[PATCH v2 3/5] dmaengine: zynqmp_ps_pcie: Adding PS PCIe DMA driver

[Ravi Shankar Jonnalagadda]

Adding support for ZynqmMP PS PCIe EP driver.
Adding support for ZynqmMP PS PCIe Root DMA driver.
Modifying Kconfig and Makefile to add the support.

Signed-off-by: Ravi Shankar Jonnalagadda <vjonnal@xxxxxxxxxx>
Signed-off-by: RaviKiran Gummaluri <rgummal@xxxxxxxxxx>
---
 drivers/dma/Kconfig               |  12 +++
 drivers/dma/xilinx/Makefile       |   2 +
 drivers/dma/xilinx/ps_pcie.h      |  44 +++++++++
 drivers/dma/xilinx/ps_pcie_main.c | 200 ++++++++++++++++++++++++++++++++++++++
 include/linux/dma/ps_pcie_dma.h   |  69 +++++++++++++
 5 files changed, 327 insertions(+)
 create mode 100644 drivers/dma/xilinx/ps_pcie.h
 create mode 100644 drivers/dma/xilinx/ps_pcie_main.c
 create mode 100644 include/linux/dma/ps_pcie_dma.h

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index fa8f9c0..e2fe4e5 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -586,6 +586,18 @@ config XILINX_ZYNQMP_DMA
 	help
 	  Enable support for Xilinx ZynqMP DMA controller.
 
