Date:   Mon,  9 Dec 2019 19:53:24 +0530
From:   shubhrajyoti.datta@...il.com
To:     linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Cc:     michal.simek@...inx.com, gregkh@...uxfoundation.org,
        robh+dt@...nel.org,
        Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>,
        Subbaraya Sundeep Bhatta <sbhatta@...inx.com>
Subject: [PATCH v2 1/2] uio: uio_xilinx_apm: Add Xilinx AXI performance monitor driver

From: Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>

Added driver for Xilinx AXI performance monitor IP.

Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta@...inx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>
---
v2:
Updated the header

 drivers/uio/Kconfig          |  12 ++
 drivers/uio/Makefile         |   1 +
 drivers/uio/uio_xilinx_apm.c | 358 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 371 insertions(+)
 create mode 100644 drivers/uio/uio_xilinx_apm.c

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 202ee81..de30312 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -165,4 +165,16 @@ config UIO_HV_GENERIC
 	  to network and storage devices from userspace.
 
 	  If you compile this as a module, it will be called uio_hv_generic.
+
+config UIO_XILINX_APM
+	tristate "Xilinx AXI Performance Monitor driver"
+	depends on MICROBLAZE || ARCH_ZYNQ || ARCH_ZYNQMP
+	help
+	  This driver is developed for AXI Performance Monitor IP, designed to
+	  monitor AXI4 traffic for performance analysis of AXI bus in the
+	  system. Driver maps HW registers and parameters to userspace.
+
+	  To compile this driver as a module, choose M here; the module
+	  will be called uio_xilinx_apm.
+
 endif
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index c285dd2..b3464d8 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_UIO_PRUSS)         += uio_pruss.o
 obj-$(CONFIG_UIO_MF624)         += uio_mf624.o
 obj-$(CONFIG_UIO_FSL_ELBC_GPCM)	+= uio_fsl_elbc_gpcm.o
 obj-$(CONFIG_UIO_HV_GENERIC)	+= uio_hv_generic.o
+obj-$(CONFIG_UIO_XILINX_APM)	+= uio_xilinx_apm.o
diff --git a/drivers/uio/uio_xilinx_apm.c b/drivers/uio/uio_xilinx_apm.c
new file mode 100644
index 0000000..3f69922
--- /dev/null
+++ b/drivers/uio/uio_xilinx_apm.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx AXI Performance Monitor
+ *
+ * Description:
+ * This driver is developed for AXI Performance Monitor IP,
+ * designed to monitor AXI4 traffic for performance analysis
+ * of AXI bus in the system. Driver maps HW registers and parameters
+ * to userspace. Userspace need not clear the interrupt of IP since
+ * driver clears the interrupt.
+ *
+ * Copyright (c) 2019 Xilinx Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/uio_driver.h>
+
+#define XAPM_IS_OFFSET		0x0038  /* Interrupt Status Register */
+#define DRV_NAME		"xilinxapm_uio"
+#define DRV_VERSION		"1.0"
+#define UIO_DUMMY_MEMSIZE	4096
+#define XAPM_MODE_ADVANCED	1
+#define XAPM_MODE_PROFILE	2
+#define XAPM_MODE_TRACE		3
+
+/**
+ * struct xapm_param - HW parameters structure
+ * @mode: Mode in which APM is working
+ * @maxslots: Maximum number of Slots in APM
+ * @eventcnt: Event counting enabled in APM
+ * @eventlog: Event logging enabled in APM
+ * @sampledcnt: Sampled metric counters enabled in APM
+ * @numcounters: Number of counters in APM
+ * @metricwidth: Metric Counter width (32/64)
+ * @sampledwidth: Sampled metric counter width
+ * @globalcntwidth: Global Clock counter width
+ * @scalefactor: Scaling factor
+ * @isr: Interrupts info shared to userspace
+ * @is_32bit_filter: Flags for 32bit filter
+ * @clk: Clock handle
+ */
+struct xapm_param {
+	u32 mode;
+	u32 maxslots;
+	u32 eventcnt;
+	u32 eventlog;
+	u32 sampledcnt;
+	u32 numcounters;
+	u32 metricwidth;
+	u32 sampledwidth;
+	u32 globalcntwidth;
+	u32 scalefactor;
+	u32 isr;
