Thread (14 messages) 14 messages, 3 authors, 2015-03-09

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

From: Paul Bolle <hidden>
Date: 2015-02-28 16:01:05
Also in: linux-arm-kernel, linux-omap, lkml

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 <redacted>
---
 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.
quoted hunk ↗ jump to hunk
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...
quoted hunk ↗ jump to hunk
 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-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
... so this file will be either not built or built into the kernel...
quoted hunk ↗ jump to hunk
 obj-$(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 [off-list ref]");
+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
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