+config XILINX_PS_PCIE_DMA
+	tristate "Xilinx PS PCIe DMA support"
+	depends on (PCI && X86_64 || ARM64)
+	select DMA_ENGINE
+	help
+	  Enable support for the Xilinx PS PCIe DMA engine present
+	  in recent Xilinx ZynqMP chipsets.
+
+	  Say Y here if you have such a chipset.
+
+	  If unsure, say N.
+
 config ZX_DMA
 	tristate "ZTE ZX DMA support"
 	depends on ARCH_ZX || COMPILE_TEST
diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile
index 9e91f8f..04f6f99 100644
--- a/drivers/dma/xilinx/Makefile
+++ b/drivers/dma/xilinx/Makefile
@@ -1,2 +1,4 @@
 obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
 obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
+ps_pcie_dma-objs := ps_pcie_main.o ps_pcie_platform.o
+obj-$(CONFIG_XILINX_PS_PCIE_DMA) += ps_pcie_dma.o
diff --git a/drivers/dma/xilinx/ps_pcie.h b/drivers/dma/xilinx/ps_pcie.h
new file mode 100644
index 0000000..351f051
--- /dev/null
+++ b/drivers/dma/xilinx/ps_pcie.h
@@ -0,0 +1,44 @@
+/*
+ * Xilinx PS PCIe DMA Engine platform header file
+ *
+ * Copyright (C) 2010-2017 Xilinx, Inc. All rights reserved.
+ *
+ * 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
+ */
+
+#ifndef __XILINX_PS_PCIE_H
+#define __XILINX_PS_PCIE_H
+
+#include <linux/delay.h>
+#include <linux/dma-direction.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/irqreturn.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mempool.h>
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/timer.h>
+#include <linux/dma/ps_pcie_dma.h>
+
+/**
+ * dma_platform_driver_register - This will be invoked by module init
+ *
+ * Return: returns status of platform_driver_register
+ */
+int dma_platform_driver_register(void);
+/**
+ * dma_platform_driver_unregister - This will be invoked by module exit
+ *
+ * Return: returns void after unregustering platform driver
+ */
+void dma_platform_driver_unregister(void);
+
+#endif
diff --git a/drivers/dma/xilinx/ps_pcie_main.c b/drivers/dma/xilinx/ps_pcie_main.c
new file mode 100644
index 0000000..4ccd8ef
--- /dev/null
+++ b/drivers/dma/xilinx/ps_pcie_main.c
@@ -0,0 +1,200 @@
+/*
+ * XILINX PS PCIe driver
+ *
+ * Copyright (C) 2017 Xilinx, Inc. All rights reserved.
+ *
+ * Description
+ * PS PCIe DMA is memory mapped DMA used to execute PS to PL transfers
+ * on ZynqMP UltraScale+ Devices.
+ * This PCIe driver creates a platform device with specific platform
+ * info enabling creation of DMA device corresponding to the channel
+ * information provided in the properties
+ *
+ * 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 "ps_pcie.h"
+#include "../dmaengine.h"
+
+#define DRV_MODULE_NAME		  "ps_pcie_dma"
+
+static int ps_pcie_dma_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *ent);
+static void ps_pcie_dma_remove(struct pci_dev *pdev);
+
+static u32 channel_properties_pcie_axi[] = {
+	(u32)(PCIE_AXI_DIRECTION), (u32)(NUMBER_OF_BUFFER_DESCRIPTORS),
+	(u32)(DEFAULT_DMA_QUEUES), (u32)(CHANNEL_COAELSE_COUNT),
+	(u32)(CHANNEL_POLL_TIMER_FREQUENCY) };
+
+static u32 channel_properties_axi_pcie[] = {
+	(u32)(AXI_PCIE_DIRECTION), (u32)(NUMBER_OF_BUFFER_DESCRIPTORS),
+	(u32)(DEFAULT_DMA_QUEUES), (u32)(CHANNEL_COAELSE_COUNT),
+	(u32)(CHANNEL_POLL_TIMER_FREQUENCY) };
+
+static struct property_entry generic_pcie_ep_property[] = {
+	PROPERTY_ENTRY_U32("numchannels", (u32)MAX_NUMBER_OF_CHANNELS),
+	PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel0",
+				 channel_properties_pcie_axi),
+	PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel1",
+				 channel_properties_axi_pcie),
+	PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel2",
+				 channel_properties_pcie_axi),
+	PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel3",
+				 channel_properties_axi_pcie),
+	{ },
+};
+
+static const struct platform_device_info xlnx_std_platform_dev_info = {
+	.name           = XLNX_PLATFORM_DRIVER_NAME,
+	.properties     = generic_pcie_ep_property,
+};
+
+/**
+ * ps_pcie_dma_probe - Driver probe function
+ * @pdev: Pointer to the pci_dev structure
+ * @ent: pci device id
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int ps_pcie_dma_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *ent)
+{
+	int err;
+	struct platform_device *platform_dev;
+	struct platform_device_info platform_dev_info;
+
+	dev_info(&pdev->dev, "PS PCIe DMA Driver probe\n");
+
+	err = pcim_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot enable PCI device, aborting\n");
+		return err;
+	}
+
+	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
+	if (err) {
+		dev_info(&pdev->dev, "Cannot set 64 bit DMA mask\n");
+		err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (err) {
+			dev_err(&pdev->dev, "DMA mask set error\n");
+			return err;
+		}
+	}
+
+	err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
+	if (err) {
+		dev_info(&pdev->dev, "Cannot set 64 bit consistent DMA mask\n");
