[PATCH v4 4/6] uio: Add X-Gene QMTM UIO driver

[Ankit Jindal]

The Applied Micro X-Gene SOC has on-chip QMTM (Queue manager
and Traffic manager) which is hardware based Queue or Ring
manager. This QMTM device can be used in conjunction with
other devices such as DMA Engine, Ethernet, Security Engine,
etc to assign work based on queues or rings.

This patch allows user space access to X-Gene QMTM device.

Signed-off-by: Ankit Jindal <ankit.jindal@xxxxxxxxxx>
Signed-off-by: Tushar Jagad <tushar.jagad@xxxxxxxxxx>
---
 drivers/uio/Kconfig          |    8 ++
 drivers/uio/Makefile         |    1 +
 drivers/uio/uio_xgene_qmtm.c |  271 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 280 insertions(+)
 create mode 100644 drivers/uio/uio_xgene_qmtm.c

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 5a90914..76b1858 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -135,4 +135,12 @@ config UIO_MF624
 
 	  If you compile this as a module, it will be called uio_mf624.
 
+config UIO_XGENE_QMTM
+	tristate "Applied Micro X-Gene QMTM driver"
+	depends on OF
+	help
+	  Userspace I/O interface for the X-Gene QMTM. The userspace part of
+	  this driver will be available for download from the Applied Micro
+	  web site (http://www.apm.com/).
+
 endif
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index d3218bd..633eaa0 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_UIO_PCI_GENERIC)	+= uio_pci_generic.o
 obj-$(CONFIG_UIO_NETX)	+= uio_netx.o
 obj-$(CONFIG_UIO_PRUSS)         += uio_pruss.o
 obj-$(CONFIG_UIO_MF624)         += uio_mf624.o
+obj-$(CONFIG_UIO_XGENE_QMTM)	+= uio_xgene_qmtm.o
diff --git a/drivers/uio/uio_xgene_qmtm.c b/drivers/uio/uio_xgene_qmtm.c
new file mode 100644
index 0000000..0695eb2a
--- /dev/null
+++ b/drivers/uio/uio_xgene_qmtm.c
@@ -0,0 +1,271 @@
+/*
+ * X-Gene Queue Manager Traffic Manager (QMTM) UIO driver (uio_xgene_qmtm)
+ *
+ * This driver exports QMTM CSRs, Fabric and memory for queues to user-space
+ *
+ * Copyright (C) 2014 Applied Micro - http://www.apm.com/
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uio_driver.h>
+
+#define DRV_NAME "qmtm_uio"
+#define DRV_VERSION "1.0"
+
+#define QMTM_CFG_MEM_RAM_SHUTDOWN	0x0000d070
+
+#define QMTM_DEFAULT_QSIZE		65536
+
+struct uio_qmtm_dev {
+	struct uio_info *info;
+	struct clk *qmtm_clk;
+};
+
+/* QMTM CSR read/write routine */
+static inline void qmtm_csr_write(struct uio_qmtm_dev *qmtm_dev, u32 offset,
+		u32 data)
+{
+	void __iomem *addr = qmtm_dev->info->mem[0].internal_addr;
+
+	writel(data, addr + offset);
+}
+
+static inline u32 qmtm_csr_read(struct uio_qmtm_dev *qmtm_dev, u32 offset)
+{
+	void __iomem *addr = qmtm_dev->info->mem[0].internal_addr;
+
+	return readl(addr + offset);
+}
+
+static int qmtm_reset(struct uio_qmtm_dev *qmtm_dev)
+{
+	u32 val;
+	int wait = 1000;
+
+	/* reset the internal memory of the device */
+	qmtm_csr_write(qmtm_dev, QMTM_CFG_MEM_RAM_SHUTDOWN, 0);
+
+	/* check whether device internal memory is out of reset or not */
+	while (wait--) {
+		val = qmtm_csr_read(qmtm_dev, QMTM_CFG_MEM_RAM_SHUTDOWN);
+
+		if (val != 0xffffffff)
+			return 0;
+
+		udelay(1);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int qmtm_probe(struct platform_device *pdev)
+{
+	struct uio_info *info;
+	struct uio_qmtm_dev *qmtm_dev;
+	struct resource *csr;
+	struct resource *fabric;
+	struct resource qpool;
+	unsigned int num_queues;
+	unsigned int devid;
+	phandle qpool_phandle;
+	struct device_node *qpool_node;
+	int ret;
+
+	qmtm_dev = devm_kzalloc(&pdev->dev, sizeof(struct uio_qmtm_dev),
+				GFP_KERNEL);
+	if (!qmtm_dev)
+		return -ENOMEM;
+
+	qmtm_dev->info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!qmtm_dev->info)
+		return -ENOMEM;
+
+	/* Power on qmtm in case its not done as part of boot-loader */
+	qmtm_dev->qmtm_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(qmtm_dev->qmtm_clk)) {
+		dev_err(&pdev->dev, "Failed to get clock\n");
+		ret = PTR_ERR(qmtm_dev->qmtm_clk);
+		return ret;
+	}
+
+	csr = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!csr) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "No QMTM CSR resource specified\n");