+	bool is_32bit_filter;
+	struct clk *clk;
+};
+
+/**
+ * struct xapm_dev - Global driver structure
+ * @info: uio_info structure
+ * @param: xapm_param structure
+ * @regs: IOmapped base address
+ */
+struct xapm_dev {
+	struct uio_info info;
+	struct xapm_param param;
+	void __iomem *regs;
+};
+
+/**
+ * xapm_handler - Interrupt handler for APM
+ * @irq: IRQ number
+ * @info: Pointer to uio_info structure
+ *
+ * Return: Always returns IRQ_HANDLED
+ */
+static irqreturn_t xapm_handler(int irq, struct uio_info *info)
+{
+	struct xapm_dev *xapm = (struct xapm_dev *)info->priv;
+	void *ptr;
+
+	ptr = (unsigned long *)xapm->info.mem[1].addr;
+	/* Clear the interrupt and copy the ISR value to userspace */
+	xapm->param.isr = readl(xapm->regs + XAPM_IS_OFFSET);
+	writel(xapm->param.isr, xapm->regs + XAPM_IS_OFFSET);
+	memcpy(ptr, &xapm->param, sizeof(struct xapm_param));
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * xapm_getprop - Retrieves dts properties to param structure
+ * @pdev: Pointer to platform device
+ * @param: Pointer to param structure
+ *
+ * Returns: '0' on success and failure value on error
+ */
+static int xapm_getprop(struct platform_device *pdev, struct xapm_param *param)
+{
+	u32 mode = 0;
+	int ret;
+	struct device_node *node;
+
+	node = pdev->dev.of_node;
+
+	/* Retrieve required dts properties and fill param structure */
+	ret = of_property_read_u32(node, "xlnx,enable-profile", &mode);
+	if (ret < 0)
+		dev_info(&pdev->dev, "no property xlnx,enable-profile\n");
+	else if (mode)
+		param->mode = XAPM_MODE_PROFILE;
+
+	ret = of_property_read_u32(node, "xlnx,enable-trace", &mode);
+	if (ret < 0)
+		dev_info(&pdev->dev, "no property xlnx,enable-trace\n");
+	else if (mode)
+		param->mode = XAPM_MODE_TRACE;
+
+	ret = of_property_read_u32(node, "xlnx,num-monitor-slots",
+				   &param->maxslots);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,num-monitor-slots");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,enable-event-count",
+				   &param->eventcnt);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,enable-event-count");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,enable-event-log",
+				   &param->eventlog);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,enable-event-log");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,have-sampled-metric-cnt",
+				   &param->sampledcnt);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,have-sampled-metric-cnt");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,num-of-counters",
+				   &param->numcounters);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,num-of-counters");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,metric-count-width",
+				   &param->metricwidth);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,metric-count-width");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,metrics-sample-count-width",
+				   &param->sampledwidth);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property metrics-sample-count-width");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,global-count-width",
+				   &param->globalcntwidth);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,global-count-width");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "xlnx,metric-count-scale",
+				   &param->scalefactor);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no property xlnx,metric-count-scale");
+		return ret;
+	}
+
+	param->is_32bit_filter = of_property_read_bool(node,
+						"xlnx,id-filter-32bit");
+
+	return 0;
+}
+
+/**
+ * xapm_probe - Driver probe function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Returns: '0' on success and failure value on error
+ */
+
+static int xapm_probe(struct platform_device *pdev)
+{
+	struct xapm_dev *xapm;
+	struct resource *res;