+		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (err) {
+			dev_err(&pdev->dev, "Cannot set consistent DMA mask\n");
+			return err;
+		}
+	}
+
+	pci_set_master(pdev);
+
+	/* For Root DMA platform device will be created through device tree */
+	if (pdev->vendor == PCI_VENDOR_ID_XILINX &&
+	    pdev->device == ZYNQMP_RC_DMA_DEVID)
+		return 0;
+
+	memcpy(&platform_dev_info, &xlnx_std_platform_dev_info,
+	       sizeof(xlnx_std_platform_dev_info));
+
+	/* Do device specific channel configuration changes to
+	 * platform_dev_info.properties if required
+	 * More information on channel properties can be found
+	 * at Documentation/devicetree/bindings/dma/xilinx/ps-pcie-dma.txt
+	 */
+
+	platform_dev_info.parent = &pdev->dev;
+	platform_dev_info.data = &pdev;
+	platform_dev_info.size_data = sizeof(struct pci_dev **);
+
+	platform_dev = platform_device_register_full(&platform_dev_info);
+	if (IS_ERR(platform_dev)) {
+		dev_err(&pdev->dev,
+			"Cannot create platform device, aborting\n");
+		return PTR_ERR(platform_dev);
+	}
+
+	pci_set_drvdata(pdev, platform_dev);
+
+	dev_info(&pdev->dev, "PS PCIe DMA driver successfully probed\n");
+
+	return 0;
+}
+
+static struct pci_device_id ps_pcie_dma_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_XILINX, ZYNQMP_DMA_DEVID) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_XILINX, ZYNQMP_RC_DMA_DEVID) },
+	{ }
+};
+
+static struct pci_driver ps_pcie_dma_driver = {
+	.name     = DRV_MODULE_NAME,
+	.id_table = ps_pcie_dma_tbl,
+	.probe    = ps_pcie_dma_probe,
+	.remove   = ps_pcie_dma_remove,
+};
+
+/**
+ * ps_pcie_init - Driver init function
+ *
+ * Return: 0 on success. Non zero on failure
+ */
+static int __init ps_pcie_init(void)
+{
+	int ret;
+
+	pr_info("%s init()\n", DRV_MODULE_NAME);
+
+	ret = pci_register_driver(&ps_pcie_dma_driver);
+	if (ret)
+		return ret;
+
+	ret = dma_platform_driver_register();
+	if (ret)
+		pci_unregister_driver(&ps_pcie_dma_driver);
+
+	return ret;
+}
+
+/**
+ * ps_pcie_dma_remove - Driver remove function
+ * @pdev: Pointer to the pci_dev structure
+ *
+ * Return: void
+ */
+static void ps_pcie_dma_remove(struct pci_dev *pdev)
+{
+	struct platform_device *platform_dev;
+
+	platform_dev = (struct platform_device *)pci_get_drvdata(pdev);
+
+	if (platform_dev)
+		platform_device_unregister(platform_dev);
+}
+
+/**
+ * ps_pcie_exit - Driver exit function
+ *
+ * Return: void
+ */
+static void __exit ps_pcie_exit(void)
+{
+	pr_info("%s exit()\n", DRV_MODULE_NAME);
+
+	dma_platform_driver_unregister();
+	pci_unregister_driver(&ps_pcie_dma_driver);
+}
+
+module_init(ps_pcie_init);
+module_exit(ps_pcie_exit);
+
+MODULE_AUTHOR("Xilinx Inc");
+MODULE_DESCRIPTION("Xilinx PS PCIe DMA Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/dma/ps_pcie_dma.h b/include/linux/dma/ps_pcie_dma.h
new file mode 100644
index 0000000..d11323a
--- /dev/null
+++ b/include/linux/dma/ps_pcie_dma.h
@@ -0,0 +1,69 @@
+/*
+ * Xilinx PS PCIe DMA Engine support header file
+ *
+ * Copyright (C) 2017 Xilinx, Inc. All rights reserved.
+ *
+ * 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
+ */
+
+#ifndef __DMA_XILINX_PS_PCIE_H
+#define __DMA_XILINX_PS_PCIE_H
+
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+
+#define XLNX_PLATFORM_DRIVER_NAME "xlnx-platform-dma-driver"
+
+#define ZYNQMP_DMA_DEVID	(0xD024)
+#define ZYNQMP_RC_DMA_DEVID	(0xD021)
+
+#define MAX_ALLOWED_CHANNELS_IN_HW	4
+
+#define MAX_NUMBER_OF_CHANNELS	MAX_ALLOWED_CHANNELS_IN_HW
+
+#define DEFAULT_DMA_QUEUES	4
+#define TWO_DMA_QUEUES		2
+
+#define NUMBER_OF_BUFFER_DESCRIPTORS	1999
+#define MAX_DESCRIPTORS			65536
+
+#define CHANNEL_COAELSE_COUNT		0
+
+#define CHANNEL_POLL_TIMER_FREQUENCY	1000 /* in milli seconds */
+
+#define PCIE_AXI_DIRECTION	DMA_TO_DEVICE
+#define AXI_PCIE_DIRECTION	DMA_FROM_DEVICE
+
+/**
+ * struct BAR_PARAMS - PCIe Bar Parameters
+ * @BAR_PHYS_ADDR: PCIe BAR Physical address
+ * @BAR_LENGTH: Length of PCIe BAR
+ * @BAR_VIRT_ADDR: Virtual Address to access PCIe BAR
+ */
+struct BAR_PARAMS {
+	dma_addr_t BAR_PHYS_ADDR; /**< Base physical address of BAR memory */
+	unsigned long BAR_LENGTH; /**< Length of BAR memory window */
+	void *BAR_VIRT_ADDR;      /**< Virtual Address of mapped BAR memory */
+};
+
+/**
+ * struct ps_pcie_dma_channel_match - Match structure for dma clients
+ * @pci_vendorid: PCIe Vendor id of PS PCIe DMA device
+ * @pci_deviceid: PCIe Device id of PS PCIe DMA device
+ * @board_number: Unique id to identify individual device in a system
+ * @channel_number: Unique channel number of the device
+ * @direction: DMA channel direction
+ * @bar_params: Pointer to BAR_PARAMS for accessing application specific data
+ */
+struct ps_pcie_dma_channel_match {
+	u16 pci_vendorid;
+	u16 pci_deviceid;
+	u16 board_number;
+	u16 channel_number;
+	enum dma_data_direction direction;
+	struct BAR_PARAMS *bar_params;
+};
+
+#endif
-- 
2.7.4