+		goto out_err;
+	}
+
+	if (!csr->start) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "Invalid CSR resource\n");
+		goto out_err;
+	}
+
+	fabric = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!fabric) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "No QMTM Fabric resource specified\n");
+		goto out_err;
+	}
+
+	if (!fabric->start) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "Invalid Fabric resource\n");
+		goto out_err;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node, "qpool-memory",
+					&qpool_phandle);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "No qpool-memory resource specified\n");
+		goto out_err;
+	}
+
+	qpool_node = of_find_node_by_phandle(qpool_phandle);
+	if (IS_ERR_OR_NULL(qpool_node)) {
+		ret = PTR_ERR(qpool_node);
+		dev_err(&pdev->dev, "Failed to get node by phandle\n");
+		goto out_err;
+	}
+
+	ret = of_address_to_resource(qpool_node, 0, &qpool);
+
+	of_node_put(qpool_node);
+
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to get qpool resource from node\n");
+		goto out_err;
+	}
+
+	if (!qpool.start) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "Invalid qpool resource\n");
+		goto out_err;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node, "num-queues",
+			&num_queues);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "No num-queues resource specified\n");
+		goto out_err;
+	}
+
+	/* check whether sufficient memory is provided for the given queues */
+	if (num_queues * QMTM_DEFAULT_QSIZE > resource_size(&qpool)) {
+		ret = -ENOSPC;
+		dev_err(&pdev->dev, "Insufficient Qpool for the given queues\n");
+		goto out_err;
+	}
+
+	ret = of_property_read_u32(pdev->dev.of_node, "devid", &devid);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "No devid resource specified\n");
+		goto out_err;
+	}
+
+	info = qmtm_dev->info;
+	info->mem[0].name = "csr";
+	info->mem[0].addr = csr->start;
+	info->mem[0].size = resource_size(csr);
+	info->mem[0].memtype = UIO_MEM_PHYS;
+	info->mem[0].internal_addr = devm_ioremap_resource(&pdev->dev, csr);
+
+	if (IS_ERR(info->mem[0].internal_addr)) {
+		ret = PTR_ERR(info->mem[0].internal_addr);
+		dev_err(&pdev->dev, "Failed to ioremap CSR region\n");
+		goto out_err;
+	}
+
+	info->mem[1].name = "fabric";
+	info->mem[1].addr = fabric->start;
+	info->mem[1].size = resource_size(fabric);
+	info->mem[1].memtype = UIO_MEM_PHYS;
+
+	info->mem[2].name = "qpool";
+	info->mem[2].addr = qpool.start;
+	info->mem[2].size = resource_size(&qpool);
+	info->mem[2].memtype = UIO_MEM_PHYS_CACHE;
+
+	info->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "qmtm%d", devid);
+	info->version = DRV_VERSION;
+
+	info->priv = qmtm_dev;
+
+	/* enable the clock */
+	clk_prepare_enable(qmtm_dev->qmtm_clk);
+
+	/* get the qmtm out of reset */
+	ret = qmtm_reset(qmtm_dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to reset QMTM\n");
+		goto out_clk;
+	}
+
+	/* register with uio framework */
+	ret = uio_register_device(&pdev->dev, info);
+	if (ret < 0)
+		goto out_clk;
+
+	platform_set_drvdata(pdev, qmtm_dev);
+	return 0;
+
+out_clk:
+	clk_disable_unprepare(qmtm_dev->qmtm_clk);
+
+out_err:
+	return ret;
+}
+
+static int qmtm_remove(struct platform_device *pdev)
+{
+	struct uio_qmtm_dev *qmtm_dev = platform_get_drvdata(pdev);
+	struct uio_info *info = qmtm_dev->info;
+
+	uio_unregister_device(info);
+
+	clk_disable_unprepare(qmtm_dev->qmtm_clk);
+
+	return 0;
+}
+
+static struct of_device_id qmtm_match[] = {
+	{.compatible = "apm,xgene-qmtm",},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, qmtm_match);
+
+static struct platform_driver qmtm_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = qmtm_match,
+	},
+	.probe = qmtm_probe,
+	.remove = qmtm_remove,
+};
+
+module_platform_driver(qmtm_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DRV_VERSION);
+MODULE_AUTHOR("Ankit Jindal <ankit.jindal@xxxxxxxxxx>");
+MODULE_AUTHOR("Tushar Jagad <tushar.jagad@xxxxxxxxxx>");
-- 
1.7.9.5

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