+	int irq;
+	int ret;
+	void *ptr;
+
+	xapm = devm_kzalloc(&pdev->dev, (sizeof(struct xapm_dev)), GFP_KERNEL);
+	if (!xapm)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	xapm->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(xapm->regs)) {
+		dev_err(&pdev->dev, "unable to iomap registers\n");
+		return PTR_ERR(xapm->regs);
+	}
+
+	xapm->param.clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xapm->param.clk)) {
+		if (PTR_ERR(xapm->param.clk) != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "axi clock error\n");
+		return PTR_ERR(xapm->param.clk);
+	}
+
+	ret = clk_prepare_enable(xapm->param.clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return ret;
+	}
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	/* Initialize mode as Advanced so that if no mode in dts, default
+	 * is Advanced
+	 */
+	xapm->param.mode = XAPM_MODE_ADVANCED;
+	ret = xapm_getprop(pdev, &xapm->param);
+	if (ret < 0)
+		goto err_clk_dis;
+
+	xapm->info.mem[0].name = "xilinx_apm";
+	xapm->info.mem[0].addr = res->start;
+	xapm->info.mem[0].size = resource_size(res);
+	xapm->info.mem[0].memtype = UIO_MEM_PHYS;
+
+	xapm->info.mem[1].addr = (unsigned long)kzalloc(UIO_DUMMY_MEMSIZE,
+							GFP_KERNEL);
+	ptr = (unsigned long *)xapm->info.mem[1].addr;
+	xapm->info.mem[1].size = UIO_DUMMY_MEMSIZE;
+	xapm->info.mem[1].memtype = UIO_MEM_LOGICAL;
+
+	xapm->info.name = "axi-pmon";
+	xapm->info.version = DRV_VERSION;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "unable to get irq\n");
+		ret = irq;
+		goto err_clk_dis;
+	}
+
+	xapm->info.irq = irq;
+	xapm->info.handler = xapm_handler;
+	xapm->info.priv = xapm;
+	xapm->info.irq_flags = IRQF_SHARED;
+
+	memcpy(ptr, &xapm->param, sizeof(struct xapm_param));
+
+	ret = uio_register_device(&pdev->dev, &xapm->info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "unable to register to UIO\n");
+		goto err_clk_dis;
+	}
+
+	platform_set_drvdata(pdev, xapm);
+
+	dev_info(&pdev->dev, "Probed Xilinx APM\n");
+
+	return 0;
+
+err_clk_dis:
+	clk_disable_unprepare(xapm->param.clk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	return ret;
+}
+
+/**
+ * xapm_remove - Driver remove function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Return: Always returns '0'
+ */
+static int xapm_remove(struct platform_device *pdev)
+{
+	struct xapm_dev *xapm = platform_get_drvdata(pdev);
+
+	uio_unregister_device(&xapm->info);
+	clk_disable_unprepare(xapm->param.clk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused xapm_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct xapm_dev *xapm = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(xapm->param.clk);
+	return 0;
+};
+
+static int __maybe_unused xapm_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct xapm_dev *xapm = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_prepare_enable(xapm->param.clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return ret;
+	}
+	return 0;
+};
+
+static const struct dev_pm_ops xapm_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(xapm_runtime_suspend, xapm_runtime_resume)
+	SET_RUNTIME_PM_OPS(xapm_runtime_suspend,
+			   xapm_runtime_resume, NULL)
+};
+
+static const struct of_device_id xapm_of_match[] = {
+	{ .compatible = "xlnx,axi-perf-monitor", },
+	{ /* end of table*/ }
+};
+
+MODULE_DEVICE_TABLE(of, xapm_of_match);
+
+static struct platform_driver xapm_driver = {
+	.driver = {
+		.name = "xilinx-axipmon",
+		.of_match_table = xapm_of_match,
+		.pm = &xapm_dev_pm_ops,
+	},
+	.probe = xapm_probe,
+	.remove = xapm_remove,
+};
+
+module_platform_driver(xapm_driver);
+
+MODULE_AUTHOR("Xilinx Inc.");
+MODULE_DESCRIPTION("Xilinx AXI Performance Monitor driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.1

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