good so I am
> willing to merge to if you plan to work on defered probe :) I think its a
> fair bargain!

Deal ;)

I'll take care of the OMAP/daVinci drivers for omap-dma and edma.

-- 
Péter

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Vinod Koul]

On Fri, May 08, 2015 at 10:05:24AM +0300, Peter Ujfalusi wrote:
> On 05/08/2015 06:41 AM, Vinod Koul wrote:
> > Now as far as this series is concerned, rest of it looks good so I am
> > willing to merge to if you plan to work on defered probe :) I think its a
> > fair bargain!
> 
> Deal ;)
Wonderful :)

> 
> I'll take care of the OMAP/daVinci drivers for omap-dma and edma.
Okay, I had asked for ACK on last patch as its ARM one, or do you want me to
go ahead and apply it.. will wait till today

-- 
~Vinod

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Tony Lindgren]

* Vinod Koul <vinod.koul@intel.com> [150508 02:04]:
> On Fri, May 08, 2015 at 10:05:24AM +0300, Peter Ujfalusi wrote:
> > On 05/08/2015 06:41 AM, Vinod Koul wrote:
> > > Now as far as this series is concerned, rest of it looks good so I am
> > > willing to merge to if you plan to work on defered probe :) I think its a
> > > fair bargain!
> > 
> > Deal ;)
> Wonderful :)
> 
> > 
> > I'll take care of the OMAP/daVinci drivers for omap-dma and edma.
> Okay, I had asked for ACK on last patch as its ARM one, or do you want me to
> go ahead and apply it.. will wait till today

It's best that I queue the .dts change as a follow-up patch once
the DMA changes are merged. Otherwise it's almost guaranteed to
produce merge conflicts with other dts changes.

Peter, let us know if there's an issue with that. If so, we need
to set up an immutable branch against v4.1-rc1 with just these
patches so we can merge it in as needed.

Regards,

Tony

Re: [PATCH v5 3/8] dmaengine: Add driver for TI DMA crossbar on DRA7x

[Peter Ujfalusi]

On 05/08/2015 06:09 PM, Tony Lindgren wrote:
> * Vinod Koul <vinod.koul@intel.com> [150508 02:04]:
>> On Fri, May 08, 2015 at 10:05:24AM +0300, Peter Ujfalusi wrote:
>>> On 05/08/2015 06:41 AM, Vinod Koul wrote:
>>>> Now as far as this series is concerned, rest of it looks good so I am
>>>> willing to merge to if you plan to work on defered probe :) I think its a
>>>> fair bargain!
>>>
>>> Deal ;)
>> Wonderful :)
>>
>>>
>>> I'll take care of the OMAP/daVinci drivers for omap-dma and edma.
>> Okay, I had asked for ACK on last patch as its ARM one, or do you want me to
>> go ahead and apply it.. will wait till today
> 
> It's best that I queue the .dts change as a follow-up patch once
> the DMA changes are merged. Otherwise it's almost guaranteed to
> produce merge conflicts with other dts changes.
> 
> Peter, let us know if there's an issue with that. If so, we need
> to set up an immutable branch against v4.1-rc1 with just these
> patches so we can merge it in as needed.

Yes, the DT patches w/o the dmaengine changes will brake dra7, but it is not
true other way around.
The DT patches should be merged only when the dmaengine patches are in.

-- 
Péter

Re: [PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[Vinod Koul]

On Thu, Apr 09, 2015 at 12:35:46PM +0300, Peter Ujfalusi wrote:
> Vinod: is it OK if I send the Documnetation/dmanegine/ update a bit later when
> I have finished it?
> 
> Changes since v4:
> - Comments from Maxime Ripard addressed:
>  - long line fixed in of-dma.c
>  - node leaks has been fixed in ti-dma-crossbar
>  - Using devm_ioremap_resource() in ti-dma-crossbar
>  - u16 casting has been addressed
> - Router drivers are expected to return with ERR_PTR in case their
>   of_dma_route_allocate() callback fails.
> 
> Changes since v3:
> - Comments from Russell:
>  - Warnings removed in case of non DT boot when taking the DMA request number
>  - Reduced the number of channels presented to DMAengine
>  - removed the dma_sig parameter from omap_dma_chan_init()
> - Comments from Arnd:
>  - dma-device property renamed to dma-masters
>  - Allow list of phandes in dma-masters
> 
> Changes since v2:
> - not using regmap for the TI crossbar driver.
> 
> Changes since v1:
> - Comments from Russell King and  Paul Bolle addressed:
>  - Use the added defined in the omap-dma changes
>  - MODULE_* removed from the ti-dma-crossbar driver.
> - DMA router documentation: do not limit the #dma-cells to be the same as the
>   dma controller's #dma-cells. It might be possible to have a router which needs
>   more information than the DMA controller (direct request pairing for example)
> - Use defines in the ti-dma-crossbar driver
> - Binding document for the ti-dma-crossbar driver
> 
> Intro mail from v1:
> 
> 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.
I have applied all but last change to topic/omap

Thanks
-- 
~Vinod

Re: [PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[Peter Ujfalusi]

On 05/09/2015 02:44 PM, Vinod Koul wrote:
>> 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.
> I have applied all but last change to topic/omap

I can only find 6 patches out of the 8 in topic/omap. Patch 3 - which is the
main reason for this series seams to be missing but the binding document patch
for the ti-dma-crossbar is there.

-- 
Péter

Re: [PATCH v5 0/8] dmaengine/dra7x: DMA router (crossbar support)

[Vinod Koul]

On Wed, May 13, 2015 at 05:57:03PM +0300, Peter Ujfalusi wrote:
> On 05/09/2015 02:44 PM, Vinod Koul wrote:
> >> 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.
> > I have applied all but last change to topic/omap
> 
> I can only find 6 patches out of the 8 in topic/omap. Patch 3 - which is the
> main reason for this series seams to be missing but the binding document patch
> for the ti-dma-crossbar is there.
Oops, I thought i selected whole series except 8th one!. I have picked the
missing 3rd patch and applied now

Since noone complained so am assuming sequence isn't broken which is nice, if
you feel we should reorder and place it 3rd, let me know

-- 
~VInod

Re: [PATCH v5 8/8] ARM: DTS: dra7x: Integrate sDMA crossbar

[Tony Lindgren]

* Tony Lindgren <tony@atomide.com> [150409 12:17]:
> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 12:07]:
> > On 04/09/2015 10:01 PM, Tony Lindgren wrote:
> > > * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 11:55]:
> > >> On 04/09/2015 06:18 PM, Tony Lindgren wrote:
> > >>> * Peter Ujfalusi <peter.ujfalusi@ti.com> [150409 02:37]:
> > >>>> The sDMA requests are routed through the DMA crossbar and without the
> > >>>> crossbar only peripherals using DMA request 0-127 can be used.
> > >>>
> > >>> I assume this can be merged separately from the driver
> > >>> changes?
> > >>
> > >> Unfortunately not. We need to have the drivers in place for the DTS changes to
> > >> work.
> > > 
> > > Right but just merging the driver changes presumably won't
> > > break things?
> > 
> > No, they will not break anything. We just do not have control over the DMA
> > crossbar (in a same way as we don't have control right now).
> 
> OK good to hear.

Looks like the related DMA changes are now merged, so applying this
into omap-for-v4.3/dt thanks.

Tony