[PATCH 2/6] dmaengine: Add driver for TI DMA crossbar on DRA7x
Peter Ujfalusi
peter.ujfalusi at ti.com
Tue Feb 24 06:21:19 PST 2015
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 at 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 at 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 at ti.com>");
+MODULE_LICENSE("GPL");
--
2.3.